基于突变理论的高压岩溶隧道掌子面稳定性研究  

Stability analysis of tunnel face in high-pressure karst tunnels based on catastrophe theory

作　　者：王志杰[1] 高靖遥 张鹏[1] 关笑 季晓峰[1] WANG Zhi-jie;GAO Jing-yao;ZHANG Peng;GUAN Xiao;JI Xiao-feng(Key Laboratory of Transportation Tunnel Engineering,Ministry of Edueation,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]西南交通大学交通隧道工程教育部重点实验室,四川成都610031

出　　处：《岩土工程学报》2019年第1期95-103,共9页Chinese Journal of Geotechnical Engineering

基　　金：中央高校基本科研业务专项资金项目(SWJTU11ZT33);教育部创新团队发展计划项目(IRT0955)

摘　　要：为研究马蹄形隧道前方存在正交高压溶洞时中间岩墙的承压能力和破坏模式,在考虑溶洞位置和尺寸对中间岩墙稳定性影响的基础上,建立掌子面失稳破坏的圆锥台模型,并通过势能判据的尖点突变理论得到掌子面失稳时的溶洞临界压力。同时开展室内模型试验,揭示高压溶洞与隧道正交时中间岩墙的破坏特征,并结合数值计算对掌子面破坏模型进行了补充验证。研究结果表明:溶洞临界压力随中间岩墙厚度、围岩等级的增大而增加,随溶洞尺寸的增大而减小,且围岩弹性模量的变化对中间岩体的稳定性有显著影响;中间岩墙厚度超过0.35倍洞径后,溶洞已不是造成掌子面破坏的主要因素;引入压力扩散角?描述溶洞与隧道处于不同正交位置时中间岩墙的破坏形态,发现溶洞临界压力与靠近溶洞一侧的隧道边界曲率正相关。破坏模型贴近工程实际,所得结果与试验基本吻合,可为高压岩溶隧道的设计与施工提供参考。In order to study the bearing capacity and failure mode of the intermediate rock wall in the presence of orthogonal high-pressure caverns in front of horseshoe tunnels, a frustum model for the instability of tunnel face is established considering the influences of the location and size of the cavern on the stability of the intermediate rock wall. Based on the cusp catastrophe theory of the potential energy criterion, the critical pressure can be predicted. At the same time, similar model tests are conducted to reveal the destruction characteristics of the intermediate rock wall when the high-pressure cavern are intersected with the tunnel. The failure model for the tunnel face is additionally verified. The results show that the critical pressure of karst cavern increases with the thickness of the intermediate rock wall and the grade of the surrounding rock and decreases with the increase of the size of karst cavern. The change of the elastic modulus of the rock has a significant effect on the stability of the intermediate rock. When the thickness of the intermediate rock wall exceeds 0.35 times the hole diameter, the cavern is not the main factor causing the failure of the face. The pressure spread angle ? is introduced to describe the destruction pattern of the intermediate rock wall when the cavern and the tunnel are in different orthogonal positions, and founds that the critical pressure of the cave is positively correlated with the curvature of the tunnel boundary near the side of the cavern. The results of the proposed model are basically consistent with the test ones, which can provide reference for the design and construction of high-pressure karst tunnels.

关 键 词：高压岩溶隧道 掌子面破坏特征 相似模型试验 突变模型 压力扩散角 

分 类 号：TU473[建筑科学—结构工程]