基于隔水层位置的近浅埋煤层导水裂缝带发育机理研究

Coal resources green development and ecological mine construction is a key task of China's energy technology revolution & innovation plan action, and carrying out basic research of water preserved mining related fields is still main direction of coal industry in China. Water preserved mining in Yushenfu mining area is taken as research background, and the aquifuge is taken as research object, and uses the methods of theory analysis, similar materials simulation experiment and numerical simulation, and mining height and aquifuge position and bedrock thickness under the aquifuge and key stratum is taken as key parameters, the aquifuge fracture space-time evolution law on condition of the different key stratum positions is analyzed; the movement and deformation prediction formula of different aquifuge position is given by he method of probability integral, and the water resisting property criterion of the aquifuge is constructed; with the synergistic effect of the displacement deformation of the aquifuge and the development height of water flowing fracture zone, and the development height mathematical model of nearly shallow coal seam water flowing fractured zone is established, the development mechanism of water flowing fractured zone is revealed by nearly shallow coal seam mining. Research result shall not only promote the organic integration of mining subsidence prediction theory and fracture zone development height prediction theory, but also provide a fracture zone development height prediction method of nearly shallow coal seam, which shall provide scientific basis for realizing water preserved mining and movement & control of overburden in yushengfu mining area.

煤炭资源绿色开发与生态矿山建设是我国能源技术革命创新行动计划的一项重点任务，开展保水开采相关领域的基础研究仍是我国煤炭行业的主要方向。项目研究以榆神府矿区保水开采为研究背景，以隔水层为研究对象，采用理论分析、相似材料模拟实验和数值模拟等研究方法，以开采高度、隔水层位置、隔水层下部基岩厚度和关键层为关键参数，分析基于关键层不同位置的隔水层裂缝发育时空演化规律；应用概率积分法，给出不同位置隔水层的水平变形和曲率变形表达式，构建隔水层的隔水性判据；借助隔水层的移动变形与覆岩导水裂缝带发育高度的协同作用关系，建立基于隔水层位置的近浅埋煤层导水裂缝带发育高度数学模型，揭示近浅埋煤层开采覆岩导水裂缝带发育机理。项目研究不仅促进了开采沉陷预计理论与导水裂缝带发育高度预计理论的有机融合，也给出了一种适用于近浅埋煤层导水裂缝带发育高度的预计方法，为榆神府矿区实现保水开采和覆岩移动与控制提供科学依据。

煤炭资源绿色开发与生态矿山建设是我国能源技术革命创新行动计划的重点任务，覆岩导水裂缝发育高度与覆岩破坏形态有关，裂缝发育程度主要取决于覆岩移动变形的大小，关键层在覆岩移动变形过程中起主要控制作用。项目研究以榆神府矿区保水开采为研究背景，研究了隔水土层的相似模拟材料配比，得出了红土最优配比（沙土比1:4~1:5，骨胶比7:1，机油含量10%~25%）和黄土最优配比（骨胶比8:2、土膏比9:1、重晶石粉含量6%、硅藻土含量23%、含水率13%）；为了分析不同开采条件下覆岩的破坏形态和裂缝发育时空演化规律，自主研发了一种岩土层曲率变形相似模拟试验装置；分别以陕北红柳林煤矿、韩家湾煤矿和榆树湾煤矿为研究对象，研究了关键层位于冒落带、裂缝带和弯曲下沉带时覆岩移动变形和覆岩裂缝发育高度的关系；通过控制单一变量法设计数值模拟方案，分别研究了不同开采技术条件（开采高度、基岩厚度、松散层厚度及煤层间距）对导水裂缝带发育高度的影响规律，基于数值模拟结果，给出了开采高度、基岩厚度、松散层厚度及煤层间距与覆岩导水裂缝带发育高度的关系表达式；在此基础上，分析了关键层位于覆岩“三带”不同位置时的隔水层裂缝发育时空演化规律。以开采高度、基岩厚度和松散层厚度为关键参数，给出了不同采矿地质条件下隔水层的移动变形预计方法；分析了隔水层稳定性和覆岩导水裂缝带发育高度的相互作用关系；基于关键层“三带”不同位置确定覆岩不同层位的下沉系数；借助地表水平变形与下行裂缝发育深度和覆岩曲率变形与上行裂缝发育高度的关系，构建了基于关键层位置的近浅埋煤层导水裂缝带发育高度数学模型，进一步揭示了基于不同隔水层位置的近浅埋煤层导水裂缝带发育机理。通过实例验证了覆岩导水裂缝带发育高度数学模型的可靠性，成果促进了开采沉陷预计理论与导水裂缝带发育高度预计理论的有机融合，给出了一种适用于近浅埋煤层导水裂缝带发育高度的预计方法，为榆神府矿区实现保水开采和绿色减损开采提供科学依据。