Flexural behavior of composite box girders with corrugated steel webs and trusses

The composite box girder with corrugated steel webs (CSWs) and trusses is a bridge structure developed on the basis of traditional box girders with CSWs. In this research, experimental, numerical and analytical studies were carried out to investigate the flexural performance of simply supported composite box girders with CSWs. Two 1:5 scale models of a real bridge were fabricated and tested, including one with concrete filled steel tubes and another with hollow steel tubes. The test results show that the two specimens have good ductility and failed in a ductile manner. The concrete filled inside steel tubes reduces the deflection and increases the yield load. The cross sections of the two specimens basically satisfy the "plane section assumption". Finite element models were also developed for the two specimens and validated based on the experimental results. Afterwards, a parametric study was carried out with the validated finite element models, which shows that the steel ratios and the structure of bottom trusses strongly influences the flexural behavior. At last, a theoretical model is developed to calculate the bending moment of composite beams at the ultimate load.