Experimental and Theoretical Study on the Shear Performance of Single-Box Double-Compartment Segmental Box Girder

In this study, the failure mode and mechanism of single-box two-compartment segmental box girders under flexural shear coupling were experimentally studied. Loading tests were conducted on five scaled girders, and the effects of the design parameters on the shear performance were analyzed. The test variables included the loading methods, ratio of internal to external prestressing tendons, and key joint types (vertical and horizontal keys). The test results indicated that different loading methods produce different stress characteristics and damage modes; however, the difference in the ultimate load capacity was negligible. The greater the number of internal prestressing tendons, the greater the bearing capacity. The stress increment of the internal bottom prestress reinforcement was great than the external prestressing tendons. Monolithic box girders could maintain approximately 1.8 times as much pressure as segmental box girders. With the increase of shear span ratio, the load carrying capacity of the segmental beam decreases. Vertical key teeth had a slightly higher bearing capacity than horizontal key teeth. Vertical keys are recommended for segmental box girders owing to their excellent structural properties and ease of construction. and the structure. AASHTO can better predict the shear capacity of segmental beams, while the Chinese code is applicable to segmental beams with appropriate hoop ratio.