Application Research on Hydraulic Fracturing Roof Cutting and Pressure Relief Technology for Gob-side Entry Retaining

In this paper, the transportation roadway of 21108 working face in Gaoyang Coal Mine is taken as the research object, and the method of numerical simulation combined with field engineering test is adopted to study the large deformation and stress concentration of surrounding rock in gob-side entry retaining. The vertical stress distribution characteristics in the coal pillar after roof cutting were analyzed by numerical simulation. The hydraulic fracturing roof cutting and pressure relief scheme was implemented in the transportation roadway of working face, and the deformation monitoring station of roadway surrounding rock was set up for monitoring to comprehensively evaluate the control effect of roadway surrounding rock. The results show that the peak value of vertical stress in coal body decreases after roof cutting, and the peak position is closer to the edge of goaf. Because the roof cutting weakens the mining stress concentration intensity, the stress concentration coefficient decreases. The field application effect of hydraulic fracturing roof cutting and pressure relief scheme is remarkable. The end hanging roof is successfully solved, the influence of lateral pressure stress is reduced, and the deformation of surrounding rock of roadway is greatly reduced. After simple treatment, it can meet the mining demand.