Model experimental study of shear lag effect on the girder of a cable-stayed bridge

The purpose of this study is to find out the shear lag effect at bridge deck of a concrete cable-stayed bridge during cantilever construction. The girder of the bridge has two small triangulate boxes at each side. A sectional model experiment of scale 1:20 with organic glass has been carried out. The shape and the boundary conditions of the experiment model are similar to the real bridge. Stress distributions at typical sections are obtained. Therefore the shear lag coefficient can be figured out. Theoretical stress distributions of sectional model are derived by applying the energy variational principle to the model. The stress distributions of two different methods are similar. This study shows that the shear lag effects are positive under dead loads or the construction loads during cantilever construction.