Effects of Different Damping Modes on the Seismic Response of Cable-Stayed Bridges

The damping makeup of long-span cable-stayed bridge is complicated and every mode has distinct damping.In order to study the influence of different damping modes on the seismic analysis results of cable-stayed bridges,a case study was performed on the 448-meter-span scheme of Northern Channel Bridge in Hangzhou Bay Bridge.Modal strain energy proportional damping theory reflecting effects of the damping distribution was used in seismic response analysis of the bridge to check the applicability of commonly used constant damping and Rayleigh damping.It shows that the results of seismic response depend on the damping theory used in the analysis.Constant damping can not represent structural damping characteristics.The seismic response results of Rayleigh damping highly depend on the reference modes chosen.The damping characteristics are overestimated or underestimated by Rayleigh damping in large frequency range which shows great random.Modal strain energy proportional damping theory which reflects the distributing property of cable-stayed bridges is comparatively reasonable.