矩形断面盾构隧道在火灾高温作用下的力学性能研究  

Evaluation and Analysis of the Performances of Rectangular Section Shield Tunnels under the High Temperature Effect in a Fire Scenario

作　　者：廖若倩 蔡永昌[1,2] LIAO Ruoqian;CAI Yongchang(Department of Geotechnical Engineering,Tongji University,Shanghai 200092;State Key Laboratory for Disaster Reduction in Civil Engineering,Tongji University,Shanghai 200092)

机构地区：[1]同济大学土木工程学院地下建筑与工程系,上海200092 [2]同济大学土木工程防灾国家重点实验室,上海200092

出　　处：《现代隧道技术》2018年第5期146-158,共13页Modern Tunnelling Technology

摘　　要：矩形断面盾构隧道以其显著的空间利用优势得到了越来越多的应用与推广,但其特殊的断面型式也导致了衬砌结构内力的不合理分布,往往需要专门设计承载力较高的复合管片及接头构型,而且一旦在矩形断面盾构隧道中发生升温速率快、峰值温度高的大型火灾,以复合管片为基本单元的衬砌结构在火灾高温作用下极易劣化,严重威胁结构安全。文章以上海市某大断面矩形盾构隧道为工程背景,基于不同量级的火灾温升曲线建立了相应的热-力耦合有限元模型,讨论了衬砌结构的温度场、位移场及应力场分布。研究表明,导致矩形盾构隧道不满足正常使用极限状态的温度量级在Tem400左右;而导致结构不能继续承载的温度量级在Tem600左右。Rectangular section shield tunnels have been widely applied and promoted with its obvious advantages of high space utilization. However, its special section form also leads to the irrational distribution of the internal force of the lining structure, requiring specially designed composite segments and joint forms with high bearing capacity. Furthermore, once a large fire accident with high heating rates and high peak temperatures occurred in a rectangular section shield tunnel, the lining structure with the composite segments as its basic unit is easily deteriorated under the high temperature of fire and poses a serious threat to the safety of the tunnel structure. In this paper, a large-diameter rectangular shield tunnel in Shanghai is taken as the engineering background. Based on various temperature rise curves being consistent with different scales of fire, the corresponding thermo- mechanical coupled finite element models are established. The temperature field, displacement field and stress field of the lining structure are analyzed to evaluate the fire resistance of the lining structure of the shield tunnel with a rectangular section. The results show that as for rectangular section shield tunnels, the temperature scale is about Tern 400 for unsatisfying the serviceability limit state, and the temperature scale is about Tern 600 for losing the bearing capacity.

关 键 词：矩形断面盾构隧道 热-力耦合有限元模型 抗火研究 

分 类 号：U458[建筑科学—桥梁与隧道工程] U451.4[交通运输工程—道路与铁道工程]