| As the increase of coal mining depth, roof dynamic roadway of soft and thick coal seam often appear bolt support failure phenomenon. It is out of shape for surrounding rock, so much as causing serious impact pressure phenomenon which will bring great security risks to the mine safety and efficient production,cause significant casualties and economic losses.For the high stress and thick coal seam, bolt support is defeated. Geological conditions and supporting technology of B4 coal seam of 212 working face in Qujiang coal mine is used as background, using anchorage failure theory, FLAC3 D to numerical simulation, bolt support thchnology study the mechanism of the high stress deep coal roadway bolting failure. The research results is as follow:(1)This paper is to analyze the mechanism of bolting failure and is out of shape. Bolting anchoring is broken rock, roadway maintenance status is depended to mechanical properties of coal and rock anchor.Bolt support failure is broken coal and rock anchor in abutment pressure under the secondary breakup.(2)This paper is to reveale the mechanism of bolting failure and control it. The roof cable failure is mainly manifested as with synchronous roof downward without breaking mode.Bolt pre-tightening force is important to improve mechanical properties.(3)Numerical simulation method is used to study stress field, displacement field and damage field of deep high stress soft rock roadway surrounding rock, to analyze the influence of roadway excavation. It often appears stress concentration phenomenon of the new roadway surrounding rock and deformation to a great extent. At the same time, the degree of damage is serious and with the passage of time continues to increase.(4)From the perspective of support technology, tunnel deformation control, the coordination mechanism of bolt and anchor cable, and construction technology, it is to study bolt supporting reinforcing scheme and parameters design, come up with supporting scheme which effective control roadway deformation by the prestress truss support,support system of bolt(cable),strip and bolting with wire mesh combined support support technology.(5)Through numerical simulation and field measurement, the roadway surrounding rock stress concentration decreased significantly,roadway surrounding rock deformation decreased obviously, the damaged area of surrounding rock is significantly reduced, roadway surrounding rock deformation has been effectively controlled by use new support(6)The roadway anchor failure of work face 212 in Jianxin Coal is analyzed, and the technology programme of roadway support is designed optimally, Introduce new technologies for coal roadway surrounding rock control, and have achieved good effects of control distortion, greatly improving the production efficiency of the mine, It has a certain significance for the deep high stress dynamic pressure roadway support. |
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