BSC(HONS) IN ARCHITECTURE BUILDING STRUCTURE (BLD61003)
STRUCTURAL DESIGN POST MORTEM GROUP MEMBERS PAVITRA YOGANATHAN CELINE PACHECO MERCY CHIDINMA NKATHA OGBONNA REYSHMI RATCHANIYA MASHRUK ASAD TUTOR: MR. RIZAL
0332425 0333005 0333261 0329773 0322188
TABLE OF CONTENTS 1.0 INTRODUCTION OF BUILDING 1.1 INTRODUCTION OF BUILDING 1.2 BASIC CONCERNS OF STRUCTURAL DESIGN 2.0 ORIGINAL ORTHOGRAPHIC DRAWINGS 2.1 PLANS 2.2 ELEVATIONS 2.3 SECTIONS 3.0 DESIGN APPRAISAL & PROPOSED SOLUTIONS 3.1 FOUNDATION 3.1.1 STRENGTH AND SAFETY 3.1.2 STABILITY 3.2 COLUMNS AND BEAMS 3.2.1 FEASIBILITY 3.2.2 STABILITY 3.2.3 STRENGTH 3.3 ROOF 3.3.1 FEASIBILITY 3.3.2 STRENGTH AND ECONOMY 3.3.3 STABILITY 3.3.4 INTEGRATION 3.4 WALL 3.4.1 FEASIBILITY 3.4.2 STRENGTH AND ECONOMY 3.4.3 STABILITY 3.4.4 SAFETY 4.0 EDITED ORTHOGRAPHIC DRAWINGS 4.1 FLOOR PLANS 4.2 ELEVATIONS 4.3 SECTIONS 5.0 CONCLUSION LIST OF FIGURES REFERENCES
1.0 INTRODUCTION 1.1 INTRODUCTION OF BUILDING
Figure 1.1.1 Rendered 3D view of pre-modiďŹ ed VIC
Kampung Pulai is a village located in Gua Musang, Kelantan and is a little village surrounded by beautiful scenery and is famous for the Pulai Princess Cave and other agricultural elements. Hence, the project is to build a visitor interpretive centre (VIC) for the village. The concept chosen for this project is to bring a sense of community and ownership to the place. It revolves around bringing the community back together and through the journey in the VIC, it will be able to evoke a revisit to the history of Kampung Pulai and to embrace the present.
Figure 1.1.2 Rendered 3D view of pre-modiďŹ ed VIC
1.2 BASIC CONCERNS OF STRUCTURAL DESIGN
1.
Safety : Safety is the major concern in structural design. In a way, a building that has structural designs without concerning safety issues can be defined as a failed building design because of the potential of harming a human life. Safety is the root for several concern points such as stability, strength, economy and etc. In local buildings, safety concerns can also be materialized in materiality such as fire resistance. Taking into consideration the Malaysian climate and weather, fire is the main concern for structural designs.
2.
Economy : In most cases, the overall cost of the structure is the first and most important factor that was considered. Obviously, the cost of the structure is made up of the cost of the materials, the labour cost and the time allocated for the construction. Expensive structures often do not add any value in the way that expensive finishes or hardware may. Thus, the economy is important for the whole building construction project in terms of materiality, time used and labour work.
3.
Strength : Strength is the state or quality of being physically or mentally strong. The ability to withstand or exert large amounts of force, stress or pressure. It is something that is regarded as being beneficial or a source of power where their chief strength is technology.
4.
Feasibility : Feasibility is focusing on the possibility to construct something based on the structural strength, stability and rigidity. Structures must use materials and products which are available and can be handled by the production organization. Feasibility studies are usually conducted before designing a structure to have a reference from a successful building.
5.
Stability : Stability is often used to describe buildings or structures that will not collapse or break.
6.
Integration : In a successful design project, building systems and materials must be integrated to create a unified whole that is able to achieve the desired functional purpose.
