Research and application of hydraulic fracturing technology in shallow-buried dynamic pressure mining roadway

In order to improve the stability of surrounding rock of narrow pillar mining roadway with shallow depth, taking the narrow pillar mining roadway of 15217 working face of Hongliulin Coal Mine as the engineering background, based on the distribution characteristics of roof rock strata, the main force sources inducing roadway deformation are analyzed, the mechanism of roof hydraulic fracturing pressure relief is analyzed, the reasonable fracturing layer height is determined, the hydraulic fracturing pressure relief technical scheme is formulated, and successfully applied to the underground test.The test results show that after the roof hydraulic fracturing, the influence of the advance ground pressure of the mining roadway is small, the stress of the bolt and its change range are small when the working face is behind, the maximum stress is 88.7 kN, and the stress growth in the shallow part of the coal pillar is prominent, indicating that the structural dimension of the lateral overhanging roof of the coal pillar decreases after the hydraulic fracturing, and the stress of the roof rock layer gradually transfers to the direction of solid coal.The deformation of the stoping roadway is mainly manifested as the collapse of the shoulder cavity.The roof shallow separation is 3.0 mm, and the deep separation is 4.5 mm.The overall support effect of the roadway is good, and indicating that the hydraulic fracturing pressure relief technology has a good control effect on the deformation of surrounding rock in shallow-buried narrow pillar mining roadway.