Numerical study of characteristic behavior of steel plate girder bridges

Abstract

The conventional design for a steel plate girder bridge is based on the simple beam and grid theories. As a steel plate girder bridge is a complicated structure consisting of main girders, a concrete slab and a stiffening system, the conventional design does not necessarily reflect the real behavior of a steel plate girder bridge. Against this background, the three-dimensional finite element analyses (FEA) of steel plate girder bridges are conducted in this study, and three levels of stiffening systems are considered. The results thus obtained indicate that cross beams and vertical stiffeners are not playing an important role under vertical load and that vertical stiffeners can suppress the deformation of the web under lateral load as good as cross beams. Therefore, it may be concluded that there is a good chance of removing crossbeams, whereas care must be taken for the further removal of vertical stiffeners, as a steel plate girder bridge without any stiffening system may suffer from rather large deformation under wind load. This study confirms that the conventional steel plate girder bridge design practice, where only cross beams are assumed to distribute loads to main girders, is not necessarily based on the real behavior of the bridge. It further suggests that there is a good chance of removing crossbeams, whereas care must be taken for the further removal of vertical stiffeners because a steel plate girder bridge without any stiffening system may suffer from rather large deformation under wind load.