Seismic Performance of Bridge Piers Reinforced with Shape Memory Alloys in Plastic Hinge Region

Abstract

The recent earthquake reconnaissance reports revealed that a large residual displacement had led to the devastation of bridge piers due to serviceability concerns. Shape Memory Alloys (SMA) is the distinctive category of smart materials, which can sustain enormous deformations and reappear to a parent shape after removal of loading or by removal of heat. Replacing the typical steel reinforcement with SMA reinforcement in the potential plastic hinge regions of bridge piers could reduce the residual displacement of a pier. This study is focused on the numerical investigation of circular bridge piers with SMA-based reinforcement in the plastic hinge regions to mitigate the residual displacement. The numerical model of a bridge pier is validated using the experimental results of SMA-reinforced bridge pier. Dynamic time history analyses are performed to compare the performance of SMA-reinforced bridge piers with steel-reinforced bridge piers under the effect of various earthquake ground motions. The results are represented in terms of displacement, base shear, and ductility. Moreover, the influence of several parameters on the performance of bridge piers is investigated, i.e., aspect ratio, axial load ratio, and compositions of SMA. The numerical results have indicated the effectiveness of bridge piers reinforced with SMA by reducing the residual displacement after major earthquake events.