Seismic performance of circular concrete-encased steel columns for bridges

Abstract

This paper presents the seismic performance of a bridge with concrete-encased steel columns that include an I-section steel profile encased in concrete. In this research, the potential use of the proposed system in moderate seismic regions is studied. Also, using a model of a bridge made with CSI bridge software, a comparison between reinforced concrete (RC) piers and the equivalent alternative composite system is made in terms of service and damages after seismic hazards. The Canadian code CSA S6-19 design criteria are used to design RC and composite columns based on the performance-based design (PBD) method in which the ground motions are selected and matched with Montreal’s target spectrum. Finally, the effect of using concrete-encased steel sections on the confinement of concrete is discussed and considered in the modeling of plastic hinges. The results show that the composite system can perform as well as the RC column in a lifeline bridge.