2.0 ORIGINAL ORTHOGRAPHIC DRAWINGS 2.1 FLOOR PLANS
GROUND FLOOR | 1:150
FIRST FLOOR | 1:150
2.0 ORIGINAL ORTHOGRAPHIC DRAWINGS 2.1 FLOOR PLANS
GROUND FLOOR | 1:150
FIRST FLOOR | 1:150
2.0 ORIGINAL ORTHOGRAPHIC DRAWINGS 2.2 ELEVATIONS
NORTH | 1:150
SOUTH | 1:150
2.0 ORIGINAL ORTHOGRAPHIC DRAWINGS 2.2 ELEVATIONS
EAST | 1:150
WEST | 1:150
2.0 ORIGINAL ORTHOGRAPHIC DRAWINGS 2.3 SECTIONS
SECTION AA’ | 1:150
SECTION BB’ | 1:150
3.0 DESIGN APPRAISAL & PROPOSED SOLUTIONS 3.1 FOUNDATION 3.1.1 STRENGTH & SAFETY PROBLEM The building initially lacked a proper foundation system and was simply elevated on concrete stilts. Research proved these stilts were not able to support the large scale of the building because they lack ability to transfer the load of the building into the ground appropriately to ensure stability hence this system is inappropriate for the building.
Figure 3.1.1.1 Section BB’ of pre-modified foundation on stilts.
SOLUTION Introduction of the pad footing foundation to the building was necessary for the following reasons: ● To distribute the weight of the structure over the large area so as to avoid overloading of the soil beneath. ● To anchor the structures against the changing natural forces like earthquakes, floods or wind. ● To load the sub-stratum evenly and thus prevent unequal settlement. ● To provide a level surface for building operations. ● To take the structure deep into the ground and thus increasing the stability and preventing overloading. ● Specially designed foundation helps in avoiding the lateral movements of the supporting material.
The foundation material chosen is reinforced concrete because foundations made out of poured concrete are extremely strong and durable and sometimes the angle of the column may not be precise, but it can still tolerate the uneven loading. Due to their compressive and exural strength, unlike other types of foundations, they do not shift if the soil under the building shifts. They are also maintenance-free as their resistant to rot and decay.
Size of Pad Footing The measurements of the foundation according to standard size measurements of the building height are 1000mm by 1000mm by 500mm. It is offset below the ground level by 2500mm. To make sure the foundation of our VIC is always connected to the columns, it is well reinforced with rebars and these extend beyond the stump level and act as starter bars for the columns above.
Figure 3.1.1.2 Pad footing showing reinforcement and column connection.
Figure 3.1.1.3 Section AA’ of pre modified foundation
Figure 3.1.1.4 Section AA’ showing modified pad footing foundation type
Figure 3.1.1.5 Section BB’ of pre-modified foundation type
Figure 3.1.1.6 Section BB’ of modified pad footing foundation type.
3.1.2 STABILITY PROBLEM The site is beside a river and therefore, the soil in the area is unstable because of the soil getting waterlogged due to the tropical climate, and once the water evaporate, the soil ends up with air spaces in it making it unstable. These factors also cause the are to be more prone to ooding and hence, it requires a proper method of load distribution to ensure its stability. The substratum is more stable than the top soil and this is why the building requires a proper foundation system to transfer this load into the deeper, more stable soil SOLUTION The foundation is inserted slightly more deeper than normal levels of pad footing, to provide extra support to the building due to the soil condition described above. The building is also slightly elevated to prevent the water from entering the building in the case of ooding.Due to their strength, density and joint-free construction, poured concrete foundations are less like to develop water problems than other foundations.
Figure 3.1.2.1 Depth of pad footing
Advantages of pad foundations are: ● ● ● ● ●
Economic Shallow pad footing requires less excavation Size and shape can be varied depending on the site condition Easy to construct Reinforcement for tension and shear can be added.
Disadvantages of pad foundations are: ● ●
Foundation size may become very large depending on the loads Slightly weaker against uplift forces and lateral forces
3.2 COLUMNS AND BEAMS 3.2.1 FEASIBILITY
Figure 3.2.1.1 3D view of pre-modiďŹ ed column arrangement
PROBLEM The column arrangements are not aligned with the grid line system and the foundation system which will affect the load transfer in a way that the load will be divided irregulary from the roof to the column . It is also more diďŹƒcult to construct the building without a regular measurement and arrangement and will result in a lot of wasted time during the construction process as well as labour work. SOLUTION Columns should be arranged using a grid line system from the plans. This is to ensure that everything is aligned besides looking more orderly in the building design. A grid column placement is always preferred in order to reduce point loads and unnecessary complications during construction. There are few extra columns added for better support due to an asymmetrical plan.
