Research on structural evolution characteristics of overburden rock for shallow buried thick coal seam mining

Abstract

In order to grasp the structural evolution characteristics of overburden rock in shallow buried thick coal seam mining, the mechanism of overburden rock destabilization in the mining of 42106 comprehensive release workings in the 4-2 coal seam of Bultai coal mine was analyzed by using theoretical analysis, similar simulation and numerical simulation. The results show that: with the increase of the workface recovery length, the overburden of the comprehensive release workface experiences a continuous dynamic sinking process; the initial pressure step is about 95m, and the initial breakage position of the key layer is located at the back of the workface, and the periodic pressure step is about 25m, and the breakage position is located in front of the coal wall; when the workface recovery distance is from 65m to 95m, the overburden support stress of the comprehensive release workface appears to rise abruptly at the initial pressure. trend.