A new approach for evaluation of slope stability in large open-pit mines: a case study at the Dexing Copper Mine, China

The slope stability has already become one of the most important factors directly related to the safety production and development of a mine, which is principally controlled by the properties of geological discontinuities of slope, such as bedding planes, faults, cleavage and joints. In this study, a new approach for the evaluation of slope stability in large open-pit mines was presented based on a comprehensive investigation of the geometry and shear strength of the geological discontinuities. This approach follows three steps: (1) graded kinematic analysis using stereographic projection techniques; (2) field estimation of shear strength of discontinuities with the consideration of the impact of uncertainty and scale dependency; and (3) slope stability assessment based on deterministic analysis by FoS and the probabilistic analysis by PoF. A case study, namely, the Yangtaowu Slope in the Dexing Copper Mine, was selected for the application of this approach. The stability assessment result shows good agreement with field observation, illustrating the ability of the proposed method in effectively predicting the stability of open-pit mine slopes. Furthermore, the comparison of the calculated results based on the precise and generalized calculation models demonstrated that the accuracy of the geometric model has a high influence on the stability assessment.