DENG Wenqin1, 2, MIAO Chengxiang1, ZHANG Qing3, ZHANG Lei1, GU Jiancheng1
Journal of Vibration and Shock. 2026, 45(18): 245-256.
To improve the seismic performance of socket-connected precast bridge piers and reduce the reliance on large embedment depths, a socket connection with an embedded steel tube at the bottom of the pier column is proposed. Five scaled specimens were designed and fabricated, and quasi-static cyclic tests were conducted to comparatively investigate the seismic performance of cast-in-place piers, conventional concrete shear-key socket-connected piers, and embedded steel tube socket-connected piers, in terms of failure modes, hysteretic behavior, backbone characteristics, cumulative energy dissipation, stiffness degradation, and residual displacement. In addition, finite element models were established to analyze the influence of embedment depth on the seismic performance of embedded steel tube socket-connected piers. The results indicate that plastic deformation of the cast-in-place and shear-key socket-connected specimens is mainly concentrated at the column base and the pier-cap connection region. In particular, the shear-key socket-connected specimens exhibit pronounced interface shear failure, significant pinching in hysteretic loops, and relatively poor cumulative energy dissipation and stiffness retention. In contrast, for the embedded steel tube socket-connected piers, the plastic hinge is distinctly shifted upward to the vicinity of the top of the embedded steel tube, interface damage is significantly alleviated, hysteretic curves become fuller, and post-peak degradation of the backbone curves is more gradual. Their peak load capacity, ductility coefficient, and cumulative energy dissipation are all significantly higher than those of conventional socket-connected piers, reaching a level equivalent to or even superior to that of cast-in-place piers. The use of shear studs or circular reinforcement at the embedded steel tube interface has little influence on the seismic performance. When the embedment depth exceeds 0.5D, the seismic performance indices of the piers tend to stabilize, and further increases in embedment depth result in no significant improvement. Considering both seismic performance and engineering economy, the minimum rational embedment depth for embedded steel tube socket-connected precast bridge piers is recommended to be 0.5D.
