SHOCK SAFE NEPAL TEAM 3 FINAL REPORT
CARLIJN VAN HOOGDALEM SEBASTIAAN KLAVER LODEWIJK LUKEN JASPER SONNEVELD JORIS VAN ZEBEN
Low-Budget Earthquake Resistant Housing Design in Rural Nepal.
Low-Budget Earthquake Resistant Housing Design in Rural Nepal. Carlijn van Hoogdalem Sebastiaan Klaver Lodewijk Luken Jasper Sonneveld Joris van Zeben
MSc. Structural Engineering MSc. Hydraulic Engineering MSc. Architecture MSc. Construction Management Engineering MSc. Geo Engineering
Grading Professor: Academic board:
Dr.ir. Roel Schipper Dr.ir. Wout Broere Dr.ir. Erik Mosselman Dr.ir. Sander van Nederveen Drs.ir. Jules Verlaan
CIE4061-09 - Multidisciplinary Project September 2016 Delft University of Technology
4038142 4093305 4098358 4063600 4006348
IV
FOREWORD
The earthquakes of April and May 2015 left many villages in the Kathmandu valley of Nepal in ruins and thousands of people homeless. Adittionally, the earthquake destroyed historic parts of the capital, Kathmandu. More than a year after the earthquakes the need for housing has not been solved. Most people have not started to rebuild their homes because of organisational and financial shortcomings of the government. Following the initiative of Cas de Stoppelaar, the Honorary Consul General of Nepal to the Netherlands, TU Delft commenced the multidisciplinary student program “Shock Safe Nepal” – a program that allows engineering students of any discipline to apply and expand TU Delft’s research on earthquakes and earthquake safe constructions through field and volunteer work in disaster areas. Shock Safe Nepal is an ongoing project for which groups of students alternate every two months to continue the research. The end goal of the project is to work with the people of Nepal to develop affordable earthquake-resistant housing. Many organizations, including government and non-government agencies as well as international agencies, are involved in the reconstruction process. Despite the many earthquake resistant technologies and building methods that are available, there remains a lot of work to be done before a real paradigm shift in the building process can occur whereby people can afford time, money and skills to rebuild their homes. It is in this context that Shock Safe Nepal Team 3 conducted this study to assess the performance of locally available building materials and optimised traditional building methods, and to build awareness amongst the home owners on the technical and organisational aspects of the rebuilding process. The team members of Shock Safe Nepal Team 3: Carlijn van Hoogdalem Sebastiaan Klaver Lodewijk Luken Jasper Sonneveld Joris van Zeben
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VI
ACKNOWLEDGEMENTS
The project of SSN 3 has been a great success, mainly because of the support, input and critical views of a number of people and organisations. Firstly we want to thank Drs. ir. Jules Verlaan, Dr. ir. Roel Schipper, Dr. ir. Erik Mosselman, Dr. ir. Sander van Nederveen and Dr. ir. Wout Broere for supervising our project as academic representatives from the TU Delft. We would like to thank Support4Nepal, who offered us a suitable location to conduct our research after working together with team 2. The village of Ratankot has been a driving factor in the SSN project for a number of months now. We would also like to thank Nishant Upadhyay from INTACH, for his critical feedback on the designs. Thanks to Engineers Without Borders Denmark and Concern Worldwide we have been able to participate and learn from workshop sessions in Patan about demolition and waste management. These aspects are both of great importance in the Nepal reconstruction. The Abari Foundation has been very helpful by letting us visit their own housing projects, similar to ours, and gave us new insights for rammed earth and bamboo constructions. Also, we would like to thank Kam for Sud, for getting involved in our project and inviting us to the Children’s Home Tathali, a very inspiring project for us as young engineers. Also for giving us feedback on different design aspects and proposals. Furthermore, we would like to thank Cas de Stoppelaar as well, for staying involved in the entire Shock Safe Nepal project, even after one year since its inception. We would like to give credit to DIMI and Delft Global, as their involvement in the project has made it possible for us to travel to Kathmandu and conduct our research there for eight weeks. Thank you Anna Molleman and Jennifer Kockx for the continuing support for Shock Safe Nepal. Thank you to all the individual donors that helped funding our research through 1%club. Lastly, we would like to thank the two previous teams of Shock Safe Nepal, for their involvement in our project, as well as their valuable research that preceded ours.
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EXECUTIVE SUMMARY
This is the final report of the third team of Shock Safe Nepal (SSN), that has conducted research in Nepal from April 2016 to June 2016. Two other teams preceded their research. The previous teams performed extensive research on the aftermath of the earthquakes that hit Nepal on the 25th of April 2015. Team 1 focused on state of the country after the earthquake and classified different types of settlements, urban cores, urban villages, urban historical settlements, rural villages and remote villages. Team 2 continued the research for rural villages because it is believed SSN can provide the most assistance in these areas. They focused on the implementation of earthquake safe construction techniques and developed a framework for this involving aspects such as education and economic growth. Team 3 has continued the research in rural villages and shifted the focus to design. An analysis of the rules and regulations given by the Government of Nepal (GoN) has been made. Combined with the design and reconstruction a demolition and waste management plan is developed. Resources are limited in Nepal and an affordable housing design is vital for the reconstruction effort. Proper management of the reusable resources from the demolished houses is important to achieve this. The GoN has chosen for an owner driven reconstruction. This means that houses that were damaged or destroyed in the earthquake will be reconstructed by the homeowners with financial support from the GoN. The National Reconstruction Authority (NRA) has been established to lead the reconstruction. Each homeowner can apply to receive NPR 200.000, circa USD 2000, in several installments. They will also receive technical support through their Village Development Committee, comparable to a municipality, by state trained engineers. The engineers will perform checks in several stages of construction to guarantee that the reconstruction is performed according to regulation and is safe for future earthquakes. The NRA has released a Design Catalogue with model houses. Costs for these designs could be around 2.5 times the amount of the government funds (SSN2, 2016). A survey done by the NRA shows that 498.697 households were fully damaged and another 256.617 households VIII
were partially damaged. This generated approximately 14 million tons of debris waste in the 14 priority districts (Disaster Waste Management Policy (Concern sess.1), December 2015). Demolition and reconstruction of these houses has been very slow. Still 50% of the population needs to demolish their homes (UN, 2016). Of the 74% of households that reported damage, 5% has completed repairs or rebuilding works by November 2015 (Nepal Shelter Cluster, 2015). SSN has performed a multicriteria analysis on approved building methods. The criteria used were adopted for a rural village in Nepal. From the analysis three different housing designs were deemed viable for future research and design, stone masonry, wattle and daub combined with rammed earth and compressed earth bricks (CEB) masonry. The focus in the design is to achieve a feasible and affordable housing design. With the money provided by the NRA it is not possible to reconstruct the same size house as before. This is why the designs have an incremental component built in. The basic house can be expanded at a later point when more resources become available while maintaining the earthquake safe design. The stone masonry design is an adaptation of the most common building technique in rural Nepal. This design is expandable in vertical direction. The first floor is constructed from wattle and daub to save costs and to make it easily expandable in the future. Because it is an adaptation of a known building technique, acceptance by the population will be less of a problem. The second design combines wattle and daub with rammed earth columns. The design consists of strong rammed earth columns with light and flexible wattle and daub infill. The basic house consists of three rooms which can easily be expanded in a horizontal direction. By keeping the house only on ground level safety is increased during earthquakes. The materials in the design make it possible to use local materials and limit transport costs. Future research is needed on how the combination of the rammed earth columns and wattle and daub infill will work together during earthquakes. Lastly a design using CEB masonry has been made. The design is similar to masonry work with conventional burned
brickwork but has the advantage of local production with local resources. This saves costs and helps build local economic activities. The design is expandable vertically in a similar method as stone masonry. Earthquake resistance is achieved using reinforced concrete horizontal and vertical tension bands. Because of the combination of concrete and brickwork the house gets a more modern look which is similar to houses seen in cities. This makes it attractive for rural villagers who like a modern house. A cost estimation has been made for the designs. The aim is to be as realistic as possible to the subsidy given by the GoN while maintaining the requirements for housing. Preliminary research has shown that this is highly unlikely, but a housing design that will approach this price can be of high value for all Nepali. In the estimation material, labour and transport costs are taken into account. Labour costs can be lowered if a borrowed labour system is used. The cost estimation for the housing designs range from 2500 USD for the basic stone masonry house to 3500 USD for the basic CEB masonry house. To demonstrate the reconstruction strategy developed by SSN2, a worked out example case has been made using structures in Ratankot. For the damaged community center a demolition and waste management plan has been made, as well as a concept design based on the resources recovered from the demolition. The same has been done for a house in Ratankot. Rural villages have a limited water supply at the end of the dry season. The proposed system aims to partly relieve the local population of their water related issues, by using rainwater storage as a primary water source, especially during the dry months. Water quality is ensured by the different treatment steps in the system. The system is designed that maintenance is simple and does not require additional expensive resources. People will need to be educated on the use and maintenance of the system.
the teams are setup within the curriculum. The future of SSN should therefore not lie in sending teams to Nepal, but to do scientiďŹ c research in Delft on the various construction methods. A clear short and long term vision for SSN can help guide this research.
The designs made by team 3 are model designs to show several options for reconstruction in Nepal. They lack context and need to be adapted if a site is chosen. Therefore a case study is elaborated in order to show the implementation process. Further testing of the designs is needed as they are solely based on the Nepali Building Code. The actual cost of the houses will probably be higher because of the need of education and contingencies. The next team can help implement the knowledge gained by the previous teams. A pilot project can provide valuable insight into the execution aspects of constructing in Nepal. The effect of SSN in Nepal is limited because of the way
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TABLE OF CONTENTS
1 2. 2.1 2.2 2.3 3 3.1 3.1.1 3.1.2 3.1.3 3.1.4 3.1.5 3.1.6 3.2 3.3 3.3.1 3.3.2 3.3.3 3.4 3.4.1 3.4.2 3.4.3 3.5 3.6 3.6.1 3.6.2 3.6.3 3.6.4 3.7 4 4.1 4.2 4.3 4.4 4.5 4.6 5 5.1 5.2 6 7. 8.
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Foreword Acknowledgements Executive summary List of ďŹ gures List of tables Introduction Research setup Scope Objectives Methodology Analysis rural Nepal Context of Nepal Post disaster reconstruction Earthquake housing reconstruction program Priority districts District: Sindhupalchok VDC: Sunkhani Ratankot Demolition & waste management Suitable areas for rural areas Solution space Multicriteria Analysis MCA results Cost analysis Material costs Labour force Transport costs Principles in earthquake resistant construction Rainwater harvest Overview system Water quality Discharge & quantities Operation & maintenance Borrowed labour Housing designs Requirements Cost analysis per house design Design choice and alternatives Stone masonry with mud mortar Rammed earth and wattle and daub Compressed earth bricks Community center Ratankot Demolition & waste management proposal Community center proposal Conclusions Discussion Recommendations
V VII VIII XIII XV 1 2 2 3 4 6 6 7 8 10 12 12 13 16 20 20 21 22 24 24 24 25 26 28 28 29 31 32 33 34 34 34 35 36 37 38 39 40 46 48 62 66
Shock Safe Nepal
Literature Appendices A: List of contacts of Shock Safe Nepal Team 3 B: Annexes from Disaster Waste Management Guidelines, Berg, 2011. B1: Annex II. Waste hazard ranking tool B2: Annex III. Waste handling matrix C: MCA: C1: 0-Scenario C2: More remote scenario C3: No subsidy scenario C4: Solution space C5-C24: MCA sheets per building method: C5: Adobe C6: Bamboo C7: Brick masonry in cement mortar C8: Compressed earth brick (CEB) C9: Concrete in-situ shear wall C10: ConďŹ ned masonry C11: Dhajji Dewari C12: Earthbags C13: Hollow concrete brick masonry C14: Interlocking bricks C15: Lightweight steel proďŹ le building systems C16: Low strength (brick) masonry C17: Low strength (stone) masonry C18: Prefab framed in-situ concrete C19: Rammed earth C20: Reinforced cement concrete frame (RCC) C21: Single panel walling system C22: Steel C23: Stone masonry in cement mortar C24: Timber construction D: Cost analysis survey E: Precipitation maps of Nepal. Department of Hydrology and Meteorology. 2013. F: Floor plan damaged community center Ratankot (SSN2, 2016)
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Shock Safe Nepal
LIST OF FIGURES
Figure 2.1: Partial strategic action plan team 2. The actions highlighted in blue are those that team 3 focused on. (SSN2, 2015) 2 Figure 3.1: Geographical map of Nepal showing the five regions, from the Terai (dark red) to the High Himal (dark blue). (Department of Hydrology and Meteorology, 2013) 6 Figure 3.2: Top-down structure of the organisation for the reconstruction of Nepal. (SSN3, 2016) 7 Figure 3.3: The five reconstruction phases, according to the Nepal Rural Housing Reconstruction Program. (NRHRP, 2016) 8 Figure 3.4: Location of the two earthquake epicentres with respect to the fourteen priority districts (in gray). (HRRP, 2015) 10 Figure 3.5: Enrollment status for June 9th of 2016 and August 12th of 2016. (HRRP, 2016) 11 Figure 3.6: District administrative map for Sindhupalchok. Maps shows major and smaller infrastructure, settlements, and VDC borders. The VDC of Sunkhani is located in the South-East of the distrcit. (HRRP, 2016) 12 Figure 3.7: Map of the VDC of Sunkhani, with the locations of Ratankot 7 and 9 in the East of the VDC. Map is created by combining different images. (HRRP, 2016 & SSN2, 2016) 13 Figure 3.8: Map of Ratankot, showing main road in black and smaller pathways in yellow. Households are depicted in red, yellow and orange rectangles. The gray lines are isohypses. (SSN2, 2016) 14 Figure 3.9: Flowchart for demolition and waste management. (Concern, 2016) 16 Figure 3.10: Different failure modes for in plane load paths: diagonal tension cracks (a), sliding (b), tilting (c) and rocking (d) (Concern, 2016) 16 Figure 3.11: Photograph of a building in Kathmandu being strutted for stability. (SSN3, 2016) 17 Figure 3.12: Example layout for a demolition and wastemanagement site. (Concern, 2016) 18 Figure 3.13: Example for different piles for wastes in a waste management site. (Concern, 2016) 18 Figure 3.14: Forces on an irregular floor plan (left) and regular floor plan (right) 26 Figure 3.15: Effect of reinforcement. (SSN3, 2016) 26 Figure 3.16: Horizontal bands. (SSN3, 2016) 26 Figure 3.17: Effect of sill and lintel bands. (SSN3, 2016) 26 Figure 3.18: Bond masonry and timber bands. (SSN3, 2016) 27 Figure 3.19: Openings in load bearing walls according to the DUDBC. (DUDBC, 2015) 27 Figure 3.20: Strut and tie model of a wall with opening. (SSN3, 2016) 27 Figure 3.21: Dimensions foundation. (Minke, 2001, p.34) 27 Figure 3.22: Foundation-wall connection. (SSN3, 2016) 27 Figure 3.23: Schematization of the proposed water system for households. (SSN3, 2016) 28 Figure 3.24: Schematization for a first flush diverter. (rainharvesting.com.au, 2015) 28 Figure 3.25: Schematic drawing of a bio-sand filter. (ohorizons.org, 2015) 28 Figure 3.26: Schematization of a floating inlet in a water tank. (rainwater-shop.eu, 2015) 29 Figure 3.27: Average monthly precipitation data for Kathmandu. (www.weather-and-climate.com, 2015) 30 Figure 3.28: Mean annual precipitation map for Nepal. (Department of Hydrology and Meteorology, 2013) 30 Figure 6.1: Picture of the situation with house 1 on the right and house 2 on the left (Upadhyay and De Mey, 2016) 49 Figure 6.2: Site plan (Upadhyay and De Mey, 2016) 49 Figure 6.3: Section YY’ (Upadhyay and De Mey, 2016) 49 Figure 6.4: Design dicisions site plan 51 Figure 6.5: Site plan 1:200 52 Figure 6.6: Section 1:200 52 Figure 6.7: House 1 floor plan first floor1:100 53 Figure 6.8: House 2 floor plan first floor 1:100 53 Figure 6.9: House 1 floor plan ground floor 1:100 53 Figure 6.10: House 2 floor plan ground floor 1:100 53 Figure 6.11: Section 1:100 54 XIII
TITLE OF CHAPTER
Anum hos perem inverus hostili buntemp ervider untilin ve, porum in Itatiquam niqueme publium, dit? Bis huit. Fineris, que o ex st videt factatum restus. Cat dicauconsus, quo il hilic viveribenam isulestra nos, ur a norum sentrae publius efacrec verum lis imo et; nerum factam desitempris, quam sedees supior que me nondum vero vico es tust quonsu me apestem con taliam nost vivasdam in ta imis conver publissus est qui pervideat. Ebus. Nonlocu legita ressed nonsum depora dentem med corendeo, cero cricepe ctebemus, ditis con atquo viritem deatam tum ius conterum fortum ocatiam enihilicio etem tem perum moli porem quam quid siliustast? Tis vidius prortum ili etessentem voc, con derternimus ceri sedem conde publica; C. Fec re esi patis elleren telarbis sentiostrus nirmium pati, C. Grarbem occhuiu quam. Mulegilis, sicaece conium dum addum Patque huc forum nentist oraedeme comaximus, vat, deterfi tatimus virimax imihilius, me vis. Gra at. Onsulin teninici practan dactum te, nocci turox moere, patum tam audaciamque nontionferum ommorbitisse et; ex se et; habultod C. Ci inpribusqua rei senducipse, erfestrat inclatus confit, fac re achuius sperdi, novenat uspiman teretiam hostim conius estilic ienarte ressenitia tum nocauterit? Ihilin hoste noruntem, spio intus castrox sentia itionfi rmantiem ut gracrit iessilia? quastis ete vir ina, non tem. Ta, que quem et pratque esiller fecepertium ego publica turnihiliem, criam nercertuus sid C. Go im patia viverfes C. Aximpoti pulii pariae consimanum public tum pes cotia sentu iam in inatiam in deorit; horisultum in publinc uperestumus, quodius fauctus et aucipic atuscre me nos in restide peris, Cat Catiam morem pere con denterox sed iam tero ussolin atimmoenatum notis, conditiam seni etorte, ommover aedemquon ne hemo iactuamdiis vicae no. Ilinata virmilis ressuli quonsum inpratiure cresse, mercepotiam a audes tessu erum iae audena, noraequodit gratess olusum nonvervis bonsulum, diissidii se tem in tenihil ibuspior am non Itam ubliusatque in hus, stabes! Nam esse tus octum a vessent itanum adduc tui publium ulicum ius paricauciam que pulut videm o et re ilis. Hebatodit? Nihilic aetius hos in publius; int. Cerivivem no. Efectuamdiis sum manulic urorumus con vissilicam hos, vivestem furnita nostrae mo ta, quidit. Talius opoti, mus, tatquam publiss ulocchum hostrat xiv
Anum hos perem inverus hostili buntemp ervider untilin ve, porum in Itatiquam niqueme publium, dit? Bis huit. Fineris, que o ex st videt factatum restus. Cat dicauconsus, quo il hilic viveribenam isulestra nos, ur a norum sentrae publius efacrec verum lis imo et; nerum factam desitempris, quam sedees supior que me nondum vero vico es tust quonsu me apestem con taliam nost vivasdam in ta imis conver publissus est qui pervideat. Ebus. Nonlocu legita ressed nonsum depora dentem med corendeo, cero cricepe ctebemus, ditis con atquo viritem deatam tum ius conterum fortum ocatiam enihilicio etem tem perum moli porem quam quid siliustast? Tis vidius prortum ili etessentem voc, con derternimus ceri sedem conde publica; C. Fec re esi patis elleren telarbis sentiostrus nirmium pati, C. Grarbem occhuiu quam. Mulegilis, sicaece conium dum addum Patque huc forum nentist oraedeme comaximus, vat, deterfi tatimus virimax imihilius, me vis. Gra at. Onsulin teninici practan dactum te, nocci turox moere, patum tam audaciamque nontionferum ommorbitisse et; ex se et; habultod C. Ci inpribusqua rei senducipse, erfestrat inclatus confit, fac re achuius sperdi, novenat uspiman teretiam hostim conius estilic ienarte ressenitia tum nocauterit? Ihilin hoste noruntem, spio intus castrox sentia itionfi rmantiem ut gracrit iessilia? quastis ete vir ina, non tem. Ta, que quem et pratque esiller fecepertium ego publica turnihiliem, criam nercertuus sid C. Go im patia viverfes C. Aximpoti pulii pariae consimanum public tum pes cotia sentu iam in inatiam in deorit; horisultum in publinc uperestumus, quodius fauctus et aucipic atuscre me nos in restide peris, Cat Catiam morem pere con denterox sed iam tero ussolin atimmoenatum notis, conditiam seni etorte, ommover aedemquon ne hemo iactuamdiis vicae no. Ilinata virmilis ressuli quonsum inpratiure cresse, mercepotiam a audes tessu erum iae audena, noraequodit gratess olusum nonvervis bonsulum, diissidii se tem in tenihil ibuspior am non Itam ubliusatque in hus, stabes! Nam esse tus octum a vessent itanum adduc tui publium ulicum ius paricauciam que pulut videm o et re ilis. Hebatodit? Nihilic aetius hos in publius; int. Cerivivem no. Efectuamdiis sum manulic urorumus con vissilicam hos, vivestem furnita nostrae mo ta, quidit. Talius opoti, mus, tatquam publiss ulocchum hostrat
Shock Safe Nepal
LIST OF TABLES
Table 3.1: List of materials and possible reuse based on the quality of the salvaged material. Table 3.2. Weighting table SSN and Nepali engineers Table 3.3: Results MCA. Table 3.4. All used materials Table 3.5: Survey results. Table 3.6: Vertical dimension of the proposed water system. Assuming a rain gutter height of 2.8m above ground level and a floor level of 0.3m above ground level. Table 3.7: Treatment efficiency in turbidity removal in percentage of NTU removed per treatment step. Values obtained from literature. Table 3.8: Volume of precipitation in april and may on a 55 square meter roof, based om mean precipitation values in Kathmandu. Table 3.9: Volume of available water after first flush diversion. Quantities based on same precipitation data and roof size as Table 3.8. Table 3.10: Projected costs for purchase of proposed water system. Table 5.1: Critical steps in safe & efficient demolition & waste management Table 5.2: Estimation of economic value of salvaged materials from demolition of community center. This possibly represents a reduction in costs for a new building. Table 5.3: Possible reuse for different wastes obtained from demolition of community center. Table 5.4: Categorization of wastes generated by demolition of community center. Table 5.5: Mass of different wastes generated by demolition of community center. Table 5.6: Two possibilities for recycling for different types of waste generated by the community center. Table 6.1: Estimation of quantities house 1 Table 6.2: Estimation of quantities house 2 Table 6.3: Cost estimation house 1 Table 6.4: Cost estimation house 2 Table 6.5: Cost estimation toilet
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ACRONYMS
AIN CEB CGI CL-PIU DCC DIMI DL-PIU DoHM DUDBC EWB GDP GoN HRRP INGO IOM KTM MCA NBC NGN NGO NPR NRHRP NRA NSET NTU OCHA PO RCC S4N SSN SRO SWOT UN UNDP UNEP USD VDC WHO
Association of International NGOs Compressed earth brick Corrugated galvanised iron Central Level Project Implementation Units District Coordination Committees Delft Deltas, Infrastructures & Mobility Initiative District Level Project Implementation Units Department of Hydrology Meteorology Department of Urban Development & Building Construction Engineers Without Borders Gross Domestic Product Government of Nepal Housing Recovery & Reconstruction Platform International Non-Governmental Organisation International Organization for Migration Kathmandu Multi-criteria analysis Nepal Building Code NGO Federation of Nepal Non-Governmental Organisation Nepalese Rupee Nepali Rural Housing Reconstruction Projection National Reconstruction Agency National Society for Earthquake Technology Nephelometric Turbidity Unit Office for the Coordination of Humanitarian Affairs Partner organisation Reinforced Cement Concrete Support4Nepal Shock Safe Nepal Sub Regional Office Strength, Weakness, Opportunity and Threat (analysis) United Nations United Nations Development Program United Nations Environment Program United States Dollar Village District Committee World Health Organisation
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Shock Safe Nepal Anum hos perem inverus hostili buntemp ervider untilin ve, porum in Itatiquam niqueme publium, dit? Bis huit. Fineris, que o ex st videt factatum restus. Cat dicauconsus, quo il hilic viveribenam isulestra nos, ur a norum sentrae publius efacrec verum lis imo et; nerum factam desitempris, quam sedees supior que me nondum vero vico es tust quonsu me apestem con taliam nost vivasdam in ta imis conver publissus est qui pervideat. Ebus. Nonlocu legita ressed nonsum depora dentem med corendeo, cero cricepe ctebemus, ditis con atquo viritem deatam tum ius conterum fortum ocatiam enihilicio etem tem perum moli porem quam quid siliustast? Tis vidius prortum ili etessentem voc, con derternimus ceri sedem conde publica; C. Fec re esi patis elleren telarbis sentiostrus nirmium pati, C. Grarbem occhuiu quam. Mulegilis, sicaece conium dum addum Patque huc forum nentist oraedeme comaximus, vat, deterfi tatimus virimax imihilius, me vis. Gra at. Onsulin teninici practan dactum te, nocci turox moere, patum tam audaciamque nontionferum ommorbitisse et; ex se et; habultod C. Ci inpribusqua rei senducipse, erfestrat inclatus confit, fac re achuius sperdi, novenat uspiman teretiam hostim conius estilic ienarte ressenitia tum nocauterit? Ihilin hoste noruntem, spio intus castrox sentia itionfi rmantiem ut gracrit iessilia? quastis ete vir ina, non tem. Ta, que quem et pratque esiller fecepertium ego publica turnihiliem, criam nercertuus sid C. Go im patia viverfes C. Aximpoti pulii pariae consimanum public tum pes cotia sentu iam in inatiam in deorit; horisultum in publinc uperestumus, quodius fauctus et aucipic atuscre me nos in restide peris, Cat Catiam morem pere con denterox sed iam tero ussolin atimmoenatum notis, conditiam seni etorte, ommover aedemquon ne hemo iactuamdiis vicae no. Ilinata virmilis ressuli quonsum inpratiure cresse, mercepotiam a audes tessu erum iae audena, noraequodit gratess olusum nonvervis bonsulum, diissidii se tem in tenihil ibuspior am non Itam ubliusatque in hus, stabes! Nam esse tus octum a vessent itanum adduc tui publium ulicum ius paricauciam que pulut videm o et re ilis. Hebatodit? Nihilic aetius hos in publius; int. Cerivivem no. Efectuamdiis sum manulic urorumus con vissilicam hos, vivestem furnita nostrae mo ta, quidit. Talius opoti, mus, tatquam publiss ulocchum hostrat iussoliciem perniam lartenatuus esignoximo in rena, quod ius cae, consilisultu interfin ditalabem mus re quamplie que in venductam a vero inatuus; ius bonsimoendam utum. Alem tam que ego clus eti, nihilicendi publingula aturace rninatil hiciem taliae nium, se rene tem ad Catum publinatas es silicaescrio aucis publibus ad iam publiae orum imantrac vis, Ti. Erites intem opubli, nimmorum, signostam Patis popticu pplius, et; inata tenti, cum publiu virterio essa diu se fecri finverfit? in publiamdi pero, Cat faute, nondacii
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Anum hos perem inverus hostili buntemp ervider untilin ve, porum in Itatiquam niqueme publium, dit? Bis huit. Fineris, que o ex st videt factatum restus. Cat dicauconsus, quo il hilic viveribenam isulestra nos, ur a norum sentrae publius efacrec verum lis imo et; nerum factam desitempris, quam sedees supior que me nondum vero vico es tust quonsu me apestem con taliam nost vivasdam in ta imis conver publissus est qui pervideat. Ebus. Nonlocu legita ressed nonsum depora dentem med corendeo, cero cricepe ctebemus, ditis con atquo viritem deatam tum ius conterum fortum ocatiam enihilicio etem tem perum moli porem quam quid siliustast? Tis vidius prortum ili etessentem voc, con derternimus ceri sedem conde publica; C. Fec re esi patis elleren telarbis sentiostrus nirmium pati, C. Grarbem occhuiu quam. Mulegilis, sicaece conium dum addum Patque huc forum nentist oraedeme comaximus, vat, deterfi tatimus virimax imihilius, me vis. Gra at. Onsulin teninici practan dactum te, nocci turox moere, patum tam audaciamque nontionferum ommorbitisse et; ex se et; habultod C. Ci inpribusqua rei senducipse, erfestrat inclatus confit, fac re achuius sperdi, novenat uspiman teretiam hostim conius estilic ienarte ressenitia tum nocauterit? Ihilin hoste noruntem, spio intus castrox sentia itionfi rmantiem ut gracrit iessilia? quastis ete vir ina, non tem. Ta, que quem et pratque esiller fecepertium ego publica turnihiliem, criam nercertuus sid C. Go im patia viverfes C. Aximpoti pulii pariae consimanum public tum pes cotia sentu iam in inatiam in deorit; horisultum in publinc uperestumus, quodius fauctus et aucipic atuscre me nos in restide peris, Cat Catiam morem pere con denterox sed iam tero ussolin atimmoenatum notis, conditiam seni etorte, ommover aedemquon ne hemo iactuamdiis vicae no. Ilinata virmilis ressuli quonsum inpratiure cresse, mercepotiam a audes tessu erum iae audena, noraequodit gratess olusum nonvervis bonsulum, diissidii se tem in tenihil ibuspior am non Itam ubliusatque in hus, stabes! Nam esse tus octum a vessent itanum adduc tui publium ulicum ius paricauciam que pulut videm o et re ilis. Hebatodit? Nihilic aetius hos in publius; int. Cerivivem no. Efectuamdiis sum manulic urorumus con vissilicam hos, vivestem furnita nostrae mo ta, quidit. Talius opoti, mus, tatquam publiss ulocchum hostrat iussoliciem perniam lartenatuus esignoximo in rena, quod ius cae, consilisultu interfin ditalabem mus re quamplie que in venductam a vero inatuus; ius bonsimoendam utum. Alem tam que ego clus eti, nihilicendi publingula aturace rninatil hiciem taliae nium, se rene tem ad Catum publinatas es silicaescrio aucis publibus ad iam publiae orum imantrac vis, Ti. Erites intem opubli, nimmorum, signostam Patis popticu pplius, et; inata tenti, cum publiu virterio essa diu se fecri finverfit? in publiamdi pero, Cat faute, nondacii
1 INTRODUCTION TITLE OF CHAPTER
This report of the teambuntemp 3 of Shock Safe Nepal Anumis the hos final perem inverus hostili ervider untilin (SSN), that has conducted research in Nepal from ve, porum in Itatiquam niqueme publium, dit? Bis huit.April 2016 otherrestus. teamsCatpreceded the Fineris,toqueJune o ex2016. st videtTwo factatum dicauconsus, research. Septemberisulestra and October 2015, the first quo il hilicInviveribenam nos, urofa norum sentrae team Nepal to perform in various publiusarrived efacrecin verum lis imo et; nerumresearch factam desitempris, locations in order to map quam sedees supior que the me existing nondumproblems. vero vico es tust quonsu me apestem con taliam nost vivasdam in ta imis The first report est provides a context of Nepal, including conver publissus qui pervideat. information onlegita geology andnonsum plate tectonics, geography Ebus. Nonlocu ressed depora dentem med and climate, politics, economy, social corendeo, cero cricepe ctebemus, ditisand conethnic atquoaspects, viritem as well astum a list importantfortum stakeholders. report deatam iusofconterum ocatiamTheenihilicio gives insights on the financial situation of post-earthquake etem tem perum moli porem quam quid siliustast? Tis Nepal, well as an of allvoc, the damages. In order vidius as prortum ili indication etessentem con derternimus to the problems thatesiarepatis present in ceribetter sedemunderstand conde publica; C. Fec re elleren Nepal, a classification has been made of the different telarbis sentiostrus nirmium pati, C. Grarbem occhuiu types settlements: urban cores, villages, urban quam. of Mulegilis, sicaece conium dumurban addum Patque huc historical settlements, rural villages and forum nentist oraedeme comaximus, vat,remote deterfi villages. tatimus The second and third team been focusing rural virimax imihilius, me vis. Grahave at. Onsulin teninici on practan villages, is believed SSN tam is able to provide dactum because te, nocciitturox moere,that patum audaciamque the most assistance in these areas. nontionferum ommorbitisse et; ex se et; habultod C. Other final documents presented by team 1 include Ci inpribusqua rei senducipse, erfestrat inclatus confit, information on earthquake safe construction methods, as fac re achuius sperdi, novenat uspiman teretiam hostim well as estilic an extensive of all the different building conius ienarteassessment ressenitia tum nocauterit? Ihilin hoste techniques present in Nepal. noruntem, that spioare intus castrox sentia itionfi rmantiem ut The of ete SSN conducted in gracritsecond iessilia?team quastis vir has ina, non tem. Ta,research que quem Nepal in February and March of Their research et pratque esiller fecepertium ego2016. publica turnihiliem, was on the implementation of earthquake safe criamfocused nercertuus sid C. Go im patia viverfes C. Aximpoti construction techniques in rural Nepal. Team 2 introduced pulii pariae consimanum public tum pes cotia sentu iam ainstrategic planhorisultum and an education and dissemination inatiam action in deorit; in publinc uperestumus, strategy. These plans wereatuscre based on in the village quodius fauctus et aucipic mefindings nos in restide peris, of in thepere district of Sindhupalchok andussolin were CatRatankot Catiam morem con denterox sed iam tero validated in other rural villages. The cooperation of team 2 atimmoenatum notis, conditiam seni etorte, ommover with the Belgian NGO iactuamdiis Support4Nepal Ratankot served aedemquon ne hemo vicaeinno. Ilinata virmilis as a base for the research team 3.mercepotiam a audes ressuli quonsum inpratiureofcresse, tessu erum iae audena, noraequodit gratess olusum As recommended bydiissidii team 2, of ibuspior team 3 has nonvervis bonsulum, se the tem focus in tenihil am shifted towards a more technical order to non Itam ubliusatque in hus, stabes!approach, Nam esseintus octum substantially contribute to the reconstruction process. a vessent itanum adduc tui publium ulicum ius paricauciam After the videm research by the first two teams, a que pulut o etperformed re ilis. logical next Nihilic step inaetius further research formed the main goal Hebatodit? hos in publius; int. Cerivivem no. of team threesum proved to be:urorumus con vissilicam hos, Efectuamdiis manulic vivestem furnita nostrae mo ta, quidit. “To proof,publiss affordable and feasible Taliusdesign opoti,earthquake mus, tatquam ulocchum hostrat
housing for perem the population of ruralbuntemp Nepal” ervider untilin Anum hos inverus hostili ve, porum in Itatiquam niqueme publium, dit? Bis huit. During the ocourse of this research it Cat wasdicauconsus, decided to Fineris, que ex st videt factatum restus. broaden scope of this research othersentrae topics quo il hilicthe viveribenam isulestra nos,towards ur a norum that are closely related to the reconstruction in Nepal, publius efacrec verum lis imo et; nerum factam desitempris, namely: quam sedees supior que me nondum vero vico es tust -quonsu Demolition & wastecon management of vivasdam currently in damaged me apestem taliam nost ta imis structures. conver publissus est qui pervideat. -Ebus. Social & economical development throughdentem means med of a Nonlocu legita ressed nonsum depora community center and/or guest houses in Ratankot. corendeo, cero cricepe ctebemus, ditis con atquo viritem -deatam (Drinking)water issuesfortum in Ratankot. tum ius related conterum ocatiam enihilicio etem tem perum moli porem quam quid siliustast? Tis This mainly focuses on presenting earthquakevidiusreport prortum ili etessentem voc, con derternimus proof and feasible foresi housing rural ceri sedem conde technical publica; solutions C. Fec re patis in elleren Nepal, and specifically the village of Ratankot. Though telarbis sentiostrus nirmium pati, C. Grarbem occhuiu the actual designs are preceded by an analysis chapter, quam. Mulegilis, sicaece conium dum addum Patque huc which a general context of Nepal that provides forum includes nentist oraedeme comaximus, vat, deterfi tatimus insight the top-down organisational of the virimaxon imihilius, me vis. Gra at. Onsulinstructure teninici practan reconstruction thatturox has been adopted the audaciamque GoN, as well dactum te, nocci moere, patumbytam as the current situation of the et; reconstruction itself. ThisC. is nontionferum ommorbitisse ex se et; habultod followed by a cost for construction and materials Ci inpribusqua rei analysis senducipse, erfestrat inclatus confit, in facNepal. re achuius sperdi, novenat uspiman teretiam hostim In addition this, chapters are included that discuss the conius estilictoienarte ressenitia tum nocauterit? Ihilin hoste demolition of damaged structures, well as the waste noruntem, spio intus castrox sentiaasitionfi rmantiem ut management that is associated with it. Other issues that are gracrit iessilia? quastis ete vir ina, non tem. Ta, que quem present in rural Nepal are addressed well, such as water et pratque esiller fecepertium egoaspublica turnihiliem, scarcity during thesiddry Thisviverfes analysisC.provides criam nercertuus C. months. Go im patia Aximpotia solution space for the design of earthquake proof housing pulii pariae consimanum public tum pes cotia sentu iam in rural Nepal, including demolition & wasteuperestumus, management inatiam in deorit; horisultum in publinc and a proposal a solution to water scarcity. quodius fauctusfor et aucipic atuscre me nos in restide peris, The demolition of and forsed a new community Cat Catiam morem perepossibilities con denterox iam tero ussolin center in Ratankot are also discussed. This community atimmoenatum notis, conditiam seni etorte, ommover center couldneplay a iactuamdiis major role vicae in the aedemquon hemo no.reconstruction Ilinata virmilis process. ressuli quonsum inpratiure cresse, mercepotiam a audes Finally, recommendations be made gratess for future SSN tessu erum iae audena, will noraequodit olusum teams and bonsulum, the reconstruction oftem Nepal in general. nonvervis diissidii se in tenihil ibuspior am non Itam ubliusatque in hus, stabes! Nam esse tus octum a vessent itanum adduc tui publium ulicum ius paricauciam que pulut videm o et re ilis. Hebatodit? Nihilic aetius hos in publius; int. Cerivivem no. Efectuamdiis sum manulic urorumus con vissilicam hos, vivestem furnita nostrae mo ta, quidit. Talius opoti, mus, tatquam publiss ulocchum hostrat 11
2 RESEARCH SETUP
This chapter will focus on the how the project will be structured in order to achieve the main goals of SSN. The current phase of the reconstruction will be analysed to determine which steps need to be taken during this research project to contribute as much as possible to the rebuilding of Nepal within the given timeframe. This scope will influence the objectives that are set for this research project and both will be taken into account in the build up towards the main research question. Thereafter, the methodology of answering the research question throughout this project will be elaborated.
