Research and Application of Roof Cutting and Pressure Release Technology of Retracement Roadway in Large Height Mining Working Face

In this paper, according to problems of large deformation, high stress and strong disturbance exist in the retracement roadway during the equipment withdrawal of 18,205 large height mining working face in Xiegou mine. The method of roof cutting and pressure release by deep-hole blasting is put forward. Based on the analysis of the characteristics of different roof cutting depth on the stress and deformation of surrounding rock of the retracement roadway by using Phase numerical simulation software, the optimum roof cutting depth suitable for safe retracting of working face is obtained. The support scheme of retracement roadway of the working face and its cross area with the mining gateway is put forward and realize the safely equipment retreat of the working face. The research results show that the stress of surrounding rock and the development depth of plastic zone as well as the displacement of roof, floor and left side of the retracement roadway are effectively reduced after roof cutting, and the larger of the roof cutting depth, the more obvious the pressure release effect will be. The optimal roof cutting position of the working face is calculated and the monitoring results of mine pressure show that the deformation of the retracement roadway and the cross area of the roadway after cutting off the roof and unloading is small, and the support scheme could effectively control the destruction of the surrounding rock of the retracement roadway.