Seismic research on CFST arch bridges based on existing shaking table test

Based on an existing shaking table test on a CFST arch bridge, three constitutive relations for CFST members are adopted and compared using OPENSEES software and IDA method to investigate their effects on the seismic behavior of CFST arch bridges. In addition, the constitutive relation which takes confining effect of CFST members into account has been selected for the research on the failure mode and failure mechanism of CFST arch bridges under severe earthquakes. It can be found from the results that under a series of earthquake actions whose peak accelerations gradually increase, the springs of the CFST arch bridges would firstly turn to plasticity due to the significant base shear force and overturning moment, then the arch tops would as well become plastic induced by remarkable out-of-plane deformation, and thus the arches will be under the combination effect of both material nonlinearity and geometry nonlinearity, finally the internal force could not counterpoise the earthquake actions leading to dynamic buckling of the CFST arch bridges. The stress-strain development diagram obtained under the ultimate peak acceleration shows that, the CFST arches present favorable hysteretic behavior as well as good ductility and energy dissipation under the earthquake attacks.