Fragility Analysis of Water Supply Systems

A. Jacobson and M. Grigoriu

MCEER-08-0009 | 03/10/2008 | 150 pages

Keywords: Water supply systems.  Fragility analyses.  Seismic performance.  Hazard models.  Lifelines.  Monte Carlo simulations.  Pipelines.  Permanent ground deformations.  Fault displacements.  Damage.

Abstract: This report describes a procedure to assess the seismic performance of water supply systems.  Seismic hazard models are developed to generate random samples of earthquake activity at both single and multiple sites.  Methodologies to obtain the fragility of a given pipeline are developed, including several hazard conditions: continuous and jointed pipelines subjected to seismic waves, pipelines subjected to permanent ground deformation (PGD) hazards, and pipelines subjected to fault displacements.  Fragility information for other components of the water supply system is obtained from several published sources.  These parameters are integrated into an algorithm that uses Monte Carlo simulation to determine the damage states of individual components, and hydraulic analyses to estimate the performance of the damaged water system.  The algorithm is applied to a sample water supply system, consisting of a reservoir, pump, water tank and several pipelines, and fragility surfaces are produced under different limit states.  In addition, a procedure to estimate the life cycle damage of a water supply system is presented.  Since each type of damage is associated with a cost, the total cost due to seismic hazards during its lifespan can be estimated.