Transcript Document 7605391

IMPACTS OF EARTHQUAKES
ON
WATER RESERVOIRS,
PIPELINES, AQUEDUCTS, AND
DISTRIBUTION SYSTEMS
Walter Hays, Global Alliance for
Disaster Reduction, University of
North Carolina, USA
OVERVIEW OF
EARTHQUAKE RISK
WATER RESERVOIRS, PIPELINES,
AQUEDUCTS, AND DISTRIBUTION
SYSTEMS FACE DIFFERENT RISKS
FROM THE POTENTIAL DISASTER
AGENTS OF EARTHQUAKES
WATER RESERVOIRS, PIPELINES,
AQUEDUCTS, AND DISTRIBUTION SYSTEMS
• Have POINT-SENSITIVE and
AREA-SENSITIVE components, …
• which have varying vulnerabilities
when exposed to the TIME – and
SPACE- DEPENDENT potential
disaster agents of EARTHQUAKES.
TIME HISTORY AND SPECTRUM
RISK ASSESSMENT
•EARTHQUAKES
•INVENTORY
•VULNERABILITY
•LOCATION
ACCEPTABLE RISK
RISK
WATER,RESERV.,
AQUEDUCTS,
PIPELINES,, AND
DISTRIBUTION
DATA BASES
SYSTEMS
AND INFORMATION
UNACCEPTABLE RISK
GOAL: DISASTER
RESILIENCE
PPLICIES:FOR
RESILIENT SYSTEMS
HAZARDS:
GROUND SHAKING
GROUND FAILURE
SURFACE FAULTING
TECTONIC DEFORMATION
TSUNAMI RUN UP
AFTERSHOCKS
PREPAREDNESS
•PROTECTION
•EMERGENCY RESPONSE
•RECOVERY
ELEMENTS OF
UNACCEPTABLE RISK
DAMAGE;
INJURIES
FAILURE;
DEATHS
RISK
LOSS OF
FUNCTION
ECONOMIC
LOSS
SEISMICITY
TECTONIC
SETTING &
FAULTS
EARTHQUAKE
HAZARD MODEL
THE BASIC FAULT MODELS
Strike-Slip
Reverse
Normal
LOCATION OF
WATER
SYSTEMS
IMPORTANCE AND
VALUE OF SYSTEM
AND CONTENTS
EXPOSURE
MODEL
QUALITY OF
DESIGN AND
CONSTRUCTION
ADEQUACY OF
LATERAL-FORCE
RESISTING SYSTEM
VULNERABILITY
MODEL
WATER RESERVOIRS, PIPELINES,
AQUEDUCTS, AND DISTRIBUTION SYSTEMS
• Vulnerability is a function of
materials, age, maintenance,
and the system’s exposure as
a site-specific, or a spatiallydistributed above-or-belowground system.
CONSTRUCTION MATERIALS HAVE
DIFFERENT VULNERABILITIES TO
GROUND SHAKING
MEAN DAMAGE RATIO,
% OF REPLACEMENT VALUE
35
30
25
20
15
10
5
0
V
VI
VII
INTENSITY
VIII
IX
COMMENTS ON DAMAGE
• MMI VI DENOTES TO ONSET OF DAMAGE
DUE TO LIQUEFACTION
• MMI VII DENOTES DAMAGE FROM
CRACKING; APPROXIMATELY 12% g
• MMI VIII DENOTES SEVERE DAMAGE,
TYPICALLY AT JOINTS OF PIPES;
APPROXIMATELY 25 % g
• MMI IX DENOTES VERY HEAVY DAMAGE,
MANY BREAKS/KM; 50 %^ g.
FAULT RUPTURE
DAMAGE/LOSS
EARTHQUAKE
GROUND
SHAKING
DAMAGE/LOSS
TSUNAMI
DAMAGE/ LOSS
TECTONIC
DEFORMATION
DAMAGE/ LOSS
FOUNDATION
FAILURE
DAMAGE/ LOSS
SITE
AMPLIFICATION
DAMAGE/ LOSS
LIQUEFACTION
DAMAGE/ LOSS
LANDSLIDES
DAMAGE/ LOSS
AFTERSHOCKS
DAMAGE/ LOSS
FIRE
DAMAGE/ LOSS
CAUSES
OF
DAMAGE
INADEQUATE RESISTANCE TO
HORIZONTAL GROUND SHAKING
SOIL AMPLIFICATION
PERMANENT DISPLACEMENT
(SURFACE FAULTING, LIQUEFACTION & LANDSLIDES)
EARTHQUAKES
“DISASTER
LABORATORIES”
IRREGULARITIES IN ELEVATION
AND PLAN, AND [OOR ROUTE
TSUNAMI IMPACTS
POOR DETAILING AND WEAK
CONSTRUCTION MATERIALS
FRAGILITY OF NON-STRUCTURAL
ELEMENTS
EXAMPLES OF FAILURES
(AND ALMOST FAILURES)
IN PAST EARTHQUAKES
INADEQUATE SEISMIC DESIGN
PROVISIONS (I.E., BUILDING CODES )
MEAN
1) INADEQUATE RESISTANCE TO
HORIZONTAL GROUND SHAKING
2) COLLAPSE AND FAILURE OF
ABOVE-GROUND SYSTEMS
UNDERGROUND PIPELINES AND DISTRIBUTION SYSTEMS NEED PROTECTION
• A UTILITY CORRIDOR
IS VULNERABLE TO
LOSS OF FUNCTION
WHEN IT IS ROUTED
THROUGH SOILS
THAT ARE
SUSCEPTIBLE TO
LIQUEFACTION. (USA
1995)
INADEQUATE SEISMIC DESIGN
PROVISIONS (I.E., WATER SYSTEM
STANDARDS) AND THE ROUTING)
MEAN
1) SUSCEPTIBILITY TO
PERMANENT GROUND FAILURE
(LIQUEFACTION, LANDSLIDES),
2) FAILURE OF BELOW-GROUND
SYSTEMS
ABOVE-GROUND SYSTEMS NEED
PROTECTION FROM LANDSLIDES
• RESEVOIRS ARE
SUSCEPTIBLE TO
LANDSLIDES
INDUCED BY
EARTHQUAKES.
