Study on system transformation method of self-anchored suspension bridges using the cable-stayed-to-suspension approach

To meet a demand for rapid construction of self-anchored suspension bridges over navigable channels with restricted site conditions, the Cable-Stayed-to-Suspension (CSS) method presents a promising solution. To clarify the influence of relevant construction parameters and key factors on the system transformation process of the CSS method, this paper investigates its characteristics, control factors, and control conditions, forming a comprehensive construction analysis framework. Taking an in-progress self-anchored suspension bridge as an engineering case, three feasible system transformation schemes are proposed based on the target profile of the temporary cable-stayed structure and the sequence of hanger tensioning and stay-cable removal. The schemes are comprehensively evaluated in terms of construction economy, safety, operability, and duration via construction process simulation analysis. The results indicate that the CSS method demonstrates the advantages of minimal traffic and environmental impact over conventional construction methods. Adopting the girder profile without the second-stage permanent load as the target profile of the temporary stayed-cable bridge effectively reduces the required length of hanger extension rods and the risk of hanger–duct collision, and tensioning the hangers before removing the stay cables avoids construction overlap and reduces construction difficulty. The proposed method and conclusions provide practical solutions for similar bridge construction.