Earthquake Readiness Capacity Building Project BUILDERS TOOLKIT

WHAT TO DO WHEN PLANNING TO BUILD This presentation is part of the DEVELOPERS, DESIGNERS & BUILDERS TOOLKIT of the CDEMA Earthquake Readiness Public Awareness & Education Campaign in the Caribbean This toolkit is downloadable from

3 WHAT WE WILL LEARN Best Practices For:  Site Selection & Construction Planning  Building and Designing  Strengthening Schemes in construction  Construction along a coastline  Building in Tsunami-prone areas

4 FACT Every year, earthquakes take the lives of thousands, and destroy property. It is imperative that structures are designed to resist earthquake forces, in order to reduce the loss of life. Structural design plays an important role.

5 FACT Ground shaking from earthquakes can collapse structures; Buildings not seismically sound or placed on unsuitable soil are at risk of collapsing; When an earthquake occurs in a populated area, it may cause deaths, injuries and extensive property damage.

6 Hence the claim that " Earthquake don't kill people, buildings do."

7 THINGS TO CONSIDER The size of the earthquake does not mean there will be more damage and destruction. Rather, it is how well informed people are at responding to earthquakes and how much money can be spent on making structures able to respond to the ground movements. Design a Building to withstand Earthquakes tutorial / /

8 BUILDING CLASSIFICATIONS Seismic intensity of zone where building will be constructed; Importance of the building Stiffness of the foundation soil

9 SEISMIC ZONES Zone A: Risk of widespread collapse and destruction -MSK 1X or greater) Zone B: Risk of collapse and heavy damage (MSK V111 likely) Zone C: Risk of damage – (MSK V11 likely) Zone D: Risk of minor damage (MSK V1 maximum)

10 CATEGORISING BUILDINGS o Hospitals & Clinics o Schools/ Universities, Churches o Police & Fire stations o Cinemas & Theatres o Stadiums, museums o Meeting halls o Homes, Offices o Factories and warehouses o Hotels

11 CATEGORIES OF BUILDINGS FOR STRENGTHENING PURPOSES CategoriesCombination of conditions for categories 1Important buildings on soft soil in zone A 11Important buildings on firm soil in zone B Important buildings on soft soil in zone B Ordinary building on soft soil in zone A 111Important buildings on firm soil in zone B Important buildings on soft soil in zone C Ordinary buildings on firm soil in zone A Ordinary building on soft soil in zone B 1VImportant buildings on firm soil in zone C Ordinary buildings on firm soil in zone B Ordinary building on firm soil in zone B Firm soils refer to those have safe bearing value; Weak soils are liable to compaction and liquefaction under earthquake conditions

All structures should be designed and built to stand up to earthquakes. Ensure that the land to be developed is suitable and the proposed building is adequately designed to survive an earthquake. The more you know, the better prepared you are. Knowing … that’s where reducing vulnerability starts. 12

Investigate F ind out whether the area in which you intend to build is susceptible to rockslides or land slippage 13

TALK TO OLD- TIMERS 14

CONSULT ZONAL MAPS AVAILABLE THROUGH THE PUBLIC SERVICE 15

RESEARCH BUILDING CODES 16

EMPLOY BEST PRACTICE BUILDING AND DESIGN STANDARDS 17

 Consult a qualified engineer, architect or other authority to find out how safe your location is.  Build on stable soil in an area not prone to natural hazards.  Construct only in approved Construction zones. WHEN PLANNING TO BUILD Site selection

GET APPROVAL Site selection… Get planning approval in principle/outline approval. Coastal areas are vulnerable to tsunamis. Set back to higher ground where possible. 19

DESIGN 20

21  Design in accordance with the recommended building codes. *  Ensure that “seismic-proofing” takes into account the need to secure critical equipment.  Design connections of building elements (footings, floor, wall, roof, etc) properly. DESIGN

Select favourable building envelope geometry. DESIGN 22

23 Source: Ebook – General concepts of Earthquake resistant design

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26 3 D CONCEPTS Interrelated, refers to buildings ability to suffer extensive deformation without collapsing Buildings ability to suffer extensive damage without partial or complete collapse Ductability /Deformability Damageability

 Set back at least 6 m from the back/crest of terrace, and 6m from the back of the slope.  Build away from large, mature trees approx. 6 m away or a distance equal to the tree height. 27 CONSTRUCTON

CONSTRUCTION Brace building elements properly. Design the columns to be stronger than the beams 28

CONSTRUCTION 29

CONSTRUCTION  Use quake-resistant building techniques  Use correct quality construction materials  Store construction materials properly 30

 Protect window and door openings to keep the envelope watertight.  Protect foundations from scour, build the ground floor above flood water level.  Locate top of footings 600 mm (2’) minimum below the external ground.  Position the ground floor 300 mm (12”) minimum above the external ground. CONSTRUCTION 31

