Journal de la métallurgie des poudres et des mines

Abstrait

Full Three-dimensional Finite Element Analysis of the Stress Redistribution in Mine Structural Pillar

M.Sepehri, D.B. Apel,J. Szymanski

The assessment of the magnitudes and directions of the in situ and mining induced stresses is a vital part of an underground excavation design. In this study, the finite element method is used to develop and establish a full three-dimensional numerical model using Abaqus/Standard (Dassault Systèmes) software to evaluate the stress redistribution and the ground stability in main production level of an underground hard rock mine located in Northern Canada. The in-situ stresses are calculated based on the unit weight of the overburden rock. The ratio of the average horizontal stress to vertical stress is assumed to be 1.5. This value is selected based on the average stress ratios obtained from the neighboring mines. The behavior of the rock is assumed to be elasto-plastic. To verify and calibrate the numerical model, the obtained displacements values are compared with the values obtained from the ground movement monitors installed in this area. Based on the results of the numerical model, it was concluded that benching of the floor in the 7340E access drift by an additional 2m would increase the zones of failure in the studied pillar. Moreover, the zones of failure in the adjacent tunnels which were inside of the zone of influence of the 7340E access drift would be increased dramatically.