Research on the Validation of the Vibration Model of a CFT Arch Bridge(New Saikai Bridge)

The New Saikai Bridge is a CFT arch bridge with a concrete-filled steel tube (CFT) adopted for the arch ribs of the road bridge for the first time in Japan. lt is necessary to understand the natural vibration and response characteristics of the CFT bridge. The authors measured microtremors of the bridge to estimate the natural frequency and damping constant. The validity of the analysis model was evaluated by comparing the measured natural frequency with the analysis result. In addition，the author carried out a non-linear seismic response analysis using two analysis models，.i.e. one with the confinement effect and the other without the confinement effect，to evaluate the confinement effect of steel pipe on the increase in the strength of concrete