(CHINA 2008)
AQUEDUCTS: ABOVE-GROUND SYSTEMS
THAT CARRY WATER FROM “A” TO “B”
• AQUEDUCTS ARE
SUSCEPTIBLE TO
LANDSLIDES
INDUCED BY
EARTHQUAKES.
(ARIZONA);
AQUEDUCTS: ABOVE-GROUND SYSTEMS
THAT CARRY WATER FROM “A” TO “B”
• ELEVATED
AQUEDUCTS ARE
VERY SUSCEPTIBLE
TO GROUND
SHAKING.
CHINA 2008: RESERVOIRS NEED
PROTECTION IN AN EARTHQUAKE
JAPAN 2011: ABOVE GROUND SYSTEMS
NEED PROTECTION IN AN EARTHQUAKE
SICHUAN, CHINA: ABOVE GROUND
SYSTEMS NEED PROTECTION
HAITI 2010: ABOVE-GROUND
SYSTEMS NEED PROTECTION
TURKEY 2010: ABOVE GROUND SYSTEMS
NEED PROTECTION
KEY CONSIDERATIONS FOR
PROTECTIVE DESIGN AND
SMART ROUTING
WATER RESERVOIRS, PIPELINES,
AQUEDUCTS, AND DISTRIBUTION
SYSTEMS
WATER RESERVOIRS, PIPELINES,
AQUEDUCTS, AND DISTRIBUTION SYSTEMS
• Above-ground siting makes waterreservoirs and aqueducts more
vulnerable to earthquake ground
shaking than the buried pipelines
and distribution systems are.
EARTHQUAKE SCENARIOS
A DISASTER RISK
ASSESSMENT TECHNIQUE
FOR USE IN AN EARTHQUAKEPRONE AREA
DESIGN SCENARIOS
• Distributed Systems: The risks
need to be assessed in terms
of regional ground shaking
and ground failure maps; --• Non-distributed systems:
Assess risks in terms of sitespecific criteria.
EXAMPLE: PROBABILISTIC
GROUND SHAKING HAZARD
MAPS
PGA: 10 % P(EXCEEDANCE) IN
50 YEARS
SOURCE
GLOBAL SEISMIC HAZARD
ASSESSMENT PROGRAM
US GEOLOGICAL SURVEY
A probabilistic ground shaking hazard
map integrates physical properties
determined from geology, geophysics,
and seismology in a consistent way to
define:
1) Seismic source zones
2) Regional seismic wave attenuation
rates
• Seismic Source Zones: Each zone has
its own unique spatial and temporal
distribution of faults, magnitudes and
recurrence intervals.
• Regional Seismic Attenuation Rates:
seismic waves decay more rapidly near a
plate boundary than far from the
boundary.
GROUND SHAKING HAZARD ASSESSMENT
SESMIC SOURCES
ATTENUATION
RECURRENCE
PROBABILITY
Each map shows relative
levels of the ground shaking
hazard on a small scale in
terms of the mapping
parameter: peak ground
acceleration (and sometimes
MMI).
PEAK GROUND ACCELERATION
Peak ground acceleration
correlates best with the shortperiod asymptote of the
response spectrum, and is
related to how a short waste
water facility would respond
to ground shaking.
The maps are most useful for
small-scale applications
such as comparison of the
relative ground shaking
hazard between the endpoints of a long, distributed
water pipeline system.
• The mapping parameter, peak ground
acceleration, is not as good a
descriptor of how the ground actually
shakes as is a time history
• The response spectrum of a time
history is an approximation of how a
water system element might respond
to ground shaking of a certain period.
• The regional-scale peak ground
acceleration maps are not
appropriate for site-specific
design.
• Regional maps do not
incorporate information on soil
properties (e.g., shear wave
velocity; data related to
liquefaction; slope stability).
• Soils data require sampling
and mapping on a larger scale.
PGA SCALE FOR MAPS
Afghanistan
http://www.seismo.ethz.ch/gshap/eastasia/
RISK ASSESSMENT LEAD TO
POLICY IMPLEMENTATION
RISK ASSESSMENT
• VULNERABILITY
• COST
• EXPOSURE
“WATER
SYSTEMS”
• EVENT
EXPECTED
LOSS
• BENEFIT
•CONSEQUENCES
POLICY ASSESSMENT
RESILIENT
SYSTEMS