A New Approach for Incorporating Hoek–Brown Failure Criterion in Kinematic Approach — Case of a Rock Slope

This paper develops a novel approach to incorporate the generalized Hoek–Brown criterion in the kinematic approach. Two analytical expressions for the equivalent friction angle and the equivalent cohesion in the context of the Hoek–Brown criterion are derived as a function of the minimum principal stress. As an illustrative example, the stability of a rock slope is investigated. The spatial discretization technique is employed to generate a slope failure mechanism considering the spatial variation of the equivalent friction angle corresponding to the minimum principal stress. In order to simplify this problem, the minimum principal stress is taken as an additional parameter in the optimization process of the kinematical approach. For the numerical modeling, three kinds of stress distributions are considered in the optimization process. The proposed approach is validated by comparison with available numerical results with good agreement. It is also shown that with the uniform distribution of minimum principal stress, the proposed approach gives the same solutions as those by the classical tangential line technique, and with more complicated distributions, the proposed approach yields a better solution than the classical tangential line technique, especially for large values of geological strength index (GSI).