Numerical Simulation Study On The Stability Of The Dahongshan Copper Mine

With the increasing depth of mining activity, structure characteristics and mechanical behavior of rock mass are getting more and more complicated caused by the redistributing of field stress in rock mass, resulting much difficulty in the stability control of stope surrounding rock. Meanwhile, disturbance in surrounding rock making by blasting vibration may weaken rock strength, threaten the safety of the operators. Therefore it has practical significance of studying on the stability of surrounding rock.In this paper, numerical simulations have been conducted to investigate the stope stability of the level 385, Dahongshan Copper Mine, by using the finite difference program FLAC3D. Analysing is focused on the influence of stope excavation and blasting earthquake, and the main conclusions are:(1) uniaxial and triaxial compression, as well as Brazilian tests have been conducted, and mechanical parameters of the rocks are obtained with the rock samples taken from Dahongshan copper mme.(2) in-situ geological survey has been carried out at the position between B18-B32, level 385 of Dahongshan copper mine. lithology and fissures distribution of the in-situ rocks are then obtained. The mechanical parameters of the rock mass ars then obtained based on GSI reducing method of Hoek-Brown failure criterion with the software of RocLab.(3) Numerical models are established, and numerical simulation is conducted to analizing the mechanical response of the rocks to the blasting, as well as the influence of the excavation to the stability of the surrounding rocks, by using software FLAC3D.(4) after considering the effect of the excavation of the blasting vibration on the stability of mined out areas, the characteristics of blasting vibration effect to the stability of the surrounding rocks and failure mechanism produced by dynamic loading are revealed.