Study on Seismic Performance of a Prefabricated CFST Bridge Pier

This paper investigates the seismic performance of the prefabricated concrete-filled steel tubular (CFST) bridge pier in the bridge system-level. The proposed prefabricated CFST bridge pier is composed of circular thin-walled CFST double-column, precast I-shaped tie beams, and precast RC cap beam, which are assembled by simply on-stie assembly connections, with advantages in good seismic performance, convenient construction, and comparable material cost. A total of 12 two-span continuous beam bridge cases are designed, including 2 typical bridges with reinforced concrete (RC) piers and 10 bridges with CFST piers. Numerical research on the hysteretic performance of piers in bridge cases, dynamic responses of all bridge cases, and their seismic fragility. The results demonstrate that prefabricated CFST piers outperform RC piers in both load-bearing capacity and energy dissipation, and these piers exhibit reduced transversal displacement at the top and decreased maximum curvature when implemented in bridge systems. Besides, fragility analysis reveals the bridges with prefabricated CFST piers have significantly lower damage probabilities than their RC-pier counterparts.