EXPERIMENTAL STUDIES ON SUPER LONG-SPAN CABLE-STAYED BRIDGE BY USING MULTIPLE SHAKE TABLE TESTING

In this study, a 1:70 scaled model of a cable-stayed bridge, with a central span of 1400 m, was tested using a multiple shaking table array system at Tongji University. The effects of various structural systems, including the floating system, the elastically constrained system and the supporting pier system, on the seismic behaviors of the scaled model were investigated in the longitudinal direction. Focusing on the supporting pier system, the effects of the supplemental energy dissipation components equipped between two pylon legs on the seismic response of the scaled model were also clarified under uniform excitations in the transverse direction. Finally, the destructive testing was carried out to investigate the failure modes and catastrophe process of the scaled model in the transverse direction. The experimental results showed that:the elastically constrained system and the pier system could significantly reduce the displacement of the pylon top and the relative displacement between the pylon and the girder compared to those of the floating system; although the supplemental energy dissipation components installed between the pylon legs at the top region was not effective enough to decrease the displacement of the pylon top, it could effectively reduce the strain response of the pylon; the pylon top and bottom regions were subjected to damage under destructive testing, indicating a failure mode with double plastic hinges.