伪倾斜煤层顶板垮落规律与支护受力特征研究

Study on roof caving law and supporting stress characteristics of pseudo inclined coal seam

伪倾斜柔掩支架采煤法是急倾斜煤层开采的常用方法,深入研究伪倾斜煤层顶板垮落规律及工作面支护受力特征对煤矿安全生产具有重要意义。通过现场勘查与室内试验方法获得煤岩体的力学特性,利用3DEC离散元数值计算方法研究伪倾斜煤层泥岩顶板垮落规律,根据顶板的垮落范围及垮落步距设计工作面支护方案。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,选用弹脆塑性应变软化本构模型能够准确表征岩层力学特性;柔掩支架对倾斜泥岩顶板煤层具有良好的支护效果,液压支柱能有效改善柔掩支架受力状态,提高支架支护能力;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,证明离散元计算方法适用于倾斜煤层开采支护分析。

Pseudo inclined flexible shield support mining method is a common mining method for steeply inclined coal seam.It is of great significance for coal mine safety production to deeply study the roof caving law of pseudo inclined coal seam and the stress characteristics of working face support.The mechanical properties of coal and rock mass are obtained by on-site investigation and laboratory test.The law of mudstone roof caving in pseudo inclined coal seam is studied by using 3DEC discrete element numerical calculation method, and the working face support scheme is designed according to the roof caving range and caving step distance.The 3DEC discrete element method is used to check the mining support scheme, and it is tested in the actual project.The results show that the elastic-brittle-plastic strain softening characteristic of mudstone roof is obvious, and the elastic-brittle-plastic strain softening constitutive model can accurately characterize the mechanical properties of rock strata;The flexible shield support has a good supporting effect on the inclined mudstone roof coal seam, and the hydraulic prop can effectively improve the stress state of the flexible shield support and improve the support capacity of the support;The discrete element method is used to simulate the pseudo inclined flexible shield support mining method, and the calculated results are basically consistent with the field application effect, which proves that the discrete element method is suitable for the mining support analysis of inclined coal seam.