RESEARCH ON THE STABILITY OF MULTI-KEY LAYER STRUCTURES AND ANTI-IMPACT AND VIBRATION REDUCTION TECHNOLOGIES IN DEEPLY BURIED ROCKBURST MINES

In order to create favorable conditions for the safe production of mines with multi-key layer structures and deeply buried impact ground pressure, a study on the stability of these structures was carried out based on the Vlasov plate theory. It is found that the maximum tensile stress within thick hard rock layers is greatly influenced by the short side of the goaf, and that the maximum tensile stress in thick hard rock layers decreases as the thickness of the overlying rock layer increases. In addition, research suggests that the first key layer (thickness 5~22 m) of the 3100 working face will break when the width of the goaf reaches approximately 20-25 m, while the second key layer (thickness 33~53 m) will break when the goaf width reaches approximately 90~100 m. Subsequently, through on-site practical research methods, anti-impact and shock absorption measures were proposed for different layers of thick and hard roof, including low-level roof blasting pressure relief and high-level directional hydraulic fracturing pressure relief. Finally, a comparative analysis was conducted on the pressure relief effects of the 3100 and 3102 working faces in the same mining area of Menkeqing coal mine. Ihe results revealed that the 3100 face, which adopted multiple key layer pressure relief measures, experienced a 9.5% reduction in microseismic frequency per meter and an 86.2% reduction in microseismic energy per meter compared to the 3102 face, which did not adopt such measures. The research results have been implemented in the Menkeqing mine and have achieved positive outcomes.