岩体参数对隧洞围岩稳定性影响的敏感性分析

Sensitivity Analysis of Mechanical Parameters Influencing Stabilization of Surrounding Rocks of Tunnel

以锦屏二级水电站深埋长引水隧洞为工程实例,通过平面非线性有限元对围岩各项参数对围岩稳定性影响进行了敏感性分析.引入敏感性系数来衡量各项参数的独立作用对岩体稳定性影响的敏感程度,用正交试验设计分析的方法分析各参数存在相互关联的基础上对围岩稳定性影响的敏感程度,从而确定影响围岩稳定的主次因素.结果表明,岩体参数E,φ是影响岩体稳定性的主要因素,而岩体强度参数C和泊松比μ为次要因素.

The sensitivity analysis of four mechanical parameters which influence the stabilization of surrounding rocks of the diversion tunnel in Jinping water powerstation was performed using the nonlinear elastoplastic plane finite element method. A sensitivity coefficient is introduced to evaluate the sensitivity degree of every mechanical parameter. In order to find the law of sensitivity degree of every mechanical parameter, such as determining the principal and secondary parameters, the interrelations of mechanical parameters were discussed based on the cross test design. The results show that the sensitivities of deformation modulus and friction angle are comparatively higher than that of Poisson＇s ratio and cohesion force.