2.1 Scope Contributing to the reconstruction of earthquake resistant housing is the main goal of the SSN initiative. As this research continues on the work of former groups of the Shock Safe Nepal initiative, it is important to take the conclusions and recommendations from those projects into account. The findings help define the scope of this research and give a direction to how Shock Safe Nepal can be of most value for the people of Nepal. Building on the work of
Shock Safe Nepal a logical step is to keep focussed on the rural areas of Nepal. According to the studies of former teams, Shock Safe Nepal can contribute most efficiently to society when working in the rural areas of Nepal. This so called zone D (SSN1, 2015) has also been the focus of SSN2 and as their findings are only applicable to these rural areas, a continuation of their research has to be performed in the same area. One of the conclusions of Shock Safe Nepal include a strategic action-plan which elaborates on how to integrate an earthquake safe environment within the villages (SSN, 2016). This partial strategic action-plan (Figure 2.1) provides a clear overview of what steps need to be taken in the coming years. The complete diagram of the actionplan team 2 can be found in their report. Based on the recommendations of SSN2, a few of these steps can be taken during this research. Observations and interviews with government organisations have shown that step two of the strategic action-plan is in progress. The organisation within the government has made serious progress, given the state
Figure 2.1: Strategic action plan team 2. The actions highlighted in blue are those that team 3 focused on. (SSN2, 2015)
Shock Safe Nepal they were in one year ago and the improvement of constructional control mechanisms is starting to take shape. An analysis of this process will be provided in a later stage of the report. However, in certain regions some aspects of step two have not advanced sufficiently for the construction phase to start according to the strategic action-plan. The last three bullets of the preparation phase will therefore be addressed in this research as well. The steps following this preparation phase contain both social-economic as well as technical aspects and have yet to be applied in most parts of rural Nepal. The exact way to apply and execute these strategies of the strategic actionplan has not been properly investigated yet. However, recommendations of SSN2 suggest that “at first, a scalable solution or building model would have to be introduced with a more technical approach including already present building solutions.” Creating such a model will contribute to the main goal of Shock Safe Nepal because a building model, not location bounded design can be applied and used by further teams of Shock Safe Nepal.
2.2 Objectives The design of a model house alone is not in the best interests of the Nepali people. There are some designs available for them already but the main problem is that they are not being taught what to do with them. Therefore this research will focus on combining most steps of the strategic action-plan into a scalable housing design and present them as a complete package. This will lead up to the educational house mentioned by SSN2 for which a location will then have to be found to concretise the housing solution. Recognizing that most villages in Nepal still need to start rebuilding as there is no money available for materials, this report will also focus on the feasibility of those designs. The government has promised the people of Nepal 200.000 Nepali Rupees per homeowner to rebuild. However, the materials needed to reinforce a house to obtain an earthquake safe structure will exceed the budget. Considering this, the main goal of SSN3 will be to complete the preparation of a pilot project in a rural village, where the scalable housing solutions can be concretised. After the realisation of this pilot project, decisions can be made on how to generalise the project in the best way possible. From this goal, the following research question is derived: What is a viable design, bound by socio-cultural, financially feasible, technical, resource, functional and sustainable aspects, for housing using building methods that are
available in rural village type X which can be easily adapted for rural village type Y?
2.3 Methodology A part of the methodology leading up to the designs of the educational house can be derived from the strategic action-plan from SSN2. A couple of aspects that are stated to be very important in this process need to be developed and detailed into a plan. The aspects that are considered achievable within two months and next to that are perceived to be reachable for team 3 are the following: - Focus on locals’ own responsibility - Incorporate long term perspective - Promote safe over cheap solutions - Assess re-usable materials - Use old materials in new techniques - Build educational house Housing design The building of the educational house will not be done during this research project for the sole reason that the time frame is too small to generate a design and build within two months. However, the process leading up to the building of an educational house can partly be performed during this research. Especially the development of designs for these houses can be of high value to further SSN teams. To investigate the right building methods for rural areas, a multi-criteria analysis will be performed to determine the three most feasible building methods for future housing designs in Nepal. These three building methods will then separately be applied within three different designs as not all earthquake affected, rural regions in Nepal have the same characteristics and available materials. Incremental building To incorporate a long term perspective in the designs, the possibilities for building incrementally will also be further investigated as this might lower the costs in the short run while giving the opportunity for the home owners to expand their houses in a later stage. Whether this expandability of housing is feasible, as well as the feasibility of the housing itself, will be investigated in a cost analysis of all possible building materials, transport costs and labour charges. This analysis will be started off with a survey among villagers, NGOs and construction workers. After this clear image of costings is created, well considered decisions can be made on which materials to use to what extend in the development of the different housing designs. This follows from the strategy from the strategic action-plan that safe solutions should be promoted over cheap solutions. By performing a thorough study on both safe solutions as well
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Shock Safe Nepal as costs, a design can be made which is not only safe but also still relatively affordable. Safety and demolition The safety of the houses should not only be guaranteed after the construction, but also during the construction phase. Therefore, a detailed demolition and debris management plan will be designed to show how to safely handle the ruins of the destroyed houses. Not only will this improve safety, it will also enable the Nepali people to make the most of the materials that still remain in the ruins of their old houses. This assessment of re-usable materials follows from the strategic action-plan of Shock Safe Nepal Team 2 and can reduce the costs to a certain extent. Water management The magnitude of the earthquake of April 2015 was strong enough to move mountains. At some locations the ground was permanently lifted a meter by the earthquake which resulted in a complete change of soil structure (Pappas, 2015). An effect of these shifting of mountains is that wells have dried up which has resulted in a water shortage throughout the affected rural areas. In order to incorporate a long term perspective into the building designs, this water supply issue has to be taken into account in the housing designs. Therefore, a water management study will be performed on the rural areas of Nepal in this report. Locals’ responsibility Another aspect of the strategic action-plan is the local’s own responsibility. In this report the concept of borrowed labour (not to be confused with bonded labour) will therefore be investigated. Besides that this requires the owners complete involvement in the building process, it might decrease the direct labour costs as these “costs” will be paid back in labour in later stages. This not only involves the homeowner, but also the complete community as building one house will become a shared effort of the community. Information obtainment To be able to achieve the abovementioned targets of the project, a lot of information needs to be obtained. Most of the information to start the project will be acquired from publications, research papers and reports on the topics of Nepali culture, building in Nepal and earthquake resistant building. This will provide SSN3 with the necessary knowledge to make adequate assessments of the design process when the location of research shifts to Kathmandu.
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Upon arrival in Kathmandu meetings have been organised with all parties that are expected to be relevant. These involved parties range from governmental bodies to NGO’s and individuals that could be of relevance for the project. In Appendix A a list of all contacts of team 3 has been added and will be referred to throughout the report. In addition to these meetings, a workshop of Concern Worldwide on the topic of demolition and waste management will be attended in order to write a meaningful recommendation on this topic. On-site research To understand the Nepali culture, building methods and material availability in rural areas to the extent to be able to make valuable recommendations, a study will also be performed in the rural village of Ratankot. This village in the badly earthquake affected Sindhupalchowk area is hard to reach by road, has a high amount of destroyed houses and is in dire need of a housing solution (SSN2, 2016).
Research setup
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3 ANALYSIS RURAL NEPAL
3.1 Context of Nepal Geography & climate Nepal is an Asian country of approximately three times the size of that of the Netherlands. It borders the Chinese region of Tibet to the North and India to the South. Geographically it is divided into five regions: Tarai, Siwalik, Middle Mountain (Pahad), High Mountain (Himal) and High Himalaya (High Himal), as can be seen in Figure 3.1. The altitudes vary from 60 to 8848 meters above sea level, as Nepal is home to 8 of the 10 tallest mountains in the world. Due to its location on the Indian and Eurasian tectonic plates, Nepal is prone to a high number of earthquakes (SSN1, 2015). Due to it’s geography and location, the climates in Nepal vary heavily; from arctic to subtropical (SSN1, 2015). There is a dry, cold season in the winter, followed by a very wet season in summer, called the monsoon. More than two thirds of the yearly precipitation falls in the months June, July and August (DoHM, 2013). Monsoon precipitation can range from less than 100mm (in Mustang) to more than 4500mm (near Pokhara)(DoHM, 2013).
Financial Nepal is one of the least developed countries in the world, with a quarter of the population living below the national poverty line. Nepal ranks 145 out of 186 on the Human Development Index (HDI), and is in the top 5 least developed countries in Asia (HDI, 2015). Minimum wages are set on Rs. 8.000 per month (approximately $80), but are not widely complied with. The GDP in 2014 was $19.64 billion, only a fraction of that of the Netherlands. Agriculture forms the largest part of the GDP, as 70% of the population is working in this sector. Tourism forms a large part of the income and occupation, especially during peak seasons. Electricity availability is very low, even though there is a huge potential for hydropower generation in the Himalayas. The trade deficit is very large, as exports make up approximately 15% of the imports. The earthquakes have had an enormous impact on the economy, pushing more people into poverty, causing damages estimated to be $5 billion, with total losses of $1.8 billion (SSN1, 2015).
Figure 3.1: Geographical map of Nepal showing the five regions, from the Terai (dark red) to the High Himal (dark blue). (Department of Hydrology and Meteorology, 2013)
Shock Safe Nepal Social The people of Nepal are characterized by having a shortterm vision (SSN1, 2015). Even now, a year after the earthquakes, a lot of people lack a long-term vision for new accommodation, source of income and community development. Generally speaking, the Nepali people are not very entrepreneurial, for example, farmers in rural areas are mostly self-providing, finding it unnecessary to grow more crops than they consume themselves. An average family consists of 5 persons (Census, 2011). But many Nepali males leave the country to work abroad, where there is possibly a brighter future. The women that are left behind take over the labour of the men on the land (SSN1, 2015). Approximately 17% of the population lives in urban areas, which is increasing every year. Many educated young people migrate to the urban centers from the rural areas. This results in ageing of the rural areas and increasing poverty. Religion & castes Even though Nepal is a relatively small country, there are many different ethnic groups, religions and castes. The largest religion is Hinduism (80,6%), followed by Buddhism (10,7%) and Islam (4,2%). The castes are related to the social class of a person, and is determined by birth. Although this system was abolished in 1962, it still remains a part of Nepali culture. In many villages these castes still live separately.
3.1.1 Post disaster reconstruction The National Reconstruction Authority (NRA) has been put in charge of reconstruction works for five consecutive years, which can be extended by one year if needed (NRA, 2016). The NRAs broad policy objectives are as followed (NRA, 2016): - “To reconstruct, retrofit and restore the partiallyand completely-damaged residential, community and government buildings and heritage sites, to make them disaster resistant, using local technologies as needed;” - “To reconstruct damaged cities and ancient villages to their original form, while improving the resilience of the structures;” - “To build resilience among the people and communities at risk in the earthquake-affected districts;” - “To develop new opportunities by revitalising the productive sector for economic opportunities and livelihoods;” - “To study and research the science of earthquakes, their impact including damages and effects, and post-earthquake recovery, including reconstruction, resettlement, rehabilitation and disaster risk reduction; and” - “To resettle the affected communities by identifying appropriate sites.” The implementation structure of the NRA is a top down system that follows the current governmental structure of districts and Village Development Committees (VDCs). A visualisation of this structure can be seen in Figure 3.2. On the top the NRA assigns projects and funds to four different ministries, who each set up a Central Level Project
Figure 3.2: Top-down structure of the organisation for the reconstruction of Nepal. (SSN3, 2016)
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Shock Safe Nepal Implementation Units (CL-PIUs). These CL-PIUs will set up corresponding District Level Project Implementation Units (DL-PIUs). The NRA Sub Regional Offices (SRO) will facilitate planning and reconstruction activities and help strengthen coordination between central authorities and local bodies. The NRA SROs will coordinate the District Coordination Committees (DCCs) on district level. The DCCs operate down to VDC level where Resource Centers and VDCs are in charge. Resource Centres will disseminate information on building technologies and on assistance available from government and non-government sources and help ensure that vulnerable groups receive the assistance they require. Resource Centres will also provide technical assistance for design and construction of houses and community infrastructure, and will inspect housing, other buildings and infrastructure. VDCs will help coordinate housing reconstruction, and implement community infrastructure and other local projects. Additionally, partner organisations (POs) will aid with projects on VDC level. These are NGOs that are not part of the operational structure of the NRA. Existing coordination mechanisms for these partner organisations are Association of International NGOs (AIN), NGO Federation of Nepal (NGN) and Housing Recovery & Reconstruction Platform (HRRP). 3.1.2 Earthquake Housing Reconstruction Program Housing projects make up the largest portion of the reconstruction activities of Nepal, with the majority being located in rural areas. For housing projects, the following five stages of implementation are distinguished (NRHRP, 2016), as can be seen in Figure 3.3.
Figure 3.3: The five reconstruction phases, according to the Nepal Rural Housing Reconstruction Program. (NRHRP, 2016)
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Stage I: Survey Firstly, a survey was conducted in order to assess all damages in the districts. This was done in the first months after the earthquakes. The earthquakes of 2015 had fully damaged 498,697 households and partially damaged another 256,617 (NRA, 2015). Stage II: Identification & Validation Secondly, based on the eligibility criteria, earthquake victims were given ID passes and put on the eligibility list. This list contains the people that are eligible for financial governmental support that will be disbursed by the NRA. This list has been made available by the NRA in June 2016. Stage III: Enrollment The third step consists of setting up enrollment platform, which allows eligible beneficiaries to enroll for government funds. Enrollment centers will be set up at VDC level, with coordination from district levels and central level (NRA, 2016). All people coming to enroll for support are required to bring the following documents: Citizenship certificate, land deed and slip given to them by the surveyors or an ID number from the survey. For land in the name of someone other than the eligible person/household, there would be need for no-objection from the landowner. The enrollment step outlines the entitlements and obligations regarding key details of the program such as: - Payment - Housing construction standards and - Grievance redress mechanisms (how beneficiaries can address any complaints). During enrollment, those beneficiaries without bank accounts will be assisted with opening one or with determining another workable payment mechanism (NRA, 2016). The plan for reconstruction that has been presented is quite straightforward, however it still causes a number of issues with earthquake victims that aren’t able to enroll, because: Their citizenship certificate or other required documents are missing, either before the earthquake, or in many cases have been lost in the rubble of their homes. The administration on land ownership and land lease is in many cases not well documented. Lease contracts or ownership documents have been signed years (or even generations) ago by relatives that might have been deceased already. This results in the non-existence of these documents in some cases. Also, the information on the reconstruction plan is not arriving in many of the VDCs. Since this has been the situation for over a year now, many people inflicted by
Analysis rural Nepal the earthquake have lost their faith in the governmental support. Stage IV: Reconstruction The reconstruction stage relies on owner driven reconstruction. This implies that the home owner should take initiative for the reconstruction. This is supported by the following: - Trainings - Subsidies - Logistics hub - Implementation support - Inspection & certification The beneficiaries will be trained in resilient building techniques and materials by mobile trainings teams. They will also give training and assistance to VDCs to train artisans and contractors who are directly involved in the projects. Training centers and technical support will be set up in collaboration with partner organisations.
Inspection will be conducted to ensure that the housing reconstruction follows the NBC and is in compliance with the necessary conditions for the cash transfer. Inspection will be done per stage: - Upon signing of the Participation Agreement - Upon completion of the foundation up to the lintel/wall - Upon completion of the roof Stage V: Completion In the final stage of the program cycle, the beneficiary will obtain the “Building Construction Completion Certificate”, which precedes the occupancy of the housing unit.
In addition to training, the beneficiaries will receive governmental financial support. The support will be handed out in different stages of the reconstruction, this will facilitate owner driven reconstruction. If the reconstruction is being done in line with the NBC and is earthquake safe, the beneficiary will receive the following payments: - RS 50.000 - RS 80.000 - RS 70.000 Totalling to an amount of Rs. 200.000 or 2 lakh Rupees. Earthquake victims, INGOs and even several governmental organisations (such as DUDBC) have stated that this amount is insufficient to build a house from the approved designs in the catalogue of the DUDBC. Costs for these designs could be around 2.5 times the amount of the government funds (SSN2, 2016). The program will help guarantee a continuous supply of building materials and skilled labour, and manage potential shortage and/or adverse price fluctuations of the resources through POs. It will give information on material availability, prices, locations, labour, etc. Each VDC will have a mobile team composed of technicians and social mobilizers. The team’s main responsibility will be to conduct awareness campaigns and orientations for homeowners, provide on-the-job assistance to workers on site, and organize social gatherings and meetings to discuss problems and difficulties faced during the reconstruction phase in order to help identify solutions.
9
Shock Safe Nepal 3.1.3 Priority districts The main attention for earthquake relief and reconstruction has been focussed on the fourteen priority districts, see Figure 3.4. Approximately 5.8 million people are living in the fourteen priority districts, according to projections made for 2016. 74% of the population has reported damage to their buildings (UN, 2015). These buildings mainly were built with stones/brick and mud mortar (51%), cement mortar (41%) and smaller fractions of bamboo and wood (6% in total). In Kathmandu the majority of the cement mortar buildings are present (66% of all buildings in the fourteen districts; adding up to 80% of the buildings in Kathmandu). This is because 69% of all the RCC frame buildings are located in Kathmandu. In the rural areas the large majority of the buildings is made by stones/bricks and mud mortar (69%), with either CGI sheets (38%) or slate (28%) as roofing material. Some building have RCC frames as well (18%)(Census, 2011). Other not so commonly used building methods that are present are: hollow concrete masonry, timber constructions, adobe, dhajji dewari, rammed earth, steel, concrete in situ shear-wall, bamboo, earthbags, interlocking bricks and (stabilized) compressed earth bricks (CEB)(SSN1, 2015). In April 2016, 62% of the population of the fourteen priority districts still doesn’t know how to get reconstruction support, stating that there is lack of information where, when and how to enroll for support and there is lack of safe construction with 2 lakh, even though 69% believes that there is nothing preventing the arrival of reconstruction support at the moment (UN, 2016). Three quarters of the population in the fourteen priority districts believes that the post-earthquake reconstruction process is not making any progress. Main barriers would be lack of decisions, unclear plan and guidance, as well as delays in fund disbursement. More than half of the population is still unaware of safer building practises, among which the majority consists females and people aged above age 55. Information on safe building reached the population by radio, tv, community members and in some cases the VDC office (UN, 2016). 96% of the population states that additional support is required on top of the received support, and 76% believes that this support is not available in the community. The main additional supports needed are: finances (97%), technical support (39%), materials (40%) and labour (12%) (UN, 2016). Still 50% of the population needs to demolish their homes, stating that the costs for demolition are too high or the assessment hasn’t been completed yet (UN, 2016). In Sindhupalchok, 76% states that demolition is not necessary, possibly due to the fact that this district was one of the heaviest damaged districts. This resulted 10
in complete collapse of buildings most cases, which is easier to demolish. The fact that Sindhupalchok has received many help from international NGO’s could have contributed to this fact as well. As of August 2016, only 65% of all the eligible households have been able to enroll for government funding, see Figure 3.5. Even though government has recently (October 2015) published a new building code, as well as a catalogue with designs for houses using approved building methods, the reconstruction progress is very slow (NHRP, 2015). There are a couple of hundred international NGOs present in Nepal at the moment, many of which are involved in the reconstruction process (SWC, 2016). A legislation that disallows external funds to be used for housing projects, makes it hard to contribute to reconstruction, since finance is the largest obstacle for many people wanting to reconstruct their homes. Many NGOs organise trainings and workshops in order to teach the local population about safe reconstruction and the different possible building methods. Other projects, such as schools, foster homes and community centers can be financed by external parties. These are being used as a practical example on earthquake safe reconstructing, but are often more costly than regular housing projects.
Figure 3.4: Location of the two earthquake epicentres with respect to the fourteen priority districts (in gray). (HRRP, 2015)
Analysis rural Nepal
HRRP
NEPAL: Enrollment Status (as of 12 Aug 2016) District
CHINA
Eligible
Legend
Dhading
70,574
39,822
Dolakha
51,919
34,457
International Boundary District Boundary
Gorkha
58,504
48,354
Kavrepalanchok
67,723
37,813
Makwanpur
30,237
4,749
Nuwakot
65,772
43,572
Municipal/VDC Boundary
Enrollment Status
Okhaldhunga
19,819
17,561
Completed
Ramechhap
43,607
40,651
Ongoing
Rasuwa
11,229
4,463
Sindhuli
34,267
8,378
Sindhupalchok
78,537
63,009
532,188
342,829
TOTAL
GORKHA
Enrolled
Paused
64% enrolled RASUWA Note:
This map highlights the enrollment status in 11 of 14 most affected districts at VDC level. The table attached contains the summary of eligible beneficiaries and enrolled beneficiaries per district.
DHADING
Please note that this map is meant to be used for informative purposes only.
SINDHUPALCHOK NUWAKOT
Map Doc Name: GLIDE Number: Creation Date:
DOLAKHA KATHMANDU
Enrollment_Status_ID0186 EQ-2015-000048-NPL 15 Aug 2016
BHAKTAPUR Map Data Source: GoN, Supporting POs Geo Data Source: DoS, MoFALD, MoHA Geoportal Web Resource: http://hrrpnepal.org/maps/
LALITPUR MAKWANPUR
KAVREPALANCHOK
¯
RAMECHHAP
1 : 822,000 0
20
40 KM
OKHALDHUNGA SINDHULI
Disclaimer: The boundaries and names shown and the designations used on this map do not imply official endorsement or acceptance by the United Nations
INDIA
11 Figure 3.5: Enrollment status for June 9th of 2016 and August 12th of 2016. (HRRP, 2016)
Shock Safe Nepal 3.1.4 District: Sindhupalchowk Sindhupalchowk is one of the fourteen districts that has been prioritized, see Figure 3.6. Approximately 290.000 people live in this district, in families of an average size of 4.3 persons. Of the approximately 68.900 houses in Sindhupalchowk, almost 97% was damaged by the earthquake. The majority of these houses were build using mud-bonded bricks or stones, a building technique that was far more popular in this district than on the national average (90% versus 41% on the national average). Cement mortar and concrete was rarely (7%) ever used in this district and mainly found along main roads and transport routes (HRRP, 2016b). There is a highway or “strategic road” that passes through Sindhupalchok to Tibet. It’s a simple road, which was heavily damaged by the earthquake. Other roads are also available but not abundant. In the South, the connections to infrastructure are generally better than in the North. This is also where the most settlements are located and where most people live. But even in the densely populated South, some villages can only be accessed by hours of walking, according to locals. Overall the literacy rate in Sindhupalchok is 60%, which is on the National average, although education is lower than other regions (Census, 2011). Most of the households had simple facilities, with approximately 66% access to mobile
phones, 85% access to electricity, 66% owners of sanitary facilities and a lot less in ownership of televisions and computers (Census, 2011). Current reconstruction activities performed by HRRP and its partners are on a low level of completion in Sindhupalchok. Households lack financial assistance, model houses to learn from, construction materials and “build back safer” trainings, as well as masonry training. This is also due to the fact that neither partner organisations or the NRA are present in every VDC to perform these activities (HRRP, 2016). 3.1.5 VDC: Sunkhani Sunkhani is a VDC in the South-East of the district of Sindhupalchok, see Figure 3.6 and 3.7. There are 2520 people living in the VDC, of which 54% is female. The average household consists of 4 persons, meaning there are 626 households in Sunkhani. The majority of the population owns their own home, with only two homes being rented (Census, 2011). All foundations of houses in the VDC are built on stones/ bricks with cement mortar. The houses itself are made with the same building method, though using mud mortar. The roofs are built with CGI sheets, and minor fractions (10% each) are made from thatch/straw and tiles/slate (Census 2011). The main source of drinking water is piped water from
Figure 3.6: District administrative map for Sindhupalchok. Maps shows major and smaller infrastructure, settlements, and VDC borders. The VDC of Sunkhani is located in the South-East of the distrcit. (HRRP, 2016)
Analysis rural Nepal sources uphill (69%) and spout/fountain water, also from uphill sources (31%). The fuel used for cooking is wood, and the general power source is electricity (99%). Only 80% of all households has a toilet, of which only 33% is a flushing toilet (Census 2011). More than two thirds of the households own a radio, about 40% owns a television, but only 9 households have cable. Even less computers and internet connections are present, namely 2 in total. Mobile phones are more common, with 46% of the households owning a cellphone. Only four motorcycles are owned in entire Sukhani (Census, 2011). The largest age groups are children from 0 years to 20 years old. They make up for 40% of the population. The age group of 20 to 40 years old only takes up 26%. This does not take into account the fact that there has been a large migration towards the cities in recent years, which was amplified in the earthquake aftermath (Shyiam, 2016). The mother tongue of the majority (57%) is Nepali, the rest speaks Tamang. The Tamang make up approximately 43% of the population, the other large groups being Chetree, Kami, Thami and Gharti. The literacy rate for females is 53%, for males 63%. 19% of the population between 5 and 25 does not attend school (Census, 2011).
hours away by foot from the main road on an altitude of 1600 meters. A small road, large enough for the iconic Tata trucks, grants access from the main road to the village as well, but requires a detour of 1.5 hours (Karma, 2016). See Figure 3.8 for the map of Ratankot. A small part (15%) of the original population is living outside Ratankot, namely in Kathmandu region (70%) and the Middle East and Malaysia (30%)(S4N, 2011), fractions that have increased after the earthquake as well. The largest religion is Buddhism (90%)(S4N, 2011), and there are a handful of stupas and temples present. There are castes present, but they play a minor role in the daily lives of the people of Ratankot (SSN2, 2016). There are no Dalit present in the VDC, which also contributes to less caste related issues being present. The main profession of almost every inhabitant is farming. But because less than 30% is able to produce enough food to last a whole year, a lot of people take up other professions next to farming in order to generate alternative income, which allows them to buy food. These include: teaching, carpenting, construction work, honey making and selling alcohol (S4N, 2011). Women seem to participate more
3.1.6 Ratankot There are approximately 750 people currently living in households of five persons on average in Ratankot, a small village in the Sunkhani VDC of Sindhupalchok, located 1.5
Figure 3.7: Map of the VDC of Sunkhani, with the locations of Ratankot 7 and 9 in the East of the VDC. Map is created by combining different images. (HRRP, 2016 & SSN2, 2016)
Shock Safe Nepal in hard labour than men, such as carrying heavy bags and baskets up and down the hill. There is no entrepreneurial spirit or long term vision (SSN2, 2016). The yearly expenses for clothing, food, alcohol and cigarettes reaches approximately Rs. 20.000 (â‚Ź167) per year. Also, there is a lot of alcohol consumption. The families in the higher part of Ratankot are generally poorer (S4N, 2011). The people aged 40+ are generally illiterate, and most of the children attend school. A minority (40%) of the households has a toilet on their property, of which many were destroyed by the earthquake as well. The average water consumption per person is 20L/day (S4N, 2011). The water sources all originate higher in on the mountain. After the earthquake some of the sources dried out, causing serious water scarcity issues. In April and May, at the end of the dry period, the water sources are almost completely dry, and the local population have to retrieve water from other sources, at a relatively long distance (S4N, 2015). Because of health issues, many people, but also farm animals, become sick
regularly (S4N, 2016). This could be related to badly treated drinking water, as well as the lack of ventilation above cooking ďŹ res and general lack of hygiene. The increase in water scarcity will possibly cause an increase in health related issues. Only 55% of the population burns some of their wastes instead of throwing it away on the mountain slopes or in the surface waters. This results in noticeable piles of garbage that are potentially polluting. The animals are kept inside the homes during winter. Electricity is available, even more than in Kathmandu, but at a relatively high price for the people of Ratankot. Of all the houses in Ratankot, only one was not damaged by the earthquake. Just 6% had minor damage, all the other building were heavily damaged or even completely collapsed (SSN2, 2016). All the houses consisted of stones and mud mortar, with either slate or CGI rooďŹ ng (S4N, 2011). The people have received emergency shelters from different organisations and have set these up next to their
14 Figure 3.8: Map of Ratankot, showing main road in black and smaller pathways in yellow. Households are depicted in red, yellow and orange rectangles. The gray lines are isohypses. (SSN2, 2016)
Analysis rural Nepal homes. Some have adapted their undemolished homes with emergency shelter equipment in order to be able to resettle. This will most likely cause issues during future demolition and reconstruction. New construction projects are being started in Ratankot, be it in small numbers. A foster home has been completed in April 2016, funded by the Loof Foundation, a Swedish organisation, and managed by Shyam Lama. The building method used is stone masonry with cement mortar for the walls. The roof is made of timber and is supported by a steel frame, going through the walls, that is attached to the foundation. A new school is being built in lower Ratankot 7, funded by Build up Nepal, also a Swedish organisation. The method used is a heavy RCC frame, with interlocking stabilized CEB bricks as confined masonry. Abundant use of construction steel and cement probably ensures that the costs are high. Only the rich people of Ratankot can rebuild their homes without external funding, and less than a handful of them are rebuilding at the moment, mostly with non-traditional building methods, such as RCC frames and hollow concrete blocks. Natural construction resources that are present in Ratankot mud/clay, which is abundant, other resources such as timber and stone are available in (very) limited quantities. For steel, cement and glass, the people of Ratankot have to travel to a market in another VDC (Karma, 2016). The International Organisation for Migration (IOM) is giving trainings on earthquake resistant building techniques for stone masonry with mud mortar to the people of Ratankot and other parts of Sunkhani. However, the people are not convinced that this building method is a reliable one, since all the buildings that collapsed used the same technique, though not earthquake safe. Other than IOM, neither Housing Recovery and Reconstruction Platform (HRRP), Association of INGOs in Nepal (AIN) or NGO Federation of Nepal (NFN) are present in Ratankot. None of the villagers have been able to enroll for government funds as of June 2016 and the VDC is extremely difficult to get into contact with. Some villagers even state that the VDC was disbanded after the earthquake, due to migration to Kathmandu of all its office members. During the site visit of SSN 3 there seemed no central organisation on VDC level in Sunkhani or Ratankot, which will possibly be a cause of delays in the reconstruction process. As of August 2016, the enrollment process has finished, as 95% of the eligble population has enrolled. Distribution of government funds have not yet begun (HRRP, 2016). International NGOs that are active in Ratankot, and are involved in different reconstruction and human/community development projects are Support4Nepal (Belgium), BuildupNepal (Sweden) and Lööf Foundation (Sweden).
