衬砌厚度不足对隧道结构安全性的影响分析  

Influence of Insufficient Lining Thickness on the Safety of a Tunnel Structure

作　　者：张成平[1] 张旭[1] 冯岗[1] 张顶立[1] 

机构地区：[1]北京交通大学城市地下工程教育部重点实验室,北京100044

出　　处：《现代隧道技术》2017年第2期137-143,169,共8页Modern Tunnelling Technology

基　　金：国家科技支撑计划项目(2012BAJ01B03);中央高校基本科研业务费专项资助项目(2016JBM042);新世纪优秀人才支持计划资助项目(NCET-12-0770)

摘　　要：衬砌厚度不足缺陷的存在将显著改变隧道结构的力学状态,并对隧道结构的安全造成威胁。文章以Ⅳ级围岩双车道公路隧道为工程背景,采用数值模拟研究衬砌整体或局部厚度不足条件下隧道结构的安全状态。结果表明:衬砌厚度不足使缺陷处结构的轴力与弯矩减小,同时降低了结构的极限承载力,从而导致缺陷处隧道结构的安全系数显著降低;衬砌局部厚度不足对缺陷处隧道结构截面内力、承载力和安全系数具有显著影响,而对远离缺陷处隧道结构截面的影响相对较小;衬砌厚度整体或局部厚度不足时,衬砌厚度值与结构安全系数基本呈线性关系,经回归分析确定了满足结构安全要求的临界衬砌厚度值。研究成果可为存在衬砌厚度不足缺陷隧道的结构安全性分析及评价提供参考。Insufficient thickness of the tunnel lining will significantly change its mechanical state and threaten the safety of the tunnel structure. A numerical simulation is conducted to analyze the safety state of tunnel linings under the conditions of integral or local insufficient lining thickness based on a two-lane highway tunnel in surrounding rock of class IV. The results show that insufficient lining thickness leads to a decrease of the axial force and bending moment on the defective section of the tunnel and an obvious reduction of the ultimate bearing capacity of the tunnel structure, which significantly reduces the safety factor of the tunnel structure at the defective section. Additionally, the internal force, bearing capacity and safety factors of the defective section are strongly influenced by a local insufficient lining thickness, while sections far away from the defect are relatively less affected by this. The relationship is linear between the lining thickness and the safety factor of the tunnel structure under the condition of an integral or local insufficient lining thickness, and the critical thickness of the tunnel lining for meeting structural safety requirements is determined by a regression analysis.

关 键 词：隧道结构 衬砌厚度不足 安全系数 临界衬砌厚度 数值计算 

分 类 号：U451.4[建筑科学—桥梁与隧道工程]