Earthquake Response Analysis Of Yong-an Bridge In Fushun City

With the scale of cable-stayed bridge enlarging, earthquake response is more and more important and is critical function sometimes, so earthquake response of larger bridge must be analyzed. Yong-an Bridge in Fushun City is a concrete cable-stayed bridge with three towers and single cable plane, which is 350 meter. The geographical position is very important and the system of this bridge is peculiar. So analyzing the earthquake response of this bridge is significant.On the basis of the study achievements at home and abroad, the spectral analysis theory and dynamic time-history analysis are both used to calculate the earthquake response of the Yong-an Bridge with ANSYS and the laws of its earthquake response are obtained.Firstly, the dynamic calculation model of the Yong-an Bridge is developed with ANSYS and the dynamic properties are obtained through modal analysis during which the standard seismic response spectrum is inputted from longitudinal, transverse and vertical direction respectively.The spectral analysis is linear so the nonlinear factors can be taken into account. The dynamic properties of Yong-an Bridge are calculated also with dynamic time-history analysis considering the nonlinear factors. The earthquake response is gained according to the calculation results of the two methods. Through calculations, only the in-plane responses of longitudinal input are considered for the superstructure and the responses caused by three directions (longitudinal, transverse and vertical) input are considered for the substructure and furthermore, the dynamic response of mid-pier is stronger than that of side pier under seismic action. It is concluded that the seismic loads do not control the design by the dynamic response analysis of the displacement and internal force.These laws can be used as the basis of seismic design of the Yong-an Bridge and is useful for directing seismic response analysis of such kind bridge.