Investigation on Shear Lag Effects of Extradosed Cable-Stayed Curved Bridge under the Influence of Curvature Radius

Abstract

As a new type of bridge, extradosed cable-stayed curved bridge is widely used in mountainous areas. The box girder bears not only axial pressure, but also a considerable part of moment and shear force. The existence of curvature makes the force state more complex and the spatial stress state uneven. Moreover, the broadening of box girder leads to serious shear lag effect. Based on the engineering background of Longjing River Bridge, the positive stress distribution and shear lag effect in top and bottom slabs of the curved box girder under different curvature radius during the completion phase were studied using FEA method. The research indicated that the difference of shear lag effect between the inside and the outside of the curved box girder would be more serious if the curvature radius decreases under dead load action. The positive and negative shear lag effect would simultaneously appear in the inner and outer sides of the flange plate in one section under the influence of curvature radius. Curvature radius has a greater influence on the top plate than the bottom plate. The shear lag effect coefficient would be calculated as straight bridge when the curvature radius is greater than 800m.