Firefighting capacity evaluation of water distribution system subjected to multi-ignitions of post-earthquake fires

Abstract

Abstract Post-earthquake fire (PEF) is a hazardous secondary disaster following earthquake, and the multi-ignition of PEFs can result in huge economic loss and heavy casualties. The suppression of PEFs depends on the water distribution system (WDS) to provide water. Although a number of studies have been conducted to evaluate the firefighting capacity of WDS, their hydraulic modelling analyses fail to consider the influence of firefighting demand at one node on the water supply capability of other nodes, which may result in an overestimate of the WDS’ capability to suppress multiple simultaneous occurrence of PEFs. In this study, an integrated procedure is developed to evaluate the firefighting capacity of WDS under the effects of both seismic pipeline damage and multi-ignition of PEFs. Under the excitation of earthquakes with different intensities, the spatial distributions of PEFs and pipeline damage are simulated, and the associated uncertainties are included by Monte Carlo simulations. The firefighting capacity of WDS is defined as the probability of providing sufficient water to suppress multiple PEFs, which, combined with the probability distribution of ignition number of PEFs, can achieve the risk assessment of a city to suffer uncontrolled PEFs. The developed method is applied to a WDS currently operating in a Chinese city. Discussions are made on the influences of multiple simultaneous water demands on firefighting capacity evaluation of WDS and the possible applications of the proposed method.