Finite element analysis incorporating the shear strength reduction method was applied to study the west slope stability of an open cut mine in Australia using Mohr-Coulomb and generalized Hoek-Brown criteria. The pit of the mine had multiphase excavations and reached 180 m in depth. The study investigated three slope configurations, namely, Stage 1 inter ramp slope 43°, Stage 2 inter ramp slope 49°and optimized Stage 2 slope 54°. When implementing the generalized Hoek-Brown failure criterion,

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... e equivalent factor of safety was 1.96, 1.87 and 1.40 under dry slope for the three configurations, respectively. However, under partly saturated conditions, the optimised slope would have a factor of safety 1.16. Furthermore, the generalised Hoek-Brown criterion generated lower factors of safety than the Mohr-Coulomb failure criterion. The difference is related to an overestimation of the shear strength parameters by the linear Mohr-Coulomb criterion under low confining stresses compared with the non-linear Hoek-Brown.