SHAKING TABLES TESTING OF CONCRETE FILLED STEEL TUBULAR SINGLE ARCH RIB MODEL UNDER THE EXCITATION OF
RARE EARTHQUAKES

In order to understand the seismic behavior of concrete filled steel tubular (CFST) arch ribs under the rare earthquakes excitation of ELcentro wave and Hanshin wave, a CFST model of scaled 1∶10 was constructed on the unique Earthquake Simulator of Triple Shaking Tables Array at Fuzhou University. The testing results indicate that the CFST arch rib structure has entered into the nonlinear elastic-plastic phase since the strains of the steel tube and core concrete in the mainly sections of an arch rib are far larger than their limit elastic stains. However, the stiffness and natural frequencies of the arch rib model do not have significant decrease because of the hooping effect on the core concrete subjected by the steel tube. Moreover, there are no distinct cracks or damage on the surface of the steel tube, which reveals that the CFST arch rib structure has a favorable seismic performance. The testing results also show that the different earthquake response spectrums will relatively induce the varying seismic performance, and the magnifications of response are related to the waves’ predominant frequencies, ranges and peak vales as well as the model’s dynamic behavior. Furthermore, the responses of accelerations, displacements, and strains under the excitation in the Y-transverse direction are generally larger than that in the X-longitudinal direction, especially at the arch crown. Otherwise, compared to the strains in the top-bottom edge at the cross-section of springs, the strains in right-left edge are larger and more disadvantageous, which need to be considered.