高烈度区黄草坪山岭隧道地震动破坏机理研究

Research on the Failure Mechanism of Huangcaoping Mountain Tunnel in High Intensity Zone Subjected to Earthquake

为了研究高烈度区山岭隧道地震动破坏机理,基于G318黄草坪2"上黄草坪隧道,利用离散元分析软件建立数值分析模型,深入研究了地震波的传播特性及影响隧道地震稳定性的主控因素,具体得出以下结论:①地震波在洞口处的集中效应、地震波的卓越频带以及隧道纵向围岩的差异性是造成山岭隧道破坏的3个主控因素;②隧道位移随地震频率的增大而减小,低频地震波导致的隧道位移幅值明显高于高频地震波,因此低频地震波更易造成隧道结构的破坏;③围岩连接处容易造成衬砌的开裂和剥落,需要进行单独设计和施工。

In order to research the failure mechanism of mountain tunnel in high intensity zone, this paper establishes a numerical model using discrete element software based on the Huangeaoping tunnel at G318. The spreading characterize of seismic wave and the controlling factors which have influences on the seismic stability of mountain tunnel, the conclusions are shown as follows： first, the effects of hole, the predominate frequency of seismic wave and the differenees of the surrounding roek are the three factors causing the failures of the mountain tunnel. Second, the amplitude of displacements at the top of the surrounding rock increases with the reduction of the frequency of the seismic wave. The displacement at the top of the tunnel triggered by the high frequency band is less than that triggered by low frequency band. Therefore, the low frequency band is an important factor triggering the failure of tunnel. Third, the location between one surrounding rock and the other surrounding rock failure easily, which needs be designed and constructed alone.