生态脆弱矿区采动岩体渗透结构变异与矿井水地下储存机理研究

To build distributed groundwater reservoir by using coal-mine gob could both effectively preserve and use groundwater resources, and it could also ensure the safety of mine production. It is important method for water-preserved mining in the ecologically fragile mine area, and of great strategic significance for Coal Green Mining Technology. The background of this proposal relies on the construction of the distributed groundwater reservoir in coal-mine gob, the theoretical and practical researches will be done on the permeable structure variability of mined rock masses and groundwater storage within coal-mine gob in the ecologically fragile mine area, the following issues are to be studied: the disruption of the overburden strata, the development of caving zone and water-flowing fracture zone during the mining process, the permeable structure variability and the permeability variation law of mined rock masses, and the structural shape and gap distribution of the rock in coal-mine gob. Eventually to understand the development relationship between the storage spatial structure and storage coefficient of coal-mine gob, and multi-stream state groundwater flow in multiple structures of layers, the mechanisms of mine water storage and the variation of characteristic water levels, and methods of regulation and storage of the distributed groundwater reservoir. All the researches will provide important theoretical and practical support for water-preserved mining.

利用煤矿采空区建造分布式地下水库既能有效保护和利用地下水资源，又能保障矿井生产安全，是生态脆弱矿区保水开采的重要方式，对实现煤炭绿色开采具有重大战略意义。本申请以采空区分布式地下水库建造为研究背景，对采动岩体渗透结构变异规律和矿井水地下储存机理开展理论和试验研究，探讨采煤过程中受采动影响上覆岩层破损、冒落、导水裂隙带发育与岩体渗透结构的变异及其渗透性变化规律、以及采空区垮落岩石的结构型式和空隙分布特征，进而研究采空区储水空间与储水系数的关系及其动态变化规律、多重采空区地下水多流态渗流、矿井水储存机理与特征水位变化规律、分布式地下水库调蓄方法，为矿区保水开采提供重要的理论和方法支撑。

利用煤矿采空区建造分布式地下水库为保护和利用地下水资源开辟了新途径，本项研究以大柳塔煤矿采空区地下水库示范工程为背景，开展了矿区采动岩体渗透结构变异与矿井水地下储存机理研究。基于自行研制的大型水岩耦合试验系统和耐水相似材料的研制，完成了1:100模型比例尺的大柳塔煤矿采动岩体破坏过程和渗透结构变异的三维水岩耦合试验，揭示了上覆岩层变形发展与破坏模式、渗透压力分布与渗透特性变化、岩层与煤柱应力变化规律，结合离散元数值模拟得到冒落裂隙带空隙性与渗透性的关系；通过裂隙形态的分形特征研究，提出了上覆裂隙岩体各向异性渗透系数的分形数计算方法；大孔隙结构的渗流试验揭示了冒落带内的地下水流动属于非线性渗流特征；提出了采空区储水系数的计算方法和特征曲线以及对应的三种地下水库库容计算方法，确定了特征水位和库容曲线；揭示了采空区地下水库水质自净化机理，确定了煤矿采空区分布式地下水库的水量水位控制安全限值与优化调度模式。研究成果已成功应用于大柳塔煤矿采空区地下水库的建设，已建成的2座地下水库投入安全运行，蓄水达到200万m3，水质达到地下水国家Ⅲ类水质标准，在煤矿区水资源保护和矿井水资源化利用上发挥了重要的科技作用。