Experimental Verification of a Cable-Stayed Bridge Model Using Passive Energy Dissipation Devices

To investigate the efficiency of passive energy dissipation devices in protecting cable-stayed bridges from severe damage when subjected to high-intensity ground motions, a 1/20-scale bridge model from a typical medium-span concrete cable-stayed bridge was designed, constructed, and tested on shake tables. Yielding steel damper (YSD) and viscous fluid damper (VFD) were used as passive energy dissipation devices in the transverse and longitudinal directions, respectively. The bridge models were then excited by two ground motions with different spectral characteristics in transverse and longitudinal directions accordingly, including the Chi-Chi earthquake wave and a site-specific artificial wave. The seismic responses of the bridge models with and without the passive devices were analyzed and compared. Both numerical and test results show that the YSD applied in the transverse direction could reduce the seismic responses of the towers effectively, and the VFD applied in the longitudinal direction could reduce the displacement of the deck effectively while simultaneously limiting the seismic responses of the towers. Therefore, it is suggested that the proposed energy dissipation system, consisting of YSD transversely and VFD longitudinally along with the sliding bearing, is applied in the cable-stayed bridges for better overall seismic performance compared to the traditional isolation system that provides efficiency only longitudinally.