Theoretical Analysis of In-Plane Stability of Self-Anchored Suspension Bridges

In self-anchored suspension bridges, the steel stiffening deck is subjected to significant compression stress due to the force transmitted by the main cables. This compressive makes the in-plane stability of self-anchored suspension bridges a critical design consideration. However, the theoretical underpinnings of this stability remain unresolved, primarily due to the lack of robust comprehensive analytical models. To address this gap, this study employs theoretical analysis to investigate the in-plane stability behavior of self-anchored suspension bridges with the developed comprehensive analytical model. The analytical findings are further validated through finite element method, simulations, ensuring a rigorous evaluation of structural performance. The analysis results reveal that the main cables and the suspenders provide elastic supports for the stiffening girder, and the self-anchored suspension bridge is analogous to a prestressed column. The compression force internally exerted on the stiffening girder, resulting from the tensile force of the main cables, would not cause global buckling of the stiffening girder in the vertical direction in the elastic range. However, local buckling of the stiffening girder between suspenders could still occur in self-anchored suspension bridges. The buckling load is determined from the local buckling of the stiffening girder between two adjacent suspenders.