FE Analysis of Suspension Bridges Based on Extended Deflection Theories with Extensible Hangers and Floating Girders

This paper presents extended deflection theories of multi-span continuous suspension bridges and their FE formulations using the energy method. The proposed deflection theories take into account effects of hanger extensibility, free sliding of main cables at the saddle, and floating girders. Suspension bridge elements consisting of main girder, main cable, and tower elements are then introduced and simplified FE formulations are rigorously proposed to solve the extended deflection theories. In order to demonstrate the validity and accuracy of the presented formulation, three/four-span suspension bridge models having regular and floating support conditions of the main girder are analyzed using the simplified FEMs, and the analysis results are compared with those by the unstrained length method, which is a sophisticated FEM. Finally, three virtual earth-anchored suspension bridge models are analyzed to explore the effects of hanger extensibility.