Seismic mitigation final

1. Concepts and Terminology By,

2. Hazard, Vulnerability & Risk Assessment Kalaiselvam.A

3. Mitigation and ERR Program Development Suganya.P

Mitigation Risk Mitigation Alternatives Risk Transfer Develop the Program

Benefit-cost ratio Acceptable risk

Implement the Program Funding Seismic retrofit Emergency planning

Maintain the Program

Key TermsKey Terms

EFFECTS OF EARTH QUAKEEFFECTS OF EARTH QUAKE

MitigationMitigation

Four basic methods for Mitigation:StructuralNon-StructuralLocationalRisk Transfer

StructuralStructural (using buildings as an (using buildings as an example)example)

(a) moment frame

(d) base isolation

Bracing Types

“K”

“V”

Chevron

eccentric

“X”

diagonal(b) braced frame

(c) shear wall

(e) damped frame

CPU

(f) active control system: ground motion sensor, processor, and

controlled mass

Seismic RetrofitsSeismic Retrofits

NON-STRUCTURAL MITIGATIONNON-STRUCTURAL MITIGATION

• involves retrofitting a building’s non-structural involves retrofitting a building’s non-structural

elementselements (exterior elements, interior elements, (exterior elements, interior elements, building electrical, mechanical and plumbing systems, building electrical, mechanical and plumbing systems, and contents). and contents).

• A breakdown of common non-structural mitigation techniquesA breakdown of common non-structural mitigation techniques is presented below:is presented below:

• 1. 1. Brace Exterior Elements Brace Exterior Elements

• 2. 2. Anchor Interior ElementsAnchor Interior Elements

• 3. 3. Protect Building Electrical, Mechanical, and PlumbingProtect Building Electrical, Mechanical, and Plumbing SystemsSystems

• 4. 4. Secure Building ContentsSecure Building Contents

LocationalLocational

California Alquist-Priolo fault map, showing location of fault, and zone within which geologic investigation is required

AP Zone

Fault

Actual fault

Shaking intensity map

Single buildings

Insurance company

Single buildings

Insurance company

Single buildings

Insurance company

Reinsurance company

Risk TransferRisk Transfer

Mitigation of damage and loss is possible at each step of earthquake loss process; earthquake occurs, primary hazards, primary damage, secondary hazard/damage, primary loss, and secondary loss.

Risk Mitigation AlternativesRisk Mitigation Alternatives

EARTHQUAKE OCCURSEARTHQUAKE OCCURS

PRIMARY HAZARDS:Faulting, Shaking, Liquefaction, Landsliding, Tsunami…

PRIMARY HAZARDS:Faulting, Shaking, Liquefaction, Landsliding, Tsunami…

SECONDARY LOSS:Business / Operations InterruptionMarket Share, Reputation…

SECONDARY LOSS:Business / Operations InterruptionMarket Share, Reputation…

PRIMARY LOSS:Life / Injury, Repair Costs, Function, Communications/Control…

PRIMARY LOSS:Life / Injury, Repair Costs, Function, Communications/Control…

SECONDARY HAZARD / DAMAGE:Fire, Hazmat, Flooding…

SECONDARY HAZARD / DAMAGE:Fire, Hazmat, Flooding…

PRIMARY DAMAGE:Building / StructuralNonstructural / Equipment

PRIMARY DAMAGE:Building / StructuralNonstructural / Equipment

MITIGATION

Improved emergency planning and response; insurance…

Improved emergency planning and response; insurance…

Hazard mapping; ground remediation; tsunami walls…

Bracing and strengthening, reduction of mass, base isolation, structural control…

Improved storage/infrastructure, better emergency response…

RESULT

Demand (hazard) eliminated or reduced

Demand (hazard) eliminated or reduced

Capacity (strength…)

increased

Capacity (strength…)

increased

Loss avoided or shared

Loss avoided or shared

Secondary demandseliminated or reduced

Secondary demandseliminated or reduced

Earthquakes are a problem, in the most general sense, solving a problem has three basic phases.

Phase 1: Understanding the problem

Phase 2: Finding the solution

Phase 3:Putting the solution into effect

Outline of Risk Reduction Outline of Risk Reduction ProgramProgram

Pre-program

Assess the Risk

Develop the Program

N

Acceptable?YStop

Acceptable?

Y

N

Implement the Program


Factors - Seismic environment? - Organization / decision-making - Responsibility / liability

Data - Seismic hazard - Exposure - life - property - business / function - revenue - data - market share - reputation / image - Vulnerability - Assessment

Mitigation Options - Locational - Redundancy / backup - Move - Structural - Strengthen structures - Brace equpment / furnishings - Operational - Emerency Plan - Backup data - Transfer - Insurance - Contracts

Pre-program

Assess the Risk

Develop the Program

N

Acceptable?YStop

Acceptable?

Y

N






Pre-program

Assess the Risk

Develop the Program

N

Acceptable?YStop

Acceptable?

Y

N






Measuring BenefitsMeasuring Benefits

Internal Rate of Return is the discount rate that “sets the net present value of the stream of net benefits [and costs] equal to zero”- effectively a measure of the return on investment

( )

( cos )

PV allfuturebenefitsBCR

PV allfuture tsBenefit Cost Ratio

( ) ( cos )LCC PV allfuturebenefits PV allfuture ts

Life Cycle Cost

Cost Damage

$

Design Level

Tot Cost

Constr.Cost

Identify the assets (people, property, function) at risk.

