Replacement of the Fire-Damaged Long Suspenders of the Runyang Suspension Bridge

Abstract

Suspenders are key components of suspension bridges and are prone to corrosion, fatigue and deck fires, resulting in damage or fracture. It is necessary to study the emergency replacement technology for suspenders. In this study, a long suspender