基于变形准则的隧道围岩稳定概率分析

Probability Analysis for the stability of Tunnel Surrounding Rock Based on Deformation Criteria

研究了在隧道支护结构设计中采用变形控制时,其正常使用可靠度分析极限状态方程的建立方法,特别探讨了广义抗力和荷载问题。对于抗力,研究了各类隧道围岩最大允许变形值的确定规则;对于荷载,根据围岩与支护结构相互作用原理,揭示了坑道周边围岩变形在本质上是围岩物理力学参数的高度复杂函数,无法得到其解析关系的事实,由此导致的可靠度无法求解的问题。故此引入数值求解方法,推导了采用该方法求解基于变形准则的隧道结构状态方程时的相关计算公式,具体分析过程和详细步骤。构成了无解析式极限状态方程结构稳定可靠度计算方法。最后采用该方法分析某工程的稳定性,精度与Monte-Carlo法结果较为接近,而分析工作量却远远少于Monte-Carlo法。

In the design of tunnel support structure using deformation control, the method to establish limit state equation was usually analyzed with reliability. The general resistance and load problem were specially discussed. In regard to resistance, the rule of setting the maximum allowable deformation which is applicable to all kinds of tunnel surrounding rocks is studied. In regard to load, according to the interaction theory of surrounding rock and shoring structure, the truth is revealed that the deformation of the surrounding rock around mine is a quite complicated function about the physical mechanics parameter of surrounding rock, and there is no means to get an analytic relationship, which results in no solutions to the reliability. So a numerical computational methods is adopted to deduce some related formulas for the state equation of tunnel structure based on deformation criteria with detailed analysis and each steps. A new method to solve the limit state equation that without analysis formula is obtained. The stability of a project is analyzed by this method, it is found that the precision by this method is quite similar to that by Monte-Carlo simulation, and the workload is far less than that of Monte-Carlo simulation.