基于最小安全系数法对隧道围岩稳定性分析

Stability Analysis of the Surrounding Rockmass in Tunnel based on Minimum Safety Factor Method

隧道围岩稳定性一直是隧道施工控制的重点,本文采用最小安全系数法对隧道围岩稳定性计算进行了研究.基于随机场理论,考虑第二主应力对隧道围岩稳定性影响,结合最小安全系数法,分析隧道围岩稳定;隧道围岩存在不连续面,其参数存在变异,假设围岩的粘聚力和摩擦角服从正态分布,以参数的均值、方差和空间相关性表征,分析了隧道围岩在变异力学参数下的稳定情况.结果表明：隧道的最小安全系数在内摩擦角发生变化时,其失效概率也是变化的,即围岩稳定性是发生变化的.

The stability of surrounding rock in tunnel has always been the key point during construction control,the minimum safety factor method was used to calculate the stability of surrounding rock of tunnel. Based on random fields theory,the influence of second principal stressed on the stability of surrounding rock in tunnel was taken into consideration and discussed. Moreover,combined with the minimum safety factor method,the stability of surrounding rock in tunnel wss analyzed. There exists discontinuities in rock,as a result,the parameters of the surrounding rocks were variable. Assuming that cohesion and friction coefficient of the surrounding rock obey normal distribution,the stability of the tunnel surrounding rock under the variable mechanical parameters were analyzed by means of the mean,point standard deviations and correlation lengths.The results show that the failure probability of the tunnel is also changed when the minimum safety factor of the tunnel changes,i.e.,the stability of surrounding rock is changed.