IMPACTS OF EARTHQUAKES ONWATER RESERVOIRS, PIPELINES, AQUEDUCTS, AND DISTRIBUTION SYSTEMS

Walter Hays, Global Alliance for Disaster Reduction, University of North Carolina, USA

OVERVIEW OF EARTHQUAKE RISKWATER 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.,AQUEDUCTS, PIPELINES,, AND DISTRIBUTION SYSTEMSDATA BASES AND INFORMATIONHAZARDS: GROUND SHAKING GROUND FAILURE SURFACE FAULTING TECTONIC DEFORMATION TSUNAMI RUN UP AFTERSHOCKS

ELEMENTS OF UNACCEPTABLE RISKRISK

EARTHQUAKEHAZARD MODEL

THE BASIC FAULT MODELSStrike-SlipReverseNormal

EXPOSUREMODEL

VULNERABILITYMODEL

WATER RESERVOIRS, PIPELINES, AQUEDUCTS, AND DISTRIBUTION SYSTEMS Vulnerability is a function of materials, age, maintenance, and the systems exposure as a site-specific, or a spatially- distributed above-or-below-ground system.

INTENSITYMEAN DAMAGE RATIO, % OF REPLACEMENT VALUECONSTRUCTION MATERIALS HAVE DIFFERENT VULNERABILITIES TO GROUND SHAKING

COMMENTS ON DAMAGEMMI VI DENOTES TO ONSET OF DAMAGE DUE TO LIQUEFACTION MMI VII DENOTES DAMAGE FROM CRACKING; APPROXIMATELY 12% gMMI VIII DENOTES SEVERE DAMAGE, TYPICALLY AT JOINTS OF PIPES; APPROXIMATELY 25 % gMMI IX DENOTES VERY HEAVY DAMAGE, MANY BREAKS/KM; 50 %^ g.

GROUNDSHAKING

INADEQUATE RESISTANCE TO HORIZONTAL GROUND SHAKINGEARTHQUAKESSOIL AMPLIFICATIONPERMANENT 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 ELEMENTSCAUSES OF DAMAGEDISASTER 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 SCENARIOSA 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 YEARSSOURCEGLOBAL SEISMIC HAZARD ASSESSMENT PROGRAMUS GEOLOGICAL SURVEY

A probabilistic ground shaking hazard map integrates physical properties determined from geology, geophysics, and seismology in a consistent way to define:Seismic source zonesRegional 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

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 historyThe 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 MAPSAfghanistan

RISK ASSESSMENT LEAD TO POLICY IMPLEMENTATION

More lectures at Disasters Supercourse - http://www.pitt.edu/~super1/collections/collection52.htm*****Three types of faultsForm depending on type of plate motion and complex reaction of earths lithospheric blocksStrike-slipNormalThrust

*******This is the GSHAP seismic hazard map for east Asia. We can see how the earthquake problem in Afghanistan is shared with neighboring countries.*