Probabilistic-Based Stope Design Methodology for Complex Ore Body with Rock Mass Property Variability

This paper presents a probabilistic approach for optimizing stope design methodology while taking into consideration the variability in the rock mass properties. For this study, a complex orebody in a Canadian mine was used. Because of the variability in the rock mass properties of the orebody, it was not possible to determine precisely, the values of geotechnical design input parameters and hence the need to utilize a probabilistic approach. Point Estimate Method (PEM), a probabilistic tool, was incorporated into numerical analysis using FLAC(3D) to study the deformation magnitudes of various stope geometries to determine the optimal stope geometry with a minimum ground control problem. Results obtained for the distribution of the wall deformations and the floor heaves for each option of the stope geometry were compared to select the best geometry to achieve the optimum stability condition. The methodology presented in this study can be helpful in the process of underground mine planning and optimization in complex orebody.