高轴压和围压共同作用下受频繁冲击时含铜蛇纹岩能量演化规律

Energy evolution law of copper-bearing serpentine received frequent impact under common action of high axial compression and confining pressure

探讨高轴压和围压共同作用下频繁冲击扰动试验过程中伴随主要能量的种类,并推演冲击扰动前后弹性能、塑性能等能量的计算公式;采用预加载围压、高轴压、0.5 MPa冲击气压模拟深部岩体承受的水平应力、垂直高应力及爆破开挖扰动的影响开展动力学试验,并基于试验结果分析含铜蛇纹岩的动力学特征及能量演化规律。研究结果表明:含铜蛇纹岩能承受的扰动冲击次数随轴压增大而减小,随围压增大而增大,且动态峰值应力随扰动冲击次数增加而减小;随扰动冲击次数的增加,岩样伴随的弹性能先增大后趋于减小,伴随的塑性能呈增大的趋势发展,反射能和入射能的比值与透射能和入射能比值的变化规律相反,前者呈增大趋势,后者呈减小趋势;单位体积吸(释)能随扰动冲击次数的增加呈下凸曲线趋势变化,其均值随围压增大先减小后增大,随轴压增大而减小。

Under the common action of high axial stress and confining pressure, the main types of energy were discussed in the study of frequent dynamic disturbance firstly. At the same time, the formula for calculating elastic energy, plastic energy are deduced before and after the impact disturbance. In order to conduct dynamic test, the horizontal stress, the vertical stress, the influence of blasting excavation disturbance of the deep rock mass were simulated by pre-confining pressure, pre-high axial stress, 0.5 MPa impact pressure, respectively. Based on the experimental results, the dynamic characteristics and energy evolution of the copper serpentine were analyzed. The results show that the cumulative disturbance impact times of copper snake-like rock decrease with the increase of axial pressure, while they increase with the increasing confining pressure, and the dynamic peak stress decreases with the increasing number of disturbances. As the number of disturbances increases, the elastic energy in the rock sample increases first and then decreases, the plastic energy shows a trend of increase, and the ratio of the reflection energy to the incident energy increases while the ratio of the transmission energy to incident energy decreases. The unit volume absorption (release) energy shows the trend of the lower convex curve with the number of disturbances increases. In addition, the averages of unit volume absorption (release) energy decreases first and then increases with the increasing confining pressure, but decreases with the increase of axial pressure.