【摘要】 高应力环境中的隧道围岩岩爆机制是当前亟待研究和解决的前沿课题。为分析不同加载速率下花岗岩岩爆的时滞性破坏特征，利用真三轴岩爆试验系统模拟实际工程中隧道开挖后临空面岩体的受力情况和边界条件，通过三向六面加载且单面快速卸荷的方法对花岗岩发生岩爆时的时滞性特征、力学特性、能量演化和声发射特征进行了研究。试验结果表明：花岗岩岩样在真三轴压缩破坏过程中表现出长短不一的“时间效应”,根据时间长短将其分为“无明显时间效应”“弱时间效应”和“强时间效应”岩样；在相同的应力加载速率下，有时滞性的岩样的稳压应力与峰值应力差异较小，有时滞性的岩样弹性模量整体上大于无时滞性的岩样，且时滞性越强，岩样的弹性模量越大。在不同的应力加载速率下，低加载速率下岩样的峰值应力均小于高加载速率下的相应值；在不同的应力加载速率下，相同时滞性破坏的花岗岩岩样破坏强度随加载速率的提高而上升。相同时滞性的花岗岩岩样，能量的曲线走势总体上趋近。不同时滞性岩样在其应力加载过程声发射(acoustic emission, AE)撞击率变化特征存在较大差异，有时滞性的岩样在其初始压密阶段及线弹性阶段时岩石内部的声发射活动较剧烈。研究成果可为实际工程中的岩爆灾害预警提供有力参考和帮助。更多还原

【Abstract】 The mechanism of rock burst in tunnel surrounding rock under high stress environment is a cutting-edge topic that urgently needs to be studied and solved. To analyze the delayed failure characteristics of granite rock burst under different loading rates, a true triaxial rock burst test system was used to simulate the stress and boundary conditions of the rock mass on the free face after tunnel excavation in actual engineering. The time delay characteristics, mechanical properties, energy evolution, and acoustic emission characteristics of granite rock burst were studied by using a method of loading from three directions to six sides and fast unloading from one side. The experimental results show that granite samples exhibit varying “time effects” during the true triaxial compression failure process, according to the length of time, they can be divided into “no obvious time effect” “weak time effect” and “strong time effect” rock samples. At the same stress loading rate, the difference between the stable stress and peak stress of rock samples with time delay is relatively small, the elastic modulus of rock samples with time delay is generally greater than that of rock samples without time delay, and the stronger the time delay, the greater the elastic modulus of the rock sample. At different stress loading rates, the peak stress of the rock sample at low loading rates is lower than the corresponding value at high loading rates. Under different stress loading rates, the failure strength of granite samples with the same time delay increases with the increase of loading rate. The energy curve trends of granite samples with the same time delay are generally similar. There are significant differences in the acoustic emission(AE) impact rate variation characteristics of different time delayed rock samples during their stress loading process, the acoustic emission activity inside the rock sample with time delay is more intense during its initial compaction stage and linear elastic stage. The research results can provide favorable reference and assistance for early warning of rock burst disasters in practical engineering.更多还原