Title: Seismic Fragility Assessment of Shape Memory Alloy Reinforced Concrete Bridge Piers under Long Duration and Near-Fault Ground Motions
Author(s): Maher AL-Hawarneh, AHM Muntasir Billah, and M. Shahria Alam
Publication: Symposium Paper
Appears on pages(s): 131-159
Keywords: Seismic fragility, Shape memory alloy, Long duration motion, Maximum drift, Residual drift, Bridge pier
In recent years, shape memory alloys (SMA) have drawn significant attention and interests among researchers and structural engineers for diverse civil engineering applications. Superelasticity, shape memory effect, and hysteretic damping are the three major characteristics of SMAs that make them appropriate for bridge engineering applications in high seismic zones. Recent earthquake events have shown the most devastating earthquake loading that structures could experience are the near-fault ground motions. On the other hand, the ground motion duration effect on structural response has attracted a lot of interest over the last decade. This study aims to evaluate the comparative seismic fragility of concrete bridge piers reinforced with SMA rebars and steel rebars in the plastic hinge region under long duration and near-fault earthquakes. The bridge pier is assumed to be part of a lifeline bridge located in Western Canada and has been designed following a performance-based design approach. Fragility analysis has been conducted considering uncertainty in the material properties and the seismic hazard of the site location. Fragility curves are developed using suits of long duration and near-fault motions where each suite contains 20 ground motions. The vulnerability of the SMA-RC bridge piers and steel-RC bridge piers has been evaluated in terms of maximum drift and residual drift as the demand parameters. The outcome of this study indicates how the performance of the SMA-RC bridge pier and steel-RC bridge pier are affected by the duration of ground motion and fault location.