Knowledge of the temperature response of load-bearing structures in suspension bridges under vehicle fires is a prerequisite for fire protection measures. In this study, a double-deck suspension bridge was adopted as the engineering background. The temperature response of the main cables and slings was examined in the case of a fire on the upper vehicle deck, and the temperature characteristics of load-bearing structures such as trusses and the roof plate were investigated on the lower vehicle deck. The simulation variables included heat release rate (HRR), fire location, and ambient wind speed. The results showed that: (1) The fire temperature rose as HRR increased, and the fire temperature was inversely proportional to the wind speed. (2) When a fire occurred on the upper bridge deck, the maximum width of the high-temperature area on the main cable was 15 m, and the maximum temperature was 1040 °C. (3) When a fire occurred on the lower bridge deck, the maximum temperature of the truss was 1209 °C, and the maximum height of the high-temperature area exceeding 300 °C was 7.6 m. The maximum temperature reached in a 200 MW oil tanker fire was 1344 °C, lasting 3650 s.

中文翻译：

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双层悬索桥在车辆火灾中温度特性的数值模拟研究


了解悬索桥承重结构在车辆火灾下的温度响应是采取防火措施的前提。本研究采用双层悬索桥作为工程背景。在上部车辆甲板发生火灾的情况下，检查了主缆和吊索的温度响应，并在下部车辆甲板上研究了桁架和车顶板等承重结构的温度特性。仿真变量包括热释放率 （HRR）、火灾位置和环境风速。结果表明：（1）火温随HRR的增加而升高，且火温与风速成反比。（2）上桥面发生火灾时，主缆上高温区最大宽度为15 m，最高温度为1040 °C。（3）下桥面发生火灾时，桁架最高温度为1209 °C，超过300 °C的高温区最高高度为7.6 m。200 MW 油轮火灾的最高温度为 1344 °C，持续了 3650 秒。