Experimental investigation on the structural behavior of the steel-concrete composite segments of self-anchored suspension bridges

We studied the structural performance of steel-concrete composite segments in a self-anchored suspension bridge through a model test based on the Lecheng Bridge in Lecheng Pioneer District, Boao, Qionghai City, Hainan Province, and refined finite element analysis to ensure the smooth transfer of internal force in steel-concrete composite segments in hybrid girders. First, a partial section 1 ∶4 scaled test model was designed and fabricated in accordance with the principle of stress equivalence between the original bridge and the scaled model. The specimen was then multistep loaded with up to 1.7 times the ultimate limit load. The stress, deformation, and failure modes obtained from the experiment were compared with those acquired from finite element analysis. Finally, a segmental model with a whole section width was established to explore the transmission mechanism of internal forces. Results showed that under load-bearing conditions, the stress distribution in the composite segment was rational, and the structure was safe. Given that the stress in this particular composite segment was highly affected by the hogging moment, the potential failure mode was the slip between the steel and concrete top flanges at the steel-concrete joint section. Prestress tendons were essential for bending moment transmission, whereas other internal forces were gradually transmitted to concrete by the bearing plate and shear studs. These results can provide references for the design optimization and construction control of similar bridges. © 2023 Editorial Board of Journal of Harbin Engineering. All rights reserved.