The Analyses Of Shearlag Effect Of Longhua Songhua River Super Bridge

The box beam had great ability of resisting flexure and torsion.Moreover,it was light and had great span and was convenient to construct,so it could be widely used in all kinds of bridge structures especially in those huge and broad bridge.When the box girder in the longitudinal bending deformation,flange plate plane shear deformation cause the longitudinal bending stress distribution uneven,which happened shear lag effect,the characteristics of the beam should be taken into account in the actual project.However,the factors of the box beam shear lag effect does not have a unified theory,the domestic design specifications of box beam shear lag analysis and calculation did not make specific provisions,so the box beam shear lag effect is one of the concern engineering topics.This article take the Longhua Songhua river super bridge as the research object,analyzed shear lag effect in variable cross-section box beam of continuous semi-rigid frame bridge.The main works are as follows.1.Briefly introduced the reasons of shear lag effect happens.2.According to the principle of three bar simulation method,deducing the differential equations.3.Using the three bar simulation method to calculate and analysis the shear lag effect at the time of cantilevered stage and self-weight after the closure of the Longhua Songhua river super bridge.4.Using finite element software ANSYS to model and simulate,and to analysis the shear lag coefficients in conditions of cantilevered stage and the stage of after the closure, stagnated the coefficients and obtains distributing rule of the shear lag effect.5.Through on-site monitoring,to test and analyze shear lag effect of Longhua Songhua River Bridge.This paper using three bar simulation method,ANSYS modeling and simulation,real bridge test,to contrast,analysis,and summarized the distributing rules of the shear lag in a continuous semi-rigid frame bridge in conditions of cantilevered and the after closure stage. This article has a certain theoretical and engineering reference value.