The Safe Thickness of Top Plate in the Process of the Underground Excavation Transferred to Opencast Excavation

摘要

Zijinshan gold mine once to mining local underground copper resources, result in the mined-out area which elevation from 460 m to 570 m, the upper pit continue mining down the deep, one of the main problems in the safety production is that the large-scale mining equipment work whether fall into the mined-out area, it need to determine the problems of safe thickness of roof and reasonable value; First use six theoretical analysis methods, respectively was studied and calculating the safety thickness, then using finite difference software FLAC 3D are simulated on a 1-1 section, by comparing and comprehensive research, found that using numerical simulation method to get the calculation result is far above the theoretical calculation results. In the final analysis, determine the safe thickness of roof, which provide the decision basis for safety production.