Abstract:
Mining activity in open-pit mines may change material properties over time and as a result, shear strengths are reduced and may lead to slope failures. It is therefore important to design slope geometries with an acceptable probability of failure. In the event of slope failure occurring, the process of back-analysis to determine material properties at failure may lead to slope redesign for safety reasons. A case study is presented from the back-analysis performed on a slope failure at an open-pit coal mine in the Mpumalanga Province, South Africa. The failure occurred during December 2008 and is believed to be a progressive failure where failure in one material triggered failure through another. Back-analysis, using the method of slices, was performed to obtain material properties at failure with the aim of redesigning the slope. The back-analysis included sensitivity and probabilistic analyses using the 2D limit equilibrium slope stability analysis program, SLIDE (
