Unstrained length-based methods determining an optimized initial shape of 3-dimensional self-anchored suspension bridges

Two robust methods, a Generalized Target Configuration Under Dead Loads (GTCUD) method and a simplified analytical method are developed for 3D analysis of suspension bridges. These methods provide an optimized initial state for 3D suspension bridges under dead loads. The current study makes application to 3D self-anchored suspension bridges with spatially curved main cables and initial cambers of the main girder. Furthermore, the unstrained length method (ULM) based on the unstrained lengths is applied to the bridge structure using two procedures. Finally, it is demonstrated through a bridge example having vertical cambers that the proposed analysis methods can indeed provide an optimized initial solution by showing that both schemes lead to practically identical initial configuration with localized small bending moment distributions.