Dynamic Characteristics of an Ultra-long Cable-stayed Bridge

摘要

This paper describes the experimental and numerical modal analysis performed on the SutongrnBridge in China, the first-built large cable-stayed bridge with over one kilometer main span in thernworld. Theoretical analysis is conducted on the 3D finite element model developed from the designrndrawings combined with some measured material properties. Ambient vibration tests are carried outrnand the acceleration responses of the deck and the towers are obtained. 18 vibration modes of therndeck and the towers are identified in the frequency range 0-1.0Hz using both the peak-pickingrnmethod and the random decrement technique combined with Ibrahim time domain method.rnMoreover, modal damping ratios of all modes are estimated and their scattering ranges are narrow.rnA good correlation is achieved between the finite element analysis and experimental analysis. Thernmain assumption adopted in the FE model for dynamic analysis are assessed and summarized. Thernidentified results can be used to validate and update the finite element model.