Mechanical Calculation of Flat Steel Box Girder of Long Span Cable-Stayed Bridge

The flat steel box girder was designed for the main girder of Sutong Bridge with a main span 1 088 m.In this paper,the link finite element and mixed finite element methods are respectively used to calculate the internal force of the box girder,the plate stress of the girder has therefore been obtained and the results of calculation by the two kinds of the methods are compared.The results show that the mixed finite element method can fairly truly represent the plate stress of the main girder,especially can directly represent the stress variations of the top plate under local wheel load and the non-uniformity of the main girder stress distribution transverse to the Bridge.