西部矿区动载扰动下区段煤柱劣化失稳诱冲机理研究

我国西部大型矿井进入深部开采后，高应力和采动动载共同影响下区段煤柱失稳诱发冲击地压问题日益凸显。基于此，本项目拟采用岩石力学试验、模拟试验、理论分析和现场监测相结合的研究方法，开展以下创新性工作：①研究采动条件下区段煤柱应力分布及顶板破断震动响应，获得顶板破断动载应力波特征参数和时程曲线关系式，探究采动动载应力波对区段煤柱应力场演化规律的影响，揭示区段煤柱所受复杂动静载荷特征；②宏细观尺度结合研究静载和动载应力波耦合作用下煤体变形特性、损伤劣化规律及失稳破坏特征，阐明动载扰动作用对煤体劣化演变及破坏模式的影响机制，构建煤体损伤本构模型；③从工程尺度探究动载扰动下区段煤柱劣化失稳动态发展过程，确定区段煤柱失稳诱发冲击破坏的临界应力和扰动载荷条件，揭示动载扰动下区段煤柱劣化失稳诱冲机理及其尺寸效应，提出合理区段煤柱尺寸设计方法。本项目研究成果将为我国西部矿区煤柱冲击地压防治提供重要的理论依据。

With the mining depth of large coal mines in Western China increasing, the problem of rock burst caused by coal pillar instability under high stress and mining dynamic loads is becoming increasingly prominent. Based on this, the following innovative work will be carried out in this project by using the research methods of rock mechanics test, simulation test, theoretical analysis and on-site monitoring. First, the stress distribution of coal pillar and characteristics of roof breaking vibration under strong mining disturbance are investigated, and the characteristic parameters and expression of time history curve of dynamic stress wave caused by roof stratum fracture are obtained, and the influence of dynamic stress wave on the evolution of stress field of coal pillar is investigated, and the complex dynamic and static loads characteristics of coal pillar is revealed. Second, the deformation, damage weakening and instability failure characteristics of coal mass under static and dynamic loads are researched at macro and meso scales, and the influence mechanism of dynamic disturbance on the weakening evolution and failure mode of coal mass is clarified, and the damage constitutive model of coal is constructed. Finally, the development process of coal pillar weakening instability under dynamic loads disturbance is investigated with the engineering scale, and the thresholds of stress and disturbance loads of rock burst induced by coal pillar instability are proposed, and the mechanism and size effect of rock burst induced by weakening instability of coal pillar under dynamic disturbance are revealed. Consequently, an optimization design method of coal pillar size is set up. The anticipated outcome of this project would provide theoretical reference for the prevention and control of coal pillar rock burst under deep mining in western diggings of China.