3.2 Demolition and waste management
15
Shock Safe Nepal
Due to the 2015 earthquakes approximately 14 million tons of debris waste was generated by the 14 priority districts (Disaster Waste Management Policy (Concern sess.1), December 2015). Originally, the Nepal army was responsible for carrying out demolition works for high risk buildings in urban Nepal. But after the initial months after the earthquake, they ceased their activities (Concern, 2016). Organisations such IOM, UNDP and All Hands have assisted the Nepal government in demolition of damaged buildings (Concern, 2016). But many demolishing works still have to be carried out. According to a survey (REACH, 2015), 74% of the households in the priority districts reported damage to their homes as a result of the earthquake, of which only 5% had completed repairs or rebuilding works and only 11% reported that their house had been demolished or that the site was being cleared. Concern Worldwide and Engineers Without Borders Denmark (EWB) state that demolition and disaster waste management should be prioritized after initial earthquake relief. A good disaster waste management will facilitate the reconstruction and will improve the earthquake resilience in general (OCHA/UNEP, 2011). The following demolition and debris management strategy has been based on workshops organised by Concern Worldwide and EwB in May 2016, Kathmandu, Nepal, that were attended by the third team of Shock Safe Nepal. The integrated demolition waste management & reconstruction follows the following chart as a guideline Figure 3.9.
For the demolition of a damaged building, ďŹ rstly information should be obtained on the following: used construction materials, loadings and load paths on a structure and resulting failure mechanisms. After which a plan has to be made on how to demolish the structure safely, taking into consideration the possible hazards during demolition, construction safety according to the Nepali Building Code (NBC 2015), shoring and bracing of the structure and the eventual demolition sequencing, including weakening and pulling the structure. The construction and building types that are found in Nepal have been extensively described by SSN1. In the affected areas of rural Nepal, the majority of the buildings are made with stone masonry and mud mortar (Census, 2011). Many buildings in the affected areas were heavily damaged or even completely destroyed (SSN1, 2015 & SSN2, 2016), mostly because of the quality of the masonry and the technical properties of mud mortar. Many of the stones were not cut properly and sized differently (too small in some cases), resulting in inhomogeneous walls. Mud mortar has insufficient binding capacity to compensate for the inequalities in the stones. Mud mortar is characterised by low compressional strength and signiďŹ cantly low shear and tensile strength, compared to stabilized and cement mortars (SSN1, 2015). The earthquakes of 2015 resulted in various seismic waves, that lead to failures of the bearing structures of the buildings (SSN1, 2015). The loads and load paths that developed exceeded the capacity of the structural components and initiated cracks and failures. These eventually lead to destabilisation of the buildings, followed by collapsing in many cases. For the masonry found in rural Nepal, the loads that lead to cracks can be categorized into: in-plane and out-ofplane loadings, as can be seen in Figure 3.10. In-plane loads can result in four failure modes; diagonal tension cracks (a), sliding (b), tilting (c) and rocking (d) (Concern, 2016).
Figure 3.9: Flowchart for demolition and waste management. (Concern, 2016)
To increase feasibility of a demolition and reconstruction project, all the intermediate steps should be taken into account. The previously mentioned workshops gave insights on how to deal with the various stages in waste management and reconstruction, which are elaborated below. Demolition
16
Figure 3.10: Different failure modes for in plane load paths: diagonal tension cracks (a), sliding (b), tilting (c) and rocking (d) (Concern, 2016)
Analysis rural Nepal Out-of-plane loads can result in: horizontal cracks due to top loading, diagonal crack patterns (especially in the presence of windows), vertical cracks near walls (Concern, 2016).
important to cordon off the area. When demolishing walls or big objects controlled failure is also an option. This can be done by pulling the support structure at a safe distance with a long rope or knocking it over with a pole.
An important first step in demolition is the stabilisation of the structure. It is important to work safely and demolish the structure in a controlled manner. There are two main kinds of support, gravity load supports and stability supports. Gravity loads support are used to support roofs and floor slabs. Stability supports give extra stability to walls and buildings that have begun to heave or bulge. (Concern 2016). Stability supports can either transfer their load to the ground, raking shore, or to a vertical structure such as an retaining wall or an adjacent building, flying shore.
Site safety is important part of demolition. The Government of Nepal (GoN) has drafted construction safety requirements in the National Building Code 114 (NBC, 2015). NBC 114 contains guidelines on several aspects such as material handling, first aid, firefighting, construction, demolition and labour welfare. Important for demolition is that all plans need to be approved by an engineer. The engineer has primary responsibility for all activities on the work site. It is uncertain how much control there is by the GoN on conditions on the work site. However if it becomes apparent after a work incident that safety regulations were not followed the contractor and engineer are liable. An important exception on the code is that on owner-built construction sites the safety requirements are only advisory. As most of the housing reconstruction in Nepal will be owner driven, the NBC 114 will have limited value.
When the structure has been sufficiently been stabilized
Handling After catastrophic events, such as earthquakes, and after demolition, waste is generated. In order to facilitate and improve safety around the handling of these wastes it is important to know what kind of wastes are present at the observed location. A common method is to divide these waste into the following groups (Laurentzen, 2016): - Inert waste; debris, rubbles of concrete, masonry and stones. - Municipal waste; organic waste, solid waste from households. - Hazardous waste; harmful chemical substances, oil, asbestos, batteries, hospital waste, etc. - Disaster waste; waste caused by disasters plus municipal waste.
Figure 3.11: Photograph of a building in Kathmandu being strutted for stability. (SSSN3, 2016)
demolition can commence. Vital in this stage is to continuously identify the support elements and their loads. In principle demolition will occur top-down. Sometimes it can be easier to first demolish a lower element to gain better access to eg. the roof structure. Additional support can be needed as demolition progresses. As falling debris can land as far as 1.5 times the height of the structure it is
The majority of the disaster and demolition waste is inert waste. Municipal waste and hazardous waste need to be separated from the inert waste, that could be reused and recycled. Wastes can be ranked by priority using the tool in the “Annex II.” of the “Disaster Waste Management Guidelines” (OCHA/UNEP, 2011). The waste is ranked by looking at the age of the waste, proximity to residential areas and proximity to streams, rivers and other water sources. High priority wastes are then all household wastes, infectious wastes, camp wastes, paints, excreta and food wastes and for close proximity to household
17
Shock Safe Nepal solvents and varnishes, pesticides and fertilizers are also added to high priority ranking. The “Annex III” elaborates on how to handle all these different types of waste. Both Annex II and Annex III of the Disaster Waste Management Guidelines are added to Appendix B. Disposal For disposal sites of waste, general considerations should be made: Temporary sites should be a last resort, this saves money and time. If temporary sites are necessary, the best way to implement this is to conduct a rapid environmental impact assessment, mainly taking into account health and environmental aspects. The local population should be notified of all the potentially harmful materials stored at the temporary site. The site should be able to hold conventional demolition waste, such as rubble, wood and natural debris.
To acquire information of the amounts of waste that have to be sorted, an estimation has to be made of the total waste that will be produced by demolition. This estimate can vary from a simple guess, backed up by some minor calculations, to a fully detailed calculation, which is much more time consuming (EWB, 2016). Usually, a structured estimate, made from simple calculations of photo’s from the to-be-demolished structures results in reasonably accurate answers (EwBD, 2016). This will serve as a preliminary estimate for the volumes of demolition waste. With this information, the layout of the disposal site can be made. The disposal site will consist of sorting piles for the different materials that are obtained from demolition. An example for the different piles is give in Figure 3.13.
Also, the disposal site should be sufficiently large and at a safe distance from water sources, as well as flood plains. For safety it should also have limited access for public and be free from obstructions such as pipelines and power lines. Location should be close to the affected area and preferably on public soil for easier approval. A typical layout for a disposal site could look like the one of Figure 3.12. This layout provides easy access through the gate and area to maneuver for trucks, etc. Every type of waste is gathered at their respective piles. There is an area reserved for incoming unprocessed and unsorted debris, as well as an area reserved for recycling and sorting. Hazardous waste should get an appropriate location with the necessary safety measures. Sorting
Figure 3.12: Example layout for a demolition and wastemanagement site. (Concern, 2016)
18
Figure 3.13: Example for different piles for wastes in a waste management site. (Concern, 2016)
After demolition a final assessment should be made on the amounts of all the materials. During sorting, materials will be assigned a quality. For simplicity, two qualities will suffice: good and poor. Good materials are essentially ready for reuse and poor materials should first be recycled. Good materials do not have sustained the threshold of damage that will exclude them from reuse for different purposes. Assigning good or poor to demolition materials is based on the different desired options for reuse and recycling. Therefore it is preferred to investigate possible reuse and recycle simultaneously, if not on before hand. Recycling Recycling in this report means the altering of wastes in order to facilitate reuse. These are wastes that no longer can be directly reused in construction, mostly because they have been too heavily damaged during the disaster or demolition. During sorting, these wastes are classified as poor. In demolition and waste management, recycling mainly consists of crushing construction materials to the preferred
Analysis rural Nepal size. Crushing can be done manually and mechanically. Mechanical crushing is preferred over manual crushing, since it’s less time- and labour consuming, and in large amounts also less expensive. For smaller recycling sites, small crushers have been developed. These crushers can recycle stones, concrete and masonry into smaller waste fractions that can be used in for example concrete slabs, stabilized earth bricks, landfill, etc. Reuse All the good quality materials can directly be reused, and the recycled materials can be implemented in these structures as well. In Table 3.1 below, some examples for standard demolition material reuse have been given.
After demolition, a new structure can be built on the previous location or on a new location construction can start by using recycled materials or reusing the waste materials that are of good quality. In the design process of the new structure, the obtained waste should be considered as a construction material and thus be taken into account in the cost analysis. This process can start before demolition, when estimates are being made on the volumes of waste generated, and needs to be finalized during the construction. This will reduce the costs for new construction materials, transport and labour significantly. Assigning new functions for waste will also help to determine what wastes to reuse and recycle, and in what quantities. Wastes that are not used for construction can be recycled and sold or used elsewhere in the community.
Construction
3.6 Rainwater harvest Table 3.1: List of materials and possible reuse based on the quality of the salvaged material. Material
Quality
Stones (large)
Cut, undamaged
Housing structures, foundations, other buildings, walls
Cut, damaged
Use in gabion as retaining wall if size is sufficient. Or to fill up gaps in new structures. Repairing of or new infrastructure.
Cut, undamaged
Use in gabion walls, non-bearing structures; such as ring walls around properties.
Stones (small) Rubble stone, uncut stone
Reuse
Use in gabion walls, landfill
River stones
Round
Slate
Unbroken
Reuse as roofing
Timber
Undamaged beams
Reuse beams if quality is sufficient.
Undamaged planks Windows, doors, ornaments
Reuse for flooring if quality is sufficient. undamaged
Damaged/bent beams, planks Windows, doors, ornaments
Use in gabion walls or landfill.
Reuse if quality is sufficient Reuse in animal shelter, furniture, non-bearing structures. Use as firewood if other reuse is not possible
damaged
Concrete (reinforced) slabs, floors, roof
Reuse the wood in non-bearing structures or smaller animal shelters. Use as firewood if other reuse is not possible. If foundation and the concrete floor on top is intact and reliable for reuse, the same site can be used for new construction with same foundation and floor.
Concrete columns, beams
Send to recycling
Concrete foundation
If foundation and the concrete floor on top is intact and reliable for reuse, the same site can be used for new construction with same foundation and floor.
All poor quality concrete, reinforcement sticking out, insufficient concrete cover
Send to recycling
Glass CGI sheets
Steel beams Steel door handles, hinges
Intact
Reuse in windows.
Broken
Discard
Good condition
Reuse in roofing, for either new buildings, houses, animal shelters.
Dented, ripped, rusted beyond repair
Send to recycling.
Straight
Reuse directly in constructing
Bent, rusted
Send to recycling
Intact
Reuse with same function
Rusted
Remove rust and reuse
Piping, valves
Intact, no rust or limescale
Ready for reuse
Electric wiring
Intact, no rust or exposed metal wiring
Reuse
Mud mortar
Remove from stones and use as landfill.
Cement mortar
Send to recycling
Shock Safe Nepal
3.3 Suitable building methods for rural areas SSN1 developed a methodology to make a selection of the most suitable building methods for ribbon development in rural areas, using the Solution Space method and the Multicriteria Analysis (MCA) method. This chapter will elaborate on rural areas with bad accessibility, before defining what building methods are the most suitable for the case of Ratankot. Like the analysis for ribbon development, this will be based on the building methods as defined in the report one of team 1. To come to an accurate selection of suitable building methods for rural areas, this chapter will assess all probable building methods in Nepal. The information needed is acquired from literature, observations and interviews. 3.3.1 Solution space The essence of using a Solution Space is to rate all building methods on requirements that are considered relevant. This requires a solid set of requirements that cover all aspects that could be of importance for building earthquake safe in rural areas. These requirements will select the building methods for the MCA based upon a minimum value principle, the building methods have to score a minimum value to be entered into the MCA. Building methods In the report of SSN1, an extensive list of possible building methods in Nepal was formed, according to the new Nepalese building code and progressive insights this list has been updated for this assessment. The method of compressed earth bricks (CEB) is added, as the method of interlocking bricks differs significantly on some aspects. Compressed earth bricks consist of a mechanically compressed mixture of soil and cement, but are not necessarily shaped as interlocking bricks. Due to this composition of the material, CEB is also kept apart from brick masonry, as many properties differ. A more extensive explanation of this material and all other building methods can be found in Appendix C. This explanation is for a large part based on the findings of team 1, as the building methods are the same. However, some aspects have been redefined in order to explain how this building method would function in rural areas instead of areas with ribbon development. Selection of relevant requirements The list of 47 requirements as defined by team 1 has been reviewed and 28 requirements were assessed as being relevant for the context of rural areas. Two requirements were added. As construction in rural areas becomes
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exponentially more expensive if materials have to be imported, the availability of materials in the rural areas as well as the transport costs have been added to the criteria. There will be a difference in availability between several rural areas, so for now all material that have a chance of being locally available will be assessed as locally available. The updated list of requirements to be used in the Solution Space can be found in Appendix C4. Minimum values for rural areas Quantitative requirement values are used to score the qualitative requirement values. Minimum values are determined for all 30 requirements in order to review whether building methods could be valuable in rural areas. This value will be used to filter the least promising building methods from the most promising ones. Mainly the minimum values for Use of local materials, Use of local resources and Transport are relatively high, due to their importance in rural areas and one of the focus points of this research to aim for the use of local materials. This does not mean that building methods without local materials will automatically be declined, yet they will have to perform above average on all other requirements to make up for this shortcoming. Filtering through the Solution Space Therefore, many building methods that would fit the solution space in areas with good accessibility now fail for rural area, caused by high minimum values on the requirements related to accessibility. Other requirements that are not often met are Expandability, Construction investment, Labour experience, Ease of learning and Maintainability. Only Timber construction and Interlocking bricks fit the solution space without exceptions. Apart from that, there are four building methods that fail only on the requirements on expandability. These aspects are subjects of this research and will be conducted to a more in depth study later on. These chapters will elaborate on the possibilities to improve the building methods that fit the solution space and pass the MCA. For this reason, expandability and seismic performance are ignored in the selection of the building methods. In total six building methods then fit the solution space. Four building methods don’t fit the solution space, but are accepted by exception, as they fail on only one requirement. This leaves a set of ten building methods that will be inserted in the multi criteria analysis. Those are the following: -Low strength (stone) masonry -Dhajji Dewari -Low strength (brick) masonry -Rammed earth
Analysis rural Nepal -Stone masonry in cement mortar -Earthbags -Timber construction -Interlocking bricks -Adobe -Compressed earth bricks (The complete Solution Space can be found in Appendix C4.) 3.3.2 Multi Criteria Analysis These ten building methods appear to be suitable for building in rural Nepal. However, the set has to be narrowed down to be able to perform a solid designing phase. This limiting of possible building methods is done with a MCA. In a MCA, multiple decisions are weighed on several criteria to structurise the decision-making process. By performing a MCA, the building methods can be assessed and compared objectively on all their strengths and weaknesses. This distincts the MCA from the Solution space which is only able to assess the different building methods, but not compare them quantitatively with each other. This comparison is needed to eventually create a small list of building methods that are best appropriate for building in rural areas with a low budget. That is therefore the purpose of this MCA. The elaborate list of important categories and corresponding aspects of the Solution space has been transferred to the MCA. By valuing all the assigned grades on their worth to the complete building method, the building methods can be compared among each other on all of these categories. To determine how much each category should contribute to grading of the whole building method, two groups of experts have been consulted, the Shock Safe Nepal team and a group of Nepali Engineers. In both groups all individuals have been asked to grade the categories, after which a combined grade for both groups has been created. The outcomes of this survey can be found in Table 3.2. Table 3.2. Weighting table SSN and nepali engineers
Scenarios The future of Nepal is highly uncertain. Besides all governmental issues, the dependability of foreign emergency aid and the problems concerning water shortages, there is always the imminent threat of a new devastating earthquake. In the MCA different scenarios have been drawn up in order to distinguish the differences in possible futures. Building methods that might be perfect in one possible future, might not work in another more likely future. Below the three different scenarios are described. 0-Scenario This scenario describes the most likely future of Nepal. The expectation is that the Nepali homeowners still have insufficient funds to build a house and the government is willing to contribute 2,000 dollar per house. Therefore in this scenario the financial aspect is of a higher importance than the other categories. The technical aspects of this scenario, which include the earthquake resistance of the structure, are almost ranked at the same importance as the financial aspects. Together with the resources-category these form the most important factors in this scenario. Following from the goal of this report, this is not unlogical as these are factors from the mission statement; feasible, earthquake resistant and rural. Where the resources factor derives from the rural areas and largely comprises the availability of materials. More remote - scenario The area that can be labeled as a rural area in Nepal is a comprehensive region with lots of different characteristics between the different areas. This makes it hard to take into account one single location to design a house for. To be able to deliver a housing design that can be build in almost the whole area, also more remote villages have to be taken into account. Important to realise in this case is the difference between more remote villages in rural areas and the highly remote areas in Nepal which don’t have a connection to the civilised world at all. For this scenario, the resource aspects of the design are considered extremely important, together with the transport aspect of the financial category. Naturally, as this scenario focusses mostly on resources, the importance of technical and feasibility has been reduced a bit. Also the sustainability is less important in this aspect as the people in these areas live more sustainably already and priorities have to be given to resources in this scenario. No-subsidy scenario In the other scenario’s the financial aspects are important, however, if the government is unable to deliver any
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Shock Safe Nepal support for the building of houses, the homeowners will have to do it themselves. Realising that their funds are extremely limited, this scenario will point out the cheapest building methods, focussing less on the social, functional and sustainable aspects of the building. While at the same time taking into account the need for earthquake resistance and the availability local materials. There is still a high uncertainty around the distribution of the emergency aid among the villagers in rural areas. Although the money is available for the Nepali government, the period of time it will take to reach the homeowners is highly uncertain. 3.3.3 MCA results After all the weights are assigned to the different categories, the MCA calculates a ranking for all building methods. This ranking is shown in Table 3.3. The complete MCA for all three scenarios can be reviewed in Appendix C1-3 in order to understand how these rankings have been derived. Table 3.3:: Results MCA.
These results clearly show a distinction between four high valued building methods and the remaining six that are ranked negatively for rural Nepal. Although the rankings of the More remote scenario are closer together, the other two scenarios clearly distinguish the most suitable building methods. Therefore, only the low strength stone masonry, adobe, compressed earth bricks and rammed earth will be considered for the building designs in this report. The score of the stone masonry building can be easily explained. Due to its history in the Nepali culture, cheap materials and high availability of materials it makes a logical building method for rural areas. However, a stone masonry building without reinforcement would not be sufficient for earthquake prone areas. Therefore it is important that improvements need to be made in the field of earthquake resistance of this building method. For the other three high ranked building methods, their availability and feasibility in rural areas is clearly of importance. Although these building methods also need to be improvements in the field of earthquake resistance as their characteristics do not show a high value in this aspect. Chosen building methods In order to deliver housing designs to the homeowners in rural villages that will actually be build it is important to convince the homeowners of the importance of this design. This will be a difficult task as the Nepali in rural areas are hesitant towards new building methods, but also hesitant to building their usual stone masonry buildings as most of the buildings did not survive the earthquake. In addition, Subash Karki (Abari) explained that homeowners do not like to be forced to be build a design that is not of their own choice. To get around this problem, the theory is that if shown multiple designs to choose from, the homeowners will be thankful instead of hesitant. For this reason, it follows that multiple designs will be developed in this report. These designs will be a stone masonry building, a CEB house and a rammed earth home. By choosing three designs that differ in essence from one another, methods to construct these buildings earthquake safe will have to be studied and the diversity of structures will improve the scientific knowledge on this subject. Therefore, rammed earth or adobe would be the third preferred building method, as these contain the same composition of materials. However, rammed earth has proven more promising in the field of incremental housing if combined with wattle and daub frames. This gives the construction optimal flexibility and the construction of rammed earth
22
Analysis rural Nepal columns will be relatively easy due to the repetitive use of the same molds. In the next chapters, designs for houses with these building methods will be created. Together with improvements in order to raise the earthquake resistance.
23
Shock Safe Nepal
3.4 Cost analysis One of the main goals of this project is to create a financially feasible design for rural Nepal. The necessity of creating a cheap design is high due to the lack of financial means of the Nepali people. Their lifestyle did not require any savings and besides this fact, most of them are unable to generate any. Before the earthquake villages in rural Nepal are highly self sufficient considering the food production and almost no export was present. Now that their houses have been destroyed, no villagers are able to buy the required materials for a new house. The government has decided that 2000 dollar will be granted to each house owner whose house was destroyed. Considering that most villagers don’t have savings, the goal will be to build houses of 2000 dollars. Preliminary research has shown that this is highly unlikely, but a housing design that will approach this price can be of high value for all Nepali. Therefore, during the design phase, the costs of materials will be taken into account in order to find the most financially feasible house. By integrating the costs of materials with the design phase, instead of calculating the price afterwards, the reasoning is that important choices that have to be made during the design phase can be influenced by cost analysis. Therefore all costs need to be available during the design phase. To gather these costs, Table 3.4 has been composed which contains all materials that are required for the construction of the three building designs. Officially, Nepal uses the metric system. However, most people who want to build a house in rural areas have never used measurement tools and therefore use the imperial system.
housing of this report. The scope of this research focusses on the whole of rural Nepal and therefore there will not be a specific single rate to which building material can be purchased. This has lead to an estimation of costs on account of different experts of NGO and INGO’s and a villager in rural Nepal. Not all questioned experts were fully informed on the price of all building materials. Therefore the some costs per material are derived from less information than others. To uphold the reliability of this cost survey, extra sources have been studied on the prices of these materials. For example, the price of slate tiles was only known to two experts and differed significantly. Extra research has shown that this price can indeed vary considerably, which increases the difficulty of deriving one price for each design. However, if all lower bound prices and high prices will be taken into account for every material, the eventual price will range excessively. This has lead to the decision to take the average of the survey for most of the costs, except for the outliers. These outliers have been erased due to an improbable high or low cost price of a material. The result of this survey after adaptation is an estimation of material costs. The results of this survey are shown in Table 3.5 of which the complete survey can be found in Appendix D. The below mentioned prices are in Nepali Rupees which is the local currency in Nepal. The exchange rate of dollars to Nepali Rupees at the moment of publication of this report is 107.26. For the rest of the cost analysis the Nepali currency will be used, as this analysis will be most useable if prices are given in Nepali Rupees. Table 3.5: Survey results.
Table 3.4. All used materials
3.4.1 Material costs Surveys among villagers in rural Nepal, NGO’s and INGO’s have shown that these costs of building material can differ between each village in Nepal. This has to be taken into account during the development of a frame of material costs that will eventually be used to value the designed
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Besides the material costs, there are two other aspects that make up the total costs of houses in Nepal. Just like in Western countries, the labour costs are a large part of the total construction costs of a house but next to this, it is extremely expensive (in comparison to the material cost) to transfer material through rural Nepal. Therefore, the third category of costs that will be separately analysed is the transport costs.
Analysis rural Nepal 3.4.2 Labour force The category labour force can be divided into two categories, unskilled and skilled labour. For unskilled labour can usually be performed by any villager building a house, whereas the skilled labour activities comprises construction techniques that require a certain level of knowledge. Frequent skilled labourers are carpenters, masons and plumbers. The distinction between skilled and unskilled labour is very important for this research because of the large amount in salary difference, the possibilities of borrowed labour and the overall view of a constructions complexity. If a construction mainly requires much skilled labour, this implies that the design will take much more effort to construct. The same is applicable for designs that require a lot of unskilled labour, however, unskilled labourers are more available than the skilled labourforce. This is partly because the skilled workers are less attainable, but also because most of these people are also part-time farmers and therefore have other priorities. The costs per worked day have been obtained from the same survey as the material costs. However, the estimation of the expected days will be performed differently for each housing design. This will be calculated per meter wall to make the expected construction time dependent on the size of the house. Only the expectation of the construction time of the roof structure is dependent on the area of the roof, to make it dependent on the size too. All techniques that have to be performed to build a wall of one of the designs have been analysed and separated from each other in order to estimate both the required unskilled work days and skilled work days per technique. During the cost calculation of the building designs these days will be added to pinpoint the complete construction time. In Appendix D the labour time per technique can be found.
had different means of measuring transportation costs. Therefore the results were in cubic feet per material, truckloads, cubic meter per kilometer, cubic feet per hour, kilograms per kilometer and more. To reduce these answers to an applicable transport cost estimation two categories were made in this research, long distance transport and close range transport. The products that can be obtained from nearby areas of most villages are large stones, mined from the hills. The rest of all material needs to be transported to site by truck. Usually the stones are carried several kilometres from a mining site towards the construction site. The survey has shown that this often happens at a rate of 750.- NRP per cubic meter stone. The distance of all villages to markets in rural Nepal differ, therefore the transport costs of long distance transport will be measured by truck loads in order to make this research into costs applicable for all villages. The average price of a truck has been determined on 18,000.- NRP for a truck that can load around six tonnes. Therefore it can happen that with different volumes of materials, the same transport cost applies as the costs of a truck do not linearly increase with each kilogram of extra material. These obtained ďŹ gures will be used during the design phase of the houses in order to make reasonable decisions regarding costs of building materials. The developed model for material and cost calculation will also be distributed to later Shock Safe Nepal teams for future use in optimisation and cost calculation.
3.4.3 Transport costs Transport through rural Nepal is difficult. Roads to all villages are rarely asphalted and are mostly made of rubble stones and sand. Besides the bad quality of the roads, landslides sometimes completely block off a path or the monsoon season degrades the roads to mud pools. Bridges are expensive to build and it is therefore not uncommon that a road will lead a car two hours around a valley, while it is possible to cross the valley on foot in almost half the duration. It is for these reasons that transportation is relatively very expensive in comparison to other more accessible countries in the world. The surveys performed on transportation costs showed some divergent results. For a ďŹ rst because all experts
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Shock Safe Nepal
3.5 Principles in earthquake resistant construction General design rules for earthquake resistant buildings can be found in several papers and books and have been applied for many different cases worldwide. Shock Safe Nepal Team 1 has explained some of these general design rules of which a recap is given below. Other design rules that have been applied in the housing designs for rural Nepal are explained as well. Regularity in the plan Open shapes of the plan of the building are unfavourable in earthquake sensitive areas, since these shapes have a center of mass different from the center of rigidity, leading to torsional forces (SSN1, 2015). For the horizontal stability of the building the length/width ratio should not exceed 1:3 and a wall longer than 12 times its thickness requires a buttress. (DUDBC, 2015a).
Figure 3.15: Effect of reinforcement
The DUDBC Design Catalogue describes the minimal needed horizontal reinforcement (DUDBC, 2015a).
Roof band Lintel band Sill band Floor band
Force Force
Figure 3.16: Horizontal bands
The oor and roof band are to tie the walls together. The sill and lintel band tie the openings in the walls together. Figure 3.14: Forces on an irregular oor plan (left) and regular oor plan (right)
Regularity in elevation Also in the vertical direction the shape of the cross section should be regular to avoid torsional forces (SSN1, 2015). When the stiffness of the building changes in the vertical direction, it is advisable to provide the building with a dilatation at the position of the change of stiffness. When subjected to a seismic load, parts of a building with different stiffnesses will vibrate differently because their eigenfrequency differs. At the transition point where these different vibrations meet, the shear force will be at its maximum. When a dilatation is provided at that location, the structure is allowed to move horizontally thus the shear force will be zero, leading to lower stresses in the structure at the point of changing stiffness. Reinforcement When subjected to seismic loads, a structure experiences tensile forces. A building consisting of brittle materials, like masonry, needs to be reinforced to encounter these forces. Horizontal and vertical ductile elements will tie the building together, making it move as a rigid box. The ductility is important for these elements must be able to take bending loads when there are lateral forces against the walls.
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Figure 3.17: Effect of sill and lintel bands
In order to prevent the walls from buckling and falling, the connection between wall and horizontal band must be very strong. It is not always easy to obtain a good bond between the wall and the reinforcement, for example when masonry and timber is used. In this case the stones should be in such a way that they integrate with the timber bands as good as possible, possibly with the addition of vertical pins attached to the bands that stick into the masonry.
Analysis rural Nepal and reach 40 cm or more into the soil, depending on the rigidity of the soil. The foundation should also protect the structure from splashing rain water, and should therefore reach at least 30 cm above the soil. (Minke, 2001).
Figure 3.18: Bond masonry and timber bands
Openings in walls The Nepal Building Code sets requirements to the dimensions of openings in walls as shown in Figure 3.19 (DUDBC, 2015a). Cross wall L1
L2
b2
b7
b6
Figure 3.21: Dimensions foundation (Minke, 2001, p.34) h2
h2
b1
b5 h1
b5 b4
b4
b4
b4
b1 + b2 < 0.3 L1 for one storey, 0.25 L1 for one plus attic storeyed
The joints between foundation and wall have to have a good bond in order to be able to transfer shear forces. The easiest solution is to integrate a vertical wooden rod every 30 to 50 cm. (Minke, 2001).
b6 + b7 < 0.3 L2 for one storey, 0.25 L2 for one plus attic storeyed, three storeyed. b4 > 0.5 h2 but not less than 600 mm. b5 > 0.25 h1 but not less than 450 mm.
Figure 3.19: Openings in load bearing walls according to the DUDBC
The openings can not be too close to the cross walls or to each other, because the disrupted area in the wall needs enough space to transfer the load ďŹ&#x201A;ow, otherwise cracks will occur at the openings. The strut and tie model is a generally used method to describe the force ďŹ&#x201A;ow through a wall in a schematised manner, so the forces at critical points can be analysed. At the locations where tensile forces develop the wall needs to be reinforced.
Figure 3.20: Strut and tie model of a wall with opening
Foundation To reduce the displacements in the structure during an earthquake, the structure needs to be connected to the soil so that the structure will not bounce loosely upon the ground during an earthquake. For a wall of 30 to 40 cm thick a sufficient foundation should usually be 20 cm wider
Figure 3.22: Foundation-wall connection
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Shock Safe Nepal
3.6.1 Overview system The water system that is proposed for the new housing projects that will be discussed in chapter four is a combination of the current communal water system, expanded by rainwater harvest from the roofs. Ratankot has water shortages in April and May (S4N, 2015), when the sources located in upper Ratankot dry out. In these months, the local population has to obtain water from a different source further away, from where there is no appropriate infrastructure and which also might be of lesser quality (S4N, 2015). Also, due to the earthquakes, there seems to have been some sort of subsoil change that also changed the discharges of the springs and even drying out some completely (S4N, 2015). A new drinking water project is being implemented, increasing the storage capacity, as well as enlarging the system’s resilience and water quality (Shyam, 2016). However, this does not solve the water scarcity issue. Either the new location of the sources, if there are any, have to be found, or the local population has to construct a new water system from a remote existing source, in order to resolve the water issue. The proposed system aims to partly relieve the local population of their water related issues, by using rainwater as a primary water source, especially during the dry months. A schematic overview of the proposed system is seen in Figure 3.23.
First flush diverter The first flush of every rainfall is potentially contaminated by dust, bird droppings, etc. and has to be diverted to outside the system. This is done by installing a first flush diverter, which diverts a certain volume to the soil, before letting the harvested clean rainwater enter the water system. A schematic drawing of a first flush diverter is given in the Figure 3.24.
Figure 3.24: Schematization for a first flush diverter. (rainharvesting.com. au, 20150
Buffer storage tank Secondly, the harvested rainwater enters a buffer storage tank, which ensures that the system will not overflow because of the low flow speeds through the filter. Water filter The buffer tank is connected to the filter, which further treats the water from potential contamination that might not have been diverted. This could be a (bio)sand filter such as in the Figure 3.25. Because the communal water is of unknown quality, and possibly linked to the present health issues (S4N, 2015), it is recommended to also treat the source water before drinking. The communal water enters the buffer storage tank as well.
3.23: Schematization of the proposed water system for households. (SSN3, 2016)
Roof and gutters Both galvanised steel and slate roofings are suitable for rainwater harvest. The precipitation is harvested from the roof by raingutters. Large leaves and branches will be trapped in the screens that are in front of the water system.
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Figure 3.25: Schematic drawing of a bio-sand filter. (ohorizons.org, 2015)
Analysis rural Nepal Main storage tank After filtering, the water is stored in the storage tank. Inside both tanks, a floating inlet is installed, where only water from the surface of the stored water can flow in, as can be seen in Figure 3.26. This ensures that the storage tank also acts as a sedimentation tank for solid particles, that will settle at the tank’s bottom. Also, floating valves should be installed in the tanks, so that the tanks will not overflow and the filter will stop running when the storage tank is full.
To minimize energy consumption, the proposed system doesn’t require a waterpump in order to work properly. At sufficient height of the raingutters, and if a syphon is present in the filter, the rainwater should be able to flow through the whole system without any external interference. Below in Table 3.6 the vertical measurements of every component is stated, resulting in a final valve height at 65cm above floor level, stated that the raingutter is at a level of 280cm above groundlevel. Table 3.6: Vertical dimension of the proposed water system. Assuming a rain gutter height of 2.8m above ground level and a floor level of 0.3m above ground level.
