Study On Stability Of Surrounding Rock Of Roadway With Before And After Underlying Coal Seam Mining

The paper research the relationship between the pan three mine17101(3) of high level suction roadway and11-2Coal Seam Mining, in-depth study of the impact of before and after lower coal seam mining the stability of overlying roadway surrounding rock.On the underlying17101(2) coal mining process, using a laser range finder, multi-point displacement convergence meter gauge and hollow inclusion stress method and so on measure method. Field test of17101(3) high pumping roadway surrounding rock deformation, loose circle range and the rock stress variation, by finite difference numerical simulation software FLAC3D to simulate the overlying stress of surrounding rock before and after the underlying coal seam excavation, come to the underlying17101(2) coal mining on overlying17101(3) the degree of deformation and failure affect the size of the roadway.Through field test results each measuring point consists of two principal stress directions near the horizontal direction, and the other principal stress direction nearly perpendicular direction; maximum principal stress is the general direction of the mine south west25°; vertical elevation at the measuring point straight about15.25MPa, the average maximum principal stress is21.62MPa, ground stress field of the mine based on the level of tectonic stress based. Average maximum principal stress after the underlying coal seam is20.87Mpa, compared with the previous underlying coal seam average maximum principal stress21.62MPa, the maximum principal stress is reduced by3%.By FLAC3D simulated receive the average both sides of the roadway of the maximum principal stress is22.17MPa before the underlying coal seam mine, The average of both sides of the roadway of the maximum principal stress is21.63MPa after the underlying coal seam mine, The maximum average principal stress decreased by2.4%, basically consistent with the simulation results; The maximum displacement of Roof fall is258mm, the results of numerical simulation of roadway roof displacement is280mm, both results are basically consistent; The maximum displacement of loose rock loose circle is12.9mm. Comparative analysis of the results of field testing and simulation description the underlying coal mining on the stability of the overlying rock roadway greater impact, roadway support should be further reinforced.