Response characteristics of rupture mechanism and source parameters of mining tremors in frequent coal burst area

Mining tremors are the essential factor for the formation and initiation of coal bursts. It is crucial to investigate the fracture mechanism of the mining tremors to integrity the coal burst mechanism. An inversion mechanism based on the source group is proposed based on the relative moment tensor inversion principle to effectively analyze the rupture mechanism and response characteristics of source parameters. Based on the background of the application in coal mines，the inversion matrix is constructed firstly. In addition，the minimum ray number and source number conditions are deduced，and the identification method of source rupture type of mining tremors is optimized，which improves the inversion accuracy and efficiency. The mechanism of seismic rupture mechanism and the response law of source parameters in the fold structure area，deep buried fault structure area，and high stress roadway coal pillar area are analyzed statistically. The results show that the strong mining tremors’ focal parameters and rupture mechanism are related to the geological structure，focal layer，and stress environment. The tensile fracture is dominant in the roof，and the shear fracture is prevalent in the coal mass belonging to the fold structure area. The difference of source rupture strength and stress adjustment degree between tensile type and shear type is slight，while the disturbance scale of tensile type is more extensive. The tensile type has more muscular rupture strength，and the shear type has a larger disturbance scale. Seismic source types in high stress area coal pillar dominated by shear fracture are easily along the coal pillar under the roof，and floor of the clamping stress along the edge direction occurs shear damage continuity. The average shear source parameters (in addition to the apparent stress) significantly higher tensile type mining tremors show that shear when mining tremors risk is considerably higher than tensile type mining tremors. Source parameters and rupture mechanism characteristics under different conditions can provide a reference for accurate identification and mechanical mechanism research of strong mining tremors.