高应力单双轴加载条件下爆破扰动后片麻岩损伤规律研究

There are so frequent blasting disturbance during excavation process in deep metal mines under high stress environment. Stress rearrangements occur inside rock mass together with micro-fractures and damage accumulates and evolves gradually, eventually leading to increasingly prominent dynamic disasters. Aiming at the scientific problem that is lack of fundamental theory of damage evolution of geniss samples with blasting disturbance in high stress, a series blasting experiments under the condition of uniaxial and biaxial loading would be carried out based on high precision acoustic emission monitoring technique. Space-time evolution law of rock micro-crack and exponential order attenuation characteristic of rock acoustic emission activity after blasting disturbance are researched to establish an acoustic emission activity attenuation model. An identifying method of rock stress state in accordance to attenuation index of acoustic emission activity will be present through the corresponding relationship between acoustic emission activity attenuation index and stress intensity. It is planned to apply the ratio of the total number of acoustic emission activity to that of total number during entire experiment to represent the degree of gneiss damage. In order to reveal damage evolution, the damage after every blasting disturbance is analyzed for the influence to the entire damage process. This project can provide theoretical method and technical support for the research on rock dynamic instability process and field stability evaluation of rock mass.

深部金属矿山岩体处于高应力状态，在开挖过程的频繁爆破扰动下，岩体内部应力调整，微破裂、损伤逐渐积累演化，进而引发动力灾害问题日益突出。针对高应力爆破扰动后片麻岩损伤规律研究不清这一科学问题，项目拟采用高精度声发射监测技术开展一系列单轴和双轴加载条件下的片麻岩爆破实验，研究岩石微裂纹时空演化规律，总结爆破扰动后岩石声发射活动性幂律衰减特征，建立适用不同应力条件的爆破扰动后声发射活动性衰减模型，揭示声发射衰减指数与应力大小的对应关系，提出依据声发射衰减指数大小的岩石应力状态判别方法；采用声发射事件累计数与试验全过程声发射事件总累计数的比值表征片麻岩损伤程度，分析每次爆破扰动损伤对于岩石损伤全过程的影响程度，研究片麻岩爆破扰动应力调整过程及损伤演化规律。项目的开展将为岩石动力失稳过程研究和现场岩体的稳定性评价提供理论方法和技术支撑。

深部金属矿山岩体处于高应力状态，在开挖过程的频繁爆破扰动下，岩体内部应力调整，微破裂、损伤逐渐积累演化，进而引发动力灾害问题日益突出。针对矿山动力灾害监测基础理论欠缺和岩体损伤状态评估困难这一科学问题，项目开发了一种未知波速的粒子群定位算法，取得了良好的定位效果；采用高精度声发射监测技术开展一系列单轴和双轴加载条件下的片麻岩相似材料爆破实验，研究岩石微裂纹时空演化规律，总结爆破扰动后岩石声发射活动性幂律特征，建立了爆破扰动后声发射活动性衰减模型，揭示了声发射衰减指数与应力大小的对应关系，提出依据声发射衰减指数大小的岩石应力状态评估方法；采用声发射事件累计数与试验全过程声发射事件总累计数的比值表征片麻岩损伤程度，分析了每次爆破扰动损伤对于岩石损伤全过程的影响程度；在此基础上，开展了现场多次爆破扰动下岩体损伤演化规律研究。项目的开展将为岩石动力失稳过程研究和现场岩体的稳定性评价提供理论方法和技术支撑。