Mechanical mechanism of rock burst accidents in slice mining face under high pressure

The mechanism and prevention of rock burst are investigated based on a rare rock burst accident in which the rock burst around working face and roadway occur simultaneously in the upper slice mining face of extremely thick coal seam with thick and hard roof. The results show that the main cause is the concentrated stress from the top coal pillar, sectional coal pillar with different widths, thick and hard roof and large fault. The bottom coal under roadway and working face is the main hazard body of rock burst. The main mechanical mechanism of rock burst is that the bottom coal produces buckling failure under sudden horizontal stress, and then slips to roadway and working face under the vertical stress. An evaluation method for the influence scope of the top coal pillar and the danger scope of rock burst is proposed in order to provide a scientific basis for making programs to resume production. The relevant programs to resume production are developed and implemented based on the research achievements. Through the implementation of pressure relief in the danger area of rock burst and the real-time monitoring of pressure bumping risk, the production is resumed and the safe mining is ensured.