Developing an Approach for Reliability Analysis of Bench Face Angle Design in Open Pits with Structurally Controlled Sliding Failure Available to Purchase

A step by step "repeatable" procedure of the reliability-based methodology for Bench Face Angle (BFA) design, which does not use in-house software, is presented in this paper. The published references on reliability BFA design use non-commercially available software as the basis for the reliability approach. In this study, a technique was developed for probabilistic reliability design which does use commercially available software to assess bench scale instabilities. Back break analysis using cumulative frequency analysis and stochastic simulations of discontinuities properties such as orientation and dips were conducted to analyze the likelihood for plane shear and wedge type failures to occur for given bench face configurations and orientations. For this purpose, Monte-Carlo generated joints analyses using Rocscience SWEDGE computer program was conducted along with stereographic analysis using Rocscience DIPS computer program to calculate the probability of failure and the related back break length at bench scale. Reliability plots for BFA were generated using a spread sheet (in Microsoft Excel) developed specifically for this study.