Resilience Evaluation of Water Supply Networks against Seismic Hazards

Abstract

It is imperative that water supply networks (WSNs) continue to perform even after subjected to natural and anthropogenic hazards, and it is even more important in the case of earthquakes for fighting fires that usually follow. Past earthquakes have caused significant damage to WSNs rendering them dysfunctional and potentially threatening human survival. Although there has been a lot of research conducted in the past on the behavior of buried pipelines, there are few metrics and models that are readily usable for improving the performance of large WSNs prone to seismic hazards. This paper proposes an easy-to-use metric for quantifying resilience and an optimization framework for improving WSN resilience subjected to budgetary constraints. The proposed resilience metric is dependent on hazard intensity, estimated pipeline response, and network topology. The use of the proposed metric and the optimization framework are demonstrated on a large (1,874 pipelines and 1,474 demand nodes), real-world WSN in a coastal region prone to earthquakes. The resilience value of the existing WSN used for demonstration is found to increase by approximately 8% with a $10 million investment. The proposed metric and the optimization framework can be helpful in rehabilitation planning and capital improvement works by water utilities.