大采深高水压煤炭开采引发水环境破坏机理研究

The continual high strength and massive coal mining is changing violently the surface and underground water environment. Especially, with the deep mining and the large scale mining of lower group coal, the hydrogeological conditions are more complex under high water and ground pressure. Therefore, studying the failure mechanism of water environment is very important for water resources protection and reasonable development. According to the water environmental problems of state owned large coal mines, the response will be proposed. The characteristics and influence factors will be also analyzed. The permeability, hydraulic connection, source of groundwater and hydrogeological boundaries will be studied by water injection test, outflow test and laboratory test of moisture content and hydrophysical property. On the basis, the affected degree of floor and roof aquifers will be determined. Numerical simulation will quantitatively analyze the evolution characteristics of the seepage field and chemical field under deep mining and high water pressure. Considering the seepage and stress field, the complex water environment failure mechanism will be put forward by comprehensively using of theoretical analysis, field test, laboratory and sampling experiment and numerical simulation.

煤炭资源长期高强度大规模开发正在深刻地改变着地表水和地下水环境，特别是随着采深不断加大和下组煤大规模开发，高水压、高地应力影响下的水文地质条件日趋复杂多样化，因此根据出现的新情况研究采煤引发水环境破坏的机理对矿区水资源保护和合理开发利用具有重要的理论和实际意义。本项目通过对我国国有大型煤矿典型水环境问题进行总结归纳，提出煤炭矿山水环境问题类型响应模式，分析各类问题的特征及其影响因素。依据钻孔注水和放水试验、室内含水率和水理性质测定实验，观测含水层的渗透性能及其水力联系，判断地下水的来源，分析水文单元边界性质，研究煤层顶底板含水层受采动影响程度，应用三维数值模拟手段定量分析大采深高水压开采条件下地下水渗流场和化学场演变规律。综合运用理论分析、现场试验、室内实验、取样测试、数值模拟等技术手段，对渗流场与围岩应力场共同作用下具有非常复杂演变过程的水环境破坏机理展开全面系统的研究。

本项目针对煤炭资源长期大规模开发诱发的水环境问题，采用现场调查、理论分析、数值模拟和归纳总结等多种方法对我国煤炭资源与水资源存在背景、水环境问题分类及其成因类型、大采深高水压条件下岩溶地下水系统演化规律进行了研究。探讨了煤矿水环境破坏机理，提出依据成因类型的矿山水环境问题分类方案，将矿山水环境问题分为含水系统结构破坏、地下与地表水体污染、矿山排（突）水、供水、生态环保三者之间的矛盾等三大类。选择百年老矿开滦岩溶地下水系统作为评价对象，应用数值模拟法评价了目前大采深高水压条件下的岩溶地下水流场状态，并预测了未来的地下水流场演变。这将有利于全面了解我国煤矿区煤炭资源与水资源开发条件，合理调配煤炭资源与水资源，积极采取措施保护好脆弱的水环境，并为已经产生水环境问题的矿山提供全效综合治理的依据。