Time-dependent combined index seismic resilience assessment of shear-critical RC bridge piers with height-varying corrosion

A comprehensive probabilistic assessment framework and methodology for evaluating the seismic resilience of in-service bridge structures have been developed, utilizing a combination of the maximum drift ratio (MDR) and residual drift ratio (RDR) indicators. This approach effectively addresses non-uniform corrosion on structural facades and the consequential shift in failure modes due to corrosive damage. To illustrate its applicability, a seismic resilience analysis was conducted over the life-cycle of a RC bridge. Based on the time-varying seismic fragility analysis, a further assessment was conducted, which encompassed post-earthquake functional loss, the recovery process, and seismic resilience. The research findings emphasize that corrosive damage significantly diminishes the seismic performance of bridge piers. As the service life progresses, both MDR and RDR gradually increase, demonstrating a positive correlation. Damage probabilities and functional losses obtained through the MDR-RDR indicators exceed those derived from single indicators. Additionally, the functional recovery time based on MDR-RDR indicators consistently exhibits an escalation. As service life and PGA levels increase, the seismic resilience assessed using various indicators displays a declining trend, with a particularly notable reduction rate observed for the MDR-RDR indicator. The results of this study underscore the importance of concurrently considering aging and combined indicators when assessing the seismic resilience of bridge structures throughout their service life. These results provide novel insights for the comprehensive assessment of seismic resilience in structures during service period.