Nisqually Earthquake Electric Utility Analysis

Abstract

The performance of an urban electric utility distribution system was evaluated for the February 2001 Nisqually earthquake. The restoration rate of the lifeline following the event was determined; the distribution of outage durations was estimated; and correlations between lifeline damage and instrumental Modified Mercalli intensity, peak ground velocity, and peak ground acceleration values were ascertained using a GIS (geographical information systems) approach. Using a logit regression analysis, a fragility curve was developed for the lifeline in a manner similar to O'Rourke's formulation of water‐line performance (O'Rourke et. al. 2000). Extrapolation of the model to the Seattle Fault earthquake scenario was made to demonstrate its feasibility for prediction.