Optimum Analysis of Main Girder with Box Cross-section Used in Cable-stayed Bridge

Abstract

By using the structural analysis program ANSYS, finite element models are established based on box girder with different thickness of the bottom slab and thickness of the inclined web and inclination of the inclined web for twin-box girders used in cable-stayed bridge. Considering the affections of the adjacent zone out of the girder section, the exerted internal-forces of two-end surface were obtained by the horizontal shaft system analysis. The weight, cable force and pre-stressed force of girder longitudinal, diaphragm transverse and inclined web vertical direction were also considered. Based on the above, the three-dimensional stresses of the box girder with different working situations were analyzed. By the result of above static analysis, some conclusions are given out, and the reasonable proposals on thickness of the bottom slab and thickness of the inclined web and inclination of the inclined web of cable-stayed bridge were proposed. Analysis shows that the stress distributions of main girder are reasonable when the bottom slab thickness is around 30 cm, the inclined web thickness is around 30 cm, and the inclined web inclination is