Local mechanical behavior of flat steel box girder for kilometer-level cable-stayed bridge

By using static load tests and FEM numerical calculation of the whole bridge and local box girder, Sutong Yangtze River bridge, whose span is the longest among the cable-stayed bridges of the world, was taken as an example to investigate the mechanical properties of the main parts of the flat steel box girder in kilometer-level cable stayed bridges. On this basis, a fine finite element model of the welded details in the steel box girder including welded conformation was built with submodel technique to analyze the stress distribution along the weld toe, which was verified through test. The research results indicate that the transverse shear lag effect of the steel girder is significant and the longitudinal stress distributions of the slab and floor beam are non-uniform, with serious stress concentration along the weld toe of the slab beam and its rib wall, which is the key part in fatigue performance research of the whole steel box girder.