Differentiation response characteristic of roadway deformation and rock supporting analysis

Deformation characteristic evolution of roadway surrounding rocks is important for roadway support applications. In this study,a mechanical model is established for circular roadway by considering the support pressure under different stress conditions,based on the elastic theory. Different response characteristics of roadway deformation are analyzed for different k ( the ratio of vertical stress to horizontal stress ). Based on the identified roadway deformation characteristics, it is suggested:① roof and floor should be reinforced when k> 1,and sidewalls should be reinforced when k< 1;② side walls should be reinforced for gob-side roadway and roadways under the front abutment pressures,while roof and floor should be reinforced for roadways under the mined area of the upper seam;③ roof and floor should be reinforced for shallow roadways,whereas sidewalls should be reinforced for deep roadways. A frield trail was performed at the 152052 roadway of a mine in Shanxi; The horizontal ( σ_x ) and vertical stresses ( σ_z ) of the studied roadway were measured. Based on the fracture development characteristics obtained by means of borehole televiwering,it was found that the sidewalls needed to be reinforced and a support scheme “bolt cable + bolt + supporting plate + metal mesh” was purposed for the roadway.