Figure 3.2.1.2 Floor plan view of pre-modified columns not arranged on grid system
Figure 3.2.1.3 Ground floor plan view of modified column arrangement and grid system
PROBLEM The span (distance) between each column should be equal, however, from the figure below, it clearly shows that the span between the columns are vary drastically. This will definitely affect the load transfer and the cost of construction.
The columns all have different span distances
Figure 3.2.1.4 Ground Floor plan view of pre-modified column distance
SOLUTION The span size between each column is 5000 mm to ensure that the load is evenly distributed throughout the building to enhance stability. This will also save more time when the construction process and labour work.There are few extra columns added for better support due to an asymmetrical plan.
The distances between the columns have been adjusted and are similar
Figure 3.2.1.5 Ground Floor plan view of modified column distance
3.2.2 STABILITY PROBLEM The dimensions of the column base is not suitable for the building height. The dimensions should be calculated for the building column based on the building load. There are insufficient beams that are supporting the floor slab and column, hence, the column is unstable and unable to stand up as a main structural member of the building.
Lack of beams
Wrong column sizing
Figure 3.2.2.1 3D view of pre-modified building showing lack of beams
SOLUTION ● ● ●
●
To include a standard column size to the building to enhance stability To construct beams into the building to connect with the column and thus increasing the overall stability of the column. Beam dimensions used are slightly smaller than the column dimensions to ensure fit and for the rebars to pass through efficiently. As a result the dimension of the column base is 300mm x 300mm and the dimension of the beam is 300mm x 200mm The column is also offset 2500mm underground to reach the foundation whereas the building is elevated 1m above the ground.
Presence of beams to support the roof.
Figure 3.2.2.3 3D view 2 of modiďŹ ed column and beam arrangement.
3.2.3 STRENGTH PROBLEM The columns and beams were not connected in order to provide support for the oor slab and this made the building very unstable and hence, unsafe due to the chances of it collapsing.
SOLUTION The column size is slightly larger than the beam; this is to enhance stability by allowing the steel reinforcement to pass through the sides as shown above, to continue with the column. Hence, it provides extra support for the beam, oor slab and the columns.
Figure 3.2.3.1 Straight beam passing through column for reinforcement
Figure 3.2.3.2 Beam passing through column for extra support and reinforcement.
PROBLEM The quantity of the columns were not sufficient to support the building. There were a few corners that do not have columns to support the structure, this could result in the building collapsing. The length and the height of the column are also not suitable for the building.
SOLUTION The quantity of the column is increased for the support of the building and thus increasing the stability of the building. The roof and the walls will be more stable after adding in columns where needed. The beams are also connected to the column and thus increasing the stability of the building.
No columns at corners
Figure 3.2.3.3 3D view of pre-modified building showing insufficient columns.
Columns added on corners
Figure 3.2.3.4 3D view of modified building with columns
3.3 ROOF 3.3.1 FEASIBILITY
Figure 3.3.1.1 3D perspective of pre-modified roof
PROBLEM The building has multiple roof slabs for each part of the building and those roof slabs do not connect to each other. This will cause rainwater to leak into the building. Other than that, the roof is also made out of reinforced concrete slabs, and concern in the VIC’s pre-modified state is that the roof slabs are too heavy and extremely large in span and number. As the material used is concrete the process of pre-fabricating or casting the roof slabs in-situ is very challenging to make and place it on top of that height. It might even collapse if the building cannot support the weight. SOLUTION The multiple roof slabs are sloped in the opposite direction to the pre-modified VIC to prevent the rain water from flooding the building. The material of the roof can be changed from concrete to light weight metal roofs, which will decrease the load on the roof as, its self weight decreases.
Figure 3.3.1.2 3D perspective of modified roof
3.3.2 STRENGTH AND ECONOMY The roofing material is part of our consideration to make sure the structure is workable for the design scheme. The pre-modified VIC roof uses concrete slabs which are too heavy for the building to withstand. This will cause the roof slabs to break/collapse especially since there are no structural systems. The roofing materials that is selected are metal sheets.
