高静应力和频繁动力扰动共同作用下矽卡岩动力学特性

为进一步揭示深部岩体受到开挖爆破等动力作用时的破坏机理，利用基于SHPB装置的动静组合加载试验系统，首次对中高应变率下矽卡岩在高静应力和频繁动力扰动共同作用时的变形特性、能量规律、破坏模式等进行了研究.随着冲击次数的增加，岩石的弹性模量先增大后减小，而每次冲击时的最大应变整体表现出先减小后增大的趋势，最后一次冲击时弹性模量骤降，最大应变突增，岩石试样发生破坏.单位体积岩石能耗为负值，说明在冲击动载的作用下岩石试样表现出释放能量的特性，这是由于高静应力作用产生的弹性应变能受动力冲击作用诱导而释放；随着冲击次数的增加，单位体积岩石释放的能量先增大后减小.结构致密、强度较高的矽卡岩试样随冲击次数的增加表现出劈裂破坏模式.

Dynamic characteristics of skarn under the combined action of high static stress and frequent dynamic disturbance

In order to further study the failure mechanism of deep rock mass under the dynamic effect of excavation and blasting,the deformation characteristics,energy laws and failure model of skarn were investigated for the first time under the medium to high strain rate and the combined action of high static stress and frequent dynamic disturbance with an experimental system of coupled static and dynamic loads based on the SHPB device. The results show that the elastic modulus of rock increases with the increase of impacts and then it decreases,at the same time,the maximum strain exhibits an overall trend of decreasing first and then increasing. The elastic modulus drops sharply and the maximum strain shoots up when the last impact comes. The energy consumption per volume of rock is negative,which indicates that the rock samples exhibit a characteristic of energy release under impact dynamic action because a great much elastic strain energy stored in rock samples under high static stress action is released by the disturbance of impact dynamic action. The energy release per volume of rock increases first and then decreases with the increase of impacts. The skarn samples which have compact structure and high strength show a failure mode of splitting.