基于广义Hoek-Brown准则边坡稳定性分析强度折减法

目前的强度折减法大多基于Mohr-coulomb准则,而较少基于Hoek-Brown准则。为了在Hoek-Brown准则中实施强度折减法,并使其得到的结果与Mohr-coulomb准则中强度折减法得到的结果等效,本文利用Hoek-Brown准则参数m、s、σci与粘结力c和内摩擦角φ之间的关系,在Hoek-Brown准则中同时对m、s实施强度折减,通过理论推导得到m、s折减系数之间的关系;并进一步推导得到m、s折减系数与基于Mohr-coulomb准则强度折减系数之间的关系;最后,由FLAC3D软件建立计算模型,采用所确定的折减方法计算边坡的安全系数,并将该结果与极限平衡法所得到计算结果进行比较,结果表明:本文确定的折减方法与极限平衡法所得到的安全系数的相差仅1.76%,验证了本文所确定的强度折减法的可行性。

Strength reduction method based on generalized Hoek-Brown criterion for slope stability analysis

The present strength reduction method was mostly based on Mohr-Coulomb criterion other than.Hoek-Brown criterion.In order to use the strength reduction method in Hoek-Brown criterion and get a result equivalent to that by Mohr-Coulomb criterion,a new strength reduction method was applied to m and s simultaneously.The relationship between the reduction factors of m and s was obtained by theoretical deduction,based on the relationship among the parameters of m,s,σci and cohesion c,internal friction angle φ in Hoek-Brown criterion.The relationship between the factors of m and s in Hoek-Brown criterion and the reduction factors in Mohr-Coulomb criterion was found.In the end,a calculation model was built using FLAC3D application.The proposed reduction method was used in calculating the safety factor of slope,and the result was compared with that obtained by the limit equilibrium method.It showed the difference between them is mere 1.76%,which proved the feasibility of the reduction method proposed in the paper.