Seismic Fragility Assessment of Concrete Bridge Pier Reinforced with Superelastic Shape Memory Alloy

In an attempt to reduce permanent displacement and damage, a hybrid reinforced concrete (RC) bridge pier configuration is considered in the present study. The plastic hinge region of the bridge pier is reinforced with superelastic shape memory alloy (SMA) and the remaining portion with regular steel. This paper focuses on fragility-based seismic vulnerability assessment for a SMA-RC bridge pier considering residual displacement, displacement ductility, and performance criteria as the demand parameters. Fragility curves are developed to assess the relative vulnerability of a SMA-RC bridge pier and a conventional steel-RC bridge pier using probabilistic seismic demand model (PSDM). The fragility curves are developed with a suite of 20 near-fault ground motions using incremental dynamic analysis. The fragility curves provide insight into the failure probability of the bridge piers and aid in expressing the impact of SMA on the bridge pier vulnerability.