急倾斜煤层覆岩运动规律与开采支护研究

Study on Movement Law and Mining Support of Overburden in Steeply Inclined Coal Seam

急倾斜煤层开采及支护是煤矿生产中的难点问题,深入研究煤矿顶板垮落规律及工作面支护受力特征是保障煤矿安全生产的关键。以红阳煤矿为背景,现场钻取岩样测得物理力学参数,基于围岩参数构建物理模型及3DEC离散元模型,对比分析顶板垮落规律。依据试验及计算结果设计急倾斜煤层开采方案,利用3DEC离散元方法对开采支护方案进行验算,并在实际工程中进行检验。研究结果表明:泥岩顶板的弹脆塑性应变软化特征明显;3DEC离散元数值计算结果与物理模型试验结果基本吻合,采用弹脆塑性应变软化本构模型可以合理获得煤岩层受力及变形特征;利用离散元方法对伪倾斜柔掩支架采煤法进行模拟计算,计算结果与现场应用效果基本相符,证明伪倾斜柔掩支架采煤法在急倾斜泥岩顶板煤层具有良好适用性。

Mining and support of steeply inclined coal seam is a difficult problem in coal mine production.It is the key to ensure the safety of coal mine production to deeply study the law of roof collapse and the stress characteristics of working face support.With Hongyang coal mine as the background,the physical and mechanical parameters were measured by in-situ drilling samples,the physical model test method and 3DEC discrete element numerical calculation method were used to study the law of shale roof caving in steep dip coal seam,the caving range and caving step of roof were analyzed,and the mining scheme of steep dip coal seam was designed.The 3DEC discrete element method is used to check the mining support scheme,and is tested in the actual project.The results show that the elastic-brittle plastic strain softening characteristics of mudstone roof are obvious.The results of 3DEC discrete element numerical calculation are in good agreement with the physical model test results.The elastic-brittle plastic strain-softening constitutive model can be used to reasonably obtain the stress and deformation characteristics of coal strata.The discrete element method is used to simulate the pseudo-inclined flexible mask support mining method.The calculation results are basically consistent with the field application results,which proves that the pseudo-inclined flexible mask support mining method has good applicability in the steeply inclined mudstone roof coal seam.