Mechanism and Prevention of Rock Burst Induced by Wide Coal Pillar in Thick Hard Coal Seam

Aiming at the phenomenon of rock burst induced by wide coal pillars in thick hard coal seam in Hujierte Mining Area, the distribution characteristics of vertical stress of wide coal pillar has been analyzed by means of field measurement and numerical simulation. The structural condition of rock burst induced by wide coal pillars has been revealed by means of theoretical analysis. Based on the “three factors” mechanism of rock burst, the rock burst mechanism of wide coal pillar are studied and the results are as follows: accumulated lateral support stress and the advanced abutment stress of working face, the stress of the wide coal pillar is highly concentrated. When the ultimate strength of the coal is unloaded, the coal cylinder body is moving at a high rate due to the stiffness of the coal pillar and the stiffness of the roof rock. On this basis, the prevention strategies that reducing the stress of coal pillar, such as small coal pillar roadway protection and broken roof blasting measures, and reducing the stiffness of coal body, large diameter boreholes and coal seam water injection are proposed. The combined prevention methods, broken roof blasting and large diameter boreholes, are proposed to reduce the stress concentration of wide coal pillar, and the control effect is more significant.