关键词: 厚煤层, 综放开采, 回撤通道, 终采方式, 预应力场

Abstract: When the pre-excavation single ( double ) retracement roadway is used to stop mining in the fully mechanized caving face of the thick coal seam, strong mine pressure, broken coal wall, and large deformation of roof occur in the stopping space, resulting in resistance to withdrawal. To study the reasonable stop mining method of the joint surface under this working condition, through the methods of field investigation, laboratory test, principle comparison, numerical analysis, and field monitoring, the comparative study of mine pressure behavior of different retracement methods of fully mechanized caving face in thick coal seam is carried out. The study shows that the pre-excavation single retracement roadway has the superposition of the advance abutment pressure of the working face and the abutment pressure of the roadway ( the increase coefficient is 3.37 ). On this basis, the pre-excavation double retracement roadways increase the superposition with the stress of the coal pillar ( the increase coefficient is 3.69 ), and the self-excavation withdrawal channel has no stress superposition during the stop mining period ( the increase coefficient is 2.53 ). At the same time, the comprehensive comparison of the advance abutment pressure, maximum shear stress, and the principal stress zoning shows that the arrangement of the self-digging retracement channel at the stop line position has the lowest mining pressure. Therefore, the stop-mining process flow based on self-excavation and retracement roadway is established. Based on the monitoring of the deep hole displacement of the roof, the support parameters of stop-mining large section space are designed and verified by pre-stress field simulation. Through field practice, the effective support of the stopping space and the smooth retracement of the supports are realized.