ANALYSIS ON INFLUENCING FACTORS OF ROCK PRESSURE IN COMPLEX STRESS COAL STRATA

In the process of coal mining, rock burst will seriously affect the underground working environment and personnel safety, delay the progress of coal mining and damage the surface ecology. Therefore, this paper discusses the factors that affect the occurrence of strata burst in the process of coal mining in complex stress coal seam. The results show that the final rock caving amount of rock burst experiment and simulation is 14.3g and 14.6g respectively. The numerical simulation model is suitable for the simulation analysis of rock burst in subsequent coal mining operation. At the same time, the rock burst condition will decrease with the increase of elastic modulus. When the elastic modulus of coal and rock is 250MPa, the rock block caving amount in the roadway is 34.65m3. However, when the elastic modulus of coal and rock increases to 750MPa, the amount of coal seam caving in the roadway decreases to 9.88 m3, which is mainly because the greater the elastic modulus is, the stronger the formation strength is, and it is more difficult for rock burst to occur. Moreover, the study also found that the increase of coal rock cohesion will restrain the caving and roadway deformation of rock burst to a certain extent. When the cohesion of coal and rock is 0.5 MPa, the amount of caving rock is 41.40 m3; while when the cohesion of coal and rock becomes 2.5 MPa, the rock burst hardly affects the caving of coal and rock. Finally, the study of the effect of in-situ stress on rock burst shows that with the decrease of in-situ stress difference, the rock burst will gradually increase. This study can provide theoretical support for avoiding or weakening the impact of rock burst on coal mining safety in complex stress coal seam.