Analysis On The Seismic Response Of The Double Cable Plane Cable-stayed Bridge Of Twin Towers

In recent years, with the rapid development of China’s economy, long span cable-stayed bridge has been widely applied in road traffic engineering by virtue of its novel structure, reasonable stress form and strong span ability. Long span cable stayed bridge as a regional transportation hub project, has a strong driving effect on regional economic development. Therefore, to ensure its safety, the research of long-span cable-stayed bridge under earthquake response is quite necessary. This paper first introduces the development of cable-stayed bridge in modern times. As well as the current widely used seismic response analysis method. Then, use the existing Twin Towers double cable plane cable-stayed bridge(reinforced concrete structure) for the engineering background, using large finite element analysis software MIDAS/CIVIL to build the three dimensional finite element model of cable stayed bridge, analyzed and studied the vibration characteristics, as well as the seismic response of the cable-stayed bridge. Study as follows:(1) Firstly, this paper introduces the basic characteristics and the development course of large span cable-stayed bridge. Discussed the the necessity of analysis of the seismic response of large span cable-stayed bridge, and some problems in the analysis of the seismic response of the current cable-stayed bridge.(2) This paper introduces some basic theories of the analysis of the ground motion response of the bridge, which mainly introduces the current use of a more extensive response spectrum method and time history analysis method and gives the corresponding formula.(3) Using finite element software MIDAS/CIVIL as the analysis platform, Establishing the three dimensional finite element model of Engineering examples to analyze the structural characteristics of the natural vibration period and mode shape of cable-stayed bridge.(4) By calculating the effective vibration mode participation quality of the cable-stayed bridge, to determine the vibration mode shapes of the response spectrum method. At the same time, according to the relevant regulations and the site conditions, the design response spectrum of the structure is determined. I carried out the response spectrum analysis of five kinds of seismic loads.(5) According to the relevant regulations and the seismic characteristics of bridge sites, the appropriate seismic wave is chosen as the ground motion input. I focus on the effect of material nonlinearity on seismic response of cable-stayed bridge.Carried out linear time history analysis and nonlinear time history analysis under uniform excitation, among them, the nonlinear analysis of tower using fiber model.(6) By comparing the response spectrum method and time history analysis method, get the internal force and displacement results of different loading and draw relevant conclusions.