Life-cycle cost assessment of self-centering tall-pier bridges

Abstract

Self-centering (SC) tall-pier bridges show strong potential for application in high-intensity seismic regions because of their excellent recentering ability and rapid post-earthquake functional recovery. However, their more complex structural system and additional components generally lead to higher initial construction costs than conventional reinforced concrete (RC) tall-pier bridges. To evaluate their practical feasibility, this study proposes a life-cycle cost assessment framework that accounts for initial construction cost, operation and maintenance cost, end-of-life cost, earthquake-induced loss, and environmental cost. Based on extensive nonlinear time-history analyses, probabilistic seismic demand models are established, and system-level fragility assessments are performed. The life-cycle costs of SC and conventional RC tall-pier bridges are then systematically compared. Results indicate that the SC tall-pier bridge has lower system fragility at all damage states, reflecting superior seismic resilience and post-earthquake recoverability. It also significantly reduces earthquake-induced economic losses and life-cycle carbon emissions. The initial construction cost ratio and discount rate are identified as the primary factors governing life-cycle economic performance. The SC bridge remains economically advantageous when its initial cost is controlled within 1.31 times that of the RC bridge, while this threshold decreases to 1.15 when a 10% target return is required. Overall, despite a higher initial cost, the SC bridge provides better life-cycle economic and environmental performance.