Mechanism of rock bursts caused by “Roof-Rock pillar” in mining steeply-inclined and its prevention and treatment

Due to the complexity of geological conditions and the particularity of mining methods, dynamic disasters occur frequently in the process of horizontal sublevel mining in the south area of Wudong Coal Mine.In order to reduce the risk of rock burst, this paper takes B₃₊₆ and B₁₊₂ coal seams in the south mining area of Wudong Coal Mine in Urumqi mining area as the research object.By means of field investigation and theoretical analysis, the mechanism of rock burst under the mining condition of vertical extra-thick coal seam is studied, the structure between roof and coal seam is analyzed and the mechanical model is established, and the stability of rock pillar between coal seams is studied.The results show that: the distribution of “induced rock burst events” in the mining process of B₃₊₆ coal seam has obvious regional distribution, and the microseismic distribution in the roof and rock pillar area of B₃₊₆ coal seam has obvious concentration phenomenon; The fracture, slip and rupture of roof and local failure of rock pillar provide dynamic conditions for the occurrence of rock burst in B₃₊₆ coal seam, and the superposition of dynamic disturbance and high static stress of coal seam is the main reason for the occurrence of rock burst in B₃₊₆ coal seam although it is shallow buried and shallow.Based on the results of the analysis and combined with field practice, the development of roof and rock pillars pre-splitting blasting pressure relief and rock pillars in advance ground blasting pressure relief measures, the prevention and control of field practice shows that adopting method can effectively reduce the intensity of stress concentration and activity of surrounding rock of coal or rock, reduce the probability of rock bursts occurred in nearly erect, thick coal seam, for the east mine nearly erect, the impact of the thick coal seam mining provides a scientific basis for prevention and control.