SHAKING TABLES TESTING OF CONCRETE FILLED STEEL TUBULAR ARC RIB MODEL

During the last two decades, a large number of concrete filled steel tubular (CFST) arch bridges have been built in China. However, the seismic response of the CFST structural arch rib is seldom studied. In order to understand the seismic response of CFST arch bridges, based on the similitude law of artificial mass, a CFST arch rib model scaled 1:10 of the Qunyi Bridge was constructed and tested. The test was carried out on the earthquake simulator of a unique triple shaking table array system in Fuzhou University. The Sine wave and several recorded ground motion waves such as Taft wave and artificial waves based on Chinese code were adopted to evaluate the seismic response of the model. The waves were input both in the longitudinal direction and in the transverse direction. The testing results indicate that the effects of transverse seismic responses of the models are more distinct than the effects of longitudinal seismic ones by exciting the artificial waves of E1 and E2, and that nevertheless Taft wave are reversed. The acceleration magnification in crown is several times compared to arch springing while in uniform excitations, which are related to the predominant period. Whereas, the axial internal force and bending moment in arch springs will be increased or decreased while in no-uniform excitations and will be more disadvantageous to the model. The model cannot crack or fail for all testing cases, which reveal that CFST arch rib structure has a favorable aseismic performance.