FOUNDATIONS 32 SOME REQUIREMENTS FOR STRUCTURAL SAFETY

33 SOME REQUIREMENTS FOR STRUCTURAL SAFETY  Design free standing walls to be as safe as a vertical cantilever.  Horizontal reinforcement is necessary to transfer load  Walls should be tied.  Place shear walls on both axes of the building

34 SOME REQUIREMENTS FOR STRUCTURAL SAFETY  A shear wall must be capable of resisting all horizontal forces.  Roof and floor elements tied and able to exhibit diaphragm action  Trusses must be anchored to the supporting walls and have an arrangement for transferring their own inertia force to the end walls

35 FOUNDATIONS

DOWNLOAD INFORMATION Safer Building Handbook for Homeowners in the Caribbean also 36 cs/FinalCDERACodeofPracticefor ConstrofHouses.pdf

37 Common seismic problems

IN WOOD FRAME BUILDINGS 38 Lack of foundation bolts

39 Cripple wall collapse IN WOOD FRAME BUILDINGS

COMMON SEISMIC PROBLEMS 40 Soft storey park under parking

REDUCING DAMAGE THROUGH STRUCTURAL MODIFICATION 41

STRENGTHENING SCHEMES 42

– Water tanks – Water heaters – Gas cylinders – Storage wall units IF IT CAN FALL/OPEN – VOLT BRACE OR FASTEN! Brace or fasten - Heavy furniture - Mirrors - Light fixtures - Shelves - TVs 43

OTHER STRENGTHENING SCHEMES 44  Add plywood sheathing to soft story  Manufactured strong-walls  Mechanical energy-dissipation devices  Lots of measures for household contents – Strap water heater to frame – Latches on cabinets – Strap tall furniture to frame – Shelf lips

REMEMBER ….. A high percentage of earthquake loss is caused by failure of : o ceilings o windows o doors o partitions o cupboard and shelves o external cladding/siding o electrical & mechanical systems o & other components of buildings 45 OTHER STRENGTHENING SCHEMES

EARTHQUAKE ENGINEERING 46 PERFORMANCE BASED Source © Keith A. Porter, PE, PhD, GW Housner Senior Researcher California Institute of Technology

47 PERFORMANCE BASED EARTHQUAKE ENGINEERING ( Estimating the future seismic performance of buildings and other facilities in terms of repair costs, health impacts, and repair durations. Dollars, deaths and downtime)”

48 Step 1: DEFINE STRUCTURE TO BE BUILT Building Site, soil

49 Step 2: HOW STRONGLY DOES THE GROUND SHAKE Building Site, soil Fault Rupture: magnitude, other features

50 Step 3: HOW MUCH DOES BUILDING DEFORM Building Site, soil Fault Rupture: magnitude, other features

51 Step 4: WHAT GETS BROKEN? Building Site, soil Fault Rupture: magnitude, other features

52 Step 5: WHAT DOES IT COST TO FIX? Building Site, soil Fault Rupture: magnitude, other features

53 In other words, where is it likely to be cost- effective to seismically strengthen a structure?

WHEN PLANNING TO BUILD >>> TSUNAMIS & FLOOD PRONE AREAS 54

 Know the risk for tsunamis in the area.  Consider a Tsunami Evacuation Point higher than 35 metres above sea level. Download Checklist for Designing to Counteract Natural Hazards from Site Selection 55

Design & Construction (Tsunami)  Elevate coastal buildings because most tsunamis waves are less than 30 metres high 56  Install features to divert waves away from the property.

Tsunamis & Flood prone areas Additional Shoreline protection 57 Protect coral reefs. Stabilise dunes

 Maintain and/or build wetlands and mangroves and keep them healthy. These act as natural shock absorbers, soaking up destructive waves. In the 2004 tsunamis in Asia, wetlands were believed to have protected lives and properties. Mangroves can absorb 70-90% of the energy from a normal wave. BBC News 25 Dec Tsunamis & Flood prone areas Additional Shoreline protection 58

Tsunamis & Flood prone areas Additional Shoreline protection 59. Shrubs, grasslands, and marshes will not provide adequate protection against tsunami waves, but will help to absorb flood water.

Tsunamis & Flood prone areas Additional Shoreline protection  Where possible, build structures to help protect the shoreline from tsunami damage.  Build seawalls and revetment structures to help protect the shore from storm waves. 60

And finally… A Caribbean Building Code?  There is currently no regional building standard to guide and enforce safe building.  The Caribbean Regional Organisation for Standards Quality (CROSQ) Regional Building Standard project is intended to review base codes, prepare Caribbean Application Documents, train users, strengthen building authorities and build consensus among key stakeholders.  For more information, visit