3D numerical simulation of a mine using cohesion-softening, friction-softening and hardening behavior

摘要

Numerical modeling is a potent tool to evaluate stability and to assist in long term planning of a mine along with predictive modeling of planned mining situations. However, selection of proper input properties regarding the rock mass still intrigues the Rock Mechanics community. A well-documented case study of a hard rock mine situated in moderately high stress regime practicing sublevel open stoping has been simulated using 3D finite difference method (FLAC3D). The mine was modeled using three types of constitutive material model - Mohr-Coulomb with strain-softening post peak, bi-linear Mohr-Coulomb with strain-softening post peak, Mohr-Coulomb with cohesion softening/friction hardening (CSFH) post peak. Outcome of all approaches have been compared with actual ground conditions. The comparison revealed that the numerical models using the bi-linear Mohr-Coulomb with strain-softening post peak provides most realistic match to the observations in the mine including instability of the crown pillars.