Seismic fragility analysis of enhanced SC ‐ UHPC piers adaptive to different seismic intensities zones

Self‐centering (SC) bridge piers effectively mitigate peak seismic displacements and residual deformations, yet their application in high‐intensity zones remains limited by insufficient seismic performance. This study proposes two optimized SC pier configurations: ultra‐high‐performance concrete with carbon fiber‐reinforced polymer tendons (UHPC‐CFRP) for high‐intensity zones, and UHPC‐Steel (non‐bonded prestressed steel‐strand UHPC) for low‐intensity zones. Through OpenSees‐based finite element analysis and seismic fragility evaluations, key findings reveal: Enhanced SC‐UHPC piers match normal concrete (NC) piers in seismic response while exhibiting superior self‐centering capacity. Under rare earthquakes with 1.5 g peak ground acceleration in high‐intensity zones, the SC‐UHPC piers reduced exceedance probabilities by 0.2%–26.7% across four damage states. CFRP tendon activation post‐yielding enables effective displacement control, reducing seismic damage risks by 9.57%–47.24% compared to NC piers. The proposed dual‐configuration system demonstrates adaptable seismic resilience, enabling targeted deployment across varying intensity zones with enhanced safety and recoverability.