The corresponding losses for people, property and function are death and injury, financial loss, and business interruption, revenue, market share.

Establishing (i.e. quantifying) the seismic hazard

It is a representation of how strongly the ground will shake and how often it is likely to do so.

Developing performance objectives No loss of life (no significant collapse hazard), limited

property loss, no loss of essential equipment, and restoration of operation onsite or backup site within the time appropriate for the organization.

Performing first a risk screening and then, for selected structures, a more detailed review

Assess the RiskAssess the Risk

Developing the program, which consists of determining the acceptable risk, the opinions that exist for reducing the current risk to an acceptable level, the costs of doing that, and how it should be accomplished.

Having performed risk screening, facilities may be usefully grouped into several categories, such as

I. Probable high risk II. Possible high risk III. Probable low risk

The category I and category II facilities should be subjected to a more detailed analysis.

All the category I and II facilities can be ranked according to their risk, mitigation costs, or other criteria. The ranking is based on a benefit-cost ratio.

The final decision as to what facilities to mitigate will depend on available budget and is the final expression of the organization’s acceptable risk.

Develop the ProgramDevelop the Program

Retaining seismic retrofit design professionals: Initial investigation and screening Detailed investigation and conceptual retrofit design Construction documents and construction support

Funding the program; the following sources should generally considered when planning programs of seismic mitigation.

General operating and maintenance funds Bond issues Special use fee Hazard mitigation grants Tax preferences and credits

Coordinating with other parts of the organization; it is very important to include earthquake risk mitigation measures with other facets of an organization’s asset management program.

Implement the ProgramImplement the Program

Organizations are dynamic and facilities, operations, and personnel are constantly changing. Thus documentation of the step taken, including the process and criteria, is an important step to complete.

As new facilities or operations are developed, the same or enhanced criteria can be applied to them, thus retaining the overall balance of earthquake mitigation program.

As new personnel join the organization, they can review the earthquake mitigation program documentation and maintain the overall goals.

Maintain the ProgramMaintain the Program

DETERMINE THE LEVEL OF DETERMINE THE LEVEL OF SEISMIC HAZARDSEISMIC HAZARD

Figure 3-1: USGS Earthquake Hazard Map

Suggested Community Seismic Hazard Programs Based on Suggested Community Seismic Hazard Programs Based on Seismic Hazard LevelsSeismic Hazard Levels

Map ColourMap Colour SeismicSeismic

HazardHazard

LevelLevel

Suggested CommunitySuggested Community

Seismic HazardSeismic Hazard

Mitigation ProgramMitigation Program

Comments on Cost-Comments on Cost-

EffectivenessEffectiveness

RedRed HighHigh Extensive programExtensive program

Mitigation of these facilities first priorityMitigation of these facilities first priorityMany, but not all mitigationMany, but not all mitigation

projects.projects.

Red OrangeRed Orange ModeratelyModerately

HighHighSubstantial programSubstantial program

Mitigation of theseMitigation of these

facilities a high priority.facilities a high priority.

Some, but not all mitigationSome, but not all mitigation

projectsprojects

Light OrangeLight Orange ModerateModerate Mitigation of highlyMitigation of highly

critical and highlycritical and highly

Vulnerable facilities should be considered.Vulnerable facilities should be considered.

Few mitigation projectsFew mitigation projects

YellowYellow ModeratelyModerately

LowLowMitigation of very criticalMitigation of very critical

and very vulnerableand very vulnerable

facilities should befacilities should be

considered.considered.

Very few projectsVery few projects

GreenGreen LowLow Mitigation of exceptionallyMitigation of exceptionally

critical and exceptionallycritical and exceptionally

vulnerable facilities shouldvulnerable facilities should

be consideredbe considered

Mitigation projects willMitigation projects will

rarely be cost-effectiverarely be cost-effective

except in uniqueexcept in unique

circumstancescircumstances

BlueBlue Very LowVery Low Seismic risk probably notSeismic risk probably not

significant. Mitigation ofsignificant. Mitigation of

these facilities a lowthese facilities a low

priority.priority.

Mitigation projects are mostMitigation projects are most

likely not required or notlikely not required or not

cost-effectivecost-effective

GrayGray NegligibleNegligible Seismic risk negligible.Seismic risk negligible.

Mitigation not required.Mitigation not required.Mitigation not requiredMitigation not required

SummarySummaryAn Earthquake Risk Reduction Program involves the following

steps:

1. ASSETS: Identify and map the assets at risk – the people, property, business and cultural treasures. Where are they, how many are they, what is their value?

2. HAZARDS: Map the earthquake hazards that threaten these assets. Hazards include faulting, shaking, liquefaction, tsunami, landslide, fire.

3. VULNERABILITY: Assess the vulnerability of each asset to the hazards – is an highly vulnerable, moderately, or just low?

4. ANALYZE: Combine the information on Assets, Hazards and Vulnerability into a Risk Analysis. Map the areas of High Risk.

5. MITIGATION: Based on the assets, hazards and vulnerabilities, identify various ways in which the risk can be lowered. Select the mitigation method that makes the most sense – ie, is most effective for the least cost.

6. DEVELOP THE PROGRAM: Having a mitigation package, gather community support and find ways to pay for the mitigation. Develop a Plan for doing the mitigation over a several year timeframe.

7. IMPLEMENT THE PROGRAM: Do it. Don’t stop. Earthquakes won’t wait.

Seismic mitigation final

Education

Transcript of Seismic mitigation final