Damage Movement Characteristics of Overlying Strata in Near-fault Mining of Extra-thick Coal Seam

Based on the study of the actual strata mining in a coal mine in Fushun Mining Area of Liaoning province, the characteristics of the overburden failure of the near-fault mining in thick coal seam of the giant reverse fault are analyzed. Based on the spatial structure idea of overlying strata, the influence of excavation mining was analyzed by the instability on the spatial state structure of the overburden. The similarity experiment was used to analyze the macroscopic changes and verify the rationality of the theory. The results show that the overburden is not only broken in the vertical direction, but also tends to slip along the inclination in the horizontal direction. The tension zone is easy to form the cavity structure, and the compression zone is easy to form the ridge support. In the process of coal seam mining distance away the fault from the far to near, the fault slip shows a steady state to dynamic to steady state three-phase change law; the degree of fault crack increases with the depth of strata and presents the variation rule of “wide-narrow” after the fault activation.