Stress distribution and failure characteristics of deep inclined seam and overhead mining along strike longwall floor

Based on a case study, this paper presents the stress distribution characteristics and plastic zone distribution characteristics of a deep inclined seam and overhead mining along strike longwall (ICMSL) floor by considering the results from numerical simulations, theoretical calculations, and field measurements. The results show that the vertical taper structure is formed by the roof, the interconnection, and the maingate. The vertical taper structure is formed by the floor, the face, and tailgate. The movement and deformation are mutually restricted by the vertical taper structure, which leads to the stress concentration of vertical stress and maximum shear stress. The maximum failure depth is 20 m, and the failure zone is mainly concentrated in the vicinity of the interconnection and face. The maximum failure depth of the coal seam floor is 21.32 m by theoretical calculation, and between 18.19 m and 20.24 m by in situ field tests.