Characteristics of water-bearing media in Jurassic strata and groundwater occurrence and migration law in Yili Mining Area, Xinjiang
XU Zhimin;CHEN Tianci;LIU Shuanshuan;SUN Yajun;REN Dongdong;HUAN Bocheng;ZHANG Panjie
中国矿业大学 资源与地球科学学院矿山水害防治技术基础研究国家级专业中心实验室兖矿新疆能化有限公司伊犁一矿陕西小保当矿业有限公司
以新疆伊犁矿区为研究区,结合该区天山雪融水径流强、侏罗系富煤地层渗透性不均一等典型水文地质特征,通过采用现场取样、电镜扫描、压汞实验、X-衍射、抽水试验等方法,系统研究矿区主要含(隔)水层的宏观水文地质条件、微观含水介质特征及地下水赋存规律,揭示其特殊地层地貌条件下的含水层水动力学特征及地下水运移规律。结果表明:研究区侏罗系主采煤层顶底板砂岩含水层有效孔隙率范围为17.1%~29.5%,新近系与侏罗系隔水层有效孔隙率范围为17.6%~29.0%,含(隔)水层均含有较高的黏土矿物,遇水膨胀泥化,特殊的微观结构及矿物成分使含(隔)水层表现出孔隙率高、渗透性较差的含水介质特征;区域上,第四系孔隙含水层与侏罗系主采煤层顶底板砂岩含水层富水性较弱,部分区域表现出中等富水,以静储量为主,具有区块化特征;系统研究了主要含(隔)水层的水动力学特征与运移规律,第四系受山前宏观地貌及含水介质条件影响,形成了以“斜坡过境流”为代表并以孔隙潜水形式高强度流动的水动力学特征,同时受到下部新近系泥岩隔水层阻隔,与煤系顶板砂岩含水层无水力联系,对煤层回采存在影响的主要为5煤底板砂岩含水层,并针对该层施工了“横向截流,侧向掩护”的“厂”字形大范围疏降且疏降效果显著,为井下回采创造了良好的水文地质条件。相关研究成果揭示了研究区侏罗系富煤地层受沉积环境影响所形成的特殊含水介质特征及储水控水规律,可为研究区及西部矿区相似开采条件下矿井防治水工作提供一定的理论及工程依据。
Taking the Yili mining area in Xinjiang as an example, combined with the typical hydrogeological characteristics of the Tianshan Mountains, such as strong snowmelt runoff and uneven permeability of Jurassic coal-rich strata, the macroscopic hydrogeological conditions, microscopic water-bearing media characteristics and water-rich law of the main aquifers (aquicludes) layers in the mining area were systematically studied by means of field sampling, electron microscope scanning, mercury injection experiment, X-ray diffraction and pumping test. The hydrodynamic characteristics and migration law of aquifers under special stratigraphic and geomorphological conditions are revealed. The results show that the effective porosity range of the sandstone aquifer in the roof and floor of the Jurassic main coal seam in the study area is 17.1%-29.5%, and the effective porosity range of the Neogene and Jurassic aquiclude is 17.6%-29.0%. The aquifers (aquicludes) layer contains high clay minerals, which are expanded and argillized in water. The special microstructure and mineral composition make the aquifers (aquicludes) layer show the characteristics of high porosity and poor permeability. In the study area, the water abundance of the Quaternary pore aquifer and the Jurassic main coal seam roof and floor sandstone aquifer is weak, and some areas show moderate water abundance, mainly static reserves, with block characteristics. The hydrodynamic characteristics and migration law of the main aquifers (aquicludes) are systematically studied. The Quaternary system is affected by the macro-geomorphology and hydrogeological conditions of the piedmont, showing the dynamic characteristics of ‘slope transit flow’ in the form of pore phreatic water with high intensity flow. At the same time, it is blocked by the lower Neogene mudstone aquifuge and has no hydraulic connection with the sandstone aquifer of the roof of the coal measures. The sandstone aquifer of the 5# coal seam floor mainly affects the coal seam mining, in view of this layer, the “factory” shape of “lateral closure and lateral cover” was constructed in a large range and the dredging effect was remarkable, which created good hydrogeological conditions for underground mining. The relevant research results reveal the characteristics of special water-bearing media and the law of water storage and water control formed by the Jurassic coal-rich strata in the study area under the influence of sedimentary environment, which can provide certain theoretical and engineering basis for water prevention and control under similar mining conditions in the study area and western mining area.
jurassic system;characteristics of water-bearing medium;hydrodynamic characteristics;water storage and control;roof and floor water disaster prevention and control
主办单位:煤炭科学研究总院有限公司 中国煤炭学会学术期刊工作委员会