Seismic Performance of Steel-SMA Reinforced Columns: Numerical Investigation

Abstract

The residual displacement of a bridge column governs its functionality after a severe earthquake. A box girder bridge was selected as a case study. Pushover analysis, quasi-static cyclic analysis, incremental dynamic analysis and fragility analysis were conducted to compare the seismic performance of the reinforced concrete column, the unbonded prestressed reinforced concrete column (UBPRC column) and the unbonded prestressed reinforced concrete column using superelastic shape memory alloy (UBPRC-SMA column). The threshold loading plateau axial load ratio was recommended in designing a UBPRC-SMA column, thereby ensuring the self-centering performance of a bridge column with fewer superelastic SMA bars. The self-centering performance was considered in the fragility analysis, and the results show that the UBPRC-SMA column suffers the least damage for the collapse damage state.