Shake Table Studies of Seismic Structural Systems of a Taizhou Changjiang Highway Bridge Model

Taizhou Changjiang Highway Bridge is the longest three-pylon two-span suspension bridge in the world. To investigate the seismic performance of different connecting configurations between the deck and pylons, which are referred to as seismic structural systems, a $1/40\text{-scale}$ model of Taizhou Changjiang Highway Bridge incorporating different seismic structural systems was tested on the shake tables at Tongji University, Shanghai, China. In this paper, the design, construction, instrumentation, and loading protocol of the test model are introduced first. The fundamental frequencies of the eight bridge models are identified and are compared with numerical results. The damping ratios corresponding to the fundamental frequencies are obtained by the half-power bandwidth method. The test results show that the seismic responses of the three-pylon two-span suspension bridge under seismic loads are highly dependent on the connecting configurations between the deck and pylons. The relative displacement responses between the deck and the pylons in the longitudinal direction can be decreased effectively by viscous dampers or elastic cables. In addition, the influences of variations in those viscous dampers and elastic cables on the response of the model are investigated. Numerical results and test results are compared, and good agreement is achieved.