Abstract:
To address the technical challenge of large-area roof hanging and induced strong strata behaviors in deep mines with hard roof strata, a study on pressure relief using hydraulic fracturing technology was conducted by taking the 1012006 working face in Yuanzigou Coal Mine as the engineering background. Through geological survey and key stratum theory analysis, a low-position key stratum located 23 m above the roadway roof was identified as the target layer for fracturing. True triaxial hydraulic fracturing experiments coupled with acoustic emission (AE) monitoring revealed a synchronous response characterized by a sudden drop in injection pressure and a rapid increase in AE counts, which established a quantitative correlation between rock mass fracturing and AE characteristics, providing a theoretical basis for field microseismic monitoring. Based on the “one-hole-two-track” borehole layout principle, a fracturing network comprising 6 drilling fields and 12 directional long boreholes was designed, with a total drilling length of
5727 m and 120 planned fracturing stages. Specialized equipment was selected for implementation. Field monitoring results demonstrated that the maximum fracturing influence radius was 27.8 m; the average daily frequency and total energy of microseismic events decreased by 50.65% and 27.73%, respectively; the stress in the deep part of the roadway decreased by 17.69%.