Analysis On Seismic Performance Of High-pier Long-span Curve Bridge Under Long-period Ground Motion

Along with the construction of highway from the city to the mountains in our country, more and more curved bridges have been built up, because of course the limitation of linear requirements and terrain conditions. At the same time, the seismic demage of the long-period ground motion is gradually increased in recent years, and the study of long-period ground motion is still in a relatively immature stage. Compared with the ordinary seismic wave, the influence of long-period seismic waves on the dynamic response of a long-span curved bridge with high-rise piers is much bigger, so seismic problems cannot be ignored for such big flexibility structures.Based on the above problems, with the help of parametric modeling based on the finite element software, the high piers of long span curve continuous beam bridge and continuous rigid frame bridge under long-period seismic wave excitation response influence and the thorough research to the vibration problem are analyzed, and the main research content and innovation points of this paper are as follows:(1) High pier curve of long-span continuous girder bridge finite element model is established, with considering the influence of pile-soil interaction, and the different boundary conditions and different pier height and radius of curvature of the result of the structural dynamic characteristics of the model are compared. With different pier height and radius of curvature, models in the long and short cycle of seismic response under the seismic excitation of the problems are analyzed. Long-period seismic waves of high pier model is found. Compared with the straight bridge, the high pier seismic response of long span curve continuous beam bridge is more complicated.(2) The high piers of long span curve continuous rigid frame bridge finite element model is set up, Different pier height, span and radius of curvature of structural dynamic characteristics and the long-period seismic waves and ordinary seismic response under the seismic excitation of the problem are studied.Traveling wave excitation for the models of different span is conducted. Compared with consistent motivation,the general rule of the effects of traveling wave effect are studied.(3) To make a preliminary study of the structure of shock absorption, viscous dampers are set to the end of the beams of the curve continuous beam bridge and continuous rigid frame beam bridge. Compared to the original bridge structure, damping effects of viscous dampers for two bridge are analyzed under long-period seismic wave excitation. And different parameters of viscous dampers for the influence on the effect of shock absorption are discussed. Finally comimg to a conclusion that , the damping effect mainly depends on speed and the damping coefficient when the velocity index value is fixed.