Analysis of Shear Lag Effect in Thin-walled Box Girder

• 1、Department of Bridge Engineering, Tongji University, Shanghai 200092
• 2、Department of Bridge Engineering，Tongji University，Shanghai 200092)

Abstract：Firstly, the principle of the bending load shear lag effect were reviewed, Use software ANSYS for numerical analysis of a thin-walled box girder shear lag effect, compared with numerical solution of literature , the measured and theoretical values, verifyed the correctness of the model. Then through Mechanical characteristics analysis of bending box girder,obtained each factor for shear lag coefficient,and summarized the shear lag coefficient vertical distribution laws along the span.Further analyzed the relationship of Longitudinal distribution of shear lag coefficient and the flange plate shear flow in the case of axial force only and pure bending.Then combined with engineering practice,caculated the case under dead load ,live load and prestressed for comparative analysis. full prestressed structure can reduce the peak of shear lag coefficient.The conclusion was helpful for engineering practice. Finally, discussed shear lag effect of box girder plastic state and draw the appropriate conclusions.

Keywords： bending load prestressed shear lag coefficient vertical distribution plastic stage