(1. College of Mechanics and Engineering Science，Liaoning Technical University，Fuxin，Liaoning 123000，China； 2. School of Civil and Hydraulic Engineering，Dalian University of Technology，Dalian，Liaoning 116085，China)
Abstract：The main features for this kind of rock cavern in a hydraulic power station are high walls，large span and long axial-length，the axial length of this kind of underground rock cavern is mainly ranging from 300 to 400 m. In order to study the influence of wave passage effect on the dynamic non-linear response of underground rock cavern under uniform and wave-passage seismic excitation，separately，a great many 3D nonlinear finite element numerical simulations are conducted by considering three different amplitudes of seismic motions. The damaged plasticity model is adopted for the rock mass. Geometric nonlinearity is also considered in each simulation. For a given seismic motion with specified frequency-spectrum features，the results show that：(1) seismic response of the cavern mainly depends on the amplitude of the seismic motions；(2) As the amplitude of seismic motions is small(for example，the peak ground acceleration is less than 0.1 g). The wave passage effect has no negative impact on the underground cavern，and the wave passage effect can be ignored. (3) However，as the peak ground acceleration is greater than 0.2 g，the wave passage effect dramatically aggravates the failure of underground cavern，which indicates that the wave passage effect should be considered once the rock cavern is built in regions with highly seismic activity.
