深埋隧洞围岩稳定性分析

Stability analysis of surrounding rock of deep underground tunnel

为研究深埋隧洞围岩的稳定性,依据弹塑性理论推导衬砌支护反力与洞壁周边位移的解析表达式,得到围岩和衬砌支护特征曲线。基于数值模拟和现场实测方法,研究隧洞围岩和衬砌变形过程。结果表明:围岩的裂纹扩展可以划分成裂纹萌生、裂纹迅速扩展、裂纹缓慢增加和裂纹稳定4个阶段;衬砌支护反力与洞壁周边位移相互影响,衬砌支护反力越大,洞壁位移越小;洞壁周边的移动速度表现出先增大后减小的变化规律。对隧洞围岩进行衬砌支护后,围岩破坏裂纹总数和移动速度明显减小。

For researching into surrounding rock stability of deep buried tunnel,analytic expressions of the lining support reaction and tunnel wall periphery displacement are obtained according to elastic-plastic theory,and deformation of tunnel surrounding rock and lining is studied by using of theoretical analysis,numerical simulation and field measurement method. The results show that the surrounding rock crack propagation can be divided into four stages： cracking initiation,fast cracking,slow cracking,and cracking termination,that the greater the lining support reaction is,the smaller the tunnel wall periphery displacement will be,that the movement speed of tunnel wall periphery first increases and then decreases,and that the total number of cracks and the movement speed without lining support are significantly greater than those with lining support.