In the process of underground coal mining,it happens that the original roadway section doesn't meet the normal production and needs to be expanded.In order to solve the problems of declining stability of roadway wall rock,inadequate construction technology and supporting design due to expansion,in terms of the occurrence of belt conveyor roadway and the ongoing support conditions in the north wing panel of No.5-2 coal seam at Huixing Coal Mine as an example,the safety and stability of surrounding rock and the limit span of roof were studied by combining theoretical analysis with numerical simulation,and the feasibility of expanding the slope and increasing the width of belt conveyor roadway in the north wing panel was demonstrated.The stress evolution law of surrounding rock,the development characteristics of plastic zone and the safety and stability of roadway coal pillars before and after slope expansion were compared and analyzed.Combining with the limit self-stable equilibrium arch theory of roadway support,it was concluded that the failure depth of the two sides before and after the expansion of the belt conveyor roadway in the north wing panel is basically unchanged,and the roof failure height and the limit equilibrium arch height after the expansion are increased by 13.1%and 10.9%,respectively.On this basis,the support parameters of the expansion section were determined,and the expansion construction technology of"reinforcing the anchor cable in the roof before the expansion,supporting the new excavation roof and the expansion side in time during the expansion"was proposed.Finally,the expansion construction and support field application research were carried out.The results showed that there was neither obvious fissures in the surrounding rock of the expansion section,nor obvious spalling or moving deformation on the surface of the surrounding rock.The roadway was safe and stable.
关键词
煤层巷道/扩帮增跨/数值模拟/围岩稳定性/支护设计/施工工艺
Key words
coal roadway/span enlarging/numerical simulation/stability of surrounding rock/support design/construction technics
维普
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