| In the past several decades, the failure of rock, under static or dynamic loading, was studied extensively and many significant achievements, which paid an important role in the development of rock mechanics and engineering practices, have been achieved. However, most of these researches are usually concentrated on the conditions solely under static or dynamic loading. The insufficiencies still exist for the rock failure under coupled static and dynamic loading. In fact, the natural rock, especially that in deep underground engineering, the rock is highly stressed before subjected to the dynamic loading, and therefore, the dynamic disturbance is one key factor to trigger the instable failure of underground rock mass. Therefore, the failure of highly stressed rock triggered by dynamic disturbance is of great scientific significance and engineering practices.Under the support of national science foundation of China (NSFC), this work is aimed to study the failure of highly stressed rock that is triggered by dynamic disturbance. The basic work is briefed as follows:(1) Firstly, the failure of rock under coupled static and dynamic loading is tested using Split Hopkinson Pressure Bar (SHPB) apparatus, based on which, the effect of static stress level on the dynamic failure process is observed.(2) Secondly, the failure of rock under static, dynamic or coupled static-dynamic loading is numerically simulated using RFPA-Dynamics, a numerical code capable of reproducing the failure of rock. The effect of a variety of factors, such as static stress level, dynamic stress wave forms (i.e. amplitude and duration of stress wave), on the dynamic rock failure are analyzed.(3) At last, the numerical simulations on the failure of underground tunnel triggered by dynamic disturbance are presented. The effect of in situ stress, depth of the tunnel and waveforms of dynamic disturbance on damage and failure of underground tunnel is characterized. This numerical simulation may highlight the importance of considering the contribution of coupled static-dynamic loading conditions in order to clarify the mechanism associated with the collapse of underground opening especially when the effect of the dynamic loading can not be ignored. |
