Application Research On Supporting Technology Of Roof-cutting Roadway In Z-type Mining Face

In view of the engineering geological conditions of high mine pressure and large deformation of Dongdong Mine in the northern part of Weinan Mining Area,the cost of labor and material cost of coal mine roadway is large,in order to reduce costs and reduce expenditure,testing the roof-cutting roadway in common roadway of 50107 and 50109 mining faces.The main consideration is the relationship between the pressure of the mining face,the time of staying and the time of the working time.Based on this,the support technology of the Z-shaped mining face top-loading pressure relief along the roadway is proposed.That is,an automatic roadway technology in which a roadway is cut by a coal machine and cut into a top-eye blast is automatically formed and pushed forward together with the mining face.The research mainly centers on three key factors of retaining roadway:roadway support,roadside support and roadway cut-off roof.Based on mechanical analysis and combined with geological conditions,the supporting characteristics of overburden strata in cut-off roadway is studied,and the key role of bolt-mesh-cable support in roadway support is determined.The effect of lateral stress on two sides of roadway is studied.The lateral pressure of roadside supporting components bearing broken and bulging gangue in goaf can not be ignored.Based on this theoretical basis,curved gangue retaining pillars are designed.Based on the characteristics of roadside roofs rotational subsidence,the study of yield-pressure slip of overlapping curved pillars is explored by experiment,and the factors affecting the cutting height and angle of the roof outside the roadway are studied.Considering the factors that need to be further improved in the process of roof-cutting and roadway-retaining in Z-type mining face in industrial test,Y-type and Z-type self-formed roadways are tested in one roadway along the return air passage,so that the authenticity of the two kinds of roadway-retaining technologies can be compared and studied,and the numerical simulation of the two kinds of roadway-retaining methods is carried out.Based on the analysis of monitoring data of Engineering practice,the characteristics of the surrounding rock deformation and the relationship between the three elements of the retaining lane of the Z-shaped mining face are studied,and further guidance is provided for the practice under similar conditions.