Dynamic Behavior of Uplift‐Rocking Tall Bridge Bent Systems: Theoretical Modeling, Verification, and Dimensionless Analysis

Uplift‐rocking systems, characterized by alternating uplift behavior, have emerged as a highly regarded solution for enhancing the seismic resilience of frame piers, such as the bridge bent systems. However, limited attention has been paid to the dynamic response of such systems in different directions. This study presents an analytical investigation into the dynamic behavior and seismic performance of deformable uplift‐rocking tall double‐column bent (UR‐TDCB) systems. A theoretical model incorporating distributed mass effects, as well as geometric and contact nonlinearities, is developed for the system in both the longitudinal and transverse directions. The predictive capability of the proposed model is subsequently validated against an optimized numerical model implemented in OpenSees. Comparison results in terms of the global dynamic responses and local nonlinear behavior demonstrate the accuracy and computational efficiency of the theoretical models. Based on the validated model, the governing motion equations of the UR‐TDCB system in dimensionless domain are derived under the mathematical model of the near‐fault ground motions. Dimensionless rocking spectra analysis is also performed to examine the influences of various structural parameters and ground motion characteristics on the non‐rocking stage, rocking responses, and overturning behavior of the system. Parametric analysis results confirm that enhanced stability in both the longitudinal and transverse directions is achieved with increasing dynamic slenderness and dimensionless diagonal length. Furthermore, the dimensionless mass and damping ratio, typically neglected in the rigid‐body models, primarily govern the uplift conditions and the generalized displacement demand.