Seismic Responses Analysis Of Cable-Stayed Overpass Bridge In Zhengzhou Downtown

Bridges are the lifeline of human production activities, but strong earthquake leads crashing destruction for bridge structure, so seismic research for bridge is been payed more attention to. Seismic research of large-span cable-stayed bridge is to guarantee the structure adequate security when earthquake occurred. Cable-stayed Overpass Bridge in Zhengzhou downtown with twin towers and three-span is a concrete cable-stayed bridge, with a total length of 460 m, belongs to seismic intensity 7 and first class building. Therefore, seismic response analysis is very important and meaningful. Finite element analysis software MIDAS/CIVIL is used to carry out a detailed seismic response analysis for this bridge. Following main aspects is completed:(1) MIDAS/CIVIL is used to construct the space finite element dynamic model and subspace iteration is used for free vibration analysis;(2) Response spectrum method and CQC-type combination are taken for the dynamic analysis. Longitudinal, horizontal, vertical and seismic response combination was considered;(3) Dynamic time-history analysis is used to calculate the internal force and displacement response, to analyse the seismic response of cable-stayed bridge under seismic excitations. El-Centro seismic wave which is carried to the strength, spectrum adjustment, and Northridge seismic wave which only is carried to the strength adjustment are selected to calculate the displacement and internal forces of the bridge. By comparing the results, influence of seismic wave spectrum for seismic response of bride is performanced quantitatively.(4) Results of response spectrum and time-history analysis are contrasted, and applicability of response spectrum mehod for this bridge is evaluated scientifically.