铁路隧道整体式衬砌火灾力学响应特性数值模拟  

Numerical analysis on mechanical properties of monolithic lining at railway tunnel under fire

作　　者：陈长坤[1,2] 杨建[1] 陈杰[1] 

机构地区：[1]中南大学防灾科学与安全技术研究所,长沙410075 [2]建筑消防工程技术公安部重点实验室,天津300381

出　　处：《火灾科学》2015年第1期26-31,共6页Fire Safety Science

基　　金：湖南省自然科学基金重点项目(12JJ2033);中央高校基本科研业务费专项资金资助;建筑消防工程技术公安部重点实验室开放课题资助(KFKT2014ZD02)

摘　　要：通过ANSYS有限元数值模拟软件,建立了铁路隧道整体式衬砌的二维热力耦合有限元计算模型,基于ISO834标准火灾温升曲线,对不同单双线和不同等级围岩的铁路隧道整体式衬砌(单线III级围岩衬砌、双线III级围岩衬砌、单线IV级围岩衬砌、双线IV围岩衬砌)的火灾力学响应行为进行了数值模拟研究,获得了火灾作用下,不同的铁路隧道整体式衬砌拱顶竖向位移、边墙侧向位移、压应力、剪切应力的变化情况。结果表明:双线整体式衬砌拱顶的竖向位移大于单线整体式衬砌,围岩等级越大整体式衬砌拱顶的竖向位移越大,整体式衬砌承受的最大压应力和最大剪切应力随时间集中在不同厚度层的混凝土区域上。所获得的结论可为铁路隧道整体式衬砌的防火设计和安全性研究提供理论参考。A two-dimensional thermo-mechanical coupled finite element model of the railway tunnel monolithic lining has been established by ANSYS. On the basis of the ISO834 standard fire temperature rise curve, the mechanical response behavior in fire of the monolithic lining at railway tunnel （single-track and double-track tunnel under grade III surrounding rock, single- track and double-track tunnel under grade IV surrounding rock） has been investigated by numerical method. Variations in crown vertical displacement, lateral displacement of side wall, the compressive stress and shear stress of the railway tunnel monolithic lining exposed to fire are obtained. The results indicate that the crown vertical displacement in double-track tunnel monolithic lining is greater than that in single-track tunnel monolithic lining, and the crown vertical displacement of the monolithic lining under grade IV surrounding rock is greater than that in grade Ill surrounding rock. It is also found that the maximum compressive stress and maximum shear stress would vary along the layer in concrete against time.

关 键 词：衬砌结构 火灾 数值模拟 力学特性 

分 类 号：X928.7[环境科学与工程—安全科学] X932