Seismic Pounding Response of a Single-Span Simply Supported Skew Bridge Based on Shaking Table Tests

To investigate the seismic pounding response characteristics of a single-span simply supported reinforced concrete skew slab bridge and evaluate the applicability of different pounding models, shaking table tests were conducted on a 45° skew bridge, and a finite element model was established using SAP2000. The Kelvin and Hertz-damp models were compared under different pounding stiffness values (0.1–0.5k). The experimental results indicate that, without pounding, the acceleration response exhibits a pronounced dynamic amplification effect, while longitudinal and transverse displacements are larger on the acute side than on the obtuse side, accompanied by slight in-plane rotation of the girder. When pounding is considered, the bridge exhibits altered in-plane rotational behavior, which is restrained by the abutment. Meanwhile, the acceleration response is significantly amplified, with peak accelerations reaching 5–22 times the input peak ground acceleration (PGA), whereas the longitudinal displacement decreases and the in-plane rotational response is restrained. The numerical results demonstrate that the Hertz-damp model can reproduce the main response characteristics observed in the experiments. The quantitative error comparison indicates that stiffness values of 0.2–0.3k provide a reasonable balance between acceleration and displacement accuracy. Under the experimental and numerical conditions considered in this study, 0.2k can serve as a reference value within the investigated stiffness range. These findings provide a reference for selecting appropriate pounding models and pounding stiffness parameters in the seismic analysis of skew bridges.