Abstract:In view of the demand of 800-m oversized span concrete filled steel tube (CFST) arch bridge, the composite bridge of single-plane double-curved variable cross-section CFST swallow-type arch and self-anchored suspension cable is proposed. The thrust of swallow-type CFST arch bridge and the tension of self-anchored suspension bridge are balanced, which forms a self-balanced structure system. The arch rib structure is the main force, and the self-anchored suspension cable system is the auxiliary force. The both work cooperatively and complement to each other. In addition, using the four-limb spatial truss arch rib structure with the single-plane double-curved variable cross-section CFST, the self-weight of arch rib segment in mid span is reduced, the risk and difficulty of mid-span segment hoisting construction are reduced, and the section size at the arch foot is increased so as to effectively reduce the mass center and stiffness center of the arch bridge structure, and to increase the stability of the composite bridge. This structural type of composite bridge is applied in the actual projects to carry out the engineering parameter design. Based on the established Midas finite element model, the internal force analysis and calculation, the modal analysis and the buckling analysis are carried out to verify the superiority of the structural technical measures.
