Three-dimensional inelastic numerical back-analysis of observed rock mass response to mining in an Indian mine under high-stress conditions

摘要

Numerical modelling is increasingly being used to evaluate ground stability and to assist in the long-term planning of mining operations. However, selection of appropriate constitutive material behaviour and input parameters for the rock mass is still debated amongst the rock mechanics community. A case study of a hard rock mine practising sublevel open stoping has been simulated using 3D finite difference method (FLAC3D). The mine was modelled using four types of constitutive material models - Mohr-Coulomb with post-peak cohesion-softening/friction-softening, bi-linear Mohr-Coulomb with post-peak cohesion-softening/friction-softening, Mohr-Coulomb with post-peak cohesion-softening/friction-hardening and the improved unified constitutive model (IUCM). The outcome of all approaches has been compared with measured ground performance. The comparison revealed that the numerical model using the IUCM provides the most realistic match to the observations in the mine including the failure of the crown pillars.