残煤复采区域破碎软岩巷道变形机理及控制

Deformation Mechanism and Control on Broken and Soft Rock Drifts in Residual Coal Mining Stope

为了探讨残煤复采区域松软破碎巷道合理的控制方法,以山西梅园许村煤业2#煤层集中轨道巷为研究对象,采用现场调查、数值模拟和理论分析方法,提出了"散体-块体"结构模型,探讨了残煤复采条件下巷道变形机理、围岩控制原则及支护参数,通过理论计算及工业试验对该支护进行了评价。研究结果表明:初次回采后再生顶板可近似为"散体-块体"结构模型;顶板块体易发生剪切滑移和脱落,表现为巷道顶底板易成为破坏失稳的关键部位,使两帮承受更大载荷而发生片帮破坏;巷道支护破坏的根本原因是支护体和围岩的强度和刚度不耦合。现场工业试验表明,在支护完成60d之后,巷道围岩的变形趋于稳定,两帮移近量最大为220mm,顶底板移进量最大为540mm。该支护方式有效地解决了残煤复采后松软破碎围岩巷道的支护问题。

In order to study reasonable control method for soft-and-broken rock drift excavation in the residual coal mining stopes,the concentrated rail drift of 2#coal seam in Shanxi Meiyuan Xucun Coal Mine was taken as the research object.A ＂ bulk-block＂ structural model was proposed on field survey,numerical simulation and theoretical analysis.This paper has discussed the drift deformation mechanism,the surrounding rock control principle and supporting parameters.The support system has been evaluated through theoretical calculation and industrial tests.The results show that the new drift roof can be treated as the ＂ bulk-block＂ structure model.Shear displacement and rock falling would be easily happened in drift roof block.The drift roof is the key position of unstable failure,which further cause larger load on drift two-side wall to have spalling failure.The main reason of drift supporting failure is that the strength and stiffness of supporting system and rock are not matched.Industrial field tests show that after 60 days supporting,the deformation of drift surrounding rock tends to be stable.The maximum displacement of two-side wall was 220 mm,and the maximum displacement of roof was 540 mm.This support system can effectively work on broken-and-soft rock drift excavation residual coal mining stope.