隧道穿越高压富水断层破碎带过程分析

Analysis on the Process of Tunnel Passing through High-pressure Fault Fractured Zone with Abundant Water rich

为分析隧道穿越高压富水断层破碎带过程中围岩与结构稳定性,文章通过建立三维流固耦合数值模型,分析不同工况下掌子面推进至不同位置时,掌子面前方岩体渗流场分布、掌子面凸出变形、塑性区体积、涌水量及注浆加固圈剪切变形,最终确定合理注浆圈厚度,施工过程涌水量监测验证了模型计算的准确性。研究结果表明:隧道掌子面接近断层破碎带时前方岩体渗流场出现积聚现象,可采取超前钻孔达到排水降压的目的;掌子面到达断层破碎带中央时凸出变形最大,此时最为危险,须采取留核心土等方式保证施工安全;注浆加固圈在高压渗流场作用下会产生较大剪切变形,威胁施工与运营安全,可适度增加注浆圈厚度。

In order to analyze the stability of surrounding rock and structure in the process of tunnel passing through high-pressure water-rich fault fracture zone,a three-dimensional fluid solid coupling numerical model is established to analyze the seepage field distribution of the front rock mass,the protruding deformation of the tunnel face,the volume of plastic zone,the water inflow and the shear deformation of grouting reinforcement ring when the tunnel face advances to different positions under different working conditions.The accuracy of the model calculation is verified by the water inflow monitoring in the construction process.The research results show that:when the tunnel face is close to the fault fracture zone,the seepage field in front of the rock mass accumulates,so advance drilling can be adopted to achieve the purpose of drainage and pressure reduction;when the tunnel face reaches the center of the fault fracture zone,the protruding deformation is the largest,which is the most dangerous,so the construction safety must be ensured by reserved core;the grouting reinforcement circle will produce large shear deformation under the action of high-pressure seepage field,threatening the safety of construction and operation,and the thickness of grouting ring should be appropriately increased.