岩体抗剪强度参数对边坡安全系数的敏感性分析

Sensitivity Analysis of Rock Shear Strength Parameters to the Slope Safety Factor

云南某露天边坡岩体主要以大理岩化灰岩为主,边坡岩体整体呈中风化,随着后续开采,边坡的安全问题将制约矿山的发展。黏聚力(c)和内摩擦角(φ)是影响边坡工程和地下工程稳定性的主要因素,研究通过多种方法获得岩体力学参数,对比了由Hoek-Brown强度准则和岩体直剪试验得出的岩体参数,使用敏感性分析理论分析了内摩擦角和黏聚力对某露天矿岩质边坡的安全系数的影响。结果表明,Hoek-Brown强度准则得出的岩体抗剪强度参数比较可靠;在黏聚力和内摩擦角取值较小时,对安全系数的敏感性差异不明显,当二者取值较大时,以2%参数变化率为临界点,内摩擦角对岩质边坡的稳定性更显著。

The angle of internal friction and cohesion are main elements which affect the stability of slope project and underground project. This paper uses the sensitivity analysis theory to analyze the angle of internal friction and cohesion of its influence on the safety factor of certain open pit mine slope. The rock mass mechanical parameters are analyzed by applying Hock-Brown failure criterion and rock mass direct shear test. The research result indicates that rock mass mechanical parameters applying Hock-Brown failure criterion are credible; the sensitivity of two factors are similar when the two factors are small. Considering the parameters at 2 % rate for the critical point, internal friction Angle of rock slope stability is more significant when the two factors are comparatively large.