Seismic performance and vulnerability analysis of ECC and HSREC bridge piers with high-strength steel bars

The reliability of bridge piers under seismic action is critical to the overall seismic performance of a bridge. RC piers, though cost-effective, are prone to damage due to self-weight, brittleness, and poor crack resistance, leading to steel corrosion and reduced load capacity. To address these limitations, this study introduces an HSREC (High-Strength Reinforced Engineered Cementitious Composite) pier system utilizing ECC materials and high-strength reinforcement to enhance seismic performance. Nonlinear seismic models were developed in OpenSees and validated experimentally to analyze the seismic responses of RC, REC, and HSREC piers under varying reinforcement strengths and replacement rates. The analysis reveals that HSREC piers exhibit improved bearing capacity and displacement compared to traditional RC piers, leading to enhanced seismic resilience. Additionally, the replacement rate of high-strength steel bars was found to be a critical factor in improving energy dissipation and reducing vulnerability. The study further demonstrates that under high-intensity earthquakes, the top displacement of REC and HSREC piers was notably lower than that of RC piers. For rare seismic, the probability of severe damage was significantly reduced for both REC and HSREC piers, underscoring the substantial improvements in seismic resilience. These findings underscore the potential of integrating ECC and high-strength steel reinforcement as a promising strategy to enhance the safety, durability, and seismic performance of bridge piers in seismic-prone regions.