Research on the Mechanism and Prevention for Rock Burst of Soft Coal in Deep Mine

Rock burst of soft coal is a new strongly concealed dynamic hazard, which threatens the mining safety of deep mine due to its unknown occurrence mechanism and the difficulty in prevention and control. Taking a coal mine in a rich coal zone with hidden hazards as an example, this paper firstly studied the cause of burst hazard in the region of deformed soft coal through theoretical analysis and field measurement, analyzed the evolution of soft coal burst, revealed its mechanism and finally proposed specific prevention and control measures. The main conclusions are: (1) the primary cause of impact hazard in soft coal mines was the formation of extensive disturbance zone under high stress, which caused the dirt ban to form a structure for carrying stored energy after the stages of dispersion, suspension, sliding motion and embedded squeeze contact; (2) the evolution of the rock bust of soft coal was concealed. In the process of the formation of bearing and storage structure, external input load gradually dissipated due to the severe deformation of roadway, forming an illusion without hazard; (3) the burst of soft coal was essentially the unstable impact of dirt band, so the criteria of obtaining stress and power for structural unstable impact was reduced; (4) the measures against the burst of soft coal from identifying potential impact areas, synchronously monitoring the stress of coal and the deformation of roadway to implementing prevention measures, were proposed, which exhibited a positive effect.