鸳鸯湖矿区2号煤层顶板岩性及物理力学性质关系研究

Study on the Relationship Between Lithology and Physical and Mechanical Properties of No.2 Coal Seam Roof in the Yuanyanghu Mining Area

宁夏宁东煤炭基地是“国家级煤化工基地”之一,鸳鸯湖矿区是宁东煤炭基地的重要组成部分,位于宁东煤田中北部,拥有5座现代综合机械化生产矿井,近几年为当地和国家煤炭工业经济做出了突出贡献。与此同时,各煤矿巷道也不同程度出现了冒顶、片帮、底鼓等一系列工程地质问题,矿区也出现了大面积的地面沉陷等环境地质问题。本文以鸳鸯湖矿区2号煤层顶板岩性及物理力学性质关系为研究对象,通过分析生产矿井煤层埋藏深度、顶板岩层沉积相,顶板岩性分布及岩性组合特征,岩石矿物显微特征、物理力学性质特征,研究岩石颗粒粗细与真密度之间的关系,物理性质与力学性质之间的相关关系。研究表明:鸳鸯湖矿区2号煤层顶板岩性以灰和浅灰色长石石英、石英粉砂岩及泥质粉砂岩为主,含铝质黑灰、黑色泥岩,遇水容易软化;岩石单项抗压强度总体很低,平均饱和单项抗压强度均小于10MPa,多属于软弱、极软弱岩层的容易冒落顶板;岩石物理、力学性质关系密切,相关性强,浅埋深煤层开采后,导水裂隙带高度能够发育导通至地面。文章从煤层顶板岩性及岩石物理力学性质方面研究了矿区面临的工程地质和环境地质问题,为现代化煤矿生产与资源环境协调发展提供理论依据参考,对黄河流域生态保护和高质量发展先行区建设具有指导意义。

The Yuanyanghu mining area is an essential component of the Ningdong coal base,with five modern comprehensive mechanized production mines.In recent years,a series of geological engineering problems,such as roof collapse,wall caving,and floor heave,has appeared in various coal mine roadways,as well as environmental geological problems,such as large-scale land subsidence in mining areas.The study focused on the relationship between the lithology and physical and mechanical properties of the roof of the No.2 coal seam in the Yuanyanghu mining area.By analyzing the burial depth of coal seams in production mines,sedimentary facies of roof strata,distribution and combination characteristics of roof lithology,microscopic characteristics of rock minerals,and physical and mechanical properties,the relationship between different rock particle sizes and true density,as well as the correlation between physical and mechanical properties were studied.The results showed that the roof lithology of the No.2 coal seam in the Yuanyanghu mining area was mainly composed of gray and light gray feldspar quartz,quartz siltstone,and argillaceous siltstone,containing aluminous black ash and black mudstone,which were easy to soften when encountering water.The overall single compressive strength of rocks was deficient,with an average saturated single compressive strength of less than 10MPa,and most of them belong to weak and extremely weak rock layers,which easily form roof caving.The physical and mechanical properties of rocks were closely related and strongly correlated.