火荷载下沉管隧道结构的热-力耦合分析  

Coupling analysis of thermal field and stress field for immersed tunnels under fire load

作　　者：张孟喜[1] 黄瑾[1] 贺小强[1] 

机构地区：[1]上海大学,上海200072

出　　处：《土木工程学报》2007年第3期83-87,共5页China Civil Engineering Journal

基　　金：教育部留学回国人员科研启动基金(教外司留200314)

摘　　要：以上海外环线越江沉管隧道为背景,用有限元程序模拟火荷载作用下沉管隧道结构温度场及应力场,并将计算结果与试验数据对比分析,从而确定最佳的分析模型和边界条件,为该领域的研究提供参考依据。根据沉管隧道的结构形式及其特点建立有限元分析模型;参考隧道火灾的试验资料和研究成果确定模型边界条件;通过分析选取合理的混凝土和周围土体的本构模型;分析时还考虑到混凝土热工参数随温度的变化。通过对火灾时沉管隧道不同温度量级的稳态温度场和瞬态温度场分析,得出温度随空间和时间的变化规律,并把分析结果与试验结果进行对比分析。分别进行常温下和火灾时沉管隧道的热-力耦合分析,从而更直观地了解温度场对应力场的影响,得出沉管隧道各个部位在火灾发生时的应力分布情况以及随着不同温度量级的变化规律,以便更有效地为优化设计和防火救灾提供理论指导。最后根据计算结果,结合大量的隧道火灾资料总结火灾时隧道内部的温度场及应力场的危险区域。The analysis of thermal field and stress field for the immersed tunnel of the Outer-Ring Expressway in Shanghai under fire load was carried out by using the finite element method. Analytical theory and variation of the mechanical behavior of concrete with time were introduced. On the basis of experimental study of tunnel fire, the analytical model along with the boundary conditions was established. The appropriate structural equations were provided. From the results of the finite element analysis, the coupling of thermal field and thermal stress under different temperatures was presented. The analytical results were compared with experimental ones.

关 键 词：沉管隧道 火荷载 温度场 应力场 有限元 耦合分析 

分 类 号：U452.2[建筑科学—桥梁与隧道工程] U455.46[交通运输工程—道路与铁道工程]