强降雨影响下破碎复理岩地层隧道洞口段失稳机理  

Collapse mechanism of tunnel portal sectionin broken flysch under influence of heavy rainfall

作　　者：高阳 孙浩凯[1] 刘德军 徐飞[1] 张骞 GAO Yang;SUN Haokai;LIU Dejun;XU fei;ZHANG Qian(Key Laboratory of Structural Health Monitoring and Control,Shijiazhuang Tiedao University,Shijiazhuang 050043,China;Hebei Province Key Laboratory of Structural Health Monitoring and Control,Shijiazhuang Tiedao University,Shijiazhuang 050043,China;School of Mechanics and Civil Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China)

机构地区：[1]石家庄铁道大学大型结构健康诊断与控制研究所,河北石家庄050043 [2]石家庄铁道大学河北省大型结构健康诊断与控制重点实验室,河北石家庄050043 [3]中国矿业大学(北京)力学与建筑工程学院,北京100083

出　　处：《中南大学学报（自然科学版）》2019年第9期2295-2303,共9页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(51978425);中国博士后科学基金资助项目(171957);河北省教育厅支持项目(QN2016080,QN2016221)~~

摘　　要：针对强降雨下Kosman隧道冒顶事故,在现场实时监测基础上,结合离散元数值模拟,分析强降雨下围岩裂隙及渗流的动态变化规律。同时,用能量的方法对围岩破坏过程进行研究,分析围岩势能与动能转化过程,从能量的角度验证围岩不同区域的稳定性。研究结果表明:隧道开挖初期,围岩自承能力较好;降雨过程中,随着隧道顶部岩体节理渗流逐渐增大,岩石节理面刚度和强度逐步降低,地表至拱脚围岩扰动区出现大量剪切破坏裂缝,且数量及长度都随埋深增大而减少。贯通裂缝形成渗流通道导致降雨从拱顶处涌入洞内,洞周孔隙水压力及渗流场呈漏斗型并逐渐降低,围岩应力增大加剧沉降推动冒顶产生。Aimed at the accident of Kosman tunnel roof under heavy rainfall,the dynamic change law of surrounding rock fracture and seepage flow under heavy rainfall was analyzed on the basis of real-time monitoring and discrete element numerical simulation.At the same time,the failure of surrounding rock was studied by means of energy,and the transformation process of mechanical energy and elastic energy of surrounding rock was analyzed.The stability of different areas of surrounding rock was verified from the energy.The results show that the self-bearing capacity of surrounding rock is good at the initial stage of tunneling.During the rainfall process,as the seepage of the rock joints at the top of the tunnel gradually increases,the stiffness and strength of the rock joints gradually decrease,and a large number of shear failure cracks appear from the surface to the disturbance zone of the arched surrounding rock,and the number and length decrease with the increase of the buried depth.The seepage channel formed by the transfixion fracture leads the rain water into the hole from the vault.The pore water pressure and seepage field around the hole show a funnel-shaped pattern and gradually reduces.

关 键 词：流固耦合 渗流 冒顶 离散元 能量 

分 类 号：TU91[建筑科学—建筑理论]