The Vibration Response Analysis Of Long Span Cable-stayed Bridges With Lower Tower

With the continuing need for transport development,bridges tend to be more and more application development and composition of the light,combination of the development which greatly enriched the bridge shape. And different bridge spans have different options, especially in the 200m ~ 260m span bridges have less of the choice, cable-stayed bridge have high cost, continuous bridge, the security less reliable, cable-stayed bridges with lower tower is pulled to make up such deficiencies. In recent years, earthquakes continue to occur at home and abroad, particularly large magnitude earthquakes in China have repeatedly occurred, it poses a great threat to the life and property of people. Especially when transport lifeline after the destruction of bridges in the earthquake, movement of the delayed impact of the earthquake relief, and cause greater losses. Therefore, the new bridge seismic response analysis of research on seismic design is very meaningful.In this paper, use element analysis software MIDAS, seismic design theory results at home and abroad, from the following aspects of cable-stayed bridges with lower tower of west river seismic response analysis:(1) Analyzed the development of cable-stayed bridges with lower tower, structural characteristics, the significance of bridge seismic design and seismic design outlined some common methods.(2) Introduction to the features of the west river bridge structure and some basic design parameters. Finite element software and taking into account pile-soil on the west river bridge under the dynamic characteristics of its previous second-order vibration mode analysis.(3) Describes the the oretical response spectrum analysis methods and in accordance with the west river bridge on the site which type of bridge site and the design of seismic intensity, on the model of earthquake response spectrum analysis, and draw useful conclusions.(4) At one and two dimensional seismic wave case, the low flexibility of the cable-stayed bridges with lower tower dynamic analysis. Under different seismic input of the bridge seismic response time history analysis and response spectrum analysis results are compared.(5)In rare earthquake of 9 degrees, respectively, on the application of the two conditions with inelastic time history analysis(6) Introduced the plastic analysis of static-pushover analysis of the basic principle of the west river bridge piers using the double leg side ways three load input at the next vertical and horizontal analysis. Compare with the results of inelastic time history analysis and pushover analysis, and pushover analysis that used the possibility of such the cable-stayed bridges with lower tower. And it seismic performance evaluation, seismic design for the project to provide useful conclusions.