关键词: 分层开采, 厚硬顶板, 覆岩破坏机理, 移动变形, 应力分布

Abstract: In the stratified mining of thick coal, the failure of roof overburden structure plays a decisive role in controlling the stability of roadway and the support stability of working face. In view of the problems such as non-collapse of the hanging roof in the goaf under the condition of direct overburden of thick sandstone roof, large weighting interval, and large impact dynamic pressure after fracture, taking the 13121 upper working face of Gubei Coal Mine as the engineering background, the failure mechanism of the overlying rock structure of thick and hard roof in layered mining is revealed through theoretical analysis, field detection, mechanical test and numerical simulation, and the laws of roof movement, deformation and stress distribution are obtained. The results show that the caving step of thick and hard roof is large, the mining effect is severe, and the plastic zone is destroyed. The engineering performance is large area hanging roof in goaf and large area spalling of coal side. Accordingly, the deep-hole blasting technology of roof cutting and pre-splitting with thick and hard roof was proposed and successfully applied to 13121 upper working face in Gubei Coal Mine, which shortened the initial and periodic weighting interval and effectively controlled the surrounding rock of roadway and stope pressure．