Ultimate strength and ductility of state-of-the-art concrete-filled steel bridge piers in Japan

Briefly in this paper are described the difference in local buckling modes between cross-sections of steel and composite (concrete-filled steel) columns, the difference in cross-sections between composite columns in bridge piers and buildings, structural details of standard steel and composite columns for bridge piers, construction of composite bridge piers (bridge piers with composite columns), and the characteristics of stiffness, ultimate strength and ductility of composite piers in Japan. Reconstruction and repair using composite columns for reinforced concrete (RC) and steel piers, which collapsed or were damaged due to the Hyogoken-Nanbu earthquake which occurred on 17 January 1995, are introduced. Future research needs are also summarized for developing more rational seismic design methods for composite piers.