Study On Seismic Response Of Multi-Tower Cable-Stayed Bridges With High Piers

How to improve the seismic safety of multi-tower cable-stayed bridges with high piers, commonly as an important part of the traffic key projects and the lifeline engineering in their districts, is always a serious problem which must be paid more attention to in engineering field. Generally tow major aspects are included, methods of seismic response analysis and measures for seismic absorption and control.In seismic design and seismic analysis of bridges, it is necessary for us to understand dynamic responses of bridges during strong earthquakes, especially the responses of bridges with high piers or long span. Based on Chishi Bridge in this dissertation, the finite element models for analysis in ANASYS is built up. Then response spectrum method and time-history analysis method are employed to analyze the internal force responses and displacement responses caused by earthquakes.The main content of this thesis includes:1. An introductory review of seismic research status of Multi-tower cable-stayed bridges with high piers at home and abroad; 2. Seismic analysis methods of cable-stayed bridges are summarized; 3. The finite element models of Chishi Bridge are established for calculation on the theory of dynamics; 4. The influence of the pile-soil interaction to the seismic responses of the bridge is considered; 5. The influence of the vertical component of earthquake to the seismic response of the bridge is considered; 6. The mechanical property of the whole bridge on the work of its self-vibration characteristic is analyzed; 7. Some valuable conclusions based on spectrum response analysis and time-history analysis are obtained.8. The changes of both displacement and forces in a structure during a seismic event are analyzed when longitudinal viscous dampers are used.9. To different tower modeling of large span bridges, the effect of seismic performance varies. To A-shaped tower modeling, seismic responses of the bridge are analyzed.10. Finally, the research in this dissertation is summarized, and the prospective work and the existing Problems are pointed out.I'm hoping that the studies and conclusions of this thesis could be profitable for similar bridges on seismic designing.