Seismic Design of Concrete-Filled Circular Steel Bridge Piers

The adequacy of the existing design provisions for concrete-filled steel pipes subjected to axial forces and flexure is reviewed by comparing the strengths predicted by the CAN/CSA-S16.1-M94, AISC LRFD 1994, and the Eurocode 4 1994 codes and standards against experimental data from a number of investigators. New proposed design equations are then developed, in a format compatible with North American practice. The new equations, based on a simple plasticity model calibrated using experimental data, are shown to provide improved correlation between predicted strength and experimental data. This paper provides information and data in support of the proposed design equations, which have already been implemented in the 2001 edition of the CSA-S16-01 "limit state design of steel structures" (CSA 2001) and in the "Recommended LRFD Guidelines for the Seismic Design of Highway Bridges" (MCEER/ATC2003).