Figure 3,26: Schematization of a floating inlet in a water tank. (rainwater-shop.eu, 2015)
Inside the house The water tank will discharge water into the pipes that connect to the water system inside the house. Here, water is used by taps and shower, indoors and outdoors. Gray water is discharged into the sewerage system. This sewerage system mostly discharges onto the surface downhill, according to locals. But the environment in Ratankot could benefit from a communal waste water treatment system. This system could collect all the water from the sewerage pipes, and treat it by settlement, aeration, filtration. The toilet house uses the same water for flushing, but also harvest rainwater directly into a small reservoir. This water does not need to be treated, since it is only used to flush faeces and urine into the septic tank. The septic tank is sufficiently large that it needs 15-20 years to completely fill up, after which a new septic tank is needed and the old location can be used to fertilize and grow a Mango tree, or other plants, according to locals. Vertical dimension system
Component
Head difference
First flush diverter
15 cm
Notes
Water tanks (2x)
150cm
Two tanks of 75 cm
Biosand filter
0 cm
Siphoned between the two tanks
Valves & pipes
20 cm
Floor
30 cm
Total
215 cm
Gutters are at 280 cm, so valve indoors will be at 65 cm height.
3.6.2 Water quality Water quality is ensured by the different treatment steps in the system. The water entering the system from the communal water system is probably already sufficiently clean. 80% of the population drinks this water directly, without any additional treatment, the remaining 20% boils the water before drinking (S4N, 2015). It is hard to determine the impact of the untreated communal water on the health of the population, since there are many factors that also play a role, and the presence of health issues cannot only be attributed to poor water quality. Therefore research should be done on the communal water quality, and the VDC should implement new treatment steps for the whole communal water system if this proves to be necessary. Because of this, the location of different treatment steps in the household system remains a point of discussion. Since the rainwater harvest seems to be the most sensitive to contamination from the roof and rain gutters, the majority of the treatment steps will focus on rainwater treatment. Screens at gutter discharge points The first treatment step for rainwater is the screen that blocks leaves and other large organic materials. These remain in the gutter as the water passes into the water system. First flush diversion 29
Shock Safe Nepal The first flush of rainwater also transports dust, bird droppings and other possible contaminations into the system. Therefore the first part of every rain event must be diverted outside the system. This is done by means of a first flush diverter, as mentioned above. It ensures that the majority of the initial contamination is diverted. The water quality is determined by measuring certain constituents in the water, as well as turbidity, color and odour, a list of these can be found in the Guidelines for Drinking Water Quality from the WHO. Rainwater is presumed to be very pure and uncontaminated, especially in areas
where there is no air pollution and/or radioactivity, which is the case for Sindhupalchok. Therefore, contaminants in the harvested rainwater are believed to come from the roof itself or contaminated parts of the rest of the water system. In absence of trees and tall vegetation in the direct vicinity of the roof, such as in Ratankot, the pollution on the roof will mostly be limited to dirt and dust particles that have settled from the air. These particles increase the turbidity and are therefore a standard for the pollution of the rainwater. The WHO has set standards for turbidity in drinking water in terms of Nephelometric Turbidity Units, or NTU, which should not exceed 5. Possible initial
FIgure 3,27: Average monthly precipitation data for Kathmandu. (www.weather-and-climate.com, 2015)
Figure 3.28: Mean annual precipitation map for Nepal. (Department of Hydrology and Meteorology, 2013)
Analysis rural Nepal levels of turbidity in rainwater collected from roofs next to dirt roads can be as high as 2000 NTU (Martinson, 2005). Every treatment step removes turbidity, including first flush diversion, filtration, sedimentation. First flush diversion halves the turbidity levels for every mm of rain diverted (Martinson, 2005). Water quality in this treatment system will be limited to turbidity levels of the water, since there is a relation between turbidity of the water and other levels of constituents in the water. By lowering the turbidity to acceptable levels it is assumed that other possible contaminants have been lowered significantly as well. To confirm these assumptions, measurements must be done on site, from both the communal water and the rainwater discharged from the roof, as well as the treated rain/communal water. Slow (bio) sand filtration A slow (bio) sand filter removes heavy metals, viruses, bacteria, protozoa and turbidity, as well as colorization, odor and taste. A (bio)sand filter could also be put in front of the inlet of the communal water, as a correlation has been shown between the use of such filters and the decrease of occurrence of diarrhea (Stauber, 2012). To add to turbidity removal of the sand filter, a cloth can be put in front of the inlet. However, the flow rate through this filter must not be significantly lower than the flow rate through the gutters that are collecting the rainwater, in order to prevent potential overflow and loss of rainwater. Filtration will remove up to 95% of the turbidity levels (Ngai, 2007). Bacteria, viruses and protozoa are also reduced by biosand filters, namely by 87.9-98.5%, 70-99% and 99.9% respectively (CAWST, 2009). Sedimentation After filtration, the water is directed into the storage tank of 500 L. These tanks are widely used in Nepal and almost every household has one in urban areas. In rural areas they are not as frequently used, probably because of financial considerations. The retention time of the water in the tank is the largest in the whole water system. Therefore it is the most suitable to be used as a settling mechanism. Suspended solids and particles will fall to the bottom of the tank, and the floating inlet will retrieve cleaner water from the surface. After usage, the water is not treated anymore and is either discharged onto the surface (gray water) or into the septic tank (black water). Sedimentation will remove an additional 50-90% of turbidity levels (Hudson, 1981). A point of attention for the sedimentation tank is the remobilization of settled particles. The inflow should have sufficiently low flow speeds in order to not pick up sediments from the bottom or disturb the sedimentation
process. The filter will ensure for a slow flow rate into the sedimentation tank, thus ensuring limited remobilization. Table 3.7: Treatment efficiency in turbidity removal in percentage of NTU removed per treatment step. Values obtained from literature. Treatment step
Turbidity removal (% NTU)
First flush diverter
87,5%
3mm of first flush. Martinson, 2005
Buffer tank
50-85%
Hudson, 1981
Kanchan KAF Gem505 filter
80-95%
Storage tank
50-85%
Total NTU removal
99% or more
Other treatment
Arsenic: 85-90% Iron: 90-95% Phosphate: 80-85% Coliform: 85-99% Improvement in odour, taste and appearance
Notes
Ngai, 2007
3.6.3 Discharge & quantities Because numerical data is unaivable for the VDC of Sunkhani, and the precipitation maps of DoHM (2013) show comparable precipitation near Sunkhani and Kathmandu, it is assumed that data from Kathmandu is representative in this case. Numeric data on the precipitation are taken for Kathmandu valley, which is located 55km west of Ratankot (www.weather-and-climate.com, 2015). The precipitation per month and amount of rainy days per month are shown in the Figures 3.27 and 3.28, as well as Appendix E. As can be seen in Figure 3.27, the dry season does not coincide with the water scarcity in Ratankot, which is in April and May. These two months are actually the end of the dry season as the rainfall starts to increase until the monsoon in June. This means that there is more rain available for harvest compared to the dry season. Below in the Table 3.8 the precipitation data for April and May are compared. Table 3.8: Volume of precipitation in april and may on a 55 square meter roof, based om mean precipitation values in Kathmandu. April
May
Precipitation per month (mm)
50
90
Total volume on roof (55m^2) per month (L)
2750
4950
Rain events per month
7
11
Volume of water on roof per rain event (L)
393
450
Average household consumption for Ratankot is estimated
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Shock Safe Nepal to be 100 L per day (20 L per person)(S4N, 2015). After a median rain event, a household can use the harvested rainwater for almost three consecutive days, without requiring to go a different water source further away. In the whole of April, two thirds of the water consumption can be covered by rainwater harvest. This depends entirely on the turbidity of the runoff of the first flush and the target turbidity (Martinson, 2005). The target turbidity for drinking water is set on 5 NTU (nephelometric turbidity unit) by the World Health Organisation, but the turbidity entering the treatment system could be higher since the filtration step and the sedimentation step both remove turbidity. Based on the above and different papers (Buzunis, 1995; Doyle, 2008; Duke, 2006; Hudson, 1981; WHO, 1997), that describe turbidity removal by settling tanks, various filters and first flush diverters, a first flush of approximately the first 3 mm of rain is suggested. However, to come to a precise conclusion on the volume of the first flush, more information should be obtained on the NTU levels at the start of the rain event and the target NTU of the drinking water, as well as the turbidity removal of the two treatment steps. This results in the following first flush quantities and freshwater quantities entering the rest of the system that can be used in the household. Table 3.9: Volume of available water after first flush diversion. Quantities based on same precipitation data and roof size as Table 3.8. April
May
Volume first flush of 3 mm per rain event
165 L
165 L
Total volume of first flush per month
1155 L
1810 L
Remainder of fresh water entering system per month
1595 L
3140 L
# of potential days per month that rain is providing sufficient water for an average household
16 days
31 days
If every rainevent is a median rain for that particular month than rainwater provides enough water for the entire month of May and half of the month of April. These values are based on statistics and do not reflect actual rain events. In practice however, users should be able to expect a drastic decrease in demand for external water sources during these months. The rain intensities in rural Nepal in the middle mountains in the pre-monsoon period are approximately a factor two larger than during monsoon season (Merz, 2006). Suggesting that flow rates through the rainwater harvest system are also maximal during April and May. The rainfall intensity distribution roughly determines the flow rates
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that are needed. Depending on the rain event duration, the size of the filter, which is the main bottleneck in the system, should be determined. Therefore, by having a buffer tank in front of the filter, flow rates can be set sufficiently low, in order to maintain the treatment quality of the filter. Assuming that the 100L used by the household are consumed during the day (12 hour), an average flow rate of 8.3L/hour is required. Companies such as SmartPaani (http://smartpaani.com/) and ENPHO (http://enpho. org/) offer filters that meet this criterium. The Kamchan Arsenic Filter and Kamchan Arsenic Filter Gem505, that are considered here, also meet this criterium (Ngai, 2004). 3.6.4 Operation & Maintenance Operation The people of Ratankot are aware of water scarcity in the months of April and June. Harvesting rainwater will not entirely solve this issue. Users of this water system should be clearly informed on how to optimally use the system. The system will treat all the water, both rain and communal water, to drinking water quality. In the dry months, the buffer tank should be able to also store the next rain event. Users should therefore make sure that the communal water doesn’t fill up the buffer tank above 272L during the dry months. If water levels in the storage tank drop below 200L, water consumption/usage should be monitored and possibly decreased until the next rain event. Users should act with caution when consuming water, and make sure that the stored water does not run out. Maintenance A simple water system like this has to be manually maintained, cleaned and repaired. Maintenance and cleaning includes removing organic material in front of the screens, replace certain parts of the sand filter and cleaning of the tank by removing the settled sediments. In reference projects developed by Kam for Sud (Bernet, 2016), the wet rain gutters provided a preferred living space for pigeons. It is important to block the access to these rain gutters for the pigeons in order to prevent possible contamination by bird droppings, either by spikes or sealed gutters. Also, the gutters should be designed in a way that they can be cleaned regularly and accessed easily. Because of the height of the roof, a small ladder placed against the gutters is sufficient. Cleaning of the screens and filters should happen every three to six months, and the cleaning and emptying of the tank should happen at least once every year (Elkink, 2015). A flush should be installed at the bottom of the tanks, which can be used to flush sediments out of the
Analysis rural Nepal tank. If clogging occurs anywhere in the system, the period between cleaning should be shortened. Costs Table 3.10: Projected costs for purchase of proposed water system. Product
Source
Cost
Quantity
Total
500L Sintex water tank, 75cm
industrybuying. com
Rs. 5500/ piece
2
Rs. 11000
Kanchan KAF Gem505 filter
Ngai, 2007
Rs. 2000/ piece
1
Rs. 2000
First flush diverter
rainharvest.com
Rs. 3000/ piece
1
Rs. 3000
Rain gutter
Alibaba (various resellers)
Rs. 20-200/ meter
18 m
Rs. 3603600
PVC piping
Alibaba (various resellers
Rs. 10-300/ meter
30 m
Rs. 3009000
Valves
Alibaba
Rs. 20-200/ piece
5
Rs. 1001000
Wood (10cm x 10cm) for water frame
SSN3, 2016
Rs. 120/ meter
15 m
Rs. 1800
Lower Range
Upper range
Rs. 18560
Rs. 31400
Total
3.7 Borrowed labour Labour cost are a significant part of the cost for building a house. The labour cost is made up of skilled labour cost and unskilled labour cost. As unskilled labour can be done by people without extra schooling this cost can be easily reduced significantly. Homeowners can do this part mainly themselves and be helped by most members of the family. However skilled labour is not that easily replaced. Also some tasks can involve multiple people to execute safely. A viable solution for this is a borrowed labour system. The basic principle behind borrowed labour is exchanging work loads. For example, a carpenter works X amount of hours on your house. In exchange you work for X hours on his land or in his company. This way you exchange services and the cost of construction in monetary terms is lowered. As time is more easily available than money for a lot of people in rural areas this is a good solution. Because of the absence of money in borrowed labour there are less risks than with bonded labour. With bonded labour a monetary debt is paid through labour or services. The amount and duration of labour is often undefined and can continue for a very long time (Anti-Slavery International, 2016). With borrowed labour this is more clearly defined. If the labour is highly skilled it might be that the other party does twice as much unskilled labour. This should be properly agreed upon beforehand. Because of the scale of the rebuilding needed in Nepal, the system becomes even more viable. Whole villages need to be rebuilt demanding large numbers of work hours. If a borrowed labour system is applied to the entire village it can be highly effective. Neighbours can band together working on each others houses. This accelerates the rebuilding and strengthens the community. Work can also be optimized having more skilled people work on the reconstruction while others work their land to ensure food supply. As it does not involve a direct monetary need it is also available for families with limited funds. Unemployment is a big problem in Nepal. Borrowed labour can help to give unemployed people a new house because it relieves the cost pressure. The locals state that there is a large outflow of youths from rural villages because they can not find jobs in the village (SSN2, 2016). They either go to larger cities or abroad to find work. As the workload in the village is increased due to the rebuilding effort these youths will also be given an opportunity to become a valuable member of the community and learn job skills. This can help them to find a job or start a business themselves.
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4 HOUSE DESIGNS
In this chapter the selected building methods are elaborated in house designs.
adopt the house design to reconstruct their houses (after teaching them how to execute them).
4.1 Requirements Not depending on the chosen building methods are the requirements that they have to meet.
Incremental Currently, different types of houses are being reconstructed in Nepal: from new permanent houses to temporary shelters. To bridge the time between the earthquake and the construction of new permanent houses, the architects of Abari propose to build so called ‘transitional shelters’ (Abari, 2015). The risk of this approach is that the transitional shelters become permanent homes (which is not most desirable, because of the the lower quality compared to a permanent house). Advantage is that the transitional shelters are cheaper than permanent houses. Learning from that, the house designs as presented in this chapter, have another underlying principle: ‘incremental houses’. Permanent houses that are smaller than regular ones, but have the possibility to be expanded over time. Ways in which in the expansion can be realized, are included in the designs. This way, the initial investment is lower than the proposed permanent house designs from the goverment (Nepal Housing Reconstruction Program, 2015) and much closer to the govermental grant of maximum Rs 200,000 that is provided per household for reconstruction. Over time, the house can then be expanded.
Boundary conditions First of all there are the boundary conditions following from regulations, considering earthquake resistance and architectural design requirements. Principles of earthquake resistant building are described by SSN 1, in chapter five of report one (SSN 1, 2015). These principles form also the basis for the house designs in this chapter. In the elaboration of the chosen building method into real house designs, the necessary measures and restrictions from the building code are implemented, such as the application of seismic bands, foundation depth, etc. (DUDBC, 2015a). Also architectural design requirements are described in this building code (DUDBC, 2015b), such as room dimensions and natural light admission. Other design constraints rural Nepal Second, there are the constraints that are specifically valid for rural Nepal. These constraints were already criteria as part of the MCA for choosing the best suitable building methods, but these limitations still play a very important role in the design. The constraints are extracted from the characteristics of rural Nepal that come from the surveys carried out by team 1 and 2 and own research. Not all of those characteristics lead to constraints for the design process. The following constraints are the ones that have affected the designs: - Costs: these should be as low as possible, considering the low income (due to the lack of economic activity) of the villagers in rural Nepal. - Accessibility: the use of external materials should be kept to a minimum, as rural villages are often badly accessible. Due to tranportation costs, the use of external materials would raise the construction costs. - Social: it is important that the used building methods are applied in such a way that they the villagers are willing to 34
4.2 Cost analysis per house design Every housing design has been subjected to an extensive cost analysis based on the figures of the cost analysis in Chapter 3.4. This analysis has been a dynamic process during the development of the housing designs. For this process, a material calculation model has been developed which calculates the necessary material for any dimensions of the three houses. This has influenced the decision making stages during the design phase when a consideration had to be made between different materials or measurements. The model has been developed in an Microsoft Excel environment in order to be manageable by parties interested in using the designs for construction. As the designs are basic, most measurements and material uses can be changed or replaced. By using cost analysis model,
Shock Safe Nepal
the costs have been limited by using only strictly necessary materials and in almost all cases the cheapest available material per building method. An example is the choice for CGI sheet as roof cover instead of the higher aesthetically valued slate tiles, which saves up to 400 dollars for the stone masonry building. In order to show insight into all decisions, the full cost estimations in Appendix D have been extended with the costs of alternative building materials. Whereas most decisions are logically derived from this cost estimations, some need to be explained more thoroughly, as done in the next paragraph. Costs of stone masonry house By combining all knowledge obtained in this research, the stone masonry house design has been developed. The most important factors that lead to this design are the structural integrity and earthquake proneness, cost estimations,Nepali construction habits and dweller needs. Therefore, the creation of this house cannot solely be based on costs and is not the cheapest, but it is the cheapest solution given all other influencing factors. The result is a small house of 4 meter by 8 meter that will cost NRP 264,970.- which is equivalent to 2,470.36 dollars. Due to the fact that only 46% of this price can be accounted to material costs, the price of the material has been reduced to an extremely low rate. The chances are slim that this will be the actual outcome and therefore an unforeseen expenses factor of 20% is added to the price of the house, enabling villagers to construct a house for NRP 317,965.16. This unforeseen expenses factor is high as the cost surveys have shown uncertain surrounding many materials. With the support of NRP 200,000 of the government, the Nepali people will still have to contribute over one thousand dollars to their house. However, part of this investment can be reduced by solid debris management of the collapsed houses and possible borrowed labour within the village. This will be more elaborately explained in further chapters. Costs of rammed earth/wattle and daub house The costs of the rammed earth/wattle and daub house are limited to NRP 336,296.80 including the 20% unforeseen expenses factor. The initial expectation was that this house could potentially be economically more preferred. However, due to the fact that the construction is extremely labouring, the labour costs surpass the material costs and make up 46% of the house’s total construction costs. Where borrowed labour is a solid possibility for the stone masonry house, building with wattle and daub is less common in Nepal and therefore all builders will need more elaborate instructions. As most collapsed houses were build with stones, recycling the old houses is less
profitable for this design which also shows little possibility in reduction of the price. In the designs a floor has been inserted at the ground floor as this is reasonably cheap and it brings a lot more comfort to the living conditions of the dweller. However, these floorboards can always be left out as they are not strictly necessary. Costs of CEB house The house of compressed earth bricks is relatively expensive compared to the other designs. With a total of NRP 409,295.72 it doubles the investment of a normal Nepali family if government subsidies are available. This is mainly due to the large amount of cement needed for the reinforcement columns and bands, but also because of the high quantity of sand. The price of sand is low in comparison to cement, however, all sand needs to be transported by trucks from nearby markets. Due to the high quantity, more than one truck is needed to transport the material, raising the transport costs to over NRP 80,000.-. As the aesthetic value of a CEB house is valued reasonably high by the people in the rural areas, somewhat more wealthy families might still choose this option. One side note is that the machine used to create compressed earth bricks will cost around five thousand dollar which is an investment that can only be made by a complete community or an NGO. To reduce the price of the CEB house an option might be to replace the RCC frame by wooden beams and columns, which will already realise a cost reduction of NRP 36,700.68. However, this building technique has not yet been tested or been approved by the government. Only after this is approved, can it be implemented in the design. 4.3 Design choise and alternatives The choise for one of the house designs for a specific case depends on the location, the available materials, the skills of the construction workers, the available budget and the wishes of the owner. After choosing the most suitable design, different wishes for a certain construction material may still be present. Therefore, alternative construction materials are included in the cost estimation, that could replace the materials that are applied in the design. One could think of using slates as roofing material, rather than CGI-sheets, if those are available for free after demolition of the old house. On the following pages, the specifications of the three house designs are summarized. The full design, details and cost estimations can be found in the Design Booklet.
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Shock Safe Nepal
4.4 Stone masonry with mud mortar Stone masonry is most common in rural Nepal. Due to local availabilty of the stones and to cultural acceptance, this building method scores an 71% on the MCA, making it one of the top buildings methods for rural Nepal. Solely the bearing walls will not resist earthquake forces, for which the masonry is reinforced with timber elements as stated in the Design Catalogue (DUDBC, 2015). Advantages • Local workers are familliar with stone masonry constrcution. • Use of local materials. • Possible re-use of stones. Disadvantages • Faith in this building method has decreased after the earthquake. • Reinforcements required. • Earthquake resistance completely relies on the quality of materials and execution.
Cost estimation Materials: Skilled labour: Unskilled labour: Transportation: Unforeseen expenses: Total:
$1,145 $575 $410 $340 $480 $2,870
Main construction materials Local materials: 36.2 m3 stones 1.7 m3 clay (for mud mortar) 0.8 m3 clay (for wattle and daub) External materials: 0.4 m3 cement 3.7 m3 timber 1.6 m3 sand Extended house
Incremental concept A one-storey stone masonry house is able to be expanded with an additional floor. A solid base, consisting of the foundation and first floor, is provided as are the columns which function as vertical reinforcement and carry the roof. A light wattle and daub upper structure is connected to these columns. An advantage of expanding in this manner, is that no additional foundation is needed and no extra land is needed. Basic house
Specifications Functional area: 47.9 m2 Labourforce: 73 days skilled labour 96 days unskilled labour Cost estimation Materials: Skilled labour: Unskilled labour: Transportation: Unforeseen expenses: Total:
Specifications Functional area: 21.5 m2 Labourforce: 70 days skilled labour 76 days unskilled labour
36
$1,340 $600 $520 $510 $600 $3,570
Main construction materials Local materials: 36.2 m3 stones 1.7 m3 clay (for mud mortar) 3.7 m3 clay (for wattle and daub) External materials: 0.4 m3 cement 3.7 m3 timber 3.1 m3 sand
House designs
4.5 Rammed earth and wattle and daub Rammed earth and wattle and daub are both earth-based techniques. Rammed earth is characterised by solid and stable bearing walls, where wattle and daub, in contrary, consists of a light framework. By applying both building methods in one design, both their structural characteristics are combined. This system with rammed earth columns and wattle and daub walls form a solid and stable house that can resist the tensile forces induced by seismic loads. This building method is suitable for rural Nepal, for the main material, clay, can be found in the ground. Advantages • Simple building method, easy construction. • Use of local materials. • Flexible floorplan. • Repetivity columns: formwork can be re-used. Disadvantages • The combination of these two techniques in one building is not approed by the government of Nepal. • This design is conceptual, behaviour under seismic loads is unknown (do the rammed earth and wattle and daub work as a system?) • This building method differs from the traditional building method of rural Nepal; people need a clear demostration and training for consrtuction. Incremental concept Horizontal expansion is possible by continuation of the wattle and daub an drammed earth system. New rammed earth columns are constructed after which wattle and daub frames can be placed in between them, forming the outer walls of the expanded house. For seismic stability it is important to take into account the rectangular shape of the floor plan, meaning that expansion may not lead to L- or U-shaped floor plans.
Basic house
Specifications Functional area: 19.5 m2 Labour force: 78 days skilled labour 104 days unskilled labour Cost estimation Materials: Skilled labour: Unskilled labour: Transportation: Unforeseen expenses: Total:
$1,010 $650 $565 $375 $520 $3,120
Main construction materials Local materials: 12.8 m3 clay (rammed earth) 1.8 m3 clay (wattle and daub) External materials: 4.7 m3 timber 4.7 m3 sand Extended house
Specifications Functional area: 32 m2 Labourforce: 142 days skilled labour 187 days unskilled labour Cost estimation Materials: Skilled labour: Unskilled labour: Transportation: Unforeseen expenses: Total:
$1,525 $1,175 $1,010 $560 $850 $5,120
Main construction materials Local materials: 17.6 m3 clay (rammed earth) 2.8 m3 clay (wattle and daub) External materials: 7.0 m3 timber 5.8 m3 sand
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Shock Safe Nepal
4.6 Compressed earth bricks CEB is very similar to conventional brick work. The main advantage of CEB is the ability to use local materials such as sand and clay. The soil, raw or stabilized, for a compressed earth brick is slightly moistened, poured into a steel press and then compressed either with a manual or motorized press. This building method is dependant on vertical and horizontal reinforcement for earthquake safety. This can be done in either reinforced concrete or timber. Bricklaying is a known technique in Nepal. CEB, however, is relatively new to Nepal and need to be properly introduced so people have confidence in the material.
Unskilled labour: Transportation: Unforeseen expenses: Total:
$470 $750 $640 $3,120
Main construction materials Local materials: 9.5 m3 clay 16.6 m3 stones External materials: 1.6 m3 cement 11.2 m3 sand 0.03 m3 steel Extended house
Advantages • Local production and use of local meterials. • Modern looking brick house: cultural acceptance. • Possible business opportunity for CEB production. Disadvantages • Reinforcement required. • Preparation time needed to make the bricks. • Some experience needed to obtain the proper soil mixture. Incremental concept The house can be expanded vertically to a two storey house with an attic. The vertical reinforcement can be lengthened to achieve the required structural safety. The foundation is designed to support the expansion and does not need to be altered. The roof structure is dismanteled and rebuild during the process. Basic house
Specifications Functional area: 60 m2 Labourforce: 80 days skilled labour 129 days unskilled labour Cost estimation Materials: Skilled labour: Unskilled labour: Transportation: Unforeseen expenses: Total:
$2,110 $660 $700 $1,090 $910 $5,470
Main construction materials Local materials: 19 m3 clay 16.6 m3 stones External materials: 2.7 m3 cement 20.6 m3 sand 0.04 m3 steel Specifications Functional area: 29.5 m2 Labour force: 54 days skilled labour 87 days unskilled labour Cost estimation Materials: Skilled labour: 38
$1,510 $450
House designs
39
5 COMMUNITY CENTER RATANKOT
Integrated sustainable demolition, waste management and recycling plan for the community center in Ratankot, based on the information obtained from the demolition and waste management workshops organised by Concern Worldwide and Engineers Without Borders.
Table 5.1: Critical steps in safe & efficient demolition & waste management General safety considerations Previous structure, structural and building method Possible loadings due to earthquakes and resulting failures Analysis of construction materials
This plan consists of the actions that have to be done in preparation of demolition and waste management. Some of the steps have already been worked out using information obtained during the stay of SSN3 in Ratankot. The remaining steps will function as a detailed description on how to perform all preparations, demolition and waste handling for the community center.
5.1 Demolition & waste management proposal The community center is a building in Lower Ratankot 7. It’s located on a terrace next to the main road and in a central position of the village. During the 2015 earthquakes the building was heavily damaged and as a result the structure was no longer suitable or safe for usage. At the time of our stay in Ratankot, the structure has been partially demolished and the materials also partially sorted. However, a large part of the structure hasn’t been demolished yet. In Appendix F, a schematisation of the location and preearthquake floorplan has been made. This chapter functions as a manual for safe and effective demolition and waste management for the community hall of Ratankot. The manual consists of the sections in the Table 5.1. These should be read and carried out in the given order, in order to ensure a safe and efficient demolition of the community center in Ratankot.
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Possible reuse & recycle of materials Set up budget and determine costs for demolition Demolition preparation Demolition Waste management
In the following text it is discussed how sustainable demolition, waste management and recycling plan is integrated for the community center in Ratankot. General safety considerations The structural stability of a partially or fully collapsed building is inherently compromised. It is important to exercise caution during demolition as further collapse of the structure is highly possible. Standard safety equipment such as hard hats, safety shoes, gloves, safety belt and fire equipment should be on site and workers instructed on the use of them. For immediate care a first aid station is needed. These items can be stored in the temporary shelter/storage building next to the community center. Before demolition, the utility connections such as gas and electricity need to be checked and disconnected. During deconstruction the work site needs to be cordoned off to prevent unauthorised people access. Unstable construction elements such as walls need to be sealed off to prevent people walking in the danger zone. During work, common safety words should be appointed to warn people. Previous structure, structural and building method The community hall was constructed using the common building method of stone masonry with mud mortar. The walls consisted of three layers: two outer layers with bigger flat stones and infill between consisting of smaller stones and rubble. The roof was made of CGI sheets supported by timber
Shock Safe Nepal
PHOTOS FROM DAMAGED COMMUNITY CENTER IN RATANKOT Photos by SSN3
Damaged interior, depicting the wooden cabin where the sculptures of Buddha where located.
Damaged inner wall that was loaded in plane. Cracks and moved rocks in the wall block the door, causing a dangerous situation.
Outer wall being strutted by wooden beams. Out of plane loading caused The structural components that are most intact are made from wood, tumbling of walls. such as doors.
Photo taken from the latrine on the terrace below the community center. Photo taken from the terrace above the community hall. Although the The ruine is dangerously close to the foster home (left). structure still stands, itâ&#x20AC;&#x2122;s obvious that the remainder of the structure is hazardous.
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Shock Safe Nepal frame. Window frames were made of wood with glass windows. Some parts of the roof were supported by timber columns. The prayer room has a large wooden cabinet. The guest rooms have a small bathroom between them. Bathroom has a flush toilet bowl and shower equipment. Internal partitions between bathroom and guest rooms of concrete blocks with cement mortar create a localized increase in stiffness. Other internal partitions consist of timber frames and plywood. The foundation of the community hall is built out of stones and most likely mud mortar. The ground level floor consists of a large concrete slab of approximately 10 cm thickness, that covers the entire floorplan. Possible loadings due to earthquakes and resulting failures Construction was loaded out of plane towards the southeast. This caused the entire structure to shift towards the south-east. Walls perpendicular to the load have all shifted out of plumb, resulting in partial failure and extra loading of the cross walls. Roof construction is generally in good shape. Many doors and windows have been blocked, because the lintel, consisting of three separate parts, has failed. Glass in certain windows has shattered because of the shear loading. Walls have crumbled as a result of insufficient bonding between the layers. Approximately 40% of the building was completely destroyed and demolished by May 2016. The remainder of the building is heavily damaged, with only a few wall sections left standing, making the entire structure unstable and very dangerous. In the top-view drawings of the structure the location of the intact walls can be found, as can be seen in Appendix F. Analysis of construction materials The majority of the waste can be categorized as disaster waste, such as: stones, mud mortar, timber, cement blocks and mortar, (reinforced) concrete, CGI sheets and metal
door handles and window connections. These wastes are all part of the structure itself. Additionally, the community center has been used as a storage site since the earthquake. Items and materials stored inside are: steel bed frames, cement bags, steel columns, fabrics (cotton and synthetic clothing), polyethene sheets, plastic pipes and scrap metal. But also municipal wastes are present, such as scrap plastics, which have to be collected and brought to the appropriate municipal waste location. Potentially hazardous waste are only found in the toilet and the drainage system that probably leads to a septic tank. The entire toilet, including piping, should be disposed off with care and brought to the appropriate hazardous waste disposal site. Table 5.4: Categorization of wastes generated by demolition of community center. Community Hall wastes and contents Disaster waste
Municipal waste
Hazardous waste
Stored items
Stones
Plastic packaging
Faeces
Bedframes
Mud mortar
Contaminated toilet
Cement bags
Timber
Sewerage pipes to septic tank
Fabrics
CGI sheets
Septic tank
Polyethene sheets
Glass
Plastic pipes
Cement blocks & mortar
Steel columns
(Reinforced) concrete
Scrap metal
Metal door handles and windows connections
Table 5.2: Estimation of economic value of salvaged materials from demolition of community center. This possibly represents a reduction in costs for a new building.
42
Material
Description quality
Economic value
Stone (with mud mortar)
The stone walls consist of large, nicely cut, rectangular stones, to small, uncut, stone rubble. Undamaged stones are preferred in future construction (IOM guidelines). Assuming that 50% of the weight of the stones meet these specifications, approximately 50 ton of stone is suitable for construction. This would be approximately 2000 good stones.
Rs. 60.000,- (Rs. 30,- per stone, (different sources, 2016))
Concrete
One large slab floor (possibly reinforced). Cement blocks in good condition. Concrete and cement blocks are not easily salvaged without damaging them. Amount is based on slab that can be reused entirely, and assumed to be nonreinforced.
Rs. 125.000,- (Rs. 2.500,- per cubic metre concrete (different sources, 2016))
Steel
Almost all steel locks, handles, etc. can easily be reused; no damage, corrosion. CGI sheets have good quality as well.
Rs. 1.500,-
Timber
Majority of the timber has been kept dry. Majority of timber has not been damaged by earthquake. Assumption is made that approximately 80% is still suitable for reuse.
Rs. 44.000,- (Rs. 100,- per meter 10x10cm beam)
Glass
Some windows remain undamaged. Broken glass should be separated from undamaged glass.
Rs. 260,- per square meter
Community center Ratankot Table 5.3: Possible reuse for different wastes obtained from demolition of community center. Construction of new community center
Slope strengthening/stabilization
Infrastructure in and around Ratankot
Cut stones of sufficient size and geometry.
Gabion walls filled with stones that are unfit for reuse in community center. These stones should not be too small for gabions.
All rubble stones, from pebbles to larger stones that are unfit for reuse in community center.
Domestic use
Landfill
Timber that is not suitable for All smaller rubble reuse in construction can be stones and mud used as firewood for heating/ can be used as cooking. landfill.
Good quality timber beams and planks. Reusable CGI sheets, as well as door/window hinges and handles. Undamaged glass. Reuse the foundation and concrete slabs in new structure. Requires new building to have similar floor plan for load bearing walls.
