A stability analysis of rock slopes using a nonlinear strength reduction numerical manifold method

To investigate rock slope stability, a nonlinear strength-reduction numerical manifold method (NSRNMM) using a generalized Hoek-Brown (GHB) criterion is proposed. As it is difficult to implement the nonlinear strength reduction method (NSRM) with the use of the GHB criterion by directly reducing the GHB parameters, two equivalent Mohr-Coulomb (MC) criteria, namely, the instantaneous and average equivalent MC criteria that are derived from the GHB criterion, are adopted in the NSRNMM. The implementation details of the NSRNMM are discussed. The stability of two rock slopes, namely, a rock slope with a GHB material and a rock slope with a GHB material and two MC materials, is investigated using the NSRNMM. The numerical results indicate that 1) the proposed NSRNMM using the instantaneous equivalent MC criterion can accurately calculate the safety factor (F-s) of rock slopes and that 2) the F-s predicted with the NSRNMM using the average equivalent MC criterion is more conservative than that using the instantaneous equivalent MC criterion.

Automated summary

A nonlinear strength-reduction numerical manifold method (NSRNMM) using a generalized Hoek-Brown (GHB) criterion is proposed in this study to investigate rock slope stability. Implementing two equivalent Mohr-Coulomb (MC) criteria from the GHB criterion, the NSRNMM can accurately calculate the safety factor of rock slopes. Results show that the NSRNMM with the average equivalent MC criterion predicts a more conservative safety factor compared to the instantaneous equivalent MC criterion.