16.30: Safety evaluation of a large‐span double‐deck cable‐stayed steel bridge under fire

Abstract

This paper presents a detailed safety evaluation of a large-span cable-stayed steel bridge under fire, which is also the first large-span double-deck highway cable-stayed steel bridge in China. This steel bridge is a crucial part of urban lifeline engineering and is close to an industrial park which might raise the probability of being damaged by oil tank trucks or hazardous chemical vehicles, especially when a truck traveling on the lower deck of the bridge catches fire, it will endanger the safety of major steel bridge components supporting the upper deck and steel trusses on two sides. So, it is very important to conduct the performance evaluation and design of this steel bridge under fire. In this paper, the dangerous fire scenarios are selected and fluid dynamic simulations are conducted and the temperatures of the air and steel components are obtained, based on the component temperatures, structural analysis and capacity checks are made to offer reasonable preventive measures and solutions to protect the bridge subjected to the fire loading. The methodology presented in this paper is an effective approach for fire performance evaluation of bridge structures and has the potential for applications to other types of bridge structures.