预应力混凝土空心板梁火灾仿真分析与评估  

Simulation Analysis and Evaluation of Prestressed Concrete Hollow Slab Girder Subjected to Fire Disaster

作　　者：刘其伟[1] 王成明 罗文林[3] 

机构地区：[1]东南大学交通学院,江苏南京210096 [2]上海林同炎李国豪土建工程咨询有限公司南京分公司,江苏南京210016 [3]东南大学建筑设计研究院交通分院,江苏南京210096

出　　处：《公路交通科技》2013年第12期59-68,共10页Journal of Highway and Transportation Research and Development

摘　　要：以江苏省内某高速公路预应力混凝土空心板桥的突发性火灾为研究对象,阐述了火灾高温对混凝土、钢筋和钢绞线力学指标的影响,总结了火灾现场温度的判定方法,提出了桥梁火灾仿真分析与评估的实施步骤。通过火灾燃烧物性质分析,选择了Eurocode烃类火灾升温曲线,论述了火灾下混凝土爆裂机理,在此基础上建立了空心板混凝土与内腔封闭孔洞内空气的流固耦合传热模型,并进行了火灾温度场有限元仿真分析。根据有限元计算结果,比较了火灾作用下底板混凝土爆裂对空心板温度场的影响,最后结合火灾后材料性能的变化对板梁火损状况进行了综合评估。Taking a sudden fire which happened at a PC hollow slab bridge of an expressway in Jiangsu Province as the research object, we expounded the influences of high temperature of fire on mechanical performance of concrete, steel and strand, summarized the temperature estimating method for fire site, and proposed the implementation steps of simulation analysis and evaluation for bridge fire disaster. Through analysing the property of fire comburent, we selected the hydrocarbon temperature-time curve （Eurocode） and discussed the mechanism of concrete explosive spalling under fire disaster. On this basis, we built a fluid-solid coupling heat transferring model of hollow slab concrete and air in its closed cavity to simulate the fire temperature field. According to the result of finite element calculation, we compared the influence of bottom concrete explosive spalling subjected to fire on hollow slab temperature field. comprehensively evaluated the fire properties after fire disaster. damage situation of hollow slab by analyzing the changes Finally, we of the material

关 键 词：桥梁工程 预应力混凝土空心板梁 仿真分析 评估 火灾温度场 苯乙烯 爆裂 

分 类 号：U446.212[建筑科学—桥梁与隧道工程]