近邻双孔隧道围岩联合压力拱试验与数值分析  

Test and numerical analysis on combined pressure arch of surrounding rock in adjacent twin tunnels

作　　者：晏莉[1] 吕超慧 喻少华 文胜 杨海涛 YAN Li;LYU Chaohui;YU Shaohua;WEN Sheng;YANG Haitao(School of Civil Engineering,Changsha University of Science and Technology,Changsha 410114,China;General Con-tracting Branch of China Communications Construction Corporation Limited,Beijing 100088,China)

机构地区：[1]长沙理工大学土木工程学院,长沙410114 [2]中国交通建设股份有限公司总承包经营分公司,北京100088

出　　处：《北京交通大学学报》2022年第3期103-109,共7页JOURNAL OF BEIJING JIAOTONG UNIVERSITY

基　　金：国家自然科学基金(51408067);湖南省教育厅优秀青年项目(18B136)。

摘　　要：针对双孔隧道开挖围岩稳定性的问题,采用模型试验与离散元数值模拟的方法,对近邻双孔隧道开挖后围岩联合压力拱效应进行研究.以Ⅳ级围岩为实验对象进行室内缩尺模型试验,对不同隧道间距以及不同埋深的双孔隧道进行开挖模拟,并对围岩变形破坏过程中围岩应力及地表位移的变化规律进行分析;在此基础上,利用PFC2D软件建立颗粒流模型进一步研究了近邻双孔隧道开挖联合压力拱特性.研究结果表明:隧道埋深不变情况下,双孔隧道间径比D/R<1.0时(D为隧道间距,R为隧道直径),双孔隧道开挖上方会形成联合塌落拱;在围岩渐进性塌方破坏过程中,压力拱也渐进性地向上发展;在形成联合塌落拱的工况下,隧道间距增大,联合塌落拱的高度增大;隧道埋深增大,联合塌落拱高度也会增大.In order to solve the problem of surrounding rock stability after twin tunnel excavation,the combined pressure arch effect of surrounding rock after adjacent twin tunnel excavation is studied by model test and discrete element numerical simulation.GradeⅣsurrounding rock is used as the experi⁃mental object in the indoor scale model test,excavation simulation is carried out on the twin tunnels with different tunnel span and different buried depth,and the variation law of surrounding rock stress and surface displacement in the process of deformation and failure of surrounding rock is analyzed.On this basis,the particle flow model is established by PFC2D software to further study the characteris⁃tics of the combined pressure arch of the adjacent twin tunnel excavation.The results show that,under the condition that the buried depth of the tunnel is constant,when the diameter ratio D/R<1.0(D is the tunnel spacing,and R is the tunnel diameter),the combined collapse arch is formed above the twin tunnel excavation.In the process of gradual collapse of surrounding rock,the pressure arch also devel⁃ops upward gradually.When the combined collapse arch is formed,the tunnel spacing increases,and the height of the combined collapse arch rises.When the increasing buried depth of tunnel,the height of the combined collapse arch will also increase.

关 键 词：近邻双孔隧道 联合压力拱 模型试验 离散元模拟 

分 类 号：U451.2[建筑科学—桥梁与隧道工程]