The full period interactive response mechanism between surface subsidence and large energy events in deep mining of super-thick weakly cemented overburden

Abstract

The western mining area is an essential coal mining base in China. Because of the presence of the super-thick weakly cemented overburden, deep mining in this area faces problems such as high energy events and serious dynamic disasters, and the surface subsidence is slight in the initial stage of mining. To solve the above problems, this paper takes Ordos mine as research object, systematically studies the linkage mechanism between surface subsidence and large energy events in the full period mining. In the initial stage of mining, the two large energy mining seismic in the mining process of 1208 working face both occurred near the maximum subsidence point and were accompanied by sudden increase of surface subsidence. With the increase of mining area, there is an obvious interactive response between the subsidence incremental of surface and the energy release in high position super-thick rock strata. Moreover, based on the simulation of overburden breaking and the energy evolution of key horizon, the mechanism of action of super-thick overburden failure on surface subsidence and energy release is clarified. Based on this, the mining seismic activity for the full period of mining is predicted by the mechanical analysis. The results can provide theoretical support for large-scale continuous mining in weakly cemented mining areas in western China.