Steel Box Girder Shear Lag On The Bearing Capacity

Over the last decade, with the development of bridge engineering, many domestic and foreign experts and scholars on the shear lag effect of the concrete box beam, from the analytical theory, numerical solution and the model test and other aspects, study in box beam shear lag effect Systematic and respectively, Finally, put forward many new ideas and new theories. For the steel box beam, the flange plate and web plate is generally thin and the bending rigidity is very small, in the steel box beam geometry of large cases, the shear lag effect is more obvious, so the shear lag effect in the actual project can not be ignored, But in China, the study of the steel box girder shear lag effect is not perfect, and many domestic experts and scholars can not create a more sophisticated calculation. This article in the existing research base, through energy variational method and finite element analysis, analyze the shear lag effect of the steel box beam, the main contents include:(1) Elaborate comprehensivly the existing theory and research methods about the shear lag effect, and compared its induction.(2) This article in the energy method derives the analytical solution of the constant section steel box beam about the shear lag effect. On this basis, according to the flange vertical displacement function of the three deduced, this article puts forward beam the theoretical solution type of the shear lag effect on the steel box beam. (3) For example, GuanLei crane on the Lancang river, this article in the energy variation method and the finite element method calculate the shear lag effect of the constant section steel box beam on the Biggest bracket condition.(4) Through the comparation of the finite element analysis results and the variational method results, this article qualitatively analyzed the steel box beam bending stability capacity changes, considing to the shear lag effect.(5) This artcle uses finite element to analyze the steel box beam shear lag effect about stiffener layout and web layout, and obtains some practical conclusions.