Applicability Study of Travelling-wave Effect on Multi-tower Extradosed Cable-stay Bridges Using Symmetric Analyzing Method

摘要

Shake table test is considered to be a very intuitive and efficient way of studying structure seismic response. With more long multi span bridges been built and a larger proportional scale structure tests are towards, the capacity of shake tables and table numbers are insufficient. Sacrifice has been made when analysing bridge seismic response under multiple-support excitation by putting adjacent piers on one table. With the method used in static symmetric structure, a symmetric six-tower extradosed cable-stayed bridge under travelling wave excitation was analyzed by separating the whole bridge into symmetric and antisymmetric half bridges. The seismic loading is also dealt with symmetric method and then applied to the corresponding structure. This method is promoted from linear situation to nonlinear situation. And by adjusting Ground Peak Acceleration (PGA) and bearing constitutive relations, simulation analysis has been done. This study indicates that using symmetric analyzing method, half bridge can be used to analyze travelling wave effect effectively instead of whole bridge especially when post stiffness and PGA are in high level.