Defining good and poor materials The stones that form the two outer layers of the walls are mostly in good shape. Their size and shape is appropriate for constructing, according to the NBC. Requirements for construction stones are based on shape and size. They need to be rectangular in shape and not too thin (>10cm preferably), although smaller rectangular stones can be used to fill up gaps in the walls. The fill-in rocks that make up the inner layer of the walls are not suited for construction. They are small, uncut rocks without suitable geometry. The mud mortar is dried out and brittle and unsuitable for reuse in construction. The stones of the part of the building that has already been demolished is stacked on top of the concrete slab in the open air. These are mostly cut stones of good size and geometry, and therefore ready for construction. Most of the timber is still largely intact, since hardly any beams or planks have been broken or rotting. The timber that has not been bent significantly is categorized as good quality. Attention should be paid to the dimensions of the beams when reused in load bearing parts of the structure. The CGI sheet roofing is still intact and seemingly ready for reuse. The cement blocks and mortar walls are partially intact, but probably more suitable for recycling. The concrete slab is of good quality, since no cracks are present and could be reused if the same location for the foundation is reused in the new building. This would greatly save costs and labour during demolition. Make initial inventory of to be salvaged materials The to-be-salvaged materials consist of the construction materials that are used in the structure itself. An estimate is made on the amounts of these materials that are still in the standing structure. This will give insights on possible reuse and recycle, economic value and layout of the demolition site. The amounts below are estimates based on site visits, photo’s and assumptions, and do not represent the actual amounts of debris waste created after demolition.
Table 5.5: Mass of different wastes generated by demolition of community center. Material
Amount
Unit
Stone (with mud mortar) walls
ton
60
Concrete
ton
120
Steel
kg
20
Timber
kg
3500
Glass
kg
15
CGI sheets
m
2
225
Stones stacked on concrete
ton
38
Determine initial economic value materials The economic value of the to be salvaged materials depends on its quality. Table 5.2 describes the quality of materials that have been used in the construction and assigns an economical value to it. Economic values can be assigned to the volumes of waste generated. Possible reuse of materials Among the possibilities for reuse of materials are the implementation of these materials in new constructions, infrastructure, slope strengthening/stabilization, landfill, domestic use. The following table gives suggestions on the destination of waste materials from the community center. At this point, the demolition materials should be assigned future destinations, either as construction material for new structures or as definitive/temporary waste. Initial designs for a possible new community center should be made in order to incorporate demolition materials into the new structure.
43
action point
tools
possible hazards
day 1
clear the area in and around the building by taking away loose parts, such as stones and rubble
Shovel Wheelbarrow
- Taking away materials that are still part of the construction - Possible hazardous waste
day 1
Place shores to stabilize wall section that are stand alone or precarious
Material for strut (wood/steel) General tools (hammer/nails)
- Possible collapse of unstable structure
day 1
Remove non bearing wall section from the top down.
Sledge- hammer Pickaxe Platform
- taking away materials that are still connected to the construction - Falling objects
day 1
Build platform to ceiling and remove ceiling
Hammers Wedges Platform Wrenches
- Falling objects - Pulling structural element
day 2
Build platform up to roof level and remove rooďŹ ng material
Wrenches Steel cutters Hammer Platform
- Falling objects - Sharp edges from CGI sheets
day 2
Remove purlins
Hammer Wedges Wrench
- Falling objects - Pulling structural element
day 3
Shore bearing walls that are supported by roof truss
Material for strut (wood/steel) General tools (hammer/nails)
- taking away materials that are still part of the construction
day 3
Remove roof truss
Rope Hammer Wedges Platform Enough people (min 6)
- Falling objects - Removing while still attached - Instability of remaining structure
44
action point
tools
possible hazards
day 3
Dismantle roof truss on the ground.
Hammer Wedges Saw
-
day 3
Keep removing loose parts from free standing walls
Hammer Wedges Ropes Pickaxe
- Falling objects - Stability of connecting walls
day 4-7
Repeat previous 7 steps untill roof is removed
-
-
day 8
Remove stones around window and door frames. Do not remove the frames.
Hammer Wedges Ropes Pickaxe
- Falling objects - Stability of connecting walls
day 8
Remove beams
Hammer Wedges Rope
- Falling objects - Stability of connecting elements
day 8
Remove window and door frames
Hammer Pickaxe Wedges Ropes
- Falling objects - Stability of connecting elements
day 9
Check foundation cracks and ďŹ&#x201A;oor
Pickaxe Shovel Drill
- Possible hazardous material in soil
day 9
Inspect the foundation to determine quality and possibility of reuse. Ask people who might know details
Shovel Pickaxe
- Instability of trench
45
Shock Safe Nepal Possible recycle of materials Table 5.6: Two possibilities for recycling for different types of waste generated by the community center. Recycle to construction material for new community center
Recycle to landfill
Poor quality stones can be cut in order to be reused in constructing.
Poor quality concrete and cement mortar and small rock can be crushed to smaller fraction and used as landfill.
Poor quality concrete can be crushed and used in CEB. Poor and small quality rock can be crushed and used as aggregate in new concrete. Repair and treat wooden doors/ windows. Repair and treat damaged/corroded CGI sheets.
Set up budget and determine costs for demolition A budget must be set up according to all the activities that are to be carried out during demolition and preparation. These include the costs for labour, braces & props, transport, safety equipment. Also, possible storage and salvation of materials Demolition preparation: Assign sorting location, incorporation of rebuilding process into site management, reuse/recycle locations, hazardous waste location The site should be prepared for demolition in a way that all the materials can be sorted and stacked and that there is still sufficient space available for future construction. A good mapping of the demolition site should be based on the Figure 3.13. The areas required by the different components of this scheme must be determined by the approximated waste generated by the structure. Large piles and heavier waste should be located closer to the structure in order to improve efficiency. These are the stones and concrete waste of the structure. Metals, wood, plastics, glass, fabrics can be positioned further away, though preferably still at the demolition site of the community hall. The distinction should be made between good and poor quality materials, and they should be stacked accordingly. This will facilitate determining which materials are good for reuse and which are good for recycling. Alls piles should be easily accessible. Hazardous waste requires special attention. The location should be determined in such a way that the chances
46
of contamination to soil, water, air are minimized. This includes: safe distance from water streams in order to prevent contamination of soil water and surface waters, safe distance from crops and farmland, including cattle. Hazardous wastes should be kept well out of reach from children and animals especially. Therefore, depending on the size and weight of the waste, a different location than the community hall terrace is preferred, since it borders the local foster home “Home of Hope”. Demolition: See scheme on page 44 and 45. The step-by-step demolition plan was developed and thoroughly discussed in the workshop with Nepali engineers, that was organized by Concern in collaboration with EwB (Murray and Lauritzen, 2016). Waste management: After demolition, all the generated waste must be brought to their designated locations and sorted according to their quality. Good quality materials should be separated from poor quality materials. Additionally, good quality materials should be divided into materials suitable for reuse in construction of community hall and materials that are more suitable for different purposes. For the poor quality materials the distinction can be made if recycling is an option or not. Attention should be paid to storage location and facilities. For example, wood and other degradable materials should be safely stored under a shelter, while stones practically need no cover.
5.2 Community center proposals Possible functions One of the government’s main points of attention for the reconstruction of Nepal is the “Build Back Better” principle, which aims to reconstruct Nepal in a earthquake safe way. This involves the introduction of a new building code, as well as a catalogue with approved building methods consisting of different construction materials. The NRA and its partners are giving workshops on safe reconstruction in all priority districts. The new community center could partly take over this role during the reconstruction. It can function as a center where workshops are given and knowledge and experiences gained during rebuilding can be shared between locals and NGOs. This will contribute to a better reconstruction of Ratankot. To alleviate the financial stress on locals, a main focus of many organisations involved in the Nepal reconstruction has been “owner driven reconstruction”. This concept
Community center Ratankot means that home owners play a crucial role during reconstruction, contributing to building process itself and thereby lowering the labour costs significantly. By learning how to perform certain construction tasks in the community center, homeowners will be able to build back their own homes. In addition to the two points mentioned above, the community center could also function as a meeting place for locals that are involved in the reconstruction of their homes. They can share experiences with materials/ building methods/etc. Also, the community center could promote the concept of “borrowed labour”, allowing locals to share their construction skills with others in exchange for construction skills or other labour, such as farm work for example. This will increase the community feeling and possibly speed up the reconstruction process. Since certain construction equipment is expensive and scarce, the community could rent or buy these equipment instead. The community center could function as a workshop and storage facility where locals can rent/use these equipment. This also allows the center to be used as a workshop where handicrafts or other products can be made, that could introduce trade and economic growth for Ratankot. Also, because of the apparent absence of the VDC of the villages of Ratankot, the community center could function as a new office and meeting place for this committee. The same holds for the engineers and government officials assigned by the NRA that will be working in the VDC of Ratankot. Without proper facilities, their work will be a lot more time consuming. The demolition and reconstruction of the old community center can function as an example for all the villagers. When they participate in these activities, they will be able to learn about safe demolition and possibly useful building methods that are suitable for their own homes. Being involved in these processes might make them less hesitant on demolishing their own damaged properties and using (partly) new building methods for their own houses. Besides these newly introduced functions, the community hall could be used in a traditional way as well. It previously functioned as a meeting place for the villagers during feasts, religious gatherings and other community activities. Since the reconstruction of Ratankot will only be a temporary focus, the community hall must have these functions as well. Previously, the community center also consisted of two guest rooms, that were used mainly by NGOs, but could
be used by tourists to generate income in the future as well. It is a subject of discussion whether it is desired that the guest houses should be incorporated into the community center. But it is quite clear that the community of Ratankot will benefit from extra external incomes such as tourism, which can be promoted by the existence of a number of guest rooms or guest houses. There are a number of different functions stated above, some of which can be assigned to the same structure or even the same room in the building, be it in different stages of the reconstruction or even after the reconstruction. This decreases the costs, since one single room in the building will have different functions during the lifespan of the structure. This flexibility of use is a desired function to have for the new community center. Possible solution A possible solution that will incorporate many of the functions mentioned above is the division of the community center into two separate buildings. The location of the new community center will be the same as the old building. The current temporary structure that now functions as a storage room will be properly reconstructed as a prayer room, that will facilitate the religious activities. A new main pathway will be constructed in between the prayer room and the new main community hall, starting from the main road and going down towards the existing pathway. This new infrastructure will ensure that the community center will be on a central and easily accessible location in the village. The main entrances of both the prayer room and the community hall will face this path. The community hall itself will mainly exist from a large multifunctional space, with walls to each side and a roof. At either side of the main entry two smaller rooms are situated, which can act as storage rooms for materials/ equipment and an office. The main room can be used as learning center, for workshops, as community hall, etc. At the back of the building the roof extends further, resulting in a shaded terrace. By designing the new structures in a way that the old construction materials can be easily reused, expenses will be kept as low as possible. This includes the use of stone masonry, wooden beams and CGI sheet roofing, as well as similar dimensions for the new buildings.
47
6 CONCLUSIONS
The current problems in Nepal are not only of technical nature, but also very much a social and cultural problem. Additionally there is little trust in the government, which also contributes to a slow reconstruction. Even though many NGO’s are present in Nepal, either working together with the government or operating on their own, starting and completing a project in Nepal proves to be difficult. Lack of funds and the possibility to raise funding for households has been a major setback in the reconstruction until recently. Now that the reconstruction program of the NRA has been started, allowing eligibles to enrol for government funding and opening a bank account that will grant access to these funds, there is more confidence that the reconstruction process will speed up. The top-down organisational structure of the NRA has given options to SSN3 to contribute to the reconstruction small scale level, taking over the role of a PO. As lack of funding is the major obstacle for the reconstruction of households, new low cost earthquake resistant housing designs will facilitate reconstruction. Following an extensive MCA on different building methods and cost analysis of the three main contenders, the stone masonry with mud mortar building method seems to be the most feasible method for rural Nepal, for the following reasons: • It is earthquake safe; • It is financially feasible; • Many materials of the damaged houses can be reused, since the previous houses were built using the same materials; • Most of the materials are locally available; • It is a known building method, which is deeply rooted in culture and society; • It is the easiest method to be carried out by locals; • It is the method that requires the least construction equipment. The designs have been made feasible by applying the concept of incremental construction. Incremental housing is nothing new; since the moment humans decided to build up shelters for permanent occupation, the idea 48
of incremental growth was always present. In the three designs, this idea is elaborated by proposing smaller houses than usual, but with the possibility to expand the house over time in an earthquake safe manner. A water system has been designed that will increase the health of the members of the household by treating all in-fluent water to drinking water quality. The system is designed to be as low cost and resilient as possible, as well to have easy maintenance and operation. For highly turbid roof water runoff, the NTU removal will be more than 99% and will meet drinking water quality standards. Also a cost analysis for rural Nepal is included, to be able to calculate the construction costs of the houses as presented in this report. Multiple sources were consulted, leading to a general cost analysis. Therefore the analysis functions as a tool for making a first, rough cost estimation for housing construction in rural Nepal in general, not only for Ratankot specifically. Another aspect of the reconstruction is the demolition and waste management of the collapsed houses. In many cases the sites have already been cleared from loose parts, but some buildings are still dangerously standing. A plan for safe demolition is presented in this report. Also waste management is taken into account, by proposing ways in which the materials can be reused in construction. The Design Booklet shows designs that answer the reasearch question posed in Chapter 2: “What is a viable design, bound by social-cultural, financially feasible, technical, resource, functional and sustainable aspects, for housing using building methods that are available in rural village X, which can be easily adapted for rural village type Y.” In most cases this will be the stone masonry design. On the following pages a proposal for the implementation of one of the designs is presented, projected on a certain case in Ratankot.
Shock Safe Nepal
Implementation of a stone masonry house design As an example for a possible implementation a damaged house in Ratankot is observed and discussed. This does not provide a full integral plan for reconstruction of the village of Ratankot or any other Nepali rural village in general. However, it will provide a step-by-step implementation plan for the observed house, which could be used as a guideline during actual reconstruction or as a reference example for other projects. After an introduction on the house in question, the implementation plan will be divided into four sections: • Demolition and waste management of observed house • Applied stone masonry design • Construction • Costs
Figure 6.1: Picture of the situation with house 1 on the right and house 2 on the left (Upadhyay and De Mey, 2016) Stone wall with mud mortar Kitchen garden Ground Stone Pavement Stone Flooring Timber post Mud Flooring Cement flooring Cover (if nothing)
X
UP
The demolition and waste management will deal with the remainder of the structure that is still present. It offers a safe and efficient way for demolition and suggests reuse and recycling options for the obtained demolition materials. An adapted design of the stone masonry building method will be proposed, adjusted to the location and context of the project, as well as a construction plan including timeline. A cost framing will estimate the feasibility of the project.
UP
House 1 UP
house 1 Verandah
Y House 2 Open Courtyard Open Courtyard
Toilet UP
house 2
GROUND FLOOR PLAN
TITLE
Material
VILLAGE
Ratankot, Nepal.
X'
0
2
4
6
8
10
scale in meters
N
Site specifications The case study that is taken for this plan for implementation, is a site in the centre of Ratankot. This site is analysed and documented by Nishant Upadhyay (INTACH Belgium) and Brecht de Mey (Support4Nepal), which provide the necessary information for implementing the reconstruction approach. Two houses and a garden are situated on the site, shown in Figures 6.1 to 6.3. The main observations are (Upadhyay and De Mey, 2016): • Power is supplied via the electric poles that are installed by the government • There is no rain water management or grey water management system • There is one toilet, next to house 2 • House construction: both houses are traditional, made of stone, mud and wood. House 1 was previously three storeys high, but only the ground floor (used as storage and animal shed before the earthquake) is still standing. House 2 is two storeys high. There is an entrance to the living room on the top floor and there is a storage and animal shed below. • Visual observations of the building conditions: the severity of the damage is labelled as ‘high’ • The accessibility of the buildings is labelled as ‘good’ • The houses are owned by a family of six: father, mother, two sons, a daughter and a grandmother.
SCALE
Understanding habitats,housing,social changes in post-disaster Ratankot, Nepal. INTACH Belgium.
Figure 6.2: Site plan (Upadhyay and De Mey, 2016) LVL +7200.0 MM
LVL +4800.0 MM
LVL +2400.0 MM
LVL ±0.0 MM
LVL -1900.0 MM
SECTION ACROSS XX'
Figure 6.3 Section Y-Y’ (Upadhyay and De Mey, 2016) 49
Shock Safe Nepal Specific requirements Apart from general requirements (such as earthquake safety), the reconstruction must meet the following requirements: • Based on the described information, it is very unlikely that restoring the current houses will lead to a satisfying result. Therefore, new houses will be constructed. A demolition plan for the old houses will follow in this chapter, together with an estimation of the quantities of materials that are suitable for reuse. • Two separate houses for two households must be rebuilt, like it was before the earthquake. • The total amount of habitable floor space of the old situation is leading for the determination of the new houses. • Considering the emerging water shortages in Ratankot after the earthquake, a water system must be included so that fresh water is always available. • For health reasons, a smokeless stove must be provided in the house. • Construction materials from demolition should be reused as much as possible to reduce costs. • As in the old situation, animals are kept in the house. Demolition plan and waste management Because of structural damage to the buildings they will need to be, partially, demolished. Parts of the structure, such as window and door frames, can be re-used. The demolition of the houses is comparable to the demolition of the community hall, as described in this report. However, a difference with the community hall is that they are still in use, so the site is already cleared of loose parts and the most dangerous building components are already removed. The houses must be taken down step by step, similar to the community hall: • Bracing of walls supported by the roof structure • Removal of roof panels • Demolition of walls until bottom windows. • Removal of windows • Demolition of walls until lintel • Removal of foundations In order to reduce costs, it is obvious to re-use materials from demolition for reconstruction. In Table 6.1 and 6.2 estimations of the quantities are presented, for both house 1 and house 2. It is unknown what house 1 looked like before the earthquake. The site had been cleared of debris coming from possible upper storeys. Because house 2 could not be inspected inside, there is very limited information about the materials used. The numbers in the table are
50
therefore very rough estimates. The houses might also have some amount of concrete, steel or cement. Based on the current information this is difficult to assess. The percentages to determine the reusable amounts are based on the knowledge that was acquired during the workshop organized by Concern. The estimates are adjusted downwards in order to avoid unrealistic expectations. Table 6.1: Estimation of quantities house 1 Material
Total amount Reusable amount
Unit
Stone (with mud mortar) walls
27
13 (50%)
m3
Timber
2,0
1,4 (70%)
m3
Slates (roofing)
2,2
2,0 (90%)
m2
CGI sheets
39
32 (80%)
m2
Total amount Reusable amount
Unit
Table 6.2: Estimation of quantities house 2 Material Stone (with mud mortar) walls
42
21 (50%)
m3
Timber
3,5
2,5 (70%)
m3
CGI sheets
40
32 (80%)
m2
Implementation Based on the available materials after demolition of the old structures, the stone masonry house seems to be the most suitable design for reconstruction. The first expanded design as presented in Chapter 4 will be adopted and implemented on the location. Decisions on implementation (also shown in Figure 6.4): • The footprint of house 1 is expanded in northeastern direction. This way, space is created to avoid the necessity of a third storey. • House 2 is constructed against a retaining wall, which is wrong in terms of earthquake safety. The new location for it is right next to it, where currently the open courtyard is. • The toilet is therefore moved also, to a more private location. • The water system as presented in Chapter three is implemented in the house design. Rainwater is captured and filtered to prevent the household from water shortages throughout the year. Considering the household composition with the unmarried children, house 2 has less priority to construct than house 1. First house 1 can be inhabited by all six family members, before house 2 is constructed so that one of the children moves out to start a family in that second house. The results of the reconstruction are shown on the following pages in Figures 6.5 to 6.11.
Conclusions
Figure 6.4: Design decisions site plan
51
Communal water inlet Communal water inlet
Open courtyard Storage tank 500 liter Household system
House 2 Sewer pipes to surface discharge
Re-use existing columns Slow sand filter Veranda
First flush diverter 165 liter
Buffer tank 500 liter
Toilet
House 1
Sewer pipes to surface discharge
A
A'
Cowshed
Figure 6.5: Site plan 1:200
+5800 mm +4700 mm
+2550 mm
+0 mm
Rain gutter and screen Communal water inlet
Buffer tank 500 liter Slow sand filter Household system
-1900 mm
Storage tank 500 liter
First flush diverter 165 liter Sewer pipes to surface discharge Septic tank
Figure 6.6: Section 1:200
100
2700
9 m2 100
5 m2 100
2950 8750
2330
5 m2 100 4930
100
2700
9 m2
2300
10 m2
100
100
100
100 100
2155
100 3450
4900
3650
Figure 6.7: House 1 floor plan first floor1:100
Figure 6.8: House 2 floor plan first floor 1:100
Re-use of existing columns
8 m2
Veranda
450
600
Smokeless stove First flush diverter 165 liter
Communal water inlet
Cooking Household system
1150
Buffer tank 500 liter
14 m2 Slow sand filter 1650 Living Storage tank 500 liter 450 Communal water inlet
1150 9100
1250
Storage
2 m2
850
15 m2 900
450 Cooking
5200 600
Cowshed
7 m2
1150
600
2220
First flush diverter 165 liter Storage tank 500 liter
Slow sand filter
Living Storage
Buffer tank 500 liter
2.5 m2
450
450
3100
450
4000
Figure 6.9: House 1 floor plan ground floor 1:100
450
450
2155
900
940
450
4900
Figure 6.10: House 2 floor plan ground floor 1:100
54
Communal water inlet
160
Household system
100
Figure 6.11: Section 1:100
-1900 mm
+0 mm
+2550 mm
+4700 mm
+5800 mm
230
Smokeless stove
Sewer pipes to surface discharge
420
950
Floater Storage tank Slow sand ďŹ lter 500 liter
950
Communal water inlet
Buffer tank 500 liter
Rain gutter and screen
100
200
Household system
First ďŹ&#x201A;ush diverter 165 liter
Sewer pipes to surface discharge
Shock Safe Nepal
Conclusions
Construction plan The following paragraph shows a stepwise plan for the execution of the house reconstruction. This construction plan contains steps that are in general applicable for reconstruction of stone masonry houses with mud mortar. The goal of this simplified reproduction of the construction is to emphasise in a clear manner the critical
construction points that make or break the earthquake resistancy of the house. When executed correctly, based on the NBC and Design Catalogue, the construction steps lead to an earthquake safe house. However, when these demands are not met during construction, it might lead to an unsafe house, for the earthquake resistancy strongly depends on a well performed construction.
1. after demolition, clear also the foundations and store the stones
2. dig out all foundation trenches with dimensions 750x700 mm
3. lay the polythene sheet to protect from moist
4. lay wooden base plate
5. fix the columns on the base plates and provide temporary support. the columns are made of treated wood
6. build the foundation up to 300 mm above ground level
7. fix the columns and the stone masonry to eachother with wire
8. build the first seismic (plint) band on top of the foundation, made of treated wood
9. fix the seismic band to the columns 55
Shock Safe Nepal
10. fix the wooden bands at both sides to each other every 500 mm
11. fill the space between the bands with stones
12. continue building up to sill level and provide another seismic band
13. build the window frames on top of the sill band
14. continue building up to lintel level and provide another seismic band
15. here the ties are extended 0,5 m outwards in order to create an overhang that protects the wall
16. fix the floor beams of the first floor to the lintel band with nails and wooden keys
17. fix the timber flooring to the beams (the two finishing layers on top of it should be applied later)
18. build the seismic sill band of the first floor
19. provide bracing
20. the walls on the first floor consist of one layer of seismic bands, in line with the columns
21. continue building the wooden frame structure up to roof level and fix the window frames
56
Conclusions
22. fix the floor beams of the attic floor to the lintel band and construct the flooring of the attic
23. fix the ridge beam on top of the columns
24. construct the roof, that consists of a ridge beam, rafters, battens and CGI sheets
23. fix the rafters to the roof band
24. the rafters are supported by the ridge beam and nailed to each other where they overlap
25. nail bamboo strips or thin wood to the framework
26. apply the mud mixture to the framework to build up the wattle and daub wall
27. construct the ground floor and finish the upper floors
28. finish the walls by applying mud plaster
Cost estimation On the following pages, a cost estimation is provided for the reconstruction of both houses and the new toilet. An important conclusion of this representation of the reconstruction of an house, is that the total costs can be reduced significantly when the re-use of materials is taken into account as described in the previous paragraphs. Although the dimensions and construction of the first house are close to the extended stone masonry design of Chapter 4, the addition of miscellaneous items and the
rainwater harvest system would raise the expectation that the completion would result in a higher price. However, due to the demolition of the old building, in combination with the re-use of materials, the costs for both transport and materials can be reduced significantly. As a result, the price of the stone masonry house implemented in Ratankot, is still relatively low compared to other two story buildings that are currently being build in Nepal.
57
Shock Safe Nepal Table 6.3: Cost estimation house 1 MATERIAL Foundation Stones, large Stones, small Cement Sand Polyethene sheets Timber base Structural elements Stones, large Stones, small Clay (for mud mortar) Timber bands (soft wood, treated locally) Timber columns (soft wood, treated locally) Timber frames for attic walls (treated locally) Timber roof structure Cladding C.G.I. sheets (roof) Clay (for wattle and daub walls attic) Sand (for wattle and daub walls attic) Cladding components Doors Windows Other Timber floor boards Rubble stones (ground floor) Clay (ground floor) Nails
AMOUNT
Labour Skilled Unskilled Labour demolition Unskilled Water system (as described in chapter 3) Water system Miscellaneous Smokeless stove Stairs SUBTOTAL OTHER COSTS SUBTOTAL Unforseen expenses TOTAL COSTS HOUSE 1
MATERIAL COSTS (NPR)
15.4 m3 4.4 m3 0.6 m3 1.7 m3 12.6 m2 0.5 m3
11,665 Local 3,760 11,280 0 356
19,435 0 15,555 2,589 1,351 4,608
17.8 m3 5.1 m3 2.5 m3 1.2 m3 0.4 m3 1.3 m3 1.2 m3
13,422 Local Local 929 293 944 943
22,360 0 0 12,019 3,783 12,862 12,197
94.3 m2 3.7 m3 1.9 m3
3,523 Local 12,849
32,981 0 2,949
3.5 m2 2.0 m2
662 389
8,565 5,038
1.5 m3 5.0 m3 0.7 m3 2067
1,125 Local Local 10 62,203
14,555 0 0 493 171,341
-9,819 -1,069 -75 -1,196 -12,158
-16,358 -13,825 -700 -11,194 -42,076
SUBTOTAL MATERIAL COSTS Cost reduction (material re-use) Stones, large Timber Slates CGI-sheets SUBTOTAL COST REDUCTION
TRANSPORTATION COSTS (NPR)
13.0 m3 1.4 m3 2.0 m2 32 m2
93.6 days 102.1 days 15
83,094 59,309 8715
1
24,980
1 2
2,000 5,000 183,098
20%
312,364 62,472 NPR 374,836 USD 3,495
Conclusions Table 6.4: Cost estimation house 2 MATERIAL Foundation Stones, large Stones, small Cement Sand Polyethene sheets Timber base Structural elements Stones, large Stones, small Clay (for mud mortar) Timber bands (soft wood, treated locally) Timber columns (soft wood, treated locally) Timber frames for attic walls (treated locally) Timber roof structure Cladding C.G.I. sheets (roof) Clay (for wattle and daub walls attic) Sand (for wattle and daub walls attic) Cladding components Doors Windows Other Timber floor boards Rubble stones (ground floor) Clay (ground floor) Nails
AMOUNT 12.3 m3 3.5 m3 0.4 m3 1.3 m3 9.2 m2 0.4 m3
9,256 Local 1,979 5,938 174
15,423 0 12,344 2,054 994 3,407
12.7 m3 3.6 m3 1.8 m3 0.9 m3 0.3 m3 1.1 m3 0.9 m3
9,620 Local Local 452 156 577 463
16,029 0 0 8,889 3,053 11,316 9,079
73.4 m2 2.5 m3 1.3 m3
1,818 Local 5,812
25,662 0 2,010
3.4 m2 4.7 m2
262 360
5,138 7,053
1.2 m3 6.4 m3 0.7 m3 1467
593 Local Local 10 37,469
11,643 0 0 350 134,450
-15,859 -1,258 -793
-26,423 -24,688 -11,194
-17,910
-62,306
SUBTOTAL MATERIAL COSTS Cost reduction (material re-use) Stones, large Timber CGI-sheets
21.0 m3 2.5 m3 32.0 m2
SUBTOTAL COST REDUCTION Labour Skilled Unskilled Labour demolition Unskilled Water system (as described in chapter 3) Water system Miscellaneous Smokeless stove Stairs SUBTOTAL OTHER COSTS SUBTOTAL Unforseen expenses TOTAL COSTS HOUSE 2
TRANSPORTATION COSTS (NPR) MATERIAL COSTS (NPR)
67 days 76 days
61,255 43,868
35
20,335
1
24,980
1 2
2,000 5,000 157,438
20%
249,141 49,828 NPR 298,969 USD 2,787
Shock Safe Nepal
Table 6.5: Cost estimation toilet MATERIAL Stones, large Stones, small Cement (for cement mortar) Sand (for cement mortar) Clay (for mud mortar) Timber C.G.I sheets (roof)
AMOUNT 4.2 m3 1.2 m3 0.03 m3 0.1 m3 0.5 m2 0.3 m3 4 m2
SUBTOTAL MATERIAL COSTS Labour Skilled Unskilled SUBTOTAL OTHER COSTS SUBTOTAL Unforseen expenses TOTAL COSTS TOILET
60
0.5 days 2.5 days
20%
TRANSPORTATION COSTS (NPR) 3,172 Local 187 562 Local 196
MATERIAL COSTS (NPR)
149
5,285 0 776 129 0 2,541 1,399
4,266
10,130
444 1,453 1,897 16,293 3,259 NPR 19,552 USD 182
Conclusions
61
7 DISCUSSION
Demolition & waste management Demolition of damaged structures is not always preferred for the people who own the structure. A large fraction of the damaged buildings are still partly intact and altered in order to fulfill another function, such as storage space or animal shed. Demolition of such building will result in a (temporary) drop in quality of living. The earthquake safety of these structures is questionable and people should be convinced that reconstruction is needed. The quantities of materials suitable for reuse are rough estimates. It is difficult to determine beforehand to what extend the materials are still usable. Close inspection of quality and quantity is not always possible because of the inherent danger of damaged structures. A first estimate can therefore deviate significantly from the final yield of reusables. MCA Although the MCA shows a considerable difference between the top three building methods and the other seven remaining building methods, an MCA remains susceptible for subjectivity. This has been attempted to resolve via surveys among different engineers and members of the research team, however, these surveys produced differences between the importance of categories. The decision to take the average of both Nepali engineers and the Shock Safe Nepal team might result in a different outcome of the MCA compared to a case where only the Nepali engineers or the Shock Safe Nepal team is consulted. Another point of discussion is the high combined importance of the technical, resources and feasibility category. When a building method scores high on these aspects, the other three categories are of a low importance to the eventual outcome of the MCA. This mostly shows in the varieties between the different scenarios. The effects that these scenarios have on some categories are primarily based on a few changes in the first three categories. Due to these changes the other categories which are reasonably independent of changes in scenarios have to deviate as well to realise a sum of 100%. However, this is an unavoidable aspect of performing an MCA and the methods of the MCA used in this research take into 62
account a large amount of opinions and data to form a well-grounded conclusion on the building methods. Proposed rainwater harvest system There are a few points of discussion on the proposed water system. Firstly, the precipitation has a high spatial variation. Because data from a nearby measuring station was unavailable, the decision was made to use data from Kathmandu. Using data for Sindhupalchok or Sunkhani itself, a better estimate can be made on the potential quantities of rain harvest. Secondly, rain data are statistics, and while using average monthly data to preliminary design such a system is acceptable, it doesn’t reflect the reality. Users should be aware of this temporal variability of precipitation and not solely rely on rain harvest. The calculations were made assuming that a single rain event occurs on a rainy day, which is of course not the case. Using more accurate rain data could improve the system. Also, measurements on water quality are absent for both the rainwater entering the system through the gutters and the source water entering the system through the communal water pipes, as well as the effluent treated water. In addition to this, an optimal flow rate exists for the filter, something which has to be regulated in practice. This influences the syphon and vertical dimension of the total system. Though previous research and literature provide a basis on the knowledge of the water quality for this particular system, actual measurements are preferred and should be a priority when this system is tested or implemented. As a result, the approach chosen was to propose a resilient system that factors in these uncertainties. Assumptions were made that the quality of the water entering the system is very low, and thus requires a high level of treatment. The lower bounds of the theoretical treatment efficiency were taken in order to come up with a design that sufficiently treats the water. In practice however, the systems treatment steps could prove to be more efficient, as well as the inflowing water could be of a better quality than is assumed. By testing and measuring this system, new insights can be gained on how to improve water quality and efficiency and lower costs. A good maintenance of the system is required. The
Shock Safe Nepal users should be informed and educated on this, in order to improve the system’s resilience. The same applies to operational aspects. Lastly, the cost estimate remains an estimate. Local markets could offer components at different prices, possibly lowering the total costs. House designs Rather than only one, three house designs are made to show several options for the reconstruction of houses in rural Nepal. Specifically for the case study of Ratankot, as elaborated in this report, stone masonry was chosen. In other cases, the other house designs can be more suitable. This does not mean though, that other building methods than the ones used in these designs are per definition excluded for rural Nepal. Structural strength In terms of earthquake safety, the three designs are solely based on the Nepali Building Code (NBC) and other sources and experts consulted in Nepal. No scientific experiments (with shake tables for example) have been executed. Their behaviour under earthquake loading is unknown due to unknown material properties, unknown cooperation between tensile and bearing elements and unknown earthquake force. Therefore their strength is unknown, but assumed to be sufficient based on the NBC. The combination of rammed earth and wattle and daub in the second design has not been tested. Seperately, these building methods appear in the NBC, but not as a combination of the two in one house. It is unknown how these two materials will behave under seismic loading, and if they will work together. Therefore this design is considered to be conceptual. The corners of the horizontal bands need to be rigid in order for them to transfer bending moments under seismic loading. Of both the stone masonry design as of the rammed earth and wattle and daub design these corner-connections of the bands might not be sufficient and might need a diagonal element. The structure of the bands need to be tested in order to determine if the system is sufficient strong and stiff as it is now. Further research should be done in the strength of CEB stones. Because of the local production the composition of these stones can vary at every location. The effect on earthquake resistance due to the heterogenous nature of the stones has not been extensively researched. Expandability The expansion of the stone masonry house might not be efficient, because the cost difference might not be big enough to go to the trouble of dismantling and
reconstructing the roof. Also the quality of the roof might decrease too much when taking it down and reconstructing it by unskilled people. Adding to that, the structural system after expansion might not be stable, expanding the column should be done in such a way that the connection of the column is rigid, not a hinge. This connection needs further study to ensure the expansion of the house does not create a hinge in the columns halfway the second floor. A better expandability might be to build the basic house until the lintel band with a flat roof and expand the house over time with a light structure from there. In our design we have eventually chosen not to do this after considering the following advantages and disadvantages. Advantages: - Expanding the columns will be at a more logical point in a structural view, namely at the point where the materials change and therefore where the stiffness of the house change - the column expansion might also function as a dilatation. - Building only a simple roof structure and no attic, forms a better distribution of material use over the nonexpanded and expanded house, and therefore a better cost distribution over time. - The roof structure needs to be build only once and by eliminating the need for dismantling the structure, the quality is more likely to be better. Disadvantages: - The basic house does not have an attic, and therefore no possibility for the storage of harvest. This might be too much of a restraint that the people will not accept the house. - The basic house does not include the wattle and daub method, so people have not practised yet with this lightframe building method on their house. Therefore the transition and connection between the basic and extended house might be hard to realise. - Every roof needs a slope for rainwater to run down, so the roof cannot actually be flat. Therefore the roof structure needs to be asymmetrical; higher on one end of the house. This needs to be worked out, such that the bands remain straight and no loose stones are placed upon the band. The question is how to fill up the part above the band of the higher wall when taking the expandability into account. Execution Proper execution of the designs is vital. Construction supervision and quality control on a site and national level as known in Europe is not existent in Nepal. Combined with the low level of education of the population, this
63
Shock Safe Nepal makes it highly probable that the plans will not be executed as intended. This aspect should be kept in mind when making building plans or designs for Nepal. The design should be kept simple regarding connections. If possible an engineer with deeper knowledge of the design should be at the site to educate the builders and supervise that the work is done properly. Proper supervision can ensure that building materials are used properly and structural/ earthquake resistance is ensured. Costs of the houses The prices of the housing designs are surrounded by a number of uncertainties. This is due to the high rate of uncertainty of material prices on the market in Nepal. Following from the performed surveys and interviews with engineers, the conclusion can be drawn that these prices can range significantly. This influences the eventual price of the houses as these could be higher or lower than the final calculated price in this report. However, by using multiple observants and the deletion of extreme outliers, the obtained dataset is valuable for the calculation of further housing designs as this is a very close approximation of the real material costs. Another aspect that might raise the calculated price of the three designs is the education costs during the first tryouts. If these building methods are taken into production by home owners, they will have to adapt to the new ways of earthquake resistant construction and learn to use these methods efficiently. At first this will then lead to material wastes and failures of some constructions. However, when a system of construction has been implemented and Nepali get accustomed with these new techniques, the building time and material costs will approach the calculated price for the houses.
