重复采动下高位硬厚岩层空间结构二次失稳及动力冲击机理研究

Thick-hard strata in high position would secondary movement under repeated mining, causing more instantaneous and vigorous dynamic disasters, which make a high risk to multiple coal seam mining. According to first fractured characteristics and dynamic shock mechanism of thick-hard strata in high position, using plate mechanics to build discontinuous hinged plates model of broken strata to secondary movement during repeated mining, deduce secondary movement mechanical criteria with opening angle and displacement distance among fractured strata, define subside and slippage movement trend and dynamic shock mechanism of fractured strata in key position of stope; with experiment and numerical simulation, research spatial structure evolution features, analyze coupling relationship between spatial structure evolution and dynamic shock, clear ranges and evolution of dynamic responses, stress, displacement and energy, and replicate dynamic disaster process in laboratory; with field monitoring and theoretical analysis, using system theory comparative analyze internal differences and relativities of spatial structure evolution, dynamic shock mechanism, evolution law of multi-field in multiple coal seam mining under condition of thick-hard strata in high position. Finally, preliminary establish dynamic shock mechanism caused by secondary movement of thick-hard strata in high position under repeated mining, which provide theoretical foundation to guide multiple coal seam mining, and also give an important theoretical value and widely applied prospect.

重复采动导致高位硬厚岩层空间结构突变发生二次失稳运动，诱发剧烈的采场动力冲击，严重威胁多煤层安全开采。基于高位硬厚岩层初次破断特征及动力冲击机理，应用板块力学，建立重复采动下高位硬厚岩层二次失稳非连续铰接板块力学模型，以断裂岩块间移动张开角、横纵向错动距离等为关键因子构建失稳力学判据，明确采场关键位置岩块的沉降、滑移运动趋势及冲击机理；基于模拟实验和数值模拟，研究重复采动下高位硬厚岩层空间结构二次失稳演变特征，揭示空间结构变异与动力冲击间的耦合关系，明确微矿震活动、应力场、位移场、能量场演化规律，再现二次失稳动力冲击过程；基于现场监测及理论分析，应用系统理论对比分析高位硬厚岩层下多煤层开采空间结构演变、动力冲击机理、多场演化规律的内在差异及相关性。初步建立重复采动下高位硬厚岩层二次失稳动力冲击机制体系，为高位硬厚岩层条件下多煤层安全开采提供理论支撑，具有重要的理论价值和应用推广前景。

按照项目计划任务书，项目组综合运用现场监测、理论分析、模拟试验和数值计算等方法，系统深入研究了重复采动下高位硬厚岩层初次破断及二次失稳运动力学机制及冲击机理、空间结构演变特征和微矿震活动规律等。取得的主要研究成果如下：（1）构建了初次采动高位硬厚岩层厚板力学模型，揭示高位硬厚岩层初次损伤破断力学机制，推导了极限破断运动步距；构建了重复采动下断裂高位硬厚岩层铰接岩块力学模型，分析了断裂岩块间的力学效应和二次失稳运动力学机制。（2）开展了单一高位硬厚岩层和两层高位硬厚岩层条件下多煤层开采相似模拟试验，明确了多煤层开采高位硬厚岩层的初次破断和二次失稳运动规律和空间结构演变特征。（3）揭示了重复采动下采场不同位置高位硬厚岩层的二次失稳运动冲击机理，阐明了采场不同位置处冲击机理间的内在联系。（4）明确了多煤层开采高位硬厚岩层初次破断和二次失稳运动微矿震活动时空演化规律，揭示了内在差异性和关联性。研究成果对高位硬厚岩层条件下多煤层安全开采具有一定的指导意义和科学价值。.就相关研究成果发表学术论文12篇，其中SCI论文3篇，EI论文6篇，中文核心论文3篇；授权发明专利3项，参加国内外学术会议5次；协助培养研究生3名。