冲击-突出复合灾害孕育过程煤体力学行为演化机制研究

The compound dynamic disaster occurred frequently in deep coal mines, which was combined rockburst and outburst attributes, its catastrophe mechanism was urgent in need of investigated. The research method will combines of statistical analysis of mine geological data, physical experiments, field test, theoretical and numerical computation, starting from the evolution mechanism of mechanical behavior of multi-field solid-gas coupling for coal, analysis the solid-gas coupling mechanical behavior of coal under true triaxial text, to get the evolution law of mechanical behavior of coal affected by stress radio, gas adsorption pressure and capacity. Analysis the variation of mechanical behavior and energy of coal and compound coal-rock affected by key control factors, such as unloading and rate, then, draw out the regularities of mechanical behavior of multi-field solid-gas coupling for coal affected by mining stress, and proposes the energy criterion of compound dynamic disaster. Establish and solve the catastrophe control model of solid-gas coal affected by stress-gas-mining stress field, classification the type and level of compound dynamic disaster. Discuss the time-space evolution of acoustic emission-charge signal affected by key control factors, forming multi-parameters prediction method of compound dynamic disaster, with stress field-deform field-gas field. Provide theory bases and engineering guidance for coal mining safe and efficient.

深部矿井兼具冲击地压和煤与瓦斯突出特征的复合动力灾害频发，亟待开展冲击-突出复合灾变演化机制研究。以多场条件下固-气(瓦斯)耦合煤体力学行为演化为切入点，采用矿井地质资料统计分析、物理试验、理论与数值计算和现场测试相结合的研究方法，分析真三轴条件下固-气耦合煤体力学行为变化，获得侧压比关系、瓦斯吸附压和瓦斯含量因素影响的煤体力学行为演化规律。分析卸荷方式和速率变化等因素影响的固-气耦合煤体、组合煤岩体力学行为及能量变化，揭示采动应力影响的固-气耦合煤体力学行为演化规律，提出冲击-突出复合灾害能量判定准则。建立地应力场-瓦斯场-采动应力场作用固-气耦合煤体失稳灾变控制模型并求解，划分复合灾害主控类型和等级。综合分析声-电荷信号受主控因素影响的时空演化关系，形成应力场-变形场-瓦斯场-声电物理信号多参量的冲击-突出复合灾害预测方法，为保障煤炭安全高效开采提供理论支撑和工程指导。

针对煤矿深部矿井冲击-突出复合灾害频发、致灾机理不清这一关键科学问题。项目以多场条件下固-气(瓦斯)耦合煤体力学行为演化为切入点，自主研发了岩石力学真三轴试验系统，实现了高气体压力下的“三刚”加载方式与五加载面独立伺服控制，为探究实际开采过程中含瓦斯煤岩力学行为演化及其破坏致灾机制提供了研究条件。项目采用理论分析、物理试验和信号分析相结合的方法，开展了真三轴条件下瓦斯运移影响的煤体力学行为演化规律研究，得到了不同侧压比关系、瓦斯吸附压和瓦斯含量等因素影响的煤体力学行为演化规律，建立了考虑初始损伤和各向异性的含瓦斯煤岩及岩煤结构体力学本构关系、损伤演化模型和侧向损伤影响的渗透率模型；开展了采动应力影响的固-气耦合组合煤岩力学行为及能量演化规律研究，得到了采动应力(卸荷方式和加卸载速率变化等)影响的固-气(瓦斯)耦合煤体力学行为演化及能量耗散规律；开展了地应力-瓦斯运移-采动应力条件下固-气(瓦斯)耦合煤体失稳灾变控制模型研究，从功能转换角度，建立了含瓦斯煤岩、岩煤结构体破坏后的盈余能密度的数学表达，构建了冲击-突出复合灾害能量判定准则，通过多元信号监测划分了复合灾变主控类型和等级；开展了真三轴条件下固-气(瓦斯)耦合煤体失稳灾变过程声发射-电荷信号反演研究，得到了声发射-电荷事件数、能量、幅值和主频等煤体、组合煤岩体失稳破坏时频域反演判据，依据反演判据形成了基于应力场-变形场-瓦斯场-声电物理信号的冲击-突出复合灾害多参量预测方法。整体研究成果在国内10余处矿井开展应用，有效揭示了煤矿冲击-突出复合灾害孕灾机制，提出了合理的防治方案，防止了多起冲击-突出事故的发生，提高了矿井安全生产环境。项目研究成果对掌握复杂地质构造和采动应力影响下的含瓦斯煤体失稳致灾力学机制和实现冲击-突出复合灾害多元孕灾信息精细化监测具有重要的科学意义和工程价值。