Limit analysis for the seismic stability of three-dimensional rock slopes using the generalized Hoek-Brown criterion

The parameters that influence slope stability and their criteria of failure are fairly understood but over-conservative design approaches are often preferred, which can result in excessive overburden removal that may jeopardize profitability in the context of open pit mining. Numerical methods such as finite element and discrete element modelling are instrumental to identify specific zones of stability, but they remain approximate and do not pinpoint the critical factors that influence stability without extensive parametric studies. A large number of degrees of freedom and input parameters may make the outcome of numerical modelling insufficient compared to analytical solutions. Existing analytical approaches have not tackled the stability of slopes using non-linear plasticity criteria and three-dimensional failure mechanisms. This paper bridges this gap by using the yield design theory and the Hoek-Brown criterion. Moreover, the proposed model includes the effect of seismic forces, which are not always taken into account in slope stability analyses. The results are presented in the form of rigorous mathematical expressions and stability charts involving the loading conditions and the rock mass properties emanating from the plasticity criterion. (C) 2022 Published by Elsevier B.V. on behalf of China University of Mining & Technology.

Automated summary

The parameters and failure criteria that affect slope stability are well understood, but conservative design approaches can lead to excessive overburden removal and jeopardize profitability in open pit mining. Numerical methods are useful for identifying stable zones, but they are approximate and lack the ability to pinpoint critical factors without extensive parametric studies. Existing analytical approaches have not addressed slope stability using non-linear plasticity criteria and three-dimensional failure mechanisms. This paper bridges this gap by utilizing the yield design theory and the Hoek-Brown criterion, while also considering the effect of seismic forces.