64
Chapter name
65
8 RECOMMENDATIONS
Reconstruction in Nepal is lacking transparency at this time. The rules and regulations are not always clear and it is difficult to find reliable and easily understandable information. Especially in rural areas with limited accessibility this is a problem. Among other things this has made the trust of the rural population in the reconstruction waver. More than a year after the earthquake a large part is still living in temporary accommodation and have yet to see any real reconstruction progress. Also knowledge of safe and feasible designs is lacking in rural communities. People need to be educated in safe construction methods and guided in the reconstruction process. This means both during actual construction as well as the process of receiving government subsidy and support. The next step for SSN can be the realisation of a building project. This can be achieved following the implementation plan of team 2. Team 2 has made an extensive plan for reconstruction including education and economic development. The project does not necessarily have to be a house but this is preferred. Another viable project is a learning centre to educate the local population in earthquake resisting building techniques. Vital in this is local participation. The designs made by team 3 can form a basis for these projects. They are still model designs and need be adapted to a specific project with specific needs. This project can take place in Ratankot where Nepal already has a collaboration with Support4Nepal but could also be implemented in another region with a different partner. Knowledge about the execution of a construction project in Nepal is an valuable addition to the research of SSN. SSN can also play a role in future research on earthquake resistant construction in rural areas. There is a lack of scientific research and validation on the different construction methods. The reports of SSN in Nepal can form a basis for research at the Delft university of Technology. Scientific validation of the designs in the Nepal Building Code can be a valuable addition to the reconstruction effort. This is probably also a more effective use of the resources of the University in the reconstruction process. There are hundreds of NGO’s present in Nepal with a continuous presence. They are 66
better equipped to lead the reconstruction effort and are helped with scientific research on safe construction methods. A bachelor or master thesis on for example the connection between stone masonry and wooden tension bands would be of great relevance to Nepal. The University has the resources to do this kind of fundamental research both experimental as numerically. The future of SSN should therefore maybe not lie in a presence of teams in Nepal but in support with scientific research on topics relevant to the reconstruction of Nepal. Shock Safe Nepal has established a wide network of contacts in the GoN, NGO’s and INGO’s. Through this network the gained knowledge of this research can be distributed. The current setup of small teams of multidisciplinary students only present for 8-10 weeks in Nepal is unsuitable. The period is not long enough to guide reconstruction projects. Also the need for academic value in the project is a limitation on the scope of such a project as doing just reconstruction is not seen as an academic goal. An internship with a local partner might be a more suitable form. An internship can span a larger period and the student can transfer knowledge obtained in Delft to the partner and the people of Nepal. In exchange the student gets insight in the execution aspects of construction in Nepal. This can then be incorporated in future research in Delft. If a new team is sent to Nepal it is recommended to seek other universities to cooperate with. Many of the challenges in Nepal are not of a technical nature. Social, economic and political challenges are often much greater. These are not areas of expertise of students from Delft. However other Dutch universities do have knowledge and expertise in these fields. For example Wageningen University has an International Development Studies bachelor and master track. Also the universities of Leiden and Rotterdam can add their expertise. Students from these universities can add valuable knowledge in areas a typical Delft student is lacking. The overall effectiveness of sending a team 5 to Nepal is still debatable. For the longevity of SSN it is also important to define a
Shock Safe Nepal clear short and long term vision. The vision of SSN at the moment is “Shock Safe Nepal has envisioned itself to deliver the knowledge and network to construct 10.000 houses as a result of the performed research while contributing to knowledge development on earthquake proof building with respect to traditional and culturally accepted building methods”. While for the long term this is a clear ambition, the short term goals are not defined and the way towards the goal is also not clear. An action plan involving research goals, distribution of the knowledge and implementation of this knowledge is needed. SSN has the network in place to achieve this. Through contacts made by the teams gaps in the current knowledge of reconstruction techniques can be identified. Research subjects for a bachelor or master thesis can be derived from these. Feedback and validation of this research could be done either by partners in Nepal such as Abari, Concern Worldwide and Support4Nepal or by a new team at a later stage with a clear goal emanating from the scientific research.
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LITERATURE
Accountibilitylab, & Local Interventions Group. (2016). Nepal Community Feedback Report. Issue: Reconstruction. Abari. (2015a). How to build a transitional classroom. Abari. (2015b). How to build a transitional shelter. Abari. (2015c). Rebuilding Nepal with Bamboo & Earth. Adhikary, S., Tuladhar, B., Shrestha, P., Sherpa, M. G., Shrestha, P., Shrestha, R., … Schmidt, J. (2008). Assessment of Urine-Diverting EcoSan Toilets in Nepal. WaterAid Nepal Publications. Adviesbureau ir. J.G. Hageman B.V. (2015). NPR 9998 - Metselwerkwanden belast uit het vlak. Argles, T. W., Coe, A. L., Rothery, D. A., & Spicer, R. A. (2010). Geological Field Techniques. Economic Geology. http://doi.org/10.2113/econgeo.106.1.159 Arup. (2015). Groningen Earthquakes Structural Upgrading. Site Response Analysis. ASTM International. (2004). Standard Specification for Steel Sheet, Zinc-Coated (Galvanized) or Zinc-Iron AlloyCoated (Galvannealed) by the Hot-Dip Process 1. http://doi.org/10.1520/A0653 Basnet, P. (2016). HRRP Meeting Minutes, (March). Berg, P., Bjerregaard, M., & Jonsson, L. (2011). Disaster Waste Management Guidelines. Boen, T., & et al. (2010). Retrofitting Simple Buildings Damaged by Earthquakes. Brown, D. K., Deardorff, A. V, & Stern, R. M. (2001). Working Paper: Road User Costs. Bureau of Indian Standards. (2002). Code of practive for design loads (other than earthquake) for buildings and structures. Part 1 Dead Loads - Unit weights of building materials and stored materials. Buzunis, B. J. (1995). PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF ENGINEERING ENGINEERING. Centre for Affordable Water and Sanitation Technology. (2009). Biosand filter manual design, construction, installation, operation and maintenance. Department of Education. (2016). Approved School Designs. DHM. (2013). Agroclimatic atlas of Nepal, 170. Doyle, K. C. (2008). Sizing the First Flush and its Effect on the Storage-Reliability- Yield Behavior of Rainwater Harvesting in Rwanda By Sizing the First Flush and its Effects on the Storage-Reliability- Yield Behavior of Rainwater Harvesting in Rwanda. Department of Urban Development and Building Construction, Government of Nepal (2015a). Nepal National
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Building Code: NBC 204: Guidelines for Earthquake Resistant Building Construction Low Strength Masonry. Department of Urban Development and Building Construction, Government of Nepal (2015b). Nepal National Building Code: NBC 206: Architectural Design Requirements. Duke, W. F., Nordin, R. N., Baker, D., & Mazumder, A. (2006a). The use and performance of BioSand filters in the Artibonite Valley of Haiti: a field study of 107 households. Duke, W. F., Nordin, R. N., Baker, D., & Mazumder, A. (2006b). The use and performance of BioSand filters in the Artibonite Valley of Haiti: a field study of 107 households. Rural and Remote Health [electronic Resource]. Dupont de Dinechin, M., & Moles, O. (2006). Technical guide for master trainers: Earthquake resistant buildings using local materials in Kafal Ghar (Kashmir, Pakistan). Eawag/Sandec. (2008). Household Water Treatment and Safe Storage (HWTS). Elkink, A. (2016). Collecting drinking water from roofs. Build 151. Engineers Without Borders Denmark. (2011). Final Report. Methodology. Engineers Without Borders, & Emergency Architecture & Human Rightes. (2016). Nepal – Appraisal Mission Capacity Building on Debris Management and Recycling of building materials for Reconstruction post-earthquake Executive summary. Garnier, P., & Moles, O. (2012). Natural hazards,disasters and local development. Ghavami, K. (1995). Ultimate load behaviour of bamboo-reinforced lightweight concrete beams. Cement and Concrete Composites. http://doi.org/10.1016/0958-9465(95)00018-8 Gordon, B., Callan, P., & Vickers, C. (2008). WHO guidelines for drinking-water quality. WHO Chronicle. http://doi. org/10.1016/S1462-0758(00)00006-6 Guillaud, H., Joffroy, T., Odul, P., & Craterre. (1995). Compressed Earth Blocks : Manual of Design and Construction. HRRP. (2015). Overview of HRRP organization. HRRP. (2016a). District Profile - Sindhupalchok (as of Apr 2016), 2016. HRRP. (2016b). NEPAL : Sindhupalchowk District Administrative Map, 0. HRRP. (2016c). NEPAL: Enrollment Status (as of 09 Jun 2016) DRAFT, 2016. HRRP. (2016d). NEPAL: Enrollment Support - Partner Presence (as of 09 Jun 2016). Statewide Agricultural Land Use Baseline 2015, 1, 2016. http://doi.org/10.1017/CBO9781107415324.004 HRRP. (2016e). Partners Directory, 24–26.
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Hudson, H. E. (1981). Water Clarification Processes. ICIMOD. (2015). Strategic Framework for Resilient Livelihoods in Earthquake-Affected Areas of Nepal. IFRC. (2013). Post-disaster shelter : Ten designs. JeanCharles, M. (2007). Rainwater Harvesting Systems for Communities in Developing Countries. Jha, A. K. (2010). Safer Homes, Stronger Communities, A Handbook for Reconstructing after Natural Disasters. Worldbank. http://doi.org/10.1596/978-0-8213-8045-1 Kam for Sud. (2016). The Water System of the Children’s Home Tathali. Karna, E. J. (2016). Report on Pilot House - GOAL. Langenbach, & Randolph. (2015). ‘ GABION BANDS ’: A Proposed Technology for Reconstructing Rural Rubble Stone Houses after the 2015 Nepal Earthquakes. Lantagne, D., Quick, R., & Mintz, E. (2006). Household water treatment and safe storage options in developing countries: a review of current implementation practices. Woodrow Wilson Quarterly. http://doi.org/10.1021/es301842u Lauritzen, E. K. (2014). Lessons From Lebanon: Rubble Removal and Explosive Ordnance Disposal. Luong, T. V. (2002). Harvesting the Rain: A construction manual for cement rainwater jars and tanks. Maini, S. (2012). Earth Based Technologies. Martinson, B., & Thomas, T. (2005). Quantifying the First-Flush Phenomenon. 12th International Rainwater Catchment Systems Conference. Melorose, J., Perroy, R., & Careas, S. (2015). Seismic Vulnerability Rating: A Guideline. Statewide Agricultural Land Use Baseline 2015. http://doi.org/10.1017/CBO9781107415324.004 Merz, J., Dangol, P. M., Dhakal, M. P., Dongol, B. S., & Weingartner, R. (2006). Rainfall amount and intensity in a rural catchment of the middle mountains, Nepal. Hydrological Sciences Journal. http://doi.org/10.1623/hysj.51.1.127 de Mey, B. (n.d.). Ratankot report 2016 (S4N update van 2011), 2016. de Mey, B. (2011). Overzich Leefsituatie Ratankot. de Mey, B. (2015a). Overview of Living Situations Ratankot. de Mey, B. (2015b). Ratankot - Household Questionnaire. Minke, G. (2001). Construction manual for earthquake-resistant houses built of earth. Building Advisory Service and Information Network. Mughal, H., Ahmed, S. A., Mumtaz, H., Tanwir, B., Bilal, S., & Stephenson, M. (2005). Kashmir Earthquake 2005 Learning from the Shelter Response and Rural Housing Recovery. Murray, R., & Lauritzen, E. (2016). Nepal Demolition & Debris Management Training - Concern Worldwide. Namago, S. S., Madara, D. S., Makokha, A. B., & Ataro, E. (2015). A Model for Testing Compressive and Flexural Strength of Sisal Fibre Reinforced Compressed Earth Blocks in the Absence of Laboratory Facilities. National Reconstruction Authority. (2016a). Earthquake Housing Reconstruction Programme SOP for Enrolment, (April), 1–18.
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Stauber, C. E. (2007). the Microbiological and Health Impact of the Biosand Filter in the Dominican Republic: A Randomized Controlled Trial in Bonao. Stauber, C. E., Kominek, B., Liang, K. R., Osman, M. K., & Sobsey, M. D. (2012). Evaluation of the impact of the plastic biosand ďŹ lter on health and drinking water quality in rural tamale, Ghana. International Journal of Environmental Research and Public Health. http://doi.org/10.3390/ijerph9113806 UNSECO New Delhi, & UNDP India. (2007). Manual for Restoration and RetroďŹ tting of Rural Structures in Kashmir How to Reduce Vulnerability of Existing Structures in Earthquake Affected Areas of Jammu and Kashmir. Upadhyay, N., & de Mey, B. (2015). Report for Ratankot Reconstruction Program - Support4Nepal. Waltham, T. (2009). Foundations of Engineering Geology. http://doi.org/10.1017/CBO9781107415324.004 World Health Organisation. (1997). Guidelines for Drinking-water Quality. http://doi.org/10.1016/S14620758(00)00006-6
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APPENDICES
A: List of contacts of Shock Safe Nepal Team 3
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B: Annexes from Disaster Waste Management Guidelines, Berg, 2011. B1: Annex II. Waste hazard ranking tool B2: Annex III. Waste handling matrix
76 76 78
C: MCA: C1: 0-Scenario C2: More remote scenario C3: No subsidy scenario C4: Solution space C5-C24: MCA sheets per building method: C5: Adobe C6: Bamboo C7: Brick masonry in cement mortar C8: Compressed earth brick (CEB) C9: Concrete in-sute shear wall C10: ConďŹ ned masonry C11: Dhajji Dewari C12: Earthbags C13: Hollow concrete brick masonry C14: Interlocking bricks C15: Lightweight steel proďŹ le building systems C16: Low strength (brick) masonry C17: Low strength (stone) masonry C18: Prefab framed in-situ concrete C19: Rammed earth C20: Reinforced cement concrete frame (RCC) C21: Single panel walling system C22: Steel C23: Stone masonry in cement mortar C24: Timber construction
80 80 81 82 83 84 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103
D: Cost analysis survey
104
E: Precipitation maps of Nepal. Department of Hydrology and Meteorology. 2013.
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F: Floor plan damaged community center Ratankot (SSN2, 2016)
110
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75
Appendix A: Shock Safe Nepal List of contacts of Shock Safe Nepal Team 3. Organisation
Contact
Function
Abari
Subash Karki
Project manager Architect
hr@abari.org
Pranathi
Concern Worldwide Consulate General of Nepal for the Netherlands Delft Global Initiative
Robyn Murray
Phone website number 9841941900 http://www. abari.org/
pranathi.ar@gmail.com/ pranathi@abari.org
robyn.murray4@gmail. com mail@casdestoppelaar.nl
https://www. concern.net/ http://www. nepal.nl/ consulaat/
Jennifer Kockx
J.P.Kockx@tudelft.nl
DIMI
Anna Molleman
a.molleman@tudelft.nl
DUDBC
Parikshit Kadariya Housing department Erik Lauritzen
parikshitkadariya@gmail. com erik@iug.dk
Kam for Sud
Nishant Upadhyay Daniel Pittet
nishant.upadhyay@ outlook.in danpittet@ticino.com
http://www. delftglobal. tudelft.nl/ http://www. tudelft.nl/ onderzoek/ thematischesamenwerking/ delft-researchbased-initiatives/ delft-deltasinfrastructuresmobilityinitiative/ http://www. dudbc.gov.np/ http://www.iug. dk/ http://www. intach.com/ http://eng. kamforsud.org/
Support4Nepal
Daniel Bernet Brecht de Mey
bernet.d@gmail.com brecht_de_mey@ hotmail.com
TU Delft
Roel Schipper
Engineers without borders INTACH
Cas de Stoppelaar
Jules Verlaan
76
Consul Generaal
Head supervisor superivsor
H.R.Schipper@tudelft.nl J.G.Verlaan@tudelft.nl
http://www. support4nepal. be/ http://www.citg. tudelft.nl/index. http://www.citg. tudelft.nl/index. php?id=19550
Appendices
Organisation
Shock Safe Nepal
Contact
Function
Erik Mosselman
supervisor
e.mosselman@tudelft.nl
Sander van Nederveen
supervisor
G.A.vanNederveen@ tudelft.nl
Wout Broere
supervisor
w.broere@tudelft.nl
shocksafenepal@gmail. com
Phone number
website http://www.citg. tudelft.nl/en/ about-faculty/ departments/ departmentof-hydraulicengineering/ sections/riversports-waterwaysand-dredgingworks/staff/ mosselman-e/ http://www.citg. tudelft.nl/en/ about-faculty/ departments/ structuralengineering/ sections/integraldesign-andmanagement/ academic-chairs/ engineeringassetmanagement/ staff/drir-ga-vannederveen/ http://www.citg. tudelft.nl/en/ about-faculty/ departments/ geoscienceengineering/ sections/geoengineering/ staff/academicstaff/dr-ir-wbroere/ https:// shocksafenepal. wordpress.com/
77
Appendix B: B1: AnnexII. Waste hazard ranking tool
Shock Safe Nepal
Annex II. Waste hazard ranking tool This table presents typical disaster waste streams with corresponding possible hazards and respective priorities for the emergency and early recovery phases.
Waste stream
Is it old waste, e.g. more than one week?
Is the waste close to residential areas?
Is the waste close to streams, rivers or other water sources?
Food waste Packaging materials Excreta Wastes from relief supplies Concrete/bricks Household furnishings and belongings Other wastes such as plastics, cardboard, paper Timber Cables, etc. Soils and sediments Bulky items Waste with potential hazardous properties Hydrocarbons such as oil and fuel Paint, varnishes and solvents Pesticides and fertilizers Household cleaning products Medical waste in debris Healthcare risk waste Other potential infectious waste Household wastes Camp waste UN/military/NGO waste Commercial wastes Industrial wastes Unexploded ordnance (UXO) Landmines and ammunition within the debris Military vehicles Phosphorus and other weapon contamination Phosphorus and other weapon contaminates
High priority
78
Medium priority
Low priority
Appendices
79
Appendix B: B2: AnnexIII. Waste-handling matrix
Shock Safe Nepal
Annex III. Waste-handling matrix This matrix lists typical post-disaster waste streams and corresponding possible handling and management options for both the emergency phase (the first 8 weeks of disaster response) and the early recovery phase (2-6 months following the emergency phase). Waste stream
Cash for work
Transportation options
Disposal options
Recycling
Reuse
Not in Emergency Phase
No
Disposal at temporary site for future recycling if uncontaminated debris. Otherwise disposal at dumpsite/ landfill to be used as cover material
Attempt to store for future recycling. If not possible, then limited options for recycling in emergency phase
Can extract bricks, steel etc. for reuse
Mixed debris disposal at dumpsite/landfill
Not in emergency phase
Not in emergency phase
If separated, reuse. Otherwise dispose at dumpsite/landfill
Possible to separate timber for heating, cooking, shelter
Can extract for heating, cooking, shelter
Mixed debris disposal at dumpsite/landfill
Not in emergency phase
No
Waste from IDP camps and shelters Food waste Packaging materials
Excreta
Waste from relief supplies
Manual collection possible
Wheel barrow offload into skip for truck haulage
Disposal at dumpsite or landfill under controlled management
Manual collection not possible, use mechanical means where possible
Use appropriate trucks if removal is required
Disposal at sanitary dumpsite/landfill under controlled management
Manual collection possible
Wheel barrow offload into skip for truck haulage
Disposal at dumpsite or landfill under controlled management
Debris
Concrete/bricks
Household furnishings and belongings
Manual collection possible
Other wastes such plastics, cardboard, paper
80
Timber
Manual sorting possible
Cables etc.
Manual sorting possible
Soils and sediments
Mechanical means are often most appropriate but can use manual
Bulky items
Mechanical means most appropriate
Wheel barrow or excavator/ bulldozer offload into truck for haulage
Appendices
Waste stream
Cash for work
Transportation options
Disposal options
Recycling
Reuse
Dispose at sanitary landfill under controlled management. If no controlled disposal available, store until sanitary landfill available.
No
No
Hazardous materials and substances Heavy metal contaminated materials Hydrocarbons such as oil and fuel Paint, varnishes and solvents Pesticides and fertilizers
Manual collection possible but with PPE
Household cleaning products
Put in proper drums, bins or other container before loading onto trucks for haulage
Medical waste in the debris Healthcare risk waste
Healthcare waste (from clinics and hospitals - not considered as risk waste) Other potential infectious waste Household wastes Camp waste
Manual collection possible but with PPE
Put in proper drums, bins or other container before loading onto trucks for haulage
Dispose at sanitary landfill under controlled management. If no controlled disposal available, store until sanitary landfill available.
No
No
Excavator/bulldozer offload into truck for haulage
If hazardous, dispose of at sanitary dumpsite/landfill. Otherwise it can be disposed of at controlled dumpsite/ landfill
No
No
Under controlled measures by specialists
N/A
N/A
N/A
UN/Military/NGO waste
Commercial and industrial waste Commercial waste
Industrial waste
Mechanical means most appropriate, can use manual
In post-conflict areas Unexploded Ordnance (UXO) Landmines and ammunition within the debris Military vehicles
Handling by specialists. Incorporate SOPs for work where these may be encountered
Phosphorus and other weapon contaminates
81
82
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Appendix C: MCA C1: 0-Scenario Shock Safe Nepal
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Appendix C: MCA C2: More remote scenario Appendices
83
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Appendix C: MCA C3: No subsidy scenario Shock Safe Nepal
7HFKQLFDO
2
Environmental
Recyclable
3
2
Self-sustainability
2
Possibilities
Utilities
2
3
Elements
Protection
Impact
3
Workspace
Functional
Re-usability
3
6XVWDLQDEOH
1
Stories
Building
Expandability
)XQFWLRQDO
3
3
Use of local recources
Embedding
3
Adaptability
3
3
Construction time
Transport
3
Labourforce
Construction investment
3
Experience
3
Ease of learing
4
3
Maintainability
Use of local materials
3
Lifespan
3
3
Thermal capacity
Availibility
2
Openings
3
3
Foundation
3
2
Possibility to improve
Initial quality
3
Performance
Processing quality
3
Architectural
6RFLDO FXOWXUDO
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2
Redundancy
Building code
values
(stone) masonry
Minimum Low strength
Social / cultural
Local economy
Financial
Time
Labour
Material
Complexity
Construction
Climate
Sensitivity to surface
Seismic Performance Standard
Building components
&DWHJRU\
3
4
5
2
3
3
2
2
5
3
5
5
5
3
4
5
4
5
3
5
3
3
5
3
3
3
5
1
4
2
(brick) masonry
Low strength
3
4
4
2
3
3
2
2
5
4
3
3
3
3
4
5
3
4
4
5
3
3
5
3
3
3
5
1
4
2
cement mortar
Stone masonry in
4
3
4
3
4
3
2
2
5
5
4
3
3
3
4
5
3
5
4
5
3
3
4
4
3
3
4
3
5
3
cement mortar
Brick masonry in
4
2
2
4
5
4
2
3
5
5
2
2
2
3
4
5
2
3
4
5
3
3
5
4
4
3
5
3
5
4
masonry
Confined
5
3
2
4
4
3
2
5
4
4
1
2
3
3
3
3
2
3
3
4
2
3
4
4
2
3
3
4
5
4
brick masonry
Hollow concrete
4
2
1
5
4
3
3
5
3
4
2
3
3
4
4
4
2
2
5
5
4
4
3
3
3
3
5
4
5
4
Concrete
Cement
3
3
2
5
4
5
4
5
3
5
2
2
2
3
4
3
1
3
3
5
2
2
4
3
5
3
2
3
5
3
shear wall
3
1
1
5
5
4
3
5
3
5
2
2
2
3
4
2
1
1
4
4
1
2
4
3
4
3
2
5
5
4
construction
Concrete in-situ Timber
4
4
5
3
3
4
5
2
2
3
3
4
3
4
3
4
4
3
4
3
3
3
4
3
5
4
3
4
5
3
Adobe
4
5
4
4
3
3
3
2
5
3
5
5
5
3
3
3
5
5
3
4
3
4
4
4
2
3
5
1
3
2
Appendix C: MCA C4: Solution space Appendices
85
Appendix C5-24: MCA sheets per building method: C5:
Adobe Introduction This building method is common for low-income rural populations. The Adobe building method uses building materials such as earth, unstabilized mud-like blocks or sun-dried bricks. This building method is one of the earliest building methods in the world, dating back to 8000B.C. {Houben and Guillard 1994}. The typical building consists of a strip footing foundation, adobe material walls and floors spanned with wood joists. The roof is usually clad with clay tiles or corrugated sheet metal. {Blondet & Villa Garcia} Category
Description
Building components
Technical Adobe buildings exist of (strip-footing) foundations, load-bearing walls and varying floor- and roof
Value
systems. The heavy structures demands a firm soil as a base and concrete or stone foundation. The sun dried adobe blocks are used for both walls and roofs. The thickness of walls is limited by the thickness to height ratio of 1:8 by building codes 204:1994. Floors are mostly spanned with
Redundancy
2
Building code
3
Performance
1
Possibility to improve
3
Foundation
3
Openings
2
Thermal capacity
4
Lifespan
4
strenght brick masonry. The simple construction method is mostly self-made, simple. This method is typically non-
Maintainability
3
engineered. {Blondet & Villa Garcia}
Ease of learing
3
Initial quality
4
Processing quality
3
Availability
5
wood joists (or locally found tree trunks). The roof is clad with corrugated sheet metal clay tiles {Blondet & Villa Garcia}. The roofs can also be adobe domes or cylindrical. The load bearing walls usually have average redundancy and is comparable to low strenght brick masonry. This building method is in the building code with thumbrules and limitations on design. Seismic Performance
Traditional adobe buildings perform poor seismic behavior, causing loss in lives and property. The
Standard
earthen walls are the main seismic resistant elements; traditional structures do not have additional systems to restrain lateral loads The heavy walls generate high seismic forces. The low-strength and brittle wall experience severe cracking under seismic loads. Further seismic vulnerability is caused by insufficient connection between building elements (roof, wall separation of walls disintegration of walls." The seismic performance can be significantly improved with reinforcement of the walls. Vertical wooden posts and horizontal wooden elements embedded in walls are the expected key earthquake resistant elements in these buildings. There are succes stories of Adobe with geomesh for more (EERI)"
Sensitivity to surface
The size of the foundation is both determined by the dead weight of the structure as by the soil type. When choosing the appropriate building method, only the dead weight of the structure will be taken into account. Adobe requires a foundation comparable to brick masonry, and when the soil is beneficial the foundation as stated might even be overdimentioned.
Climate
The window openings should be limited and well spaced. The length between openings is limited to 1.2 m by the building code. The thick wall (0,25 - 0,8 m) provides thermal mass and excellent insulation and acoustic properties. The thickness of the wall will vary per climatic region {Blondet & Villa Garcia}. Walls are vulnerable to moisture; â&#x20AC;&#x2DC;damp rising from the ground, penetration of rainwater into the wall from a leaking roof and splashing of water during rainâ&#x20AC;&#x2122;, as stated in building code 204:1994.
Construction
Measures should be adopted to protect the mud/ earthen walls. Lifespan of Adobe structures can be very long when maintained correctly and sufficiently and when not exposed to extreme events(force majeure). For some building a 2-inch straw reinforced mud cover protects the wall against the weather. Every 4 to 6 years this layer has to be replaced. The structural elements require often periodic maintenance. The performance of maintenance is very easy and doen no requrie workmanship and little to no resources. The availability of the structure during maintenance is similar to low
Complexity
Material
Resources Adobe is a building material made of earth, sun-dried blocks. The wall strength dependent on the local soil quality. The right proportion of clay is essential for the performance of adobe blocks; enough is needed to bond the dry earth material, whereas excessive clay amount can cause cracking due to shrinkage while drying {Blondet & Villa Garcia}. When the right proportion of clay is available this can be a low-cost, readily available construction material.
Use of local materials
86
5
C6: Bamboo
Appendices
%DPERR ,QWURGXFWLRQ Bamboo is found in several forms in the construction practice in Nepal {Pokhrel}. It can be used as building material in combination with other materials. Floor or roof systems, or as an reinforcement for methods such as adobe or stone. Bamboo can be used practically for the majority of the housing components (walls, floors, roof, doors, windows, and stairs) but in practise is most common in the Terai region as building method and only as scaffolding in other parts of Nepal. &DWHJRU\
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Building components
7HFKQLFDO Key building elements are: (individual column footings) foundation, vertical bamboo culm
Value
members set in concrete footing, varying wall infill, varying floor systems, bamboo rafters or truss, purlins. Wall infill could be executed as a grid of split bamboo/ weaving bamboo strips
Redundancy
3
Building code
4
Performance
4
Possibility to improve
2
Foundation Openings Thermal capacity
4 5 2
Lifespan
2
Maintainability
2
Ease of learing
2
Initial quality
2
Processing quality
3
Availibility
4
plastered with cement, clay or mud. The redundancy is average to good when more colomns are used for the structural frame. Seismic Performance
Bamboo has a very high strength-to-weight ratio {Lakkad, 1981}. This is favorable for earthquake
Standard
construction. Itâ&#x20AC;&#x2122;s compressive strength outperforms wood, brick and concrete, and peers with steel in tensile strength (Rottke, 2002). Designs are made in America which are earthquakeresistant and verified. These frames cover horizontal and verticle stability, small improvements can be made with the
Size of foundation
addition of extra structural elements. This building method is relatively light weighted. The foundation as stated in the NBC is most likely over dimensioned, assuming the the soil on which the building is build meets the requirements of the NBC.
Climate
The light bamboo frame structure allows for flexible location of window openings due to the
Construction
framed construction. Bamboo structures are extremely susceptible to moisture and decay by insects, significantly limiting its life span. Protection can be provided by means of roof overhangs, drainage gutters, raised footings. There are also several ways to treat the bamboo. Treatment and design of bamboo construction largely influences the life span. The lifespan of natural bamboo is maximum 36 months, the development on threatment methods is ongoing but since the results are not visible yet the natural lifespan is considered. (National building code of India, 2005) Bamboo has high maintenance and treatment requirements
Complexity
The firm Abari has developed a promising method for bamboo treatment (Abari) Bamboo is widely used in Nepal as scaffolding and it is therefore an important material in the construction industry of Nepal. Complex connections, natural exentricity, and inhomogeneous material property makes it a very technical material. International standards for bamboo as a construction material and Nepal national building codes for Bamboo are lacking.
Material
5HVRXUFHV Matured bamboo should be used with a minimum of 3 years old. Bamboo needs to be treated properly, otherwise the material is highly vulnerable to decay by fungus and termite attacks. The natural building material does not come in an uniform shape, size or age. Processing into building panels would evade disadvantages such as uniformity and vulnerability to decay. Bamboo is one of the fastest growing plant species, and it grows on poor soil. It matures within 3
Labour
years. Bamboo is widely available in the southern part of Nepal {Habitat for Humanity, 2007}.
Use of local materials
4
Due to the trait that bamboo is a light weight material it can easily be executed by a small team of
Experience
2
Labourforce
3
Construction time
5
people (5-10). The cutting of the bamboo can be done by one person and the carrying to location by 2 or 3 depending on the size. The experience required to build with bamboo is not available in most parts of Nepal. Time
Bamboo construction allows for quick assembly due to its light weight and assembly with simple tools.
Financial
)HDVLELOLW\ The ranking is based on price indications and reference countries
Construction investment
4
Transport Use of local
4
recources
4
Bamboo grows in many parts of Nepal, but the quality differs per specie and therefore per Local economy
location. Promotion of bamboo construction could stimulate bamboo farming and thereby the local economy. Farmers and agracultural land is commonly seen in the area.
