SHAKING TABLES TESTING STUDY OF LIGHTWEIGHT BRIDGE WITH CFST COMPOSITE TRUSS GIRDER AND LATTICE PIER

In order to study the aseismic performance of a lightweight bridge with concrete-filled-steel tube (CFST) composite truss girders and lattice piers, took Ganhaizi Bridge as a prototype, one scale specimen of 1:8 with two spans and three lattice high piers was designed for a multi-shaking table test. The test was carried out on the earthquake simulator of a unique triple shaking table array system in Fuzhou University, China. Adopted the design seismic wave of a real bridge, its basic dynamic characteristics, aseismic performance and failure characteristics were studied. The results indicate that the ratios of the frequency to the displacement between a specimen and a real bridge are corresponding to a similitude relationship. Under a transverse or a longitudinal excitation, the acceleration in lattice zones significantly amplifies, and decreases the acceleration on a concrete deck. The strain under the transverse direction is larger than that under the longitudinal direction, meanwhile, it is unnecessary to consider the combination of two directions. The displacement on the top of a pier is less than the limitation value under design ground motions. The specimen is not failed for all testing cases, which reveal that a lightweight bridge with CFST composite truss girders and lattice piers has a favorable aseismic performance.