Waves On The Effect Of Incident Directions Of Seismic Waves On The Dynamic Response Of Rock-fill Dam

The model with rigid boundary was applied in the seismic response analysis of rock-fill dam currently, assumed that the seismic input of boundary points of the dam were identical, by exerting inertial force on the dam to realize seismic input, this input method was known as uniform excitation in this paper. The rigid boundary model was a closed energy system, scattered waves can not through the boundary and the reflected waves generated at the boundary continued to affect the dam. It can not consider the influence of radiation damping of foundation. In addition, with the height of dam increasing, the size of dam was also increased. There was a phase difference between different bottom points of the dam caused by seismic waves. The effects of traveling wave were significantly enhanced. From above aspects we can see, it was difficult to reflect the regular of seismic response of the dam by using uniform excitation.Recently, the analysis of seismic issues of rock-fill dam generally assumed that the incident direction was vertical to the model. However, for near-field earthquake or areas which conditions were more complex, the seismic waves incident to the surface usually at a certain angle. Therefore, it is important to discover a reasonable method to study the effects of seismic waves from different directions incident on the seismic response of rock-fill dam.In order to consider the interaction between dam and foundation and analysis the influence of radiation damping of foundation and travelling wave effects. Viscous-spring artificial boundary and its relevant equivalent load earthquake motion input method were applied in this paper. It can simulate incidence of seismic waves from different directions. The effect on the seismic response of rock-fill dam was discussed. The main work could be summarized as follows:1. This method was introduced to the dynamic response calculation of high rock-fill dams. Then the method was discussed on the simulation effects of the radiation damping of foundation and the interaction between dam and foundation. On this basis, the influence of earthquake motion input method on seismic response of rock-fill dam was studied from for respects:spectrum characteristics of seismic waves, height of dam, the peak value of acceleration and foundation stiffness. 2. Then a typical rock-fill dam finite element model was analyzed under SV/P waves by different incident angles and direction. Discussed the influence of incident directions of seismic waves and travelling wave effect from the crest acceleration amplification coefficient, slopes stability and permanent deformation of the dam.