CONCRETE ROOF It is a heavy material and the building will not be able to withstand the weight of the roof. It is also difficult to install on a sloped roof. Concrete roofs have a high compressive strength and when built with reinforcements, it has a high tensile strength. It can also resist strong winds and is a non-combustible material. Concrete roofs need to be maintained regularly and checked regularly for cracks. Lastly, concrete is an expensive material and also has a high maintenance cost. Figure 3.3.2.1 Construction detail of concrete roof
METAL SHEET ROOF Metal sheet roofs are easily installed especially on a sloped roof. Metal is a very light material but is very strong because it has a high tensile strength. Similar to the concrete roof, it is able to resist winds and is a non-combustible material. In terms of maintenance, the metal roof requires less maintenance when compared to concrete and it also costs much cheaper and has a lower maintenance cost. Figure 3.3.2.2 Construction detail of metal roof
3.3.3 STABILITY
Figure 3.3.3.1 Cross section of pre-modified roof without trusses and rafters
PROBLEM Currently the roof is placed on the walls and columns directly without any support and is lacking roof trusses and purlins to carry the load of the roof and restricts the extension of the dimensions of structures and thus creates interesting shapes that are not so stable. SOLUTION To include both trusses and purlins for better stability. This to so that the roof load is distributed to the trusses and the purlins and then only transferred to the walls. This at the same time creates aesthetically pleasing roof shape.
Figure 3.3.3.2 Cross section of modified roof with new trusses and rafters
MATERIAL OF TRUSS AND PURLINS Steel trusses and purlins are chosen to be used because steel is stronger, lasts longer, lightweight, is environment friendly and is flexible to design compared to other material choices.
3.3.3 STABILITY ARRANGEMENT OF ROOF TRUSSES
The roof truss distributes the load from the roof and they are aligned parallel to the slope, especially if the slope is steep. This helps increase the stability of the overall roof and decreases the risk of the roof to collapse. Parallel lattice roof truss is suitable for use with flat roofs or sloping roofs and they can also be used as long span purlins and are suitable for use with most external finishes from lightweight metal sheeting and also for heavier constructions. Triangular lateral bracings used in roof trusses is important as they prevent the twisting effect and the slanting that’s caused by the lateral load, usually the wind, thus holding the structure tightly and making it more stable.
PURLINS C-SECTION PURLINS These are used as continuous parallel beams to resist the shear and moment. C-section (channel) has higher moment of inertia as compared to L-section and are used because the support the metal roof sheeting and is more economical to use.
3.3.4 INTEGRATION PROBLEM Due to the high rainfall on the site, the foundation will weaken and erosion would take place, therefore harming the landscape and will increase the risk of flooding in the lower level of the building. Another issue would be the open air auditorium due to the fact the VIC is located in a tropical climate where the rainfall was quite high.
SOLUTION Gutter System Installation of a proper gutter system free of holes and gaps should be pitched properly towards the downspouts, set 3-5 feet away from the base to funnel water off from the roof and away from the centre. Sizing of the gutter used is 150mm by 150mm.
Figure 3.3.4.1 Pre-modified roof plan without gutter
Figure 3.3.4.2 Modified roof plan with gutter
The most suitable material to be used for the gutter system proposed is aluminium. Not only is this material lightweight and easy to install, this material will not rust and is aesthetically pleasing if anything. It can also be painted and is relatively cheaper than steel. 5 inch K-Style gutters are suggested as they fit well along the sides of each roof. Due to the flat side of the gutter, it can be directly nailed into the fascia board while holding large amounts of water and still having a seamless and stylish finish.
Tensile Structure The installation of a tensile structure above the auditorium provides shelter from the environment. It is able to create an expansive covered area with minimum support. A tensile fabric structure is lightweight and versatile, thus it is able to provide a range of dynamic and exciting dimension options.Tensile fabric structures are durable and designed to withstand even the most severe weather conditions.
Figure 3.3.4.3 ModiďŹ ed roof plan with tensile structure over the auditorium
3.4 WALL 3.4.1 FEASIBILITY
Figure 3.4.1.1 Pre-modiďŹ ed elevation with brick wall
PROBLEM The building uses a brick masonry wall on one side which can absorb water and cause dampness which will damage overtime when exposed to air. Besides, the construction of bricks is time consuming, more expensive and also requires a lot of labour work.
