Abstract

Bridge deck fires are a major concern in recent years because of the increasing number of relative accidents and the following serious consequences. This paper studies the process of bridge deck fire in the full-open environment by using numerical simulation method and then develops the simplified fire model with wind effects. Firstly, the essential parameters of fire scenarios simulation are determined based on previous research. Then, an existing fire experiment is simulated to verify the accuracy of FDS (Fire Dynamics Simulator) simulation program. Bridge deck fire processes with and without wind effects are simulated and the time-dependent temperature laws are obtained in FDS software. At last, a semi-empirical temperature model of bridge deck fire is established and the rationality and accuracy of the proposed model is verified. Results show that the wind effect can strongly influence the burning process of bridge deck fire. The simplified model can be adopted for heat transfer analysis of vehicle-induced bridge deck fire accidents conveniently.

摘要

近年来，由于相关事故的数量不断增加以及以下严重后果，桥面火灾成为人们关注的主要问题。本文采用数值模拟方法研究了全开放环境下桥面火灾的过程，进而建立了带风效应的简化火灾模型。首先，在前人研究的基础上确定火灾场景模拟的基本参数。然后，通过模拟现有的火灾实验来验证FDS（Fire Dynamics Simulator）仿真程序的准确性。模拟有和没有风影响的桥面火灾过程，并在 FDS 软件中获得了随时间变化的温度规律。最后，建立了桥面火灾半经验温度模型，验证了模型的合理性和准确性。结果表明，风效应对桥面火灾的燃烧过程有很强的影响。简化模型可方便地用于车辆诱发桥面火灾事故的传热分析。