基于广义Hoek-Brown破坏准则的边坡临界滑动场

CRITICAL SLIP FIELD OF SLOPE BASED ON GENERALIZED HOEK-BROWN FAILURE CRITERION

针对岩体介质非线性破坏特点,采取国际广泛接受应用的建立在地质强度指标(GSI)法基础上的Hoek-Brown屈服准则,建立基于广义Hoek-Brown破坏准则的边坡临界滑动场计算的新方法。首先,根据Hoek-Brown准则确定岩体强度参数;然后,将Hoek-Brown准则不同法向应力水平上的剪切强度逐点等效到Mohr-Coulomb强度线上,用等效内摩擦角和等效黏聚力的Mohr-Coulomb准则代替Hoek-Brown准则;最后,将基于Mohr-Coulomb破坏准则的边坡临界滑动场计算方法进行改进,建立新的迭代方法,获得边坡在满足力与力矩平衡条件下的整体和局部临界滑动面和相应的安全系数。将该方法应用于2个算例和一工程实例边坡的稳定性分析,计算结果表明,该方法既继承了临界滑动场方法快速、准确找到边坡整体局部临界滑动面的优点,又能考虑岩质边坡非线性破坏的特点,更加符合工程实际。

According to the nonlinear failure characteristic of rock mass, a new calculation method for critical slip field of slope is proposed based on generalized Hoek-Brown failure criterion. The Hoek-Brown failure criterion based on the geology strength index（GSI ） is one of the most useful criteria for forecasting and computing rock mass strength. Firstly, the parameters of rock mass strength are obtained by Hoek-Brown failure criterion. Secondly, the shear strength of each point on the Hoek-Brown strength envelope is transferred equivalently to the Mohr-Coulomb linear relation which is tangent to the nonlinear envelope with relevant cohesive and frictional parameters. Finally, the new iterative method is established and the critical slip field of slope by Morgenster-Price method is improved. And then, the most dangerous sliding surfaces are traced according to the principle of maximum thrusts with satisfying both force and moment equilibriums; and the corresponding safety factors are calculated quickly and exactly. This method is applied to the stability analysis of two slope examples and one case slope. The results show that this method absorbs the advantages of critical slip field and Hoek-Brown failure criterion and can consider the nonlinear failure characteristic of slope. The calculation result is more closer to the practical situation.