Abstract:
Due to its unique geological, stress, and mining technical conditions, the control technology methods for rock burst in steeply inclined and extremely thick coal seams are quite different from horizontal coal seams.Using theoretical derivation, numerical simulation, and field monitoring methods to study the distribution of rock bending moments and energy accumulation characteristics in steeply inclined and extremely thick coal seams, the paper reveals the weakening method of rock burst prevention in shallow layer of steeply inclined and extremely thick coal seams, obtains key parameters for rock burst prevention, and conducts engineering applications. The results show that the bending, fracturing and energy releasing of overlying strata of the steeply inclined and ex-tremely thick coal seam are the primary source of dynamic stress. the horizontal concentrated stress transmitted to the coal seam from surrounding rock mass on both sides of the gob are the primary sources of static stress and energy accumulation. To prevent rock burst in steeply inclined and extremely thick coal seams, it is necessary to weaken the stress transfer ability of the shallow rock mass to the working face, thereby reducing the dynamic stress disturbance intensity transmitted to the working face and the horizontal concentrated stress transferred and transmitted to the coal seam. Based on this, the shallow hole blasting method was proposed to weaken the shallow rock mass of steeply inclined and extremely thick coal seams for rock burst prevention. The application shows that the total energy of microseismic events on the working face decreased by 42.38% after shallow hole blasting. The total frequency of microseismic events increased by 471.74%, shifting from intense release of enormous energy to gentle release of small energy, and no more rock bursts occurred again. The risk of rock bursts was effectively controlled. The research results can support rock burst preventation in mines under similar conditions.