Effects of Stable Cable on Ultimate Load-carrying Capacity of Long-span Composite Girder Cable-stayed Bridge with Three Pylons

On the background of a long-span composite girder cable-stayed bridge with three pylons under construction for research, this paper establishes two models of the whole bridge by considering the structural geometric nonlinearity, material nonlinearity and interface slip effect in composite girder, on has stable cables between pylons but the other hasn't, then comparatively studies the failure loads and structural internal forces of the two models to achieve effects of stable cable on the ultimate load-carrying capacity of the cable-stayed bridge. This research shows that the stable cables can strengthen the vertical stiffness of structure and obviously increase the failure load of the bridge, and the internal forces in main girder, middle pylon and stayed cables are smaller and their distributions are more reasonable under the failure load than those in the bridge with no stable cables, so the stable cables can effectively improve the ultimate load-carrying capacity of long-span composite girder cable-stayed bridges with three pylons.