Seismic Performance of Prestressed Precast Segmental Bridge Column Under Combined Compression-Bending-Shear-Torsion Loads

Abstract

The prestressed precast segmental bridge columns (PPSBC) have attracted increasing attention in recent years, however, there is a research gap in the mechanical behavior and seismic performance of PPSBC under combined compression-bending-shear-torsion (C-B-S-T) loads. To address this gap, four identical PPSBC specimens named R-0, R-0.16, R-1.4 and R-∞ were designed, and corresponding to the applied torsion-bending moment ratio were 0, 0.16, 1.4 and ∞, respectively. Quasi-static tests were conducted under combined C-B-S-T loading to investigate the seismic performance of these specimens in terms of failure mode, stirrup strain, hysteresis response, stiffness degradation, ductility, energy dissipation capacity and joint behavior. The influence of torsion-bending moment ratio on the seismic performance of PPSBC was also explored. The results demonstrated that the failure mode of columns R-1.4 and R-∞ exhibited torsional failure accompanied by joint rotation and yielding of stirrups, which was different from the bending failure of columns R-0 and R-0.16. The hysteresis curves of columns R-0 and R-0.16 were pinched, while those of columns R-1.4 and R-∞ displayed spindle-like and Z-shaped due to the large torsional load. The torsion-bending moment ratio had a significant effect on the flexural strength, ductility and self-recentering capacity of the PPSBC column. When the torsion-bending moment ratio increased from 0 to 1.4, the flexural capacity of the column decreased by 27.4%, and the displacement ductility coefficient dropped from 6.3 to 3.1. The residual drift ratio of column R-1.4 was more than 1.0%, and much larger than that of columns R-0 and R-0.16. Furthermore, owing to the torsional load, column R-1.4 exhibited obvious joint rotation and enhanced energy dissipation capacity of the column. This study provides valuable insight for the improvement of the design details in related specifications and promotes the engineering application of PPSBC in accelerated bridge construction.