Seismic Response Analysis On The Double-Column Piers Bridge

With the advancement of the Development of Western Region and birth of the 13th Five-year Plan and the One Belt and One road one after another, we can prospect that in the future years, the transport undertakings in west regions of China will meet another peak.Double-column piers bridges are widely used because of the difficult terrain in the west of China. But examples of highway bridge damage by earthquake occur frequently, it’s necessary to analyze seismic performance of it.This paper focus on several common types of double-column piers bridges in western mountainous area.Response-specturum method and time-history analysis method are used to study on the piers in the longitudinal direction and the horizontal direction, when there are height difference between them.Besides,conducting a research on influence to the seismic performance with straining beam is menthioned. The following aspects are addressed:(1) By the large-scale general finite element software, three-dimension dynamic model is established. Seismic response analysis of longitudinal-direction piers on four common types of bridges (unidirectional Slope Bridge, bridges across the hill, bridges across the valley and high pier bridge) is studied on. The results show that seismic response on piers in the longitudinal direction is larger than that in the horizontal direction, and the former is twice as much as the latter.(2) Studying on seismic response analysis on piers bridges in the horizontal direction. The results show that with horizontal pier height difference increasing, the internal force difference under the seismic action is rasied.When the pier height difference is small,the degree of discretization on bridge’s internal force results become larger. With the increasing difference, force difference value change tends to converge.(3) Double column pier and the number of horizontal lines of a bridge girder structure seismic performance impact studies were compared to explore 40m high pier when laying numbers from one to five straining beam internal force trends and dynamic characteristics. The results showed that at the time were set one to five beams, the first six vibration modes of the structure are basically the same, but after the sixth-order modes are no changes in the law, showing that low-order modes of the bridge has not been increased straining beam impact, but higher modes has been significantly affected.