Research on mining disturbance characteristics and productivity of rock burst mines under different mining intensities

Mining disturbance is the root cause of the deformation, rock burst and instability of deep coal and rock mass, and the characteristics of mining disturbance are closely related to the mining intensity. After entering deep mining, the number of rock burst mines is increasing with the increase of mining intensity. Studying the mining disturbance characteristics under different mining intensities in rock burst mines, and then determining the reasonable mining intensity according to the mechanical response characteristics of mining coal ars of great significance to the prevention and control of rock burst. Taking the Binchang mining area in the typical rock burst mining area as an example,the methods of numerical simulation and theoretical analysis are used to analyze the characteristics of coal and rock mining stress, energy release and overburden caving structure under different mining intensities. The mining disturbance characteristics under different advance speeds of working face and different mining thicknesses are analyzed, the rock burst risk of mining coal body under different mining intensities is evaluated, and the application of mining disturbance characteristics in mine productivity control and mining method optimization is discussed. The results show that ① The annual coal output is in direct proportion to the number of rock burst mines, and the probability of rock burst in deep mines is significantly higher than in that shallow mines.②The top and floor stress, advanced support pressure and rock burst hazard of whole coal seam mining are all greater than those of slicing mining, and the former has obvious peak strain energy forward movement.③The mining thickness of the working face is increased that the rotation angle and fracture degree of the key block is increased, and the possibility of sliding and rotation instability is improved. The advanced speed is increased that the possibility of rotation instability is increased, and it will be easier to induce the breaking of the overlying strata and the release of large amounts of energy, thereby increasing the rock burst hazard.④The mining disturbance characteristics under different mining intensities is revealed. A method to reversely determine the reasonable mining intensity and then determine the mine productivity based on the mining disturbance characteristics under different mining intensities is proposed. Based on the characteristics of mining disturbance, the mining method of the Mengcun coal mine is optimized. It provides a scientific basis for guiding the prevention and control of rock burst disasters in mines.