IMPACTS OF EARTHQUAKES ON WATER RESERVOIRS, PIPELINES, AQUEDUCTS, AND DISTRIBUTION SYSTEMS
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Transcript of IMPACTS OF EARTHQUAKES ON WATER RESERVOIRS, PIPELINES, AQUEDUCTS, AND DISTRIBUTION SYSTEMS
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
WATER,RESERV.,WATER,RESERV.,AQUEDUCTS, AQUEDUCTS,
PIPELINES,, AND PIPELINES,, AND DISTRIBUTION DISTRIBUTION
SYSTEMSSYSTEMSDATA BASES DATA BASES AND INFORMATIONAND INFORMATION
HAZARDS: GROUND SHAKING GROUND FAILURE SURFACE FAULTING TECTONIC DEFORMATION TSUNAMI RUN UP AFTERSHOCKS
•EARTHQUAKES•INVENTORY•VULNERABILITY•LOCATION
RISK ASSESSMENTRISK ASSESSMENT
RISK
ACCEPTABLE RISK
UNACCEPTABLE RISK
GOAL: DISASTER GOAL: DISASTER RESILIENCERESILIENCE
PREPAREDNESS•PROTECTION•EMERGENCY RESPONSE•RECOVERY
PPLICIES:FOR PPLICIES:FOR RESILIENT SYSTEMSRESILIENT SYSTEMS
DAMAGE; DAMAGE; INJURIESINJURIES
ELEMENTS OF ELEMENTS OF UNACCEPTABLE RISKUNACCEPTABLE RISK
FAILURE; FAILURE; DEATHSDEATHS
LOSS OF LOSS OF FUNCTIONFUNCTION
ECONOMICECONOMIC
LOSSLOSS
RISKRISK
EARTHQUAKEHAZARD MODEL
SEISMICITY TECTONICSETTING &
FAULTS
THE BASIC FAULT MODELS
Strike-Slip Reverse
Normal
EXPOSUREMODEL
LOCATION OFWATER
SYSTEMS
IMPORTANCE AND VALUE OF SYSTEM
AND CONTENTS
VULNERABILITYMODEL
QUALITY OF DESIGN AND
CONSTRUCTION
ADEQUACY OF LATERAL-FORCE
RESISTING SYSTEM
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 spatially- distributed above-or-below-ground system.
UNREINFO
RCED MASONRY, B
RICK O
R STO
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REINFORCED CONCRETE WITH UNREINFORCED W
ALLS
INTENSITYINTENSITY
REINFORCED CONCRETE WITH REINFORCEDWALLS
STEEL FRAME
ALL METAL & WOOD FRAME
VV VIVI VIIVII VIIIVIII IXIX
3535
3030
2525
2020
1515
1010
55
00
MEA
N D
AMAG
E RA
TIO
,
%
MEA
N D
AMAG
E RA
TIO
,
%
OF
REPL
ACEM
ENT
VALU
EO
F RE
PLAC
EMEN
T VA
LUE
CONSTRUCTION MATERIALS HAVE DIFFERENT VULNERABILITIES TO GROUND
SHAKING
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.
TECTONIC DEFORMATION
EARTHQUAKE
TSUNAMI
GROUNDSHAKING
FAULT RUPTURE
FOUNDATION FAILURE
SITE AMPLIFICATION
LIQUEFACTION
LANDSLIDES
AFTERSHOCKS
FIRE
DAMAGE/LOSSDAMAGE/LOSS
DAMAGE/ LOSSDAMAGE/ LOSS
DAMAGE/ LOSSDAMAGE/ LOSS
DAMAGE/ LOSSDAMAGE/ LOSS
DAMAGE/ LOSSDAMAGE/ LOSS
DAMAGE/ LOSSDAMAGE/ LOSS
DAMAGE/ LOSSDAMAGE/ LOSS
DAMAGE/ LOSSDAMAGE/ LOSS
DAMAGE/ LOSSDAMAGE/ LOSS
DAMAGE/LOSSDAMAGE/LOSS
INADEQUATE RESISTANCE TO HORIZONTAL GROUND SHAKING
EARTHQUAKES
SOIL AMPLIFICATION
PERMANENT DISPLACEMENT (SURFACE FAULTING, LIQUE-FACTION
& LANDSLIDES)
IRREGULARITIES IN ELEVATION AND PLAN, AND [OOR ROUTE
TSUNAMI IMPACTS
POOR DETAILING AND WEAK CONSTRUCTION MATERIALS
FRAGILITY OF NON-STRUCTURAL ELEMENTS
CAUSES OF DAMAGE
“DISASTER LABORATORIES”
EXAMPLES OF FAILURES (AND ALMOST FAILURES) IN PAST EARTHQUAKES
INADEQUATE SEISMIC DESIGN PROVISIONS (I.E., BUILDING CODES )
MEAN 1) INADEQUATE RESISTANCE TO HORIZONTAL GROUND SHAKING2) COLLAPSE AND FAILURE OF
ABOVE-GROUND SYSTEMS
UNDERGROUND PIPELINES AND DISTRIB-UTION 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 water- reservoirs 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 EARTHQUAKE-PRONE 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 site-specific criteria.
EXAMPLE: PROBABILISTIC GROUND SHAKING HAZARD
MAPSPGA: 10 % P(EXCEEDANCE) IN
50 YEARSSOURCE
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 zones2)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 ASSESSMENTGROUND SHAKING HAZARD ASSESSMENT
ATTENUATION
SESMIC SOURCES 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 short-period 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 end-points 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.
http://www.seismo.ethz.ch/gshap/eastasia/
PGA SCALE FOR MAPS
Afghanistan
RESILIENT RESILIENT SYSTEMSSYSTEMS
RISK ASSESSMENT
• VULNERABILITYVULNERABILITY
• EXPOSUREEXPOSURE
• EVENTEVENT
POLICY ASSESSMENT
• COSTCOST
• BENEFITBENEFIT
•CONSEQUENCESCONSEQUENCES
RISK ASSESSMENT LEAD TO POLICY RISK ASSESSMENT LEAD TO POLICY IMPLEMENTATIONIMPLEMENTATION
““WATER WATER SYSTEMS”SYSTEMS” EXPECTED EXPECTED
LOSSLOSS