Analysis of the influence of supplementary reinforcement on the behavior of reinforced‐concrete two‐pile caps subjected to concentric and eccentric loading

This article examines the behavior of reinforced‐concrete pile caps on two piles under concentric and eccentric loading, with emphasis on the influence of horizontal and vertical supplementary reinforcement on load‐carrying capacity. Although the Strut‐and‐Tie method does not include this reinforcement in the internal equilibrium, it was found to play an important role in crack control and ductility. The study comprised two stages: calibration of three‐dimensional nonlinear numerical models using experimental tests, and a parametric analysis varying the amount and spacing of supplementary reinforcement. The results show that increasing this reinforcement enhanced strength, reduced crack widths, and improved overall structural performance. Eccentric loading decreased load capacity, but the additional reinforcement mitigated this loss, leading to better performance under different loading conditions.