顶板采动水岩耦合作用与离层水涌突致灾机制研究

The inrush hazard of the water from the separation layers has characters of large instantaneous water quantity, no obvious symptoms of the water inrush and periodicity, which seriously threatens the safety production of mine. The overburden structure model is established by considering the overburden structure, the temporal and spatial distribution characteristics of bed separation based on the evaluation of the interaction, influence degree and sequence of various factors on the inrush water in bed separation by using the Fuzzy Matter-Element theory multi-objective optimization method. The permeability variation laws of overlying strata under different loading and unloading, confining pressure and hydrostatic pressure are revealed by the fractured rock mass permeability experiment and hydraulic fracturing experiments. The model of fracture water injection expansion of different rock mass is established, and the reasonable criterion of the crack extension is suggested. The roof fracture characteristics and its precursor and mode of instability induced permeable accident are obtained under different overburden structure with mining influence and hydrodynamic(hydrostatic) pressure by solid-liquid coupling similar material model test and PFC3D numerical calculation model based on theoretical analysis and laboratory experiment. The critical permeability criteria for fracture zone are established. The mechanism of groundwater inrushing from bed separation is revealed under different conditions. It has great important theoretical value and practical significance on the enrichment and development of mine roof water disaster prevention and control theory and ensuring the safe production in coal mine.

顶板离层水害具有瞬时水量大、隐蔽性强且存在周期性等特征，已严重威胁矿井安全。课题在采用模糊物元多目标优化方法分析评价各种因素对离层水涌突致灾的相互作用及影响度序列的基础上，考虑覆岩层次结构、离层时空分布特征等建立覆岩结构模型；采用裂隙岩体渗透、注水致裂试验揭示不同加卸载、围压和动静力水压作用下覆岩的渗透性变化规律，建立不同岩体的裂隙注水扩展模型，提出注水裂隙扩展的合理判据；在理论分析和室内实验的基础上，通过固液耦合的亲水相似材料模型试验和PFC3D三维数值计算模型研究不同覆岩结构在开采矿压和动静水压作用下的破裂特征及其失稳诱发透水的前兆和模式，确立裂隙带临界透水力学判据，获得离层下位岩层破断、注水裂隙扩展、贯通形成突水通道而致灾的时空演化过程，揭示不同条件下离层水涌突致灾机制。这对丰富和发展矿井顶板水害防治理论和方法，保障矿井安全生产具有重要理论价值和现实意义。

针对顶板采动水岩耦合作用与离层水涌突致灾机制研究这一科学命题，调查分析了典型离层水害事故过程与特征，归纳了离层水突涌类型，构建突水致灾力学模型并获得离层水害突涌触发条件；构建了预制闭合裂纹类岩石试件，利用PFC离散元方法光滑节理模型，分析采动影响下不同倾角、长度条件下单裂隙和双裂隙起裂、扩展及贯通的过程，获得采动影响下裂隙岩体起裂强度、峰值强度、峰值应变、破坏模式等规律，揭示离层下位岩层涌突水形成过程中的裂隙扩展贯通灾变特征；通过3DEC数值模拟和相似材料模拟试验，对积水离层空间发育规律、覆岩运动破坏特征、离层积水及突涌过程进行了系统研究，分析在采动作用下离层上下位岩体导水裂隙的扩展、关键岩层的瞬间断裂及透水路径，重点捕获离层水体积聚、突涌的动态时空过程的演化规律及其失稳诱发透水的前兆和模式，进一步揭示了不同水岩耦合条件下的矿井离层水突涌致灾机理；选取了含水层厚度、含水层富水性、含水层水压、有效隔水层厚度、采动破坏比、工作面采高、推进布距等评价指标，将直觉模糊层次分析法作为主观权重分析，结合熵权法计算研究区实际地质参数，通过信息熵理论耦合主客观权重向量，得到更可靠的权重值。进一步通过集对分析-可变模糊集理论建立顶板离层水突涌评价模型，进行不同条件下顶板离层水突涌危险性预测，以提出相应的防治措施。本项目成果进一步完善了顶板离层水突涌致灾机理，丰富了矿井水害防治理论。.在本项目执行期间，共发表学术论文42篇，其中SCI、EI检索36篇，核心期刊6篇，出版专著2部，申请和授权国家发明专利16项，获得省部级科研奖励2项。本项目研究成果已在地质条件复杂的招贤煤矿、祁东煤矿等多个煤矿等进行了推广应用。实践证明，依据本项目成果既能有效顶板离层水害事故的发生，具有很大的实际应用价值，且可为类似地质条件下煤矿安全生产提供重要的科学依据。