混合连接预制装配式桥墩侧向变形能力计算方法研究OA

To address the limitation that existing research on the lateral deformation capacity of precast bridge piers predominantly focuses on single connection types,rendering it unsuitable for hybrid-connected precast piers with distinct structural configurations and load transfer mechanisms,a calcula-tion method for the lateral deformation capacity of such bridge piers is proposed.This study investi-gates a precast bridge pier utilizing hybrid connections,specifically,unbonded prestressing tendons,grouted sleeves,and shallow socket connections,employed in the Beijing-Xiong'an Transit Express Line.Based on a full-scale quasi-static test,a refined numerical model is established using ABAQUS,incorporating concrete damage,bond-slip behavior of longitudinal reinforcement,and the mechanical characteristics of unbonded prestressing tendons.Through parametric sensitivity analysis,the influence of various design parameters on the Plastic Hinge Length(PHL)of the precast bridge pier is elucidated.Furthermore,an empirical formula for calculating the equivalent PHL applicable to such piers is pro-posed via nonlinear regression analysis.Building upon the equivalent plastic hinge theory,a method for calculating the lateral displacement at the pier top is proposed,accounting for both the flexural deforma-tion of the pier body and the rotational deformation of the socketed section.The results indicate that the PHL increases with greater superstructure dead load,shear span ratio,longitudinal reinforcement ratio and yield strength,initial prestressing force,and socket depth.Conversely,it decreases as concrete strength and sleeve length increase.The equivalent PHLs and the load-displacement curves calculated using the proposed method align well with the experimental results,exhibiting an ultimate displacement prediction error of merely 3.96％.The results provide a theoretical reference for the deformation capacity evaluation and seismic design of precast bridge piers with hybrid connections.