Abstract:Due to the requirements of transportation functions and the limitations of terrain conditions, the irregular steel box girder bridges are often installed at the intersections of municipal roads. The irregular structure of steel box girder has the obvious spatial characteristics and complex stress conditions. In order to comprehensively reflect the spatial stress characteristics of the structure, taking a public supporting project of a waste treatment plant in Guangzhou as a research example, aiming at the irregular steel box girder structure at T-intersection, the 3D plate shell element is used to establish the finite element model for the analysis and calculation of structural stress. The results indicate that in the vertical design of T-intersection, in order to reduce the difficulties in structural design and construction, the longitudinal and transverse slopes of the structure at the intersections should be minimized as much as possible. Under the basic combination of the most unfavorable working conditions, the maximum stress on the top and bottom plates of irregular steel box girder is located near the support, and the local stress concentration effect appears. During the design, the steel plates of the top and bottom plates within the support range should be appropriately strengthened, and the support stiffening ribs should be set up. The uneven phenomenon of bridge support reaction force is quite obvious, and some supports may even experience the negative reaction force, which can easily cause support separation. It is necessary to set up the tensile ball supports or the weights. The obtained results can provide valuable experience for the design and calculation of other similar bridge structures.
