Earthquake Risk Reduction
3- Mitigation and ERR Program Development
Charles SCAWTHORN
Junji KIYONO
Kyoto University
1.
2.
3.
Concepts and Terminology
Hazard, Vulnerability & Risk Assessment
Mitigation and ERR Program Development
Key Terms
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Mitigation
Risk Mitigation Alternatives
Operational
Risk Transfer
Develop the Program
 Benefit-cost ratio
 Acceptable risk
 Implement the Program
 Funding
 Seismic retrofit
 Emergency planning
 Maintain the Program
Mitigation
Four basic methods for Mitigation:
Structural
Locational
Operational
Risk Transfer
Structural
(using buildings as an example)
Bracing
Types
“K”
“V”
Chevron
eccentric
“X”
(a) moment
frame
(b) braced
frame
(c) shear wall
diagonal
CPU
(e) damped
frame
(f) active control system: ground
motion sensor, processor, and
controlled mass
(d) base
isolation
Seismic
Retrofits
Locational
AP
Zone
Fault
Shaking intensity map
California Alquist-Priolo
fault map, showing
location of fault, and zone
within which geologic
investigation is required
Actual fault
Operational
Operational Area EOC
Finance/
Administration
Operations
Planning/
Intelligence
Local Government EOC
Finance/
Administration
Operations
EOC Director
(Management)
Logistics
EOC Director
(Management)
Planning/
Intelligence
Logistics
Risk Transfer
Insurance
company
Reinsurance
company
Single
buildings
Insurance
company
Insurance
company
Single buildings
Single
buildings
Risk Mitigation Alternatives
EARTHQUAKE OCCURS
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.
RESULT
MITIGATION
Hazard mapping; ground
remediation; tsunami walls…
Bracing and strengthening,
reduction of mass, base
isolation, structural control…
Improved storage/infrastructure,
better emergency response…
PRIMARY HAZARDS:
Faulting, Shaking, Liquefaction,
Landsliding, Tsunami…
PRIMARY DAMAGE:
Building / Structural
Nonstructural / Equipment
SECONDARY HAZARD / DAMAGE:
Fire, Hazmat, Flooding…
Demand (hazard)
eliminated or reduced
Capacity
(strength…)
increased
Secondary demands
eliminated or reduced
PRIMARY LOSS:
Life / Injury, Repair Costs, Function,
Communications/Control…
Improved emergency
planning and response;
insurance…
Loss
avoided or shared
SECONDARY LOSS:
Business / Operations Interruption
Market Share, Reputation…
Outline of Risk Reduction Program

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
Factors
- Seismic environment?
- Organization / decisionmaking
- Responsibility / liability
Pre-program
Data
- Seismic hazard
- Exposure
- life
- property
- business / function
- revenue
- data
- market share
- reputation / image
- Vulnerability
- Assessment
Assess the Risk
Stop
YAcceptable?
N
Develop the
Program
Acceptable?
N
Y
Implement the Program
Maintain the Program
Mitigation Options
- Locational
- Redundancy / backup
- Move
- Structural
- Strengthen structures
- Brace equpment /
furnishings
- Operational
- Emerency Plan
- Backup data
- Transfer
- Insurance
- Contracts
Measuring Benefits
$
Constr.
Cost
Tot Cost
Cost
Damage
Design
Level
Benefit Cost Ratio BCR  PV (allfuturebenefits)
PV (allfuture cos ts)
Life Cycle Cost
LCC  PV (allfuturebenefits)  PV (allfuture cos ts)
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
Assess the Risk
Identify the assets (people, property, function) at risk.
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Establishing (i.e. quantifying) the seismic hazard
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It is a representation of how strongly the ground will shake
and how often it is likely to do so.
Developing performance objectives
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The corresponding losses for people, property and function
are death and injury, financial loss, and business interruption,
revenue, market share.
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
Develop the Program
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
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I.
II.
III.
Probable high risk
Possible high risk
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.
Implement the Program
Retaining seismic retrofit design professionals:
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Funding the program; the following sources should generally
considered when planning programs of seismic mitigation.
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Initial investigation and screening
Detailed investigation and conceptual retrofit design
Construction documents and construction support
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.
Maintain the Program
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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.
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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.
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As new personnel join the organization, they can review the
earthquake mitigation program documentation and maintain
the overall goals.
Summary
An 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.