Bearing Capacity Calculation Method of Three-cells Steel Box Section in Arch Rib

In this paper, taking the mesh section at the junction of the main and auxiliary arches of Gongwang bridge as the research object, the local calculation model of the mesh section steel box arch rib is established by using the finite element software ABAQUS, the bearing capacity and section buckling deformation of the mesh section are studied, and the effects of the height ratio of the steel box, the thickness of the middle plate and the number of stiffeners on the section strength are analyzed. The results show that the deformation of the mesh section near the corner is greater than that of the middle part of the plate, and the design of the stiffener near the corner is the key to the design of the mesh section. The strength reduction coefficient of the mesh section is greatly affected by the thickness of the middle plate and the number of middle plates divided by the longitudinal stiffeners of the middle plate. Chinese and Japanese codes are not applicable to the calculation of strength reduction coefficient of eye shaped section; According to the fitting of the parameter analysis results, a calculation formula suitable for calculating the strength reduction coefficient of mesh steel box section considering local buckling is proposed.