Earthquake Response Of Long-span Cable-stayed Bridges

In recent years, earthquake disaster frequently occurred in whole world which brought great damage to the safety of life and property for people. If the bridges which looked as very important structures by people for connecting with people's lifecollapsed caused by earthquake, the indirect disaster will take up to bring more loss of life and property. Therefore it is necessary to study and master the seismic response of bridge for establishing reasonable seismic design system and adopting effectiveseismic measure.In this thesis, on the basis of the study achievements at home and abroad, on thebasis of TIANXINGZHOU Bridge of WUHAN City, long span cable-stayed bridge' earthquake response were studied as follows:1. All sources of geometric nonlinearity,such as cable sag, axial force-bending moment interaction in the bridge decks and towers ,and change of the bridge geometry due to large displacements are considered in the analysis. The reasonable initial shape of cable-stayed bridge is studied.2. The finite element model of the structure was formed through reasonable simplification. And structural dynamic properties were calculated by using thefamous program of ANSYS. Structural dynamic properties considering support rigidity,archrib rigidity as well as soil-structure interaction were performed.3. long span cable-stayed bridge ' responses to uniform excitation of earthquake were analysed. Structural seismic responses that seismic wave was inputted from vertical direction were discussed. Internal forces and displacements of structural crucial sections were compared and discussed for checking computation the seismic safety of the structure. Some beneficial conclusions were gained through comparing calculation results of response spectrum analysis andtime-history analysis.4. Long span cable-stayed bridges' responses to travalling-wave effect of earthquake were studied. In this study, acceleration time-history was translated into force time-history with big mass principle, and force time-history was exerted in support place.,. Finally, it compares the structural responses to the consistent and inconsistent excitations and analyzes the seismic responses of large-span structures with the different span lengths.