Numerical Analysis of Pressure-relief Effects in Liberated Layer Mining

To optimize the prevention design of rock burst and achieve safe and efficient mining, FLAC numerical simulation software is used to simulate the pressure-relief effect of 3 upper coal seam to 3 lower coal seam. The result shows that the stress concentration factor in up and down sides of 3 upper coal seam workface roadway is 3.3, in the region around the cut-hole is 3.4, in the coal before the working face is 3.5, the peak value area of vertical stress is 10 meters off working face coal walls; the strike pressure-relief protection angle around the cut-hole is 72°, before the working face is 76°, the dip pressure-relief protection angle is 85°.