Abstract:
To meet the development trend of rapid bridge construction and post-earthquake functional recovery, a new type of posttensioned precast segmental concrete-filled double skin steel tubular (CFDST) bridge pier featuring low damage and self-centering capacities was developed and the seismic design method was investigated. Based on the damage and failure mechanisms of such piers, five seismic performance levels are defined. The lateral drift ratio \theta _\textdr and residual drift ratio \theta _\textR are adopted as key design indicators in line with the concept of seismic resilience. The quantified relationship between the performance levels and indexes are established through cyclic lateral loading tests and through numerical analysis results. A performance-based seismic design method is proposed, and detailed design procedures are illustrated with representative examples. The method is validated via nonlinear time-history analyses. Research results demonstrate that the posttensioned precast segmental CFDST bridge pier meets the prescribed seismic performance levels in terms of both maximum and residual displacement responses. Moreover, controlling the residual drift ratio during the design process significantly enhances the seismic resilience of the bridge pier.