Seismic Response Analysis Of Cable-Stayed Bridge With Piers In Deep Water

In recent decades, earthquake disaster frequently occurred all over the world. And bridges are lifeline engineering, once destroyed, it will bring great damage to the lives and properties of people. It is necessary to make an in-depth study and analysis to the seismic performance of bridges, which is an important factor for safety.In this thesis, A double tower cable-stayed bridge in the Yangtse Gorges reservoir area is considered. The additional mass method on the basis of Westergaard theory is utilized to simulate the hydrodynamic pressure. Three finite element models for the cable-stayed bridge are established by MIDAS/Civil,which are model without considering water, model with half depth water and model with full depth water. Firstly, the dynamic property for each model were computed. Then, the earthquake responses including internal forces and displacement of the bridge are analysed respectively by spectrum response analysis and time-histroy analysis. Three models are all considering the effect of water depth. It is shown that:(1) Considering or not the hydrodynamic pressure, few changes for the dynamic property of bridge.(2) The hydrodynamic pressure will enhances the bridge earthquake responses ,so the effect of hydrodynamic pressure can not be ignored to seismic resisting design.(3) With the increase of water depth ,the effect of hydrodynamic pressure becoming more notable ,and the responses of structure also gradually increase .The laws, need to deeper research.It is expected to give some references for practical seismic design of cable-stayed bridges with pier in deep water.