考虑能量补给和动力扰动的高应力岩石岩爆准则与释能放大机理

Rock-burst is one of the major disasters threatening the safety of engineering projects in deep rock masses, but its mechanism is unclear. Some phenomenon like abrupt increase of energy release together with rock-burst is inexplicable. Our recent research on rock behavior under coupling static and dynamic loads has shown that small dynamic disturbance may triger violent failure of rock system with high static stress, where the released energy from rock is much larger than that from static deformation. At the same time, deep mining practice in burst-tendency hard rocks has shown that rock-burst can be avoided by reasonable arrangement of tunnelling layout and excavation intensity. Moreover, large scale fracture zone can be formed by the disturbance with small energy successfully. Therefore, it's believed that the energy replenishment and dynamic disturbance play vital roles in rock-burst accidents. Based on laboratory tests, theoretical analyses, numerical modelling and in-situ tests, the research tries to find out the contribution of energy replenishment, disturbance, initial static stress and system stiffness to rock-burst. Their interaction and influence on rock-burst will be analyzed. A new rock-burst criterion considering above-mentioned factors will be established. After exploring the evolution principles of stress and energy of burst-tendency rocks under disturbance, the mechanism of the abnormal increase of energy release during rock-bursts is expected to be revealed. The research will provides theoretical support for rock-burst prevention, mitigation and transformation for projects in deep rock masses.

岩爆是威胁深部岩体工程安全的重要灾害，但其发生机制尚不清楚，特别是动力扰动下岩爆释放能量的异常增大现象更是无从解释。我们在岩石动静组合加载研究中发现，微小的动力扰动可使处于较大静压下的岩石系统剧烈失稳，释放出的能量远大于工作岩石自身储存的能量；同时，我们在深部硬岩采矿工程中发现，在岩爆多发区段，通过合理布置工程位置和控制采掘扰动强度，可在有效避免工作区岩爆事故的同时，成功实现较小能量的大范围碎矿。因此，我们推知外界补给能量和动力扰动在岩爆发生中发挥着极其重要的作用。项目充分运用室内实验、理论数值分析和现场试验等方法，研究补给能量、动力扰动、初始应力和体系刚度对岩爆发生的定量贡献；揭示各因素在岩爆过程中的参与机理，尝试建立综合考虑以上多因素的岩爆新判据；探索动力扰动下岩爆岩体的应力、能量演化规律，阐明动力诱发岩爆时释放能量异常增大的动力学机制，为深部岩体工程的岩爆防治和良性转化提供理论支撑。

岩爆是威胁深部岩体工程安全的重要灾害，但其发生机制尚不清楚。项目通过开展受冲击岩石动力学试验，充分利用声发射技术、高速摄像仪、超动态应变仪、红外成像等在瞬态信息捕捉方面的优势，获得了动力扰动作用下高应力岩石的破裂过程与机理；侧向扰动下高初始应力岩石的贯通破坏研究揭示了动力参与下高应力岩石的岩爆式破坏机理和能量释放演化规律；分析了应力、水等因素对岩爆的影响；提出了无需预先测速的岩石破裂源定位算法，用声发射监测揭示了冲击扰动在诱发岩爆式破坏中的作用机制，一定程度上解释了深部岩石的岩爆机理；基于岩爆倾向岩石特性，建立了基于应变等效和损伤理论的岩石本构模型，提出了改进TOPSIS模型的岩爆预测方法，并初步应用于现场岩爆预测分析。项目期内共计发表标注项目编号的论文27篇，其中被SCI收录论文18篇，授权国家发明专利3项，获得湖南省自然科学一等奖1项，培养毕业硕士研究生7人，参加国际会议并做报告4次，1人入选教育部长江学者奖励计划青年学者，1人成为国家青年973项目首席科学家。