Influence of Dip Angle of Coal and Rock Combination on Outburst Tendency Based on Particle Flow Code

With the increase of coal mining depth, the interaction between coal seam and top and bottom rock layer is more obvious. This paper establishes the rock-coal numerical model of “roof-coal” structure based on the particle discrete element program PFC, and the influence of 0°, 15°, 30°, 45°, 60° dip angle on failure mode and impact tendency of composite body are studied. The macroscopic fracture of the composite is basically a shear crack of type V, and the damage mainly concentrates on the part of the coal, and the ends of the V coincide with the interface of the model. With the increase of dip angle, there are the more active particles, especially when the dip angle of the composite is greater than 45°, and the displacement and activity of the particles at the interface of coal and rock are the biggest. With the increase of dip angle, the impact energy index of the composite body decreases gradually, especially when the inclination angle is greater than 45°, the impact energy index decreases greatly.