87
C7: Brick masonry in cement mortar
Shock Safe Nepal
%ULFN PDVRQU\ LQ FHPHQW PRUWDU ,QWURGXFWLRQ This building style is similar to brick masonry and mostly found the villages and towns of the Kathmandu Valley. The brick masonry is held together with cement instead of mud mortar to construct load bearing walls. The walls usually exist out of multiple layers of brick. &DWHJRU\
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Building components
7HFKQLFDO Typical elements are foundations, load bearing brick walls, timber window frames, and varying roof/flooring systems. The walls are composed of two wythes and space between is frequently
Value
Redundancy
4
Building code
5
Performance
3
Possibility to improve light roofs systems are preferred. Soil slopes of 20° maximum (1:3, Vertical : Horizontal) are stable suitable for construction. In case
5
filled with mud, small stones and pieces of rubble {Bothara & Brzev}. The load bearing walls usually have above average redundancy. This building type is included in the BC. Seismic Performance
The materials used, the quality of the mortar and workmanship, and the pattern in which the
Standard
units are assembled can significantly affect the durability of the overall masonry construction. Sufficient bonding between mortar and bricks is needed to resist shear cracking (D’Ayala). Seismic performance is influenced by the bond between mortar and bricksconnection between wall wythesconnection between building elements (connections between walls, corners and junctions, and between walls and floors, roofs) {D’ayala} The structural integrity and seismic resistance can be strengthened by means of vertical and horizontal reinforcement (timber, bamboo, reinforced concrete). Refer to chapter on masonry reinforcement. Stiff diaphragms such as concrete slabs are favored above flexible diaphragms and
Sensitivity to surface
of proper retaining walls, steeper slopes are allowed {DUDBC, 1994}. Climate
Foundation
3
Openings
4
Thermal capacity
4
Lifespan
5
Maintainability
3
Ease of learing
3
Initial quality
5
Processing quality
4
Availibility
3
Wall openings should be as small and as centrally located as practiable, the limits on opening size are: total width of openings should be less than 0,3 of the total width of the wall. Openings should preferably be at the same level, for the continuation of lintels. Ventilators shall be 450x450mm or smaller {DUDBC, 1994}
Construction
Masonry structures held together with lime mortar can be highly durable, with an extremely high potential lifespan of more than 500 years, if well constructed and maintained and if not damaged or destructed by force majeure events {J.Morton, 1990}. On the other hand the functional lifespan is persumed to be shorter. The stone walls need limited maintenance when constructed in the right manner only regular check for cracks is needed. Timber elements are vulnerable to rotting due to moisture; therefore need regular checking and maintenance. The maintainability is good due to the fact that structural elements are reachable with some effort and maintenance does not necessarily require workmanship. The building is available during limited structural maintenance. The cement bonding increases the difficulty due to the effort required to remove specific bricks.
Complexity
This construction type is incorporated in the building code (Nepal National Building code NBC 109 : 1994 Unreinforced masonry); the codes specify substantial constraints on unreinforced
Material
masonry construction to improve seismic resistance {DÁyala}. 5HVRXUFHV Building blocks bricks. Bricks are mainly of sufficient quality, having a crushing strength of above 7.5 N/mm2 (NSET, 2009). The bonding material cement is executed as 1:6 cement sand mortar. The major factors influencing the strength of the bricks are the purity of the clay and the firing temperature. Mortars are subject to greater variation, but the basic materials used in mortar mixes are sand, water, and one or more of the bonding agents, mud, clay, or cement, depending on local availability. The proportion of bonding agent/s to sand determines the compressive and bonding strength of the mortar. {D’ayala} The bricks are made of local clay, good quality clay is available seen the fact that the Kathmandu valley used to be a lake. Over-burnt, Under-burnt and deformed bricks are not suitable for good construction. The availability of baked brick is high due to local production and the reliability of availability is high given that baked bricks are produceable all year through.
Labour
Masonry is labour-intensive, not suitable for mechanization or prefabrication. Nepal has a lot of expience with masonry.
88
Use of local materials
2
Experience
5
Labourforce
4
C8: CEB
Appendices
&RPSUHVVHG HDUWK EULFNV &(%
,QWURGXFWLRQ The soil, raw or stabilized, for a compressed earth block is slightly moistened, poured into a steel press (with or without stabiliser) and then compressed either with a manual or motorized press. CEB can be compressed in many different shapes and sizes. Compressed earth blocks can be stabilised or not. But most of the times, they are stabilized with cement or lime called Compressed Stabilised Earth Blocks (CSEB). Mostly a steel manual press is used to compress the soil into bricks. &DWHJRU\
'HVFULSWLRQ
Building components
7HFKQLFDO Not every soil is suitable for earth construction and CSEB in particular. Topsoil and organic soils
9DOXH
must not be used. Cement stabilisation will be better for sandy soils. Lime stabilisation will be better suited for clayey soils. The bricks can be plain, hollow, interlocking bricks. The plain ones will be laid with a thick mortar (1 to 1.5 cm), the hollow ones will be laid with a thin mortar (0.5
Redundancy
3
Building code
3
Performance
3
Possibility to improve
5
Foundation
3
Openings
3
Thermal capacity
3
Lifespan
5
Maintainability
4
Ease of learing
3
Initial quality
4
Processing quality
3
Availibility
4
to 1 cm), the interlocking blocks will require a thin mortar (0.5 cm), very special details and are meant for earthquake resitance. Seismic Performance Standard
The seismic performance of CEB is not proven. The bricks can be masoned with mud mortar or cement mortar. The compressive strength of CEB is comparable to adobe. The bigger the brick, the weaker it will be. The bricks can be stabilised with a chemical binder such as Portland cement, they are called compressed stabilized earth block (CSEB) or stabilized earth block (SEB). The bricks can also be enforced by fibres. Just like regular masonry vertical and horizontal tensile elements can be added to increase seismic performance.
Size foundation
The size of the foundation is both determined by the dead weight of the structure as by the soil type. When choosing the appropreate building method, only the dead weight of the structure will be taken into account. These building methods require a foundation as stated in the NBC, and when the soil is beneficial the foundation as stated might even be overdimentioned.
Climate
The building method is offers flexibility for openings however some limitations are applicible comparable to brick masonry. The thick wall (0,25 - 0,8 m) provides thermal mass and excellent insulation and acoustic properties. Walls are vulnerable to moisture measures should be adopted to protect the mud/
Construction
earthen walls. CEB can be highly durable, with a long lifespan. Well-designed CSEB houses can withstand, with a minimum of maintenance, heavy rains, snowfall or frost without being damaged. The strength and durability has been proven since half a century. The maintainability of CEB is comparable to low strenght brick or stone masonry and considered
Complexity
to be relativly easily maintainable. It is a simple technology requiring semi skills, easy to get. Simple villagers will be able to learn how to do it in few weeks. Efficient training centre will transfer the technology in a week time.
Material
5HVRXUFHV Identifying the properties of a soil is essential to perform, at the end, good quality products. Some simple sensitive analysis can be performed after a short training. Cement stabilisation will be better for sandy soils. Lime stabilisation will be better suited for clayey soils. The bigger it is, the weaker the block will be. a large area will require great compaction energy. Bad quality products can come from production by untrained teams, or un-adapted production equipment. Produced locally by semi skilled people, no need import from far away expensive materials or transport over long distances heavy and costly building materials.
Labour
Earth construction is a labour-intensive technology and it is an easily adaptable and transferable
Use of local materials
4
Experience
4
Labourforce Construction time
4 3
technology. Equipment for CSEB is available from manual to motorized tools ranging from village to semi industry scale. The selection of the equipment is crucial, but once done properly, it will be easy to use the most adapted equipment for each case. Time
Comparable to brick masonry )HDVLELOLW\
89
C9: Concrete in-situ shear wall
Shock Safe Nepal
&RQFUHWH LQ VLWX VKHDU ZDOO ,QWURGXFWLRQ Buildings made with cast-in-situ reinforced concrete walls have been practiced since 1960. This type can be widely found in urban regions of seismic hazard areas such as Canada, Chile, Romania, Turkey, Columbia and the republics of the former soviet Union {Moroni}. Shear walls are usually placed along both length and width of buildings, they carry earthquake loads downwards to the foundation. Shear walls can be executed in several ways such as, all shear wall, tunnel or limited shear wall. &DWHJRU\
'HVFULSWLRQ
Building components
7HFKQLFDO RCC construction with shear walls, often combined with a reinforced concrete strip or mat
9DOXH
foundation. The basic structure is consisting of RCC frame with reinforced concrete load-bearing walls (varying from 140 mm to 500 mm) to make the constructing resistant to lateral and transversal loads. Floors are reinforced concrete slabs and less often precast hollow-core slabs
Redundancy
4
Building code
5
Performance
5
Possibility to improve
2
Size of foundation
3
Openings
4
Thermal capacity
3
Lifespan
4
Maintainability
2
Ease of learing
1
Initial quality
4
Processing quality
4
Availability
1
{Moroni}. The redundacy is good due to the use of shear walls. Incorporated in the building code
Seismic Performance
Main lateral load bearing elements are the reinforced shear walls, providing resistance to both
Standard
gravity and horizontal loads. These shear walls need to be provided in the two principle directions. The seismic resistance is considered adequate, due to very good performance in previous earthquakes in Chile, Turkey {Moroni}. The principle of a shear wall is similar to confined masonry, the walls work to distribute the seismic loads, reinforced concrete shear walls are graded as more seismic resistant than confined masonry. (Build change, n.d.) Seismic vulnerability can be caused by inadequate construction quality, inadequate amount and detailing of wall reinforcement, soft story mechanisms, reduced wall density- torsional effects. Seismic performance can be improved by good construction practice and detailing. Strategic placement of shear walls, providing the largest arm to withstand torsional forces.
Sensitivity to surface
The size of the foundation is both determined by the dead weight of the structure as by the soil type. When choosing the appropreate building method, only the dead weight of the structure will be taken into account. This building method requires a foundation similar to RCC structure, and when the soil is beneficial the foundation as stated will probably even be overdimentioned.
Climate
Window openings are quite flexible due to the frame construction. The frame however must be designed on lateral load. Often it is only for gravitational loads and then the structure is also dependent on the masonry infill; decreasing flexibility of window openings. It is not recommended to have openings in shear walls, openings can be provided but their size must be small to ensure the least interruption to force flow through the walls. (IITK, n.d.) Insulation and acoustic properties depend mostly on type of infill. When bricks see brick masonry
Construction
When constructed in the right manner reinforced concrete walls have a long life span. Life span of RC frame construction is lower than masonry building methods. Estimated lifespans are 30-100 years RCC shear wall buildings require little maintenance, because the structural elements consist of and are protected by the concrete. However when the concrete is damaged or is in need of maintenance the work requires workmanship and much resources such as concrete injections,
Complexity
rebar replacements. Uncommon in settlement typology B, C, D, E. In the city core (A) cast in-situ concrete walls are used. The technique is used in the hydropower industry, therefore the technique is present. Cast in-situ walls are also seen in houses constructed on the downhill side of the road. The wall is the boundary between house and the hill. Non-engineered building practice forms a risk, since RC frame construction requires sufficient level of â&#x20AC;&#x2DC;technology, expertise, and workmanship, particularly in the field during constructionâ&#x20AC;&#x2122; (Yakut).
5HVRXUFHV Material
The concrete is made of a mixture of sand, cement and water. The concrete is strengthened by steel reinforcement. The infill walls are often made of baked bricks, although block and stone infills are also seen. In rural villages, combinations of stone and brick infill can be found. Availability of concrete can be considered high due to local cement factories in Nepal and the large availability of cement in India and China. The reliability can be very good when road conditions and political situations are good, but during monsoon season many roads are damaged
90
C10: ConďŹ ned masonry
Appendices
&RQILQHG PDVRQU\ ,QWURGXFWLRQ This building type is found in urban and rural areas highly seismic areas, for example Chile. This type is practiced in most countries since the last 30-35 years, the building method gets its strength from tie-columns which are cast-in-place after the masonry wall construction has been completed. Tie-columns and tie-beams work as ties that provide reinforcement to the structure. Reinforcement steel is needed to provide this tie function between the columns and beams. {Rodriquez}. &DWHJRU\
'HVFULSWLRQ
Building components
7HFKQLFDO RCC construction with brick masonry shear walls, often combined with a reinforced concrete
9DOXH
strip or mat foundation. The basic structure is consisting of unreinforced masonry load-bearing walls strengthened by a confinement with reinforced concrete tie-columns and -beams, mostly cast-in-place concrete floors and roofs. Also timber roofs are seen, combined with the RC tie-
Redundancy
4
Building code
5
Performance
4
Possibility to improve
3
Foundation
3
Openings
2
Thermal capacity
4
Lifespan
4
Maintainability
3
Ease of learing
2
Initial quality
4
Processing quality
3
beams.The walls can be masoned with several types of building block. The redundacy is good due to the use of shear walls. The method is incorporated in the Building Code Seismic Performance
The seismic behavior is considered satisfactory, if it is well constructed and if materials are used
Standard
with sufficient quality {Rodriquez}. In the confined masonry method the walls work as load bearing walls and not only als infills, with this the walls are able to withstand horizontal loads. When the wall is able to withstand load it works as a shear wall which is proven to work during earthquakes. (build change, n.d.) The seismic performance of confined masonry is total depend on the quality of the workmanship. The columns, beams and walls should be bond in the right way. Vulnerability is increased when structures are built without adequate roof-to-wall connection or without adequate wall-to-wall connections. Seismic performance can be improved by adding concrete reinforced bands on different height within a storey and by using load bearing shear walls as inner walls , providing the largest arm to withstand torsional forces.
Sensitivity to surface
The size of the foundation is both determined by the dead weight of the structure as by the soil type. When choosing the appropreate building method, only the dead weight of the structure will be taken into account. These building methods require a foundation as stated in the NBC, and when the soil is beneficial the foundation as stated will probably even be overdimentioned.
Climate
Window openings are limited due to the brick masonry load bearing walls. The integrity of the structure is dependent on the masonry infill, decreasing flexibility in possibilities for window openings. It is not recommended to have openings in the confined walls, openings can be provided but their size must be small to ensure the least interruption to force flow through the walls. Use of brick masonry can increase the thermal mass of a building and its fire resistance.
Construction
The life span of a confined masonry building is similar to a RCC frame building, estimated lifespans are 30-100 years The building does not require much maintenance, the maintenance that is done does not neccearily require workmanship and can be done by the owner, there is little or no maintenance done to the exterior wall. (world housing encyclopedia, 2010). For more structural maintenance,
Complexity
masons or more experienced workers are needed. First the brick walls are constructed stand-alone, after these are finished the concrete columns combine the walls into a building. This method increases the complexity since the stand-alone walls need to be constructed aligned to the columns. Especially the connection of the beams with the columns requires quality workmanship since this is critical to the construction. The building method requires skilled masons. (build change, n.d.)
Material
5HVRXUFHV Brick: In confined masonry the brick wall works with the columns and ties to increase the strength of the building. Therefore the bricks need to be baked to withstand the load bearing capacity. Bricks are mainly of sufficient quality, having a crushing strength of above 7.5 N/mm2 (NSET, 2009). The stones are mostly coursed and dressed into rectangular shapes. The bonding material cement is executed as 1:6 cement sand mortar. The availability of baked brick is high due to local production and the reliability of availability is high given that baked bricks are produceable
91
C11: Dhaji Dewari
Shock Safe Nepal
'KDMML 'HZDUL ,QWURGXFWLRQ Traditional building method in the western himalayas, mostly found in both Pakistan and India. Similar building methods can be found in parts of Europe and Central America {Hicyilmaz, Bothara & Stephenson, 2014}. It is largely adopted as a rebuilding method after the 2005 Kashmir earthquake. The building method exists of an extensively braced timber frame filled with either stone or brick masonry held together with mud mortar. The method is generally laid on shallow foundations stone masonry {Hicyilmaz, Bothara & Stephenson, 2014}. Flooring is done with timber beams which span wall to wall, timber floor boards on top of the beams are overlain with a layer of clay/ mud. Roof are either flat, timber logs with a mud layer pitched timber constructions with metal roof sheeting. &DWHJRU\
'HVFULSWLRQ
Building components
7HFKQLFDO The method is generally laid on shallow foundations stone masonry {Hicyilmaz, Bothara &
Value
Stephenson, 2014}. Flooring is done with timber beams which span wall to wall, timber floor boards on top of the beams are overlain with a layer of clay/ mud. Roof are either flat, timber logs with a mud layer or pitched timber constructions with metal roof sheeting. Walls consist of a
Redundancy
4
Building code
3
Performance
4
Possibility to improve
2
Foundation
3
Openings Thermal capacity
2 3
Lifespan
4
Maintainability
3
Ease of learing
3
Initial quality
3
Processing quality
4
Availibility
3
timber frame contruction with many braces and infill with irregular shaped rocks. The redundancy is good due to the frame construction and the many braces that distribute the loads evenly. This construction method is not in the building code but acceptable according to general structural Seismic Performance
principles. Timber framing combined with the masonry infill provides the main lateral load resisting system.
Standard
The timber framing acts as a stable confinement, and contributes to the limitation of out-of-plane demands on masonry infill (Hicyilmaz, Bothara & Stephenson, 2012). The low-strength mud allows yielding at relatively small lateral loads, and provides energy dissipation by means of friction between infill pieces. Building method is validated by state of the art engineering analysis {Hicyilmaz, 2011}, and is considered to provide satisfactory earthquake resistance, having more ductility than confined
Sensitivity to surface
masonry. Dhajji Dewari structures are typically built on flat terrain {Hicyilmaz, Bothara & Stephenson, 2014}. This can be accounted to the braces that have to connect to a horizontal surface or optimal load distribution.
Climate
Timber framing combined with the masonry infill provides the main lateral load resisting system. The timber framing acts as a stable confinement, and contributes to the limitation of out-of-plane demands on masonry infill (Hicyilmaz, Bothara & Stephenson, 2012). The low-strength mud allows yielding at relatively small lateral loads, and provides energy dissipation by means of friction between infill pieces. Allows for suitable climate controle
Construction The timber elements are vulnerable to deteriation however with sufficient maintenance and construction this can be a durable construction method {Hicyilmaz, Bothara & Stephenson, 2014}. Due to the large use of timber, maintenance demand is quite high. Lack of maintenance can undermine inherent seismic resistance and general structural safety. The execution of maintenance is relatively easy due to the ease of reaching structural elements. The maintenance does not necesarrily require workmanship and some resources due to the many timber elements. The availability of the structure during maintenance is good due to the high redundancy of Complexity
structural elements. This method is not common or familiar in the affected area of Nepal(2015). However in India the method is known by local builders, included in the building code and regarded as a straightforward construction technology, easy to build from local materials {Hicyilmaz, 2011}. Making transferring of knowledge from Indian builders to Nepali builders realistic and possible.
Material
5HVRXUFHV Materials used are timber for the framing, stone or brick masonry infill and local mud mortar. Materials for infill are locally available in rural and mountainous regions. The feasibility of the building method is largely dependent on the availability and affordability of wood, which is limitid by Nepali anti-deforestation programs.
Use of local Labour
The construction with Dhajji Dewari is commonly used in South Asia (http://www.worldhousing net/tutorials/other/dhajji-dewari) However this method is not very common in Nepal
92
materials
4
Experience
3
C12: Earthbags
Appendices
(DUWKEDJV ,QWURGXFWLRQ The use of piled sandbags for the creation of walls is a technique that has been used for decades in flood protection and by the military in creating strong barriers. However the application of using sturdy bags filled with local materials for use in the construction sector is fairly new. {http://www.earthbagbuilding.com/} In building with earthbags different kind of methods are developed such as regular earthbags, super earthbags, hyper earthbags and sandsbags. Earthbags have been used in many countries to develop cheap and easy to construct houses. They can incorporate barbed wire and/or rebar for the strengthening of weak spots. &DWHJRU\
'HVFULSWLRQ
Building components
7HFKQLFDO Gravel filled bags or nets that are wider than the bag walls are used for foundation purposes.
9DOXH
Earth filled bags are used as load bearing walls, window frames and non structural walls held together with barbed wire to prevent shifting of bags and rebar for strengthening weak spots. Concrete lintels over doors and windows and a concrete bonding beam can be used for extra safety. An alternative is the use of frames which can be filled with the earthbags, reducing the
Redundancy
3
Building code
2
Performance
2
Possibility to improve
4
Foundation Openings Thermal capacity
4 3 4
Lifespan
3
Maintainability
4
Ease of learing
4
Initial quality
5
Processing quality
4
Availibility
4
Use of local materials
4
Experience
3
Labourforce
3
Construction time
3
need for concrete. The exterior of the structure should be covered. {earthbagstructures} The redundancy of the structure is comparable to masonry structures and is considered average. The earthbag structures are not incorporated in the Building Code and are doubtable to fit general structural principles. Seismic Performance
Owen Geiger has claimed that more than 50 Earth Bag structures in Nepal have survived the
Standard
earthquakes of 2015. {buildsimple} Filling the earthbags with Adobe is called Superadobe. This method has been proven to resist earthquakes with 8 on the richter scale {http://windriche.com/superadobe/advantages_and_disadvantages_of_earthbag_construction.htm}.
Sensitivity to surface
Several types of vertical and horizontal reinforcement methods are possible. Earthbag buildings are substantially heavier than bricks thus require a sturdy soil to be built on. The bags require a flat surface to be built on for good distribution of forces.
Climate
Earthbags allow for the making of openings of different sizes however with limitations, the sizes of
Construction
openings can be compared to that of low strenght brick masonry structures. Different sources claim different life spans, the fact that earthbags are only used recently make it difficult to give exact numbers on the lifespan. Logically it can be derived from the deteriaton rate of the poly bags that it can vary from decades to a century. Earth Bag structures are low maintenance, since there are no hidden structural members, the main structural components are made of earth and the interior is done as desired allowing for replacement when needed. The only difficulty is when rebar is used to connect bags vertically.
Complexity
Building with earthbags is relatively easy, except for some crucial guidelines which have to be followed. e.g. placement of bag, manner of sealing bag, manner of placing rebar/barbed wire, testing bags etc. The presence of one or multiple experts is required to ensure the structural elements. Unskilled workers can be used for stacking and preparing the bags. The buildings can be made with little to no electrical or advanced tools, decreasing complexity.
Material
5HVRXUFHV "Poly bags (strong, new or unexposed to sunlight), bags in can used in different shapes and sized, such as long bags, small bags or tube bags. Barbed wire for bounding the bags, Rebar for strengthening the weak points such as corners, Earth, crushed rock, moist soil, clay or similar filling, Plaster, mud or different material for exterior covering, Roofing can be done in a multitude of ways including traditional, optional: Cement for extra bonding seems between bags,Steel, bamboo, wood or other material usable for making frame," The availability and reliability of these materials is high because many are locally available, the poly bags can be imported from manufacturers in China. {http://chinawovenbag.com/}
Labour
The labour intensity of Earth Bag structures is low, work includes filling bags with soil, placement of bags, connecting the bags, plastering the structure. The disadvantage to building with Earth Bags is the physical strain caused by the weight of the bags especially above a certain height. The experience with building with earthbags is not very much present in Nepal.
Time
When performed by 2 unskilled laborers a small Earth Bag house can be constructed in 6 weeks, however final building time is very dependent on amount of people working, amount of experience, complexity of the structure and size of the structure (boek earthbags).
93
C13: Hollow concrete brick masonry
Shock Safe Nepal
+ROORZ FRQFUHWH EULFN PDVRQU\ ,QWURGXFWLRQ Hollow concrete blocks are used around the Kathmandu Valley and are popular in certain areas {Habitat Nepal}. The blocks are designed to have hollow compartments inside in order to reduce cost, the addition of these air pockets also makes the blocks fire resistant provides insulation. {Hornbostel, 1991} The blocks are held together by cement mortar and allow for incorporation of rebar and cement in the air pockets for additional strength. &DWHJRU\
'HVFULSWLRQ
Building components
7HFKQLFDO Typical elements are foundations, load bearing hollow concrete brick walls and varying
9DOXH
roof/flooring systems. The load bearing walls usually have above average redundancy. The bricks are available in numerous rectangular dimensions and specialy shaped corner blocks. The cement bricks are bound together with mortar and the cavities in the bricks can be used for filling with
Redundancy
4
Building code
5
Performance
4
Possibility to improve Foundation Openings Thermal capacity Lifespan
5 3 3 3 3
Maintainability
4
Ease of learing
4
Initial quality
5
Processing quality
5
Availibility
2
rebar and concrete for extra strength. This building type is included in the BC.
Seismic Performance
Structurally each concrete block wall behaves as as shear wall, reducing the vulnerability of the
Standard
structure. Due to the uniform distribution of reinforcement in both vertical and horizontal directions increased tensile resistance and ductile behaviour of the elements. (Ecologic, n.d.) Shake Table testing of the Indian University proved that the compressive strength of a hollow concrete brick wall is less than a brick masonry wall (Ahmad, 2013) The structural Integrity and seismic resistance can be strengthened by means of vertical and horizontal reinforcement (timber, bamboo, reinforced concrete). Stiff diaphragms such as concrete slabs are favored above flexible diaphragms. Hollow blocks can be reinforced with steel
Sensitivity to surface Climate Construction
to increase their seismic performance. {Global Shelter Cluster, 2014} Similar restrictions as normal masonry work Similar openings to brick masonry can be managed. A lifespan of 20+ years can be managed {Global Shelter Cluster, 2014} The amount and cost of maintenance of hollow concrete brick masonry is less than brick masonry because of efflorescence in brick masonry wall. (Ahmad, 2013) When plastered the CHB walls don't absorb much moisture decreasing the need for maintenance. {Global Shelter Cluster}
Complexity
Hollow concrete bricks are already used in Nepal, the blocks are locally produced and the method of masonry is similar to brick masonry.
Material
5HVRXUFHV Waste products like fly ash can be used in the production process of hollow concrete bricks. The masonry with blocks consumes less mortar than traditional masonry styles because of the limited volume of the joints. The blocks can be filled with concrete and steel rods for extra reinforcement. The availability of these materials is high and compareble to the availability of concrete, which can be considered high due to local cement factories in Nepal and the large availability of cement in India and China. The reliability can be very good when road conditions and political situations are good, but during monsoon season many roads are damaged and limit the flow of products coming from India and China.
Labour
Only semi-skilled labour is required for the construction with hollow concrete bricks and often the constructions built with hollow cement blocks are of simple nature, also reducing the labor
Time
required. The production and construction of concrete blocks is faster compared to brick masonry
Financial
buildings. Let alone by the less amount of actions needed to finish construction. )HDVLELOLW\ The ranking is based on price indications and reference countries
Use of local materials
2
Experience
4
Labourforce
4
Construction time
4
Construction investment Transport
Local economy
3 3
Because only semi-skilled labour is required for construction with hollow concrete bricks, a large part of the work force can be utilised. The bricks can also be locally produced and are not bound to a location, the cement however comes from outside the 50 km range.
Social/ cultural
Use of local recources
2
Adaptability
4
6RFLDO FXOWXUDO Buildings constructed with hollow concrete bricks are bound to the dimensions of the bricks, the walls can be plastered to allow the appropriate social/cultural aesthetics. The walls do not allow the placement of niches for religious attributes.
94
C14: Interlocking bricks
Appendices
,QWHUORFNLQJ EULFNV ,QWURGXFWLRQ Interlocking bricks are bricks that form a connection with each other without necessarily the addition of mortar. The blocks are shaped with projecting parts, which fit exactly into depressions in the blocks placed above, such that they are automatically aligned horizontally and vertically which makes bricklaying possible without special masonry skills. The row interlocking bricks directly on the foundation is done with cement and must be completely straight. On top of that bricks can be laid down. In the end the holes can be filled up with cement and steel barns for reinforcement. Interlocking bricks can be made locally and consist of a mixture of cement and soil. &DWHJRU\ 'HVFULSWLRQ Building components
9DOXH
7HFKQLFDO Typical elements are foundations, load bearing brick walls, timber window frames, and varying roof/flooring systems. The length of each Interlocking Brick is exactly double its width in order to achieve accurate alignment. For the construction of a building there is choice of bricks which can be used for different elements such as Walls, Window Frame, Concrete Joists, Concrete Floor
Redundancy
3
Building code
3
Performance
4
Possibility to improve
2
Foundation
3
Openings
3
Thermal capacity Lifespan
3 5
Maintainability
3
Ease of learing
3
Initial quality
4
Processing quality
3
Availibility
4
Pans or Stringers, Treads for staircases and Tiles for Roofing (http://www.unicef.org/education/files/Interlocking_Earth_Bricks_technology.pdf). The interlocking brick allows for average redundancy comparable to brick masonry. The method is not incorporated in the building code but is acceptable according to structural principles. Seismic Performance
The seismic performance of interlocking bricks is not proven however the shape of the bricks can
Standard
be seen as an effective level of bonding to create mechanical interlocking and resist shear-cracking (Dâ&#x20AC;&#x2122;Ayala, n.d.) Insertion of concrete with steel reinforcement through the holes of the blocks provide reinforcement to the building, increasing the wind and earthquake resistance.
Sensitivity to surface
The size of the foundation is both determined by the dead weight of the structure as by the soil type. When choosing the appropreate building method, only the dead weight of the structure will be taken into account. These building methods require a foundation as stated in the NBC, and when the soil is beneficial the foundation as stated might even be overdimentioned.
Climate
The building method is offers flexibility for openings however some limitations are applicible comparable to brick masonry. Even though the blocks are placed with the right precision, the joints are not entirely resistant to wind, rain and therefore heat penetration. Plastering is needed to provide protection against the elements. The use of certain ingredients in the creation of the interlocking brick can add to the
Construction
increase of thermal mass and its fire resistance. Interlocking bricks can be highly durable, with a long lifespan. Bricks with the correct ratio of cement are not vulnerable to rotting or breaking, therefore the need for maintenance is limited. However when the bricks are made more of adobe type of material the need for maintenance increases. For the different use of materials refer to the corresponding comparable building method. The maintainability of interlocking brick is comparable to low strenght brick or stone masonry and considered to be relativly easily
Complexity
maintainable. This method is already used in Nepal. Nevertheless it is not widely known and therefore not a lot of knowledge is available among the local masons however the use of interlocking bricks is
Material
claimed to be relatively easy when supervised by an expert. 5HVRXUFHV Based on raw materials there are various types of bricks: - Soil-cement bricks (cement-to-soil ratio is depending on the soil quality, lies between 1:6 and 1:10) - Concrete bricks (typically mixed in Cement-to-sand-to-gravel 1:5:3) - Rice Husk Ash - cement bricks (cement-to-RHA lies around 1:4) - Clay cement bricks. To improve the strength of a building reinforcement steel and cement mortar can be used. The flexibility of materials usable for making interlocking bricks makes the availability and reliability of materials very good. Soil and clay are readily available in many places and cement can be bought from local producers or be imported from India or China with the latter being less reliable due to dependence on political situation and road conditions.
Labour
Use of local materials
4
Experience
3
Labourforce
3
Construction time
4
Designed to reduce the need for skilled labor and maximize the use of the unskilled labor forceCertain amount of training is required to ensure that walls are properly aligned and no gaps are leftTraining needed in the production of blocks, mix proportions and moisture content. Also in producing uniform sized blocks.
Time
According to the Habitech Center Interlocking bricks have the ability to utilise a large workforce and the advantage of sequential actions shortens the construction time.
95
C15: Light Weight Steel Profile Building Systems
/LJKW :HLJKW 6WHHO 3URILOH %XLOGLQJ 6\VWHPV ,QWURGXFWLRQ This method is currently not widely used in Nepal but has been used in many disaster struck countries for rapid rebuilding. The building method makes use of steel plate rolls which can be bended into profiles on location, the profiles are easily connected by bolts and nuts, the walls can be filled in with any type of material from local to styrofoam. &DWHJRU\
'HVFULSWLRQ
Building components
7HFKQLFDO Light weight steel construction with steel braces are often combined with a reinforced concrete
Value
foundation. The basic structure is consisting of a lightweight steel braced frame that creates resistance to lateral and transversal loads. The main structure is made of steel profiles that are pressed by a machine on location. The main structure walls and floors can be filled in with any
Redundancy
5
Building code
3
Performance
4
Possibility to improve
2
Foundation Openings Thermal capacity
4 4 3
Lifespan
4
Maintainability
2
Ease of learing
1
Initial quality
4
Processing quality
4
Availibility
1
kind of material desired by the owner. The building method is not incorporated in the building code but the structural principles are accepted internationally thus incorporation can be a quick Seismic Performance
process. The Steel frame building systems claim to be earthquake resistant due to their lightweight
Standard
construction while providing great strength. Steel has a high ductility which is a favorable trait during an earthquake allowing for the building to withstand lateral and transversal loads. The performance during an earthquake can be increased by use of special moment resisting frames and different types of braces such the V-brace, inverted V-brace, X-brace, two storied Xbrace etc. A combination of the properties of steel and the possibilities to enhance the frame make steel frame buildings a good construction type for seismically active areas.{lecture by Michael D Engelhardt Michael D. Engelhardt University of Texas at Austin, Design of Seismic Design of SeismicResistant Steel Building Structures} However light weight steel profile building systems often already have many braces, the improvement during seismic activity is marginal.
Sensitivity to surface
This building method is relatively light weighted. The foundation as stated in the NBC is most likely over dimensioned, assuming the the soil on which the building is build meets the requirements of the NBC.
Climate
Openings in exterior walls are only limited by possible placement of braces.
Construction
According to manufacturers the lifespan is “long” and they offer a 50 year warranty on the steel frame The steel frame requires little maintenance, maintenance of this building type would be dependent of the choice of the frame filling materials. The execution of maintenance would be a relatively easy task requiring little workmanship and some resources. Maintenance is however specialized
Complexity
work. Building with steel profile building systems in rural areas is complex, the house owner would have to hire a construction worker with steel stucture experience. The designer of the house programmes the steel pressing machine to produce the frame components and provides the drawings with coded components. Trained workers assemble the frame by connecting the joints with nuts and bolts. The infilling of the house can be done as desired by the owner and only requires experts when using complex filling materials. The method is easily teachable to workers and requires the presence of a trainng center which can train workers but also train trainers.
Material
5HVRXUFHV The resources required for light weight steel profile buildings are rolls of steel plating, material for frame filling, roofing material, exterior covering material and mortars. None of these materials are available in rural Nepal, the steel products and wall infill can be imported but is hard to reach the village. The reliability can be less good due to dependence on road conditions and political situation for the import of steel. Use of local
Labour
materials
2
Experience
2
Labourforce
4
In rural areas heavy machinery like cranes are not available. Welding and bolting materials are also not commen. The work of steel profile building systems includes feeding the machine with steel, putting the frame components in place, bolting the components together and placing of interior, exterior and roof filling.
