Life Cycle Thinking–Based Decision Making for Bridges under Seismic Conditions. II: A Case Study on Bridges with Superelastic SMA RC Piers

Abstract

Bridges reinforced with superelastic shape memory alloys (SMAs) demonstrate improved performance under earthquake excitations. In general, the capital investment for a bridge reinforced with SMAs is higher due to their high cost and special workmanship requirement. However, when accounting for postearthquake repair and maintenance costs and environmental impacts, SMA-reinforced bridges can deliver significant economic and environmental advantages over conventional structures in the long run. Based on a life cycle thinking–based decision support framework developed in a companion paper, this study thoroughly evaluated the life cycle seismic performance of a bridge reinforced with an SMA considering three different reinforcement configurations. Fragility analyses were conducted for each reinforcement configuration of the SMA-reinforced concrete (RC) bridge to assess its seismic vulnerability. A life cycle cost (LCC) assessment was performed to determine the economic impacts during their service life. Additionally, cradle-to-grave life cycle assessment (LCA) was done using SimaPro to assess the environmental impacts. Using the outcomes of the these assessments, the overall life cycle performance of the novel bridges was compared with a similar bridge reinforced with conventional steel. The results showed that the SMA-reinforced bridges presented a better seismic life cycle performance compared with a conventional RC bridge from a seismic performance and economic perspective. However, the conventional bridge showed a better overall score from an eco-friendly approach.