103 / 2023-06-15 15:32:45

Research on the design method of pre-mining rock-burst reducing of the hard roof working face in multi-seam mining

rock burst; rock-burst reducing; pre-mining design; hard roof; multi-seam mining

In view of the problems of the hard roof working face of multi-seam mining prone to burst appearances, the pre-mining rock-burst reducing method of the hard roof working face of multi-seam mining is studied with the I010101 working face to be mined in Kuan Gou coal mine as the research background. Based on the analysis of the theory of dynamic and static combined load , the static load of this working face is calculated to be 18.13~44.06MPa and the dynamic load is 18.3MPa. The critical value of burst of this working face is determined to be 50MPa~70MPa, and the dynamic and static load superposition exceeds the critical value and has certain burst hazard.The stress distribution law of the working face to be mined in steps after the overlying coal seam is mined as a protective layer is analyzed by numerical simulation, the static load stress is calculated to be 4~27MPa, the safe load calculation method of the working face is proposed, and the formula for calculating the caving step distance of the overlying hard roof under the safe dynamic load condition is derived, and the maximum value of the caving step distance of the hard roof of the I010101 working face under the safe load condition is calculated to be 20.3m.This study can provide guidance and reference for the practice of pre-mining load reduction and impact reduction in hard roof working face under similar geological conditions.