96
C16: Low strength (brick) masonry
Appendices
/RZ VWUHQJWK EULFN PDVRQU\ ,QWURGXFWLRQ This building style is very common in old villages and towns of the Kathmandu valley. The buildings tyĂŻcally consist of riverstone foundations, a combination of burned brick on the outer wall and sun dried brick masonry on the inner wall, the brick masonry is often held together with mud mortar. The he space between is frequently filled with mud, small stones and pieces of rubble The average low strength brick masonry house has a basic rectangular design. Within this category the traditional Newari building style can be classified. &DWHJRU\
'HVFULSWLRQ
Building components
7HFKQLFDO Typical elements are foundations, load bearing brick masonry walls, timber window frames, and
Value
varying roof/flooring systems. The heavy building method demands a sufficient foundation on a firm base {DUDBC, 2015). The walls are composed of two wythes, one baked, one sun dried brick. The space between is frequently filled with mud, small stones and pieces of rubble {Bothara
Redundancy
2
Building code
4
Performance
1
Possibility to improve
5
Foundation
3
Openings
3
Thermal capacity
3
Lifespan
5
Maintainability
3
Ease of learing
3
Initial quality
5
Processing quality
4
Availibility
4
& Brzev}. The load bearing walls usually have above average redundancy but the weakness of the mortar has a negative effect on this. The bonding in low strenght masonry increases the probability of partial colapse when part of the structure is damaged. This building type is included in the NBC with thumbrules and limitations. Seismic Performance
Buildings are mostly regular in plan and elevation (few cantilevers/ overhang). Load bearing brick
Standard
masonry walls provide the lateral load resisting system. Lighter structures will induce less seismic loads, and therefore less damage. Hence the wall thickness should be as thin as possible, with a minimum of 300 mm. The type and quality of the bond within the wall units contribute most to the integrity and strength of the walls. All the brick units should be properly laid in order to provide sufficient integrity {DUDBC, 2015). The heavy weight of bricks cause a high seismic vulnerability due to high inertia loads. Buildings lack adequate connections between building elements (for example side and front facade, floors and walls). The structural Integrity and seismic resistance can be strengthened by means of vertical and horizontal reinforcement (timber, bamboo, reinforced concrete). Stiff diaphragms such as concrete slabs are favored above flexible diaphragms. The out-of-plane capacity can be improved
Size of foundation
by adding of wall meshes (experimental techniques). The size of the foundation is both determined by the dead weight of the structure as by the soil type. When choosing the appropreate building method, only the dead weight of the structure will be taken into account. This building method requires a foundation as stated in the NBC, and when the soil is beneficial the foundation as stated might even be overdimentioned.
Climate
Ability for making openings with respect to daylight entrance, the size of wall openings is limited (15-25% of the wall). Traditional masonry is not dampproof, the ground floor is therefore exposed to the atmosphere. The wall can be plastered, but this is not considered good practice since the damp is stuck inside.
Construction
Brick masonry structures can have a long lifespan when maintained and not exposed to extreme events(force majeure). Timber elements are vulnerable to rotting due to moisture; therefore need regular checking and maintenance. The maintainability is good due to the fact that structural elements are reachable without much trouble and maintenance does not necessarily require workmanship. The building is
Complexity
available during most structural maintenance. This construction type is incorporated in the building code (Nepal National Building code NBC 203 : 2015 Low strength masonry). The know-how is mainly passed on informally {Parajuli, Bothara, & Upadhyay, 2015}, and skills vary per person. House-owners are mostly part of the construction team, often they are helped by local artisans/ masons. It is learnable in short time but expertise comes with the years.
Material
5HVRXUFHV The building stands on a foundation of river stones, sometimes until a meter or so to keep the moisture out. The wall build up is mostly done by sun-dried bricks on the inside of the buildings, and baked bricks on the outside. The availability of both sun dried as baked brick is high respectively due to local production and production in Nepali brick kilns. The reliability of availability is different for both sun dried as baked brick, as sun dried bricks are not produceable in the monsoon season due to heavy rainfall. Whereas baked bricks are produceable all year
97
C17: Low strength (stone) masonry
Shock Safe Nepal
/RZ VWUHQJWK VWRQH PDVRQU\ ,QWURGXFWLRQ This building style is mostly found on foothills, hills and mountains in the rural and remote areas of Nepal {Parajuli, Bothara, & Upadhyay, 2015}. The buildings typically consist of riverstone foundations, load bearing stone walls, timber window frames, and varying roof/flooring systems. The walls are composed of two layers of mountain stone and the space between is frequently filled with mud, small stones and pieces of rubble {Bothara & Brzev}. &DWHJRU\
'HVFULSWLRQ
Building components
7HFKQLFDO Typical elements are foundations, load bearing stone walls, timber window frames, and varying
9DOXH
roof/flooring systems. The heavy building method demands a sufficient foundation on a firm base {DUDBC, 2015). The walls are composed of two wythes and space between is frequently filled with mud, small stones and pieces of rubble {Bothara & Brzev}. The load bearing walls usually
Redundancy
2
Building code
4
Performance
1
Possibility to improve
5
Foundation
3
Openings
3
Thermal capacity
3
Lifespan
5
Maintainability
3
Ease of learing
3
Initial quality
5
Processing quality
3
Availability
5
have above average redundancy but the weakness of the mortar has a negative effect on this. This building type is included in the BC with thumbrules and limitations. Seismic Performance
Buildings are mostly regular in plan and elevation (no cantilevers/ overhang). Load bearing stone
Standard
masonry walls provide the lateral load resisting system. This building method has a high seismic vulnerability due to the following factors: High inertia loads due to heavy weight of stones.Lack of structural integrity out-of plane collapse, in-plane shear cracking delamination of wall wythes (two layer without proper bonding in between), failure due to irregular stone shapes {Bothara & Brzev}. The structural Integrity and seismic resistance can be strengthened by means of vertical and horizontal reinforcement (timber, bamboo, reinforced concrete, wire, meshes). Stiff diaphragms such as concrete slabs are favored above flexible diaphragms. The out-of-plane capacity can be improved by adding of wall meshes (experimental techniques). High potential of improvement
Sensitivity to surface
The size of the foundation is both determined by the dead weight of the structure as by the soil type. When choosing the appropreate building method, only the dead weight of the structure will be taken into account. These building methods require a foundation as stated in the NBC, and when the soil is beneficial the foundation as stated might even be overdimentioned.
Climate
With respect to daylight entrance, the size of wall openings is limited (15-25% of the wall).
Thick stone walls can have favorable thermal mass and insulation properties. The stones can keep the moisture out. The mortar (or lack of mortar, dry stacking) influences the wind and rain proofing of this building methods. The walls can be plastered, to increase the windproofing. Construction
Stone masonry structures can be highly durable with long lifespan due to the non deteriorating character of stones, when not exposed to extreme events(force majeure) The stone walls require little maintenance, additional timber elements or bamboo elements do need regular maintenance. The performance of maintenance can be difficult due to the replacement of stones or additional elements coverd by heavy stones. The building is accessible
Complexity
during most types of smaller maintenance. This construction type is incorporated in the building code (Nepal National Building code NBC 203 : 1994 Low strength masonry). The know-how is mainly passed on informally {Parajuli, Bothara, & Upadhyay, 2015}, and skills vary per person. House-owners are mostly part of the construction team, often they are helped by local artisans/ masons. It is learnable in short time but expertise comes with the years.
Material
5HVRXUFHV The walls are built with river stones or boulder stones. A classification can be made between uncoursed random rubble stone, uncoursed semi-dressed stone, and dressed stone {Bothara & Brzev}. Uncoursed random stones are irregular shaped, randomly placed stones whereas coursed and dressed stones are cut to regular (rectangular) shapes and placed regularly. More rectangular shapes of stones are favored with respect to structural performance. In most areas, the stones are held together with the locally available mud mortar. Where no mud of sufficient bonding quality is available the stones are dry-stacked. Building which stand near roads more frequently have cement mortar as bonding. Mud mortar is relatively weak. It can be beneficial if small cracks occur in the mud mortar, dissipating energy through frictional sliding.
98
C18: Prefab framed in-situ concrete
Appendices
3UHIDE IUDPHG LQ VLWX FRQFUHWH ,QWURGXFWLRQ Prefab-sandwich concrete panels are currently not used in Nepal but is used in countries with similar conditions. The frame exists of a simple construction made of hollow steel wire/ styrofoam panels which should be filled with concrete, the method allows for the use of rebar and other strengthenings. To be able to construct these houses in Nepal a new factory and office need to be realized that works by importing styrene fluid for the creation of foam panels. The steel wire is the same as used in car tires and therefore a material that should be locally present. For harder to reach areas a mobile production system can be attached to a truck. The interior and exterior walls can be finished in any way, giving the opportunity to safeguard the Nepali architecture and culture. &DWHJRU\
'HVFULSWLRQ
Building components
7HFKQLFDO Modules have a width of 1200 mm, and can be 12 meter long. However the normal length is one
9DOXH
floor height (ca 3 m). The thickness of the wall depends on the required strength (seismic risk) and insulation (national climate), in total 55 different variations are possible. Facades, load bearing walls, interior walls, floors and the roof can be built with this system. The average weight of each
Redundancy
5
Building code
2
Performance
4
Possibility to improve Foundation Openings Thermal capacity
3 3 4 4
Lifespan
4
Maintainability
2
Ease of learing
1
Initial quality
4
Processing quality
4
Availibility
1
element before concrete is poured in is around 30 to 35 kg per panel. The interior and exterior walls can be finished in any way, giving the opportunity to safeguard the Nepali architecture and Seismic Performance
culture. Calculation of the University of Leuven have shown that the building method is resistant to
Standard
earthquakes, also the structures built with this method have performed in earthquake prone countries over the years. (Sismouk, n.d.) The structural Integrity and seismic resistance can be strengthened by means of vertical and horizontal reinforcement (timber, bamboo, reinforced concrete). Stiff diaphragms such as concrete slabs are favored above flexible diaphragms. The out-of-plane capacity can be improved
Sensitivity to surface Climate
by adding of wall meshes (experimental techniques). Monolite structure, freedom in making a variety of forms Openings can be easily included in the building method, the width of the openings is limited due
Construction
to the structural integrity of the building. Prefab-sandwich concrete frames structures can be highly durable, with a long potential useful lifespan. The infill panels are filled with concrete and do not require much maintenance. The exterior walls do require maintenance. However when amintenance is needed it requires workmanship or even
Complexity
specialized expertise and resources. The method is not used in Nepal right now, however masons are used to work with concrete. All materials, except the styrene fluids are well known. For the fabrication of the panels a local
Material
factory is needed, as well as training for the placement of the panels. 5HVRXUFHV This method makes use of prefab panels that are filled with concrete that can be reinforced with rebar. These panels consist of styrofoam that is hold together with steel wire. (IMAGE)!!!!! Steel-wire: to give form to the panels and create the monolite system Styrofoam: insulates the panels, creates the hollow space to pour concrete Concrete: to fill up all panels, floors etc. Reinforced steel: could be added in the panels while pouring concrete in case of building in high seismic areas.
Use of local
Wood: window frames, doors etc. Labour
Since the method is not familiar in Nepal the local work force needs to be trained in working with the new building method.
Time
materials
1
Experience
1
Labourforce
3
Construction time
3
The method is designed to be quick and flexible, because of the high repetition possibilities and the presence of infill panels the method could reduce the construction time. But because all the panels are filled with concrete there is a required waiting time between the pouring of each section.
Financial
)HDVLELOLW\ The ranking is based on price indications and reference countries. The price is dependend on large scale production. When producing in large numbers (800.000 m2/ year) the depreciation of
Local economy
the investment can become less than 1 euro {SISMO}. All materials need to be imported (from abroad) Locals will be trained to work with the building method. Skilled masons and carpenters are not used when building with this building method. Also large amounts of cement will probably lead to an increase of import from India.
Construction investment Transport
1 1
Use of local recources
1
6RFLDO FXOWXUDO
99
C19: Rammed earth
Shock Safe Nepal
Rammed earth Introduction This ancient technique is mostly used for residential purposes in many different countries. Also in Nepal it is used in many places ranging from the Terai (plains) to the Himalayas. Rammed earth is the in-situ ramming of moist soil into a placed mold (Sassu & Ngoma, 2015) to make foundations, floors and walls. Rammed earth is gaining renewed interest, due to its usage of sustainable and locally available building material. The roofs are mostly made of timber or bamboo structure (pitched) and clad with corrugated iron sheets. Category
Description
Building components
Technical Rammed earth buildings exist of sturdy stone or concrete foundations, load-bearing rammed
Value
earth walls and varying floor- and roof systems. The heavy structures demands a firm soil as a base and concrete or stone foundation. Wall height is approximately 2.5 m and wall thickness Redundancy
3
Building code
4
Performance
2
earth. Possibility to improve Foundation The width of the foundation is twice the width of the wall. Weight of the walls increases the scale o Openings The window openings should be limited and well spaced. Thermal capacity Rammed earth structures are considered durable with lifespan considered to be over 100 years
5 3 2 4
ranges from 0.20 to 0.30 m. Floors are mostly spanned with wood joists (or locally found tree trunks). Roofs are mostly made of timber or bamboo structure (pitched) and clad with corrugated iron sheets. The load bearing walls usually have average redundancy and is comparable to low strenght brick masonry and adobe. This building method is in the building code with Seismic Performance
thumbrules and limitations on design. The load bearing system consists of rammed earth walls. The strength of the wall is low and
Standard
depends on compacting and quality of soil. The structures generally have little lateral load bearing capacity. The seismic performance can be significantly improved with reinforcement of the walls. Vertical wooden posts and horizontal wooden elements embedded in walls are the expected key earthquake resistant elements in these buildings. Another way of increasing the strenght is the use of stabilized rammed earth method which incorporates the use of concrete to bond the rammed
Sensitivity to surface Climate Construction
{http://www.forgreenies.com/rammed-earth-houses} and some promoters even claiming that the structures can maintain their integrity for over 1000 years. {http://www.rammedearth.info/rammed-earth-FAQ.htm}
Lifespan
5
Maintainability
4
Ease of learing
4
Initial quality
5
Processing quality
5
Availibility
5
Once a wall is rammed and sealed it requires little to no maintenance for a period between 10 to 20 years. Performing maintenance is considered to be easy because it only requires resealing of the rammed earth wall. This can be done with little to no workmanship and some resources. The availability of the structure is low during maintenance due to the average redundancy. Complexity
The building method requires many experience (THD, 2015), and the quality is dependent on consistent workmanship.
Material
Resources The technique makes use of locally available clay, sand, gravel and some cement. The wall strength dependent on the local soil quality and the compacting effort. The method can be considered low-cost with readily available construction materials that are available during the dryer periods in the year. Limiting the possibility to construct in the monsoon season.
Use of local Labour
The technique requires in-situ ramming and is considered labour intensive if there is no machinery available (powered tampers). External training and mentoring is needed to perform this technique with local builders.
Time
materials
5
Experience
3
Labourforce
3
Construction time
4
Speed of construction depends on how fast the ramming can be done, if machinery is available the ramming can be done much quicker. Construction time for a simple house is considered 2 weeks for the wall construction 1 week for the roof.
Financial
Feasibility The ranking is based on price indications and reference countries
Local economy All materials for rammed earth are locally available in most rural areas.
100
Construction investment Transport Use of local
5 4
recources
5
C20: Reinforced cement concrete
Appendices
5HLQIRUFHG &HPHQW &RQFUHWH )UDPHV ,QWURGXFWLRQ This building type can be found widespread in urban and semi-urban areas of Nepal, and is one of the most emerging building methods {Marhatta, Bothara, Magar, & Chapagain}. An important distinction can be made between engineered and non-engineered (informally constructed) concrete frames. The main structural system is a moment-resisting reinforced cement concrete skeletal frame of cast-in-place concrete beams and columns with masonry infill walls. Infill is mostly solid clay bricks, infill with stone masonry is also seen in informal structures. &DWHJRU\
'HVFULSWLRQ
Building components
7HFKQLFDO The main structural system is a moment-resisting reinforced concrete (RC) skeletal frame of cast-
Value
in-place concrete beams and columns with masonry infill walls. Infill is mostly solid clay bricks, infill with stone masonry is also seen in informal structures. The walls can be painted and plastered. Floor and roof slabs are mostly cast-in-place concrete slabs. Roof and floor diaphragms
Redundancy
3
Building code
5
Performance
3
Possibility to improve
2
Foundation
3
Openings
5
Thermal capacity
3
Lifespan
4
Maintainability
2
Ease of learing
2
Initial quality
5
Processing quality
3
Availibility Use of local
3
materials
1
Experience
3
Labourforce
4
are considered to be stiff and rigid, able to distribute lateral forces. When RCC is performed with the minimum amount of colomns they don't offer much redundancy, however inscreasing the amount of colomns and adding shear walls has a positive influence on redundency. RCC frames Seismic Performance
are encorporated in the building code. For non-engineered structures the frame is usually designed for gravity loads only {Marhatta,
Standard
Bothara, Magar, & Chapagain}. For engineered structures the monolithic beam-column connections. The lateral load system is officially the concrete frame, in reality combined action with the brick masonry infill walls - resembling a shear wall structure. The infill walls actually have to take quite a portion of the lateral load. Class C Seismic performance can be considerably improved by good construction practice, adequate detailing and sufficient reinforcement. The addition of shear walls is found to significantly reduce lateral displacement.
Sensitivity to surface
The size of the foundation is both determined by the dead weight of the structure as by the soil type. When choosing the appropreate building method, only the dead weight of the structure will be taken into account. These building methods require a foundation as stated in the NBC, and when the soil is beneficial the foundation as stated might even be overdimentioned.
Climate
Window openings are quite flexible due to the frame construction. The frame however must be designed on lateral load. Often it is only for gravitational loads and then the structure is also dependent on the masonry infill; decreasing flexibility of window openings. Insulation and acoustic properties depend mostly on type of infill. When bricks see brick masonry
Construction
Life span of RC frame construction is lower than masonry building methods. Estimated lifespans are 30-100 years RCC frame building require little maintenance, because the structural elements consist of and are protected by the concrete. However when the concrete is damaged or is in need of maintenance the work requires workmanship and much resources such as concrete injections, rebar replacements. The availability of the construction is good due to open spaces and the supporting
Complexity
elements being limited to the colomns and floors. Reinforced concrete frame with masonry infill is addressed in the national building code. Design and construction expertise is limited available due to a lack of engineers. Engineers are (if at all) involved for drawings and permits and structural design, construction monitoring and quality control. Non-engineered building practice forms a risk, since RC frame construction requires sufficient level of â&#x20AC;&#x2DC;technology, expertise, and workmanship, particularly in the field during constructionâ&#x20AC;&#x2122; (Yakut).
Material
5HVRXUFHV The concrete is made of a mixture of sand, cement and water. The concrete is strengthened by steel reinforcement. The infill walls are often made of baked bricks, although block and stone infills are also seen. In rural villages, combinations of stone and brick infill can be found. Availability of concrete can be considered high due to local cement factories in Nepal and the large availability of cement in India and China. The reliability can be very good when road conditions and political situations are good, but during monsoon season many roads are damaged and limit the flow of products coming from India and China. The availability of steel rods for rebar
Labour
is good due to much local production. Building with Reinforced Concrete Frames is a labor intensive building method due to the specificity of activities such as correctly making the cement or the placement of casts. The placement of rebar is considered to be one of the most labor intensive activities seeing that the typical unit rate costs is more expensive than other structural elements (Jarkas, 2012)
101
C21: Single Panel Walling System
Shock Safe Nepal
6LQJOH 3DQHO :DOOLQJ 6\VWHP ,QWURGXFWLRQ Rapid Building Systems make use of Gypsum plaster products that are present in debris in the building and construction industry. The panel serves both as the internal and external wall and eliminates the need for bricks, blocks, timber wall frames. The panels are load bearing and can be used in single, double, or multi storey construction. RapidWall is mainly used in India and China, the two countries in which between Nepal is landlocked. Also both surrounding countries have Rapidwall factories (2009, RapidWall, presentation UN-Habitat).. 'HVFULSWLRQ &DWHJRU\ Building
7HFKQLFDO The panels are 12 by 3 metre and 120mm thick. The panel serves both as the internal and
components
external wall and eliminates the need for bricks, blocks, timber wall frames. The panels are load bearing and can be used in single, double, or multi storey construction. This is a representation of
9DOXH
Redundancy
4
Building code
4
Performance Possibility to
4
improve
2
Foundation Openings Thermal capacity Lifespan
3 3 4 3
techniques that bond the weakspots. The method is not used in Nepal right now, however it is quite an easy building method. The
Maintainability
2
panels are delivered as prefab panels at the building site.
Ease of learing
3
Initial quality
3
Processing quality
3
Availibility
1
a Rapidwall panel. In the cavities different building services can be put such as plumbing, electrical, isolation or concrete for increasing the load bearing (2009, RapidWall, presentation UN-Habitat). Light weight ( 44kg/m2 ). Pre-fabricated (12m X 3m X 124mm) Seismic Performance Standard
Rapidwall underwent earthquake testing and achieved a maximum peak ground acceleration of 0.36gâ&#x20AC;&#x2122;s and as a result Rapidwall was rated for the equivalent of a magnitude 7 earthquake on the Richter scale. A 12 m x 3 m x 120 mm reinforced concrete wall panel weighs over 10 tonnes. A similarly sized RapidwallÂŽ panel weighs only 1.5 tonnes. This means the Rpaidwall panels are very light which can be a positive aspect for seismic permormance. The voids in Rapidwall panels can be used to add concrete with steel bars for load bearing
Size foundation
capacity. The size of the foundation is both determined by the dead weight of the structure as by the soil type. When choosing the appropreate building method, only the dead weight of the structure will be taken into account. This building method requires a foundation as stated in the NBC, and when the soil is beneficial the foundation as stated will probably even be overdimentioned.
Climate
Openings in exterior walls can easily be made when incorporated in the design, only limited by
Construction
possible placement of extra rebar. Unknown The panels do not require much maintenance but when maintenance is needed it requires workmanship and some resources. Prefab panels are difficult to maintain due to specialised
Complexity
Material
5HVRXUFHV Rapidwall panels are made of gypsum plaster and fibreglass. The prefab panels can be imported from either India or China with good availibility however the reliability is susceptible to uncertainty due to road conditions and political sitiuation. At only 44 kg per square metre, a single B-double truck can transport over 570 square metres of Rapidwall compared to 125 square metres of 120 mm thick precast concrete hollow blockwork. But if a rural village can not be reached by truck, this material can not reacht the village.
Use of local Labour
materials
1
Experience
1
Labourforce
3
Construction time
5
Since the method is not familiar in Nepal the local work force needs to be trained in working with the new building method.In the rapidwall plant manufacturing rate of 108 m2 /hr for a three table plant. At the building site a installation rate (two man crew) up to 45 m2 /hr is possible (RAPIDWALL DOCUMENT)
Time
The method is designed to be quick and flexible, because of the high repetition possibilities and the presence of infill panels the method could reduce the construction time.
Financial
)HDVLELOLW\ The ranking is based on price indications and reference countries
Construction investment
2
Transport
1
This material not available in Nepal en needs to be imporated from China or India. It is unlikely that this material can reach a rural village
102
C22: Steel
Appendices
6WHHO ,QWURGXFWLRQ Structural steel was predominately used for industrial and agricultural structures and found its uprise in the second world war. {http://www.ncibuildingsystems.com/careers/campus/mbi_history.html} After the war the use of steel as a construction material for buildings, bridges and other structures was widely accepted and accessible due to its cost- efficiency. Nowadays steel is not only used for complex structures but also for regular housing projects in seismically active areas, such as Japan where the use of steel in building housing is subsidized. &DWHJRU\
'HVFULSWLRQ
Building components
7HFKQLFDO Steel construction with shear walls or steel braces, often combined with a reinforced concrete foundation. The basic structure is consisting of steel braced frame with reinforcements to make the constructing resistant to lateral and transversal loads. Up to 5 storeys cross braces or shear
Value
Redundancy
4
Building code
5
Performance
5
Possibility to improve
3
Foundation Openings Thermal capacity
4 5 3
Lifespan
4
Maintainability
2
Ease of learing
2
Initial quality
5
Processing quality
4
Availibility
2
walls are used. Over 5 storeys reinforced concrete slips or jump formed wall are commonly used Seismic Performance
{10/5/2015, http://db.world-housing.net/building/3#tabs-4}. Seismic performance of structural steel constructions can be considered very good due to a
Standard
number of desirable attributes. It is relatively lightweight, while providing great strength. Steel has a high ductility which is a favorable trait during an earthquake. The performance during an earthquake can be increased by use of special moment resisting frames and different types of braces such the V-brace, inverted V-brace, X-brace, two storied Xbrace etc. A combination of the properties of steel and the possibilities to enhance the frame make steel frame buildings a good construction type for seismically active areas.{lecture by Michael D Engelhardt Michael D. Engelhardt University of Texas at Austin, Design of Seismic
Sensitivity to surface
Design of SeismicResistant Steel Building Structures} Steel structures can be built on slopes, however the vertical forces need to be distributed in a correct manner. A way to achieve this is by using bracings and constructing a level foundation on which the main structure can be placed. {http://web.mit.edu/cron/Backup/project/zalewski/layouts/slopes01d.pdf}
Climate
Openings in exterior walls can easily be made due to the openness of steel frames, only limited by possible placement of braces.
Construction Steel structures can have a very long lifespan (exceeding 100 years) when maintained properly. Steel structures have some disadvantages when it comes to maintenance. Steel is vulnerable to corrosion when exposed to oxygen, water and humidity, to prevent corrosion periodic painting is needed. Another issue that needs periodic maintenance is the fire protective coating that ensures the structural integrity of steel during a fire. The amount of maintenance and the consequences of not performing maintenance are both large. The maintainability of steel is relatively easy when it comes to treating the steel with a protective layer, however the maintenance that requires welding does require more workmanship and resources. The availability of the structure during maintenance is good and comparable to the RCC frame. Complexity
The complexity of constructing with steel is that it requires knowledge on correctly connecting the frame and braces. Bad detailing, due a lack of knowledge among the construction workers can result in unsafe structures. Building with steel requires special tools and the knowledge on properly handling these tools.
Material
5HVRXUFHV The main materials needed are steel beams with the correct quality marks, cement for the construction of a foundation, welding materials and the materials of choice for flooring, interior and exterior covering. The availability of materials under normal circumstances is good, a threath to the availability is the political situation with neighbouring counteries seeing that the beams need to be imported. Another factor playing a role is the conditions of the roads, especially after monsoon season when these can get swiped away by landslides. Steel is a material that is produced and readily available in Nepal, however this only concerns the production of steel rods and rebar. Very little to no producers offer structural steel beams requiring the import of steel beams for construction purposes. {http://www.fncci.org/members/page1.php?op=pageload&file=search_result&type=am&am_catid=1 8}
Labour
The labor intensity of building with steel is relatively low. A small team of workers 4 to 10 can erect a steel frame for housing. However skilled labour is needed for welding and construction with steel. Right now steel buildings are not very popular in Nepal.
Use of local materials
1
Experience
1
Labourforce
3
103
C23: Stone masonry in cement mortar
Shock Safe Nepal
6WRQH PDVRQU\ LQ FHPHQW PRUWDU ,QWURGXFWLRQ This building style is similar to stone masonry and mostly found in the more mountainous parts of nepal. The houses consists of stacked mountain stones held together by cement instead of mud mortar. &DWHJRU\
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Building components
7HFKQLFDO Typical elements are sturdy foundations, load bearing stone masonry walls, held together by
Value
cement, timber window frames, and varying roof/flooring systems. Some buildings have applied horizontal bands at sill, lintel and floor level. The heavy building method demands a sufficient foundation on a firm base {DUDBC, 2015). The load bearing walls usually have above average
Redundancy
3
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5
Performance
3
Possibility to improve
4
Foundation
3
Openings
3
Thermal capacity
4
Lifespan
4
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3
Ease of learing
3
Initial quality
5
Processing quality
4
Availibility Use of local
5
materials
3
redundancy. This building type is included in the BC.
Seismic Performance
The materials used, the quality of the mortar and workmanship, and the pattern in which the
Standard
units are assembled can significantly affect the durability of the overall masonry construction. Sufficient bonding between mortar and stones is needed to resist shear cracking. Seismic performance is influenced by the bond between mortar andstone connection, the connection between building elements such as walls, corners and junctions, and between walls and floors, roofs {Dâ&#x20AC;&#x2122;ayala}. Very low or no tensile strenght is mostly the shear failure of wall elements in the case of stone masonry. Combined with the irragular shape of stones, further destabilizes the wall by there movements (NSET 1994) The structural integrity and seismic resistance can be strengthened by means of vertical and horizontal reinforcement (timber, bamboo, reinforced concrete). Stiff diaphragms such as concrete slabs are favored above flexible diaphragms and light roofs systems are preferred.
Sensitivity to surface
The size of the foundation is both determined by the dead weight of the structure as by the soil type. When choosing the appropreate building method, only the dead weight of the structure will be taken into account. These building methods require a foundation as stated in the NBC, and when the soil is beneficial the foundation as stated might even be overdimentioned.
Climate
Wall openings should be as small and as centrally located as practiable, the limits on opening size are: total width of openings should be less than 0,3 of the total width of the wall. Openings should preferably be at the same level, for the continuation of lintels. Ventilators shall be 450x450mm or smaller {DUDBC, 2015}
Construction
Masonry structures held together with lime mortar can be highly durable, with an extremely high potential lifespan of more than 500 years, if well constructed and maintained and if not damaged or destructed by force majeure events {J.Morton, 1990}. On the other hand the functional lifespan is persumed to be shorter. The stone walls need limited maintenance when constructed in the right manner only regular check for cracks is needed. Timber elements are vulnerable to rotting due to moisture; therefore need regular checking and maintenance. The maintainability is good due to the fact that structural elements are reachable with some effort and maintenance does not necessarily require workmanship. The building is available during limited structural maintenance. The cement bonding increases the difficulty due to the effort required to remove specific stones.
Complexity
This construction type is incorporated in the building code (Nepal National Building code NBC 109 : 2015 Unreinforced masonry); the codes specify substantial constraints on unreinforced masonry construction to improve seismic resistance {DĂ yala}. The skill to build unreinforced stone masonry houses is limited, the addition of reinforcement makes the building method more complex.
Material
5HVRXUFHV The stones are mostly coursed and dressed into rectangular shapes. The bonding material cement is executed as 1:6 cement sand mortar. Mortars are subject to greater variation, but the basic materials used in mortar mixes are sand, water, and one or more of the bonding agents, mud, clay, or cement, depending on local availability. The proportion of bonding agent/s to sand determines the compressive and bonding strength of the mortar {Dâ&#x20AC;&#x2122;ayala}.
104
C24: Timber construction
Appendices
7LPEHU FRQVWUXFWLRQ ,QWURGXFWLRQ Common Nepali building practise in areas where trees are abundant. Often constructed in stud wall frame or wood frame construction, with either concrete or stone foundations. Walls are built out of vertical timber elements and are stiffened by plywood or gypsum board sheathing. The roofs are often executed out of timber joists or prefab timber trusses {Arnold}. &DWHJRU\
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Building components
7HFKQLFDO Key-building components are: usually concrete (reinforced concrete stip-footing foundations),
Value
sometimes stone foundations. Walls are built out of vertical timber elements (rectangular crosssections), and are covered (stiffened) by plywood/ gypsum board sheathing. An alternative seen in
Redundancy
3
Building code
5
Performance
4
Possibility to improve
3
Foundation Openings Thermal capacity
4 5 3
Lifespan
4
Maintainability
3
Ease of learing
3
Initial quality
3
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4
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3
materials
4
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4
Labourforce
3
Construction time
4
Japan is bracing of the timber wall with diagonal members. Floor are made with joists, covered with plywood or OSB, Roofs are executed out of timber joists or prefab timber trusses {Arnold}. Seismic Performance
The seismic performance is relatively high {Arnold} in case of sufficient material- and construction
Standard
quality. The lateral load-bearing system if formed by plywood/ OSB panels nailed to the vertical member which act as shear walls. Also diagonal timber braces can be applied. Structures have satisfactory redundancy due to the typically large number of walls and nailed connections {Arnold}. Seismic deficiencies are inadequate connections to foundation causing the building to move of the foundation, inadequate shear resistance, lacking of bracing, inadequate Joints without mechanical fasteners lack of proper maintenance {Arnold} The seismic performance can be enhanced by application of the adequate finishing; the non-load bearing walls can provide significant dissipation of energy when they are damaged {Arnold}.
Sensitivity to surface
Timber structures are have a relatively low weight. Therefore the vertical force on the foundation
Climate
is lower and a less strong foundation is required. Location of window openings is very flexible due to the timber braced frame.
Construction
The life span of timber is subjected to the amount of maintenance and the kind of wood used. With the use of the right wood and properly maintained the life span could reach to 80 years. Timber is highly subject to maintenance, it requires regular maintenance to prevent the structural elements from rotting requiring maintenance every 3 to 5 years. Maintenance can be done by the owners themselves if they have the know how and it does not require much resources. The availability of the structure during maintenance is good exept when concerning the maintenance
Complexity
of roof or floor elements. This construction type is incorporated in the building code (Nepal National Building code NBC 112: 2015 Timber). The know-how is mainly passed on informally {Parajuli, Bothara, & Upadhyay, 2015}, and skills vary per person. House-owners are mostly part of the construction team, often they are helped by local artisans/ masons. It is learnable in short time but expertise comes with the years.
Material
5HVRXUFHV For structural elements such as beams, columns, bands etc. hardwood, such as the locally available Sal wood, should be used (not soft-wood) (DUDBC, 2015). Timber should be adequately treated to prevent decay. The availability and reliability of proper timber for seismic bands and timber framing is low due to anti-deforestation programs and prices are high due to transportation costs.
Labour
Timber is locally known as a building material, there are special carpenters who are able to build with timber frames and connections. Due to the fact that timber is relatively light weight it can be done with few people, however the processing of wood for a timber frame can be time costly
Time
requiring a small team of 5 - 10 people. Timber construction is a 'dry' construction method and can therefore quickly be assembled and executed.
Financial
)HDVLELOLW\ The ranking is based on price indications and reference countries
Construction investment
3
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Appendices
109
Appendix E: Shock Safe Nepal Precipitation maps of Nepal. Department of Hydrology & Meteorology. (2013)
110
Appendices
111
Appendix F: Shock Safe Nepal Floor plan damaged community center Ratankot (SSN, 2016)
112
Appendices
113