SOLUTION Concrete block walls which are made from large rectangular bricks are strong, durable, energy eďŹƒcient and has resistance to harsh and odd weather conditions.
3.4.2 STRENGTH & ECONOMY PROBLEM Masonry bricks are not as strong as concrete or stone walls and is also not durable enough. Not only that, it is also expensive after initial construction and requires consistent maintenance. SOLUTION Since concrete block walls are made of huge rectangular bricks. It provides more strength and ďŹ rmness to different sizes of concrete structures. More importantly, concrete blocks have gained popularity due to its eďŹƒciency and cost effectiveness. This type of wall requires less maintenance and is not prone to corrosion or other forms of degradation.
3.4.3 STABILITY PROBLEM Brick walls depend completely on the foundation for stability. This means moisture and damp walls will allow cracks ato form and settle. If the cracks are not maintained, it will collapse. SOLUTION Concrete walls serve as the backbone of many buildings because of its durability and shape stability because of its granule size and strength. Also, concrete blocks have resistance against higher pressure that is employed from the outside.
3.4.2 SAFETY PROBLEM Masonry brick walls cannot be used in high seismic zones and is less safe when built as load bearing walls. However, in this site, brick is not used as a load bearing wall and the thinness of the wall can cause possible collapse.
SOLUTION Concrete block walls are highly resistant to extreme weather conditions and can prevent storms, oods and high winds. The high density of concrete blocks provide excellent acoustic insulation.
4.0 MODIFIED ORTHOGRAPHIC DRAWINGS 2.1 FLOOR PLANS
GROUND FLOOR | 1:150
FIRST FLOOR | 1:150
4.0 MODIFIED ORTHOGRAPHIC DRAWINGS 2.1 FLOOR PLANS
ROOF | 1:150
4.0 MODIFIED ORTHOGRAPHIC DRAWINGS 2.2 ELEVATIONS
NORTH | 1:150
SOUTH | 1:150
4.0 MODIFIED ORTHOGRAPHIC DRAWINGS 2.2 ELEVATIONS
EAST | 1:150
WEST | 1:150
4.0 MODIFIED ORTHOGRAPHIC DRAWINGS 2.3 SECTIONS
SECTION AA | 1:150
SECTION BB | 1:150
5.0 CONCLUSION Structural analysis of safety, feasibility , economy, integration, stability and strength highlighted the problem areas of the Visitor Interpretive Centre for proposal of amendments. The problems highlighted and amended are: 1. 2. 3. 4. 5. 6.
The addition of a pad foundation Supplying a grid and organising columns according to the plan and increasing the quantity of columns for support Addition of columns and beams for support and even load distribution Connection of the roof slabs to create a single roof span Installation of gutters around the sides of the roof Installation of tensile structure over the open air auditorium
All of the above were discussed with reference to the structural analysis done in the previous sections.We have appraised the technical standards as well as the structural design codes to be applied to the building design.
LIST OF FIGURES Figure Figure 1.1.1 Rendered 3D view of pre-modified VIC
Figure 1.1.2 Rendered 3D view of pre-modified VIC
Page 3
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Figure 3.1.1.1 Section BB’ of pre-modified foundation on stilts.
9
Figure 3.1.1.2 Pad footing showing reinforcement and column connection.
10
Figure 3.1.1.3 Section AA’ of pre modified foundation
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Figure 3.1.1.3 Section AA’ of modified foundation
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Figure 3.1.1.5 Section BB’ of pre-modified foundation type
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Figure 3.1.1.5 Section BB’ of modified foundation type
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Figure 3.1.2.1 Depth of pad footing
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Figure 3.2.1.1 3D view of pre-modified column arrangement
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Figure 3.2.1.2 Floor plan view of pre-modified columns not arranged on grid system
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Figure 3.2.1.3 Ground floor plan view of modified column arrangement and grid system
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Figure 3.2.1.4 Ground Floor plan view of pre-modified column distance
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Figure 3.2.1.5 Ground Floor plan view of modified column distance
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Figure 3.2.2.1 3D view of pre-modified building showing lack of beams
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Figure 3.2.2.3 3D view 2 of modified column and beam arrangement
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Figure 3.2.3.1 Straight beam passing through column for reinforcement
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Figure 3.2.3.2 Beam passing through column for extra support and reinforcement.
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Figure 3.2.3.3 3D view of pre-modified building showing insufficient columns
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LIST OF FIGURES Figure
Page
Figure 3.2.3.4 3D view of modified building with columns
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Figure 3.3.1.1 3D perspective of pre-modified roof
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Figure 3.3.1.2 3D perspective of modified roof
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Figure 3.3.2.1 Construction detail of concrete roof
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Figure 3.3.2.2 Construction detail of metal roof
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Figure 3.3.3.1 Cross section of pre-modified roof without trusses and rafters
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Figure 3.3.3.2 Cross section of modified roof with new trusses and rafters
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Figure 3.3.4.1 Pre-modified roof plan without gutter
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Figure 3.3.4.2 Modified roof plan with gutter
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Figure 3.3.4.3 Modified roof plan with tensile structure over the auditorium
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Figure 3.4.1.1 Pre-modified elevation with brick wall
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REFERENCES BOOKS Ching.F, Zuberbuhler, D. & Onouye, B (2014) Building Structure Illustrated (5th ed. Pp. 67-68, 130-135) New York WILEY ONLINE SOURCES Design and Construction Requirements for Flood Prone Building Structures https://theconstructor.org/building/flood-resistant-building-structures/21187 Advantages and Disadvantages of Pad Footing https://civiltoday.com/geotechnical-engineering/foundation-engineering/179-pad-foundation-advantages-disadv antages Base Foundations http://spunlite.lamp3.wiredgroup.com/technical/base-foundations/ What is Pad Foundation? Types of Pad Footing https://civiltoday.com/geotechnical-engineering/foundation-engineering/178-pad-foundation-definition-types Pad Foundation https://www.designingbuildings.co.uk/wiki/Pad_foundation Types of soil https://www.designingbuildings.co.uk/wiki/Types_of_soil Effects of high groundwater on the stability of buildings and how to control these effects https://www.academia.edu/27091028/EFFECTS_OF_HIGH_GROUNDWATER_ON_THE_STABILITY_OF_BUILDING S_AND_HOW_TO_CONTROL_THESE_EFFECTS Advantages of poured concrete foundation
http://www.grantsllc.com/articles/advantages-of-poured-concrete-foundations/ Advantages and Disadvantages of Brick Masonry Over Stone Masonry - Civil Snapshot https://civilsnapshot.com/advantages-disadvantages-brick-masonry-stone-masonry/ Advantages of brick https://www.randerstegl.com/en/wall-bricks/complete-brickworks/advantages-of-bricks Brick Masonry Definition, Types and Construction https://theconstructor.org/building/brick-masonry-definition-types-construction/25916 Bricks vs Blocks https://www.newvision.co.ug/new_vision/news/1314073/bricks-vs-blocks Design in Brickwork https://faculty.arch.usyd.edu.au/pcbw/walls/loadbearing/index.html Jamal, H. Advantages and Disadvantages of Using Bricks in Construction | Uses & Applications https://www.aboutcivil.org/bricks-advantages-disadvantages-uses.html Mercado, A. Advantages & Disadvantages of Concrete https://www.hunker.com/12003741/advantages-disadvantages-of-concrete-block-homes Russell, S. The Disadvantages of Masonry Construction https://www.hunker.com/12465558/the-disadvatages-of-masonry-construction Strength and stability in concrete blocks https://www.masterbloc.be/concrete-blocks/ Torrie, C. Properties of Concrete Blocks https://www.hunker.com/12310270/properties-of-concrete-blocks Types of Walls https://www.understandingconstruction.com/walls.html What is a Concrete Block Wall? - Definition from Corrosionpedia https://www.corrosionpedia.com/definition/5322/concrete-block-wall Why are gutters so important? https://www.leaffilter.com/blog/home-exteriors/roofing-gutters/why-are-gutters-so-important/ Types of gutters and costs https://www.houselogic.com/organize-maintain/home-maintenance-tips/types-of-gutters/ Metal sheets vs Concrete tiles roof http://www.rempros.com/comparison/metal-sheets-vs-ceramic-tiles-roof.html Naomi R. Pollock, FAIA, Nishinoyama House https://www.architecturalrecord.com/articles/7325-nishinoyama-house House in Louisiana, US