富水断层破碎带对隧道围岩稳定性的影响

Influence of Water-rich Fault Fracture Zone on Stability of Tunnel Surrounding Rock

为研究富水断层破碎带对隧道围岩稳定性的影响,以吉莲高速公路永莲隧道工程为背景,对其穿越断层破碎带的一段区域进行变形破坏数值模拟研究,并在此基础上,分析了断层破碎带厚度、倾角以及水头压力对围岩变形的影响。研究结果表明:随着隧道向前推进,掘进工作面岩体位移将在与破碎带间隔距离为9 m时开始呈'瀑布式'增长,而掘进工作面前方岩体松动圈则会在间隔距离6 m时与断层破碎带松动区相连,出现导水裂隙通道,引发突水灾害;隧道掘进工作面靠近破碎带时,其最大纵向位移与破碎带厚度关系不大,而与破碎带倾角和水头压力分别呈指数衰减和线性关系;隧道在破碎带内开挖产生的最大位移分别与破碎带厚度、倾角以及水头压力呈指数衰减、抛物线和线性关系。

To study the influence of the water-rich fault fracture zone on the stability of the surrounding rock of the tunnel,this paper takes Yonglian Tunnel Project of Jilian expressway as the background.Based on the numerical simulation results of deformation and failure of a section passing through a fault fracture zone,the influence of thickness,inclination angle and head pressure of fault fracture zone on the deformation of tunnel surrounding rock is analyzed.The results show that:the rock displacement of tunnel face will begin to grow at a distance of 9 m from the fracture zone as the tunnel advances.When the separation distance is 6 m,the loose rock ring in front of the tunnel face will be connected with the loose zone of fault fracture zone,and a water-conducting fissure channel will appear to cause a water inrush disaster.When the tunnel face is close to the fracture zone,its maximum longitudinal displacement has little relationship with the thickness of the fracture zone,and it has an exponential decay and linear relationship with the inclination and head pressure of the fracture zone respectively.The maximum displacement of the tunnel in the fracture zone is exponentially decayed,parabolic and linear with the thickness,inclination and head pressure of the fracture zone.