A Post-Earthquake Fire Spread Model considering Damage of Building Components due to Seismic Motion and Heating of Fire

Abstract

A physics-based model for post-earthquake fire spread was developed by modifying the prototype model previously proposed by the authors. In the new model, seismic motion and heating of fire are both considered as the causes of damage upon building components. The damage affects burning behavior of a fire involved building as well as behavior of building-to-building fire spread. For validation of the new model, simulation of fire spread which followed 1995 Kobe earthquake was conducted. Behavior of fire spread obtained by the numerical simulation was compared with the observed data. Reasonable agreement was obtained with regard to the number of burnt buildings.KEYWORDS: post-earthquake fire, urban fire, fire spread, physics-based model, Kobe city. NOMENCLATURE LISTING

Physics-Based Fire Following Earthquake Simulation Considering Building Seismic Damage

“…As a matter of fact, an earthquake may induce damage to walls, fire protection devices, gas systems, electrical systems, etc., which can further aggravate the fire spread. To date, only a limited number of existing fire spread models deals with building seismic damage, among which a representative model was proposed by Himoto et al [3]. The principle of the work of Himoto et al [3] is adopted in this work, i.e., assuming that the failure of the building exterior façade due to an earthquake will reduce the critical heat flux of ignition, as shown in Eq.…”

“…Note that Himoto et al [3] did not provide further discussions on how to determine the building seismic damage; instead, the damage states of buildings were randomly assigned in their work. To overcome this limitation, Section 2.1 in this work provides a more reasonable prediction of building seismic damage simulation.…”

“…where j is the failure ratio of the exterior façade, defined as the ratio of failed area to the total area of the exterior façade; can be referred to [3] and [9], respectively.…”

“…However, only a limited number of fire spread models consider the influence of building seismic damage on fire spread. The model proposed by Himoto et al [3] made a remarkable progress with respect to these effects. Nevertheless, the seismic damage of buildings was randomly assigned in the case study of Himoto et al [3] and there were no further discussions as how to simulate the building seismic damage in urban regions.…”