Study on Hydrodynamic Pressure and Dynamic Response of Pier under Long-Period Earthquakes

Based on shaking table test and finite element method, the influence of water on the natural vibration characteristics of the pier was studied. Then, the effect of long-period ground motions to hydrodynamic pressure of the pier under various water depths was discussed. As the same time, seismic responses of the pier were also analyzed under the condition of different water depths. Finally, the first order natural frequency and the distribution of acceleration peak values along the pier height were compared between the shaking table test and finite element method. The results show that the influence of the water on the natural vibration characteristic of the pier should be considered. When the water depth exceeds a critical value, the hydrodynamic pressure has a different tendency along the pier under different ground motions. The peak values of bending moment and shear force at the bottom of the pier and the acceleration and displacement on the top of the pier increase with the rise of water depth. The calculated values from model test and finite element calculation are in good agreement.