LNG油罐车火灾下的大跨径悬索桥结构热力响应  

Thermal and mechanical response of long-span suspension bridge structure in LNG tanker fire

作　　者：杨明[1] 郭晓月 刘志 黄侨[1] 宋恒宇 畅卫杰 林阳子 YANG Ming;GUO Xiaoyue;LIU Zhi;HUANG Qiao;SONG Hengyu;CHANG Weijie;LIN Yangzi(School of Transportation,Southeast University,Nanjing 211189,China;College of Civil Engineering,Tongji University,Shanghai 200092,China;Zhejiang Zhoushan Sea-crossing Bridge Limited Company,Zhoushan 316053,Zhejiang,China;Guangzhou Kaibo Bridge Engineering Limited Company,Guangzhou 511449,China)

机构地区：[1]东南大学交通学院,南京211189 [2]同济大学土木工程学院,上海200092 [3]浙江舟山跨海大桥有限公司,浙江舟山316053 [4]广州市开博桥梁工程有限公司,广州511449

出　　处：《哈尔滨工业大学学报》2025年第3期34-45,共12页Journal of Harbin Institute of Technology

摘　　要：国内某跨海悬索桥作为连接当地岛屿的交通要道,桥面上易燃物质LNG(液化天然气)的大量运输给该桥运营带来了不可忽视的安全隐患。针对该桥主桥跨中处如果发生两辆LNG油罐车追尾燃烧的小概率火灾事故,基于国内已有的油池燃烧实验,结合使用火灾动力学模拟软件FDS与有限元分析软件ABAQUS进行桥面油罐车火灾模拟与火灾下的全桥力学分析,以预测LNG油罐车火灾对桥梁结构产生的影响,为防范与应对桥面发生油罐车火灾的突发事件提供参考。仿真计算结果表明:当桥上发生LNG油罐车火灾时,局部主缆和部分吊索直接受火作用,受火主缆失去部分结构性能,受火吊索遭到破坏而失效;高温区域的桥面铺装也遭高温破坏,铺装下层的主梁钢结构所受温度影响相对较小;火灾下桥梁挠度增加0.234 m,桥梁东西两幅受力不再均衡。通过对火灾中高温区域关键构件的防火研究,ABAQUS的传热分析显示,外包双层5 mm厚的隔热气凝胶保护层设计在火灾中可有效保护桥梁主要构件。A domestic sea-crossing suspension bridge is a vital traffic artery connecting local islands.The massive transportation of flammable substances like LNG(liquefied natural gas)on the bridge poses a significant safety hazard to the operation of the bridge.This paper is based on existing oil pool combustion experiments in China,using the fire dynamics simulation software FDS and finite element analysis software ABAQUS to simulate LNG tanker fire and conduct the whole bridge mechanical analysis in the fire,in order to predict the structural impact of the LNG tanker fire and to provide reference for preventing and responding to emergencies of fuel tanker fire on the bridge.The simulation is aiming at a small probability fire accident of two LNG tankers rear-end burning in the middle of the main span of the bridge.The simulation results show that when an LNG tanker fire occurs on the bridge,the main cable and some slings are directly affected by the fire:the main cable loses part of the structural performance and two slings are damaged by heat and fail.In addition,the bridge deck pavement in high temperature area is also damaged by high temperature and the main beam steel structure under the pavement is relatively less affected by heat.The deflection of the bridge increases 0.234 m in the fire,and the forces on the east and west sides of the bridge are no longer balanced.According to the fire prevention research on key components in the high temperature area in the fire,the heat transfer analysis of ABAQUS shows that main components of the bridge can be effectively protected in the fire by the design of a double-layer 5 mm thick thermal insulation aerogel protective layer.

关 键 词：桥梁火灾 悬索桥杆系模型 LNG油罐车火灾模型 传热分析 力学响应 

分 类 号：U447[建筑科学—桥梁与隧道工程]