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

摘要: Precast concrete segmental girders have been widely used in prefabricated bridges due to its superior mechanical properties. However, the joints between the segmental section significantly impact the full structural performance of segmental bridges. In this paper, failure mode and mechanism analysis of single box two-compartment segmental assembled box girder under flexural shear coupling were experimentally studied. Loading tests were conducted on five scaled girders, the effect of design parameters on shear performance was analyzed. Test variables include loading methods, the proportion of internal to external prestress tendons, and key joint types (vertical keys, horizontal keys). Test results showed that different loading methods led to different stress characteristics and damage modes, however the difference in ultimate load capacity was negligible. The greater the number internal prestress tendons, the greater the bearing capacity. Internal bottom prestress reinforcement had a stress increment that was approximately 1.2-1.6 times that of exterior prestress tendons. The number of external prestress tendons have little effect on the ultimate shear strength of segmental girder. Monolithic box girders were capable of maintaining around 1.8 times as much pressure as segmental box girders. Vertical key teeth have a slightly higher bearing capacity than horizontal key teeth. Vertical keys, rather than horizontal keys, were recommended for use in segmental box beams for ease of construction. The Chinese code behaved better in the calculation of shear strength for segmental girders predominantly prestressed with internal tendons. While the …