Seismic Analysis And Design Optimization Of Single Pylon Cable-Stayed Bridges

Cable-stayed bridges are usually the hinges of traffic that have strategic location.The destruction of cable-stayed bridges once occurred under seismic action, it would lead to the interruption of traffic and affect emergency service and disaster relief. It must be made sure that cable-stayed bridges would not damage seriously. So it’s very important to study on seimic behavior of cable-stayed bridges.In this paper, in the background of the Baishitianhe Bridge, the writer has made a series of research of its seismic performance, the main contents of the research are as follows:1. A simulation model of this bridge is established with the finite element software (Midas Civil), the natural vibration characteristics and the main vibration mode of the bridge are analysed. The results show that the vibration modes of cable-stayed are closely concentrated, the influence of hign order mode on dynamical analysis of structures if very important.2. The seismic checking computations for Baishitianhe Bridge are done with response spectrum method. The seismic performance of different components are researched for assessment of safety of the bridge under earthquake action.The response of the bridge under the action of different seismic waves are analisysed with dynamic time history analysis method compared with the result of response spectrum method.3. Parameter sensitivity analysis is done to analyse the influence to structural dynamic characteristics of different parameter variation.4. The height of main tower and main girder are optimiazed to get the optimal solution of internal force of section located at the bottom of main tower under earthquake action.