Numerical simulation of overburden migration law in full-mechanized caving of high inclination coal seam

In this paper, a coal mine in Shandong Province is taken as an example to conduct numerical simulation research on fully mechanized caving technology of high inclination coal seam, and the overburden migration law in the process of fully mechanized caving of high inclination coal seam is simulated and analyzed. The research shows that the increase of coal seam inclination has a significant effect on rock stress distribution and roof displacement during mining. In fully mechanized caving mining, the stress of overlying strata is mainly concentrated on the coal pillar on both sides of the working face, and the lower coal pillar bears more pressure, and the pressure of the coal pillar gradually increases with the increase of the excavation distance. In terms of vertical displacement, the roof increases with the increase of the excavation distance during the excavation process, and the maximum displacement in the inclined direction can reach 267 mm. Moreover, near the interface between the excavation face and the coal seam, the vertical displacement of the roof decreases rapidly with the increase of the X-axis coordinate. In addition, with the increase of coal seam inclination Angle, the maximum pressure of coal pillar on both sides of the working face gradually decreases. When the inclination Angle increases from 35° to 55°, the pressure of coal pillar decreases from 3.15 MPa to 2.9 MPa, and the vertical displacement of the roof in the inclined direction also decreases with the increase of the inclination Angle.