Research on control technology of floor heave in deep large inclined coal roadway

In view of the problems of large floor heave and fast deformation speed in Jurassic coal roadway in the northwest mining area, this paper took Zhonger 401 return airway in Wangjiashan Coal Mine of Jingyuan Coal and Power Company as the research object. Based on theoretical analysis, FLAC^3D numerical simulation, loosening on-site testing, on-site monitoring and other technical methods, the geological characteristics of surrounding rock and the cause of floor heave were studied.The results show that the floor stratum of return air roadway are typical Jurassic soft stratum, the bearing capacity of the stratum is low and the excavation position is in the range of the peak value of the residual lateral support stress in goaf of 47407 fully mechanized caving face, which is obviously affected by high stress; the type of floor heave in return airway is mainly stress-type floor heave, supplemented by expansion-type floor heave; as the proposed control method of roadway inverted arch treatment combined with anchorage and grouting reinforcement of muddy grouting material is used for the field test, the load capacity and stability of the rock mass of the roadway floor have been significantly improved, the amount of floor heaves in the roadway has been significantly reduced and the roadway is in a stable state.