Static analysis of cable-stayed bridge with CFT arch ribs

A new type of cable supported bridge, cable-stayed CFT arch bridge, was proposed and its static strength was studied in this paper. Arch ribs consist of concrete filled steel tubes (CFT). CFTs have high resistance against bending moments and compressive axial forces and are ideal as arch ribs. A cable-stayed CFT arch bridge with a main-span of 300 m was designed and the safety of its structural members was checked by the limit state design method. Large deformation analysis was used to obtain sectional forces. The CFT arch ribs and the steel box girders and towers of the designed bridge satisfied the required safety criteria for ultimate design loads. The applied loads were further increased until the bridge collapsed when the arch ribs buckled. The amount of steel required for the cable-stayed CFT arch bridge was significantly lower than that for the cable-stayed bridge. It has been found that the proposed cable-stayed CFT arch bridge is feasible and potentially economical.