多场耦合作用下煤层底板断层活化及突水机理研究

Coal mine water inrush, one of the major disasters, affects on mine production safety, as the main form of the floor inrush water, by the significant cause of multi-field coupling synergistic effect, including the tectonic stress field, the stress field of mining, groundwater seepage field and so on. Thus, the research mentioned in this paper, multi-field coupling effect seam floor fault activation mechanism, has vast importance to mine production safety. With the methods of the theoretical analysis, the experimental testing and the numerical simulation, the tectonic ground stress distribution law of mine structure reveal the effective laws of the tectonic stress distribution on the fault activation and on the water inrush; with the fractured rock permeability test, permeability characteristics of fractured rock are described; with the study of the instability related with fault associated fracture, control equations and numerical solutions of the dynamic processes of the water pressure on the fracture surface erosion are established together with the fissures unsteady flow control equations and numerical solutions; with developing the fault activation of the water inrush test system, the fault water inrush tests reveal the water dynamics process and evolution of the water inrush under the mining conditions, getting the precursor information of fault activation and water inrush; with the kinetic model and of the multi-field coupling backplane fault activation and critical water inrush criterion, the theoretical basis for the control and prevention methods can be provided with the coal mining in the multi-field coupling induced by the mine water inrush disaster.

煤矿突水是影响矿井安全生产的重大灾害之一，底板断层突水是煤矿突水事故的主要形式，其中构造应力场、采动应力场、地下水渗流场等多场耦合作用是引发矿井突水的重要原因，因此开展多场耦合作用下煤层底板断层活化及突水机理研究对矿井安全生产具有重要意义。本项目拟采用理论分析、实验测试、数值模拟等方法，研究矿井构造地应力分布规律，揭示构造地应力分布对断层活化及突水的影响规律；进行裂隙岩石渗透性试验，获得裂隙岩石的渗透特性；研究水压作用下断层伴生裂隙的失稳问题，建立水压对裂隙面冲刷情况下连通裂隙非稳定流的控制方程和数值解；研制断层活化及突水试验系统，进行断层突水试验，揭示采动条件下断层突水的动力学过程及演化规律，获得断层活化及突水的前兆信息；建立多场耦合作用下底板断层活化突水的动力学模型和临界突水力学判据，为寻求多场耦合作用下煤炭开采诱发矿井突水灾害的控制和防治方法提供理论依据。

矿井突水是影响我国矿井安全生产的主要灾害之一，底板断层突水是矿井突水的主要形式，采动引发底板断层活化，形成连接采掘空间和含水层的导水通道，是造成底板突水的主要原因。本项目运用理论分析、相似模拟和数值模拟等研究手段，研究了多场耦合作用下底板断层活化及突水机理。研制了煤层底板突水流固耦合模拟试验系统，该试验系统主要包括水压控制系统和试验台架，实现了对水压力的自动化控制，能直接采用真实水进行流固耦合模拟试验。配制了以石蜡、白凡士林为胶结剂，砂、沉淀硫酸钡粉和超细滑石粉为骨料，二甲基硅油为调节剂的新型流固耦合相似材料，并对其单轴抗压强度、渗透系数以及亲水性进行了测试，测试结果表明可以利用该材料进行流固耦合相似模拟试验。分析了水源、水压、隔水层和地质构造等突水影响因素与断层相互作用，结果表明：断层与突水因素在突水过程中相互促进，断层的存在加重突水影响因素在突水过程中的作用，突水影响因素在一定程度上也促进断层的活化。从采动应力和水力劈裂两个角度对断层活化进行了力学分析，建立多元耦合作用下采动应力影响下断层活化的动力学模型和临界突水力学判据。采用相似模拟试验方法，研究了采动影响下底板断层活化规律及特征，揭示了采动条件下断层突水的动力学过程及演化规律，获得了断层活化及突水的前兆信息。建立了“散、细、固、重”超高压注浆防治水技术，经物探验证取得良好的注浆效果。研究成果可为煤炭开采诱发矿井突水灾害的控制和防治方法提供理论依据。