RETROFITTING before and after disaster by Michal Slรกdek
Content: - overview on retrofitting techniques - retrofitting in humanitarian shelter - challenges of retrofitting
- Definition: Definition „Retrofitting refers to the addition of new technology or features to older systems.” - In this context: “Retrofitting is the intervention on shelter that decreases vulnerability towards natural threats.“
Retrofitting in humanitarian context
Random rubble masonry wall
Strengthening walls
Brick masonry wall
Rainforced concrete wall
Additional reinforced concrete layer - „jacketing“
Masonry column jacketing
Strengthening elements
RC column jacketing Reinforced concrete beam jacketing
Seismic belt tightening
tightening of projection with a steel rod
detail of belt on lintel level seismic belt around the building
installing of seismic belt
Strengthening integrity
strengthening the openings
Timber construction
truss to top plate strapping
strenghtening
purlin to rafter strapping
additional cross-bracing
stud to top plate strapping
anchor bolts for wall-tofoundation connection
Timber construction strengthening
adaptable steel elements
prefabricated steel elements
wire
nails
screw s
bolts
ground screw mesh rebar
straps hooks
welded web
plates and angles
– Steel is principal constructional material in retrofitting practise. Most of the techniques are introducing steel elements into the existing parts of vulnerable buildings. Steel in retrofitting
During „standard“situation, just vertical loads are exerting
During hurricane or earthquake, also lateral loads arise
For the vertical loads, parts of To deal with accidental loads, the structure can be just laid on structure has to behave as a on the other block
*What makes vulnerable buildings: - Lack of knowledge ? - Lacke of resources ? Vulnerability of non-engineered structures
BUILDING POLICIES
EMERGENCY SHELTER
RETROFITTING TRANSITIONAL SHELTER
PERMANENT HOUSING
Disaster management cycle and shelter
Retrofitting practise after emergency: - Local technical knowledge - Simple technologies - Local materials - Driven by families
Retrofitting in emergency
Good use of tarpaulins from IFRC shelter kit in Myanmar 2008 The image cannot be display ed. Your computer may not hav e enough memory to open the image, or the image may hav e been corrupted. Restart y our computer, and then open the file again. If the red x still appears, y ou may hav e to delete the image and then insert it again.
During reconstruction after the floods, imporved design of traditional hut was introduced. Uganda 2007. The design of hut was „retrofitted“. „retrofitted“
Plinth foundations on plastic sheet Roof elements wire strengthening
Reconstruction phase – build back better
Core 200 shelter Sri Lanka 2008. The resistant structure can be finished by owners. Initial deing
Initial design with good resistance: steel reinforcment in structural elements and corrugated iron roof. Development phase – core approach
before retrofitting
after:
seismic belt crossbracing wall-toroof connectors
Sultan Dagi high school, Kasmir Mitigation by retrofitting
* 8 October 2005 an earthquake hits Kasmir. (Sultan Dagi school suffered just moderate damage). -> Documentation and assessment of damage has been made -> -> Decision about retrofitting was taken -> -> Engineered project was prepared -> -> Retrofitting has been realised. realised
Drawings and execution
Note: This is a multi-room public edifice, designed and engineered. Retrofitting process
Rising awarness is a part of mitigation activities: Retrofitting instruction should take place, as at this informational poster from Bangladesh for owner-driven retrofitting. HOWEVER, emerging issues like: - population growth - urbanisation in disaster prone areas - non-engineer use of modern material are making retrofitting complex
Mitigation
Evaluation table of retrofitting for humanitarian use advantages
obstacles
- sustainable solution – helps to build resilient communities
- expensive solution, requires an invasive intervention on building
- displacement of housing or people is avoided
- high level of engineering is required*
- self-driven and stepwise retrofitting possible
- time consuming procedure (assessment, project, realisation)
- less resources are used compared to building new NOTES: *More heavy the structure is, more complex is the retrofitting. Cost of retrofitting is relevant in consideration the possible collapse.
Evaluation
Resistant building = resources + time + knowledge - In post-disaster period, there is lack in resources and affected community is often in pressing situation. - Resistance can be added in several steps over a longer period of time, when resources become available. - Knowledge is the part, where most of improvements can be made in every stage of humanitarian response. Not only concerning local communities and authorities, but as well donors and humanitarian actors. Design should consider the possible retrofitting in future.
Resistance and retrofitting conclusion
Retrofitting is part of the humanitarian response tools. Though it has a specific position and principal challenges to face: - How to spread quite sophisticated technical knowledge into the communities and also to local authorities? - After humanitarian shelter intervention, how to keep the level of construction once the humanitarian mission is over? - How to rise resources for retrofitting. In post-disaster period most resources are in use for the affected families, which became homeless. In pre-disaster period the is no emergency. Can international humanitarian organisation act in some areas because af high risk? Can there be a humanitarian response without disaster?
Oustanding challenges
Acknowledgements for principal source of illustrations: UNESCO/UNDP India „Manual for Restoration and Retrofitting of Rural Structures in Kashmir“ Prepared for UNESCO by Rajendra Desai, Rupal Desai and the team of the National Centre for Peoples’- Action in Disaster Preparedness (NCPDP). India, 2007 UN Habitat „IASC Emergency Shelter Cluster SHELTER PROJECTS 2008“ UN Habitat 2008 UN Habitat „IASC Emergency Shelter SHELTER PROJECTS 2009“ UN Habitat 2009 Zarins, Jake „‘CORE 200’ SHELTER INTERVENTION PROJECT REPORT & METHODOLOGY DISCUSSION“ Norwegian refugee council, Sri Lanka 2008 & Myanmar Red Cross Society 2008.
RETROFITTING before and after disaster Michal Sládek michalsladek@stonline.sk
Thank you for your attention!