Optimizing seismic performance of self-centering precast concrete bridge columns reinforced with steel and hybrid Steel-BFRP Reinforcement: A parametric study

This study investigates the seismic performance of self-centering precast concrete bridge columns through a comprehensive parametric analysis. A validated finite element model was developed for precast segmental bridge columns reinforced with traditional steel and a hybrid of steel and basalt fiber-reinforced polymer (BFRP) bars. A parametric study was then conducted to analyze the seismic behavior of the columns, focusing on five key variables: axial load ratio, concrete compressive strength, energy dissipation steel bar ratio, the number of column segments, and replacement ratios of steel with BFRP bars. Four key performance metrics) damage distribution, hysteretic load-displacement behavior, energy dissipation capacity, and residual displacement) were evaluated to identify optimal design strategies for enhanced seismic resilience. The results indicate that increasing the axial load ratio enhances lateral resistance by 44 % and reduces residual displacements by 43 %, while maintaining consistent energy dissipation capacity; however, it also exacerbates concrete damage. An energy dissipation steel bar ratio of 0.75 % provides an optimal balance, ensuring sufficient energy dissipation while keeping residual displacements within the permissible limit (below 1.0 %, meeting post-earthquake serviceability targets). A BFRP replacement ratio of 25 % is recommended, as it reduces residual displacements by up to 110 % while maintaining reasonable energy dissipation capacity and acceptable damage patterns. The number of column segments has a negligible impact on structural performance, and selection should be based on practical considerations. The findings underscore the importance of optimizing design parameters to achieve a balance between seismic resilience, self-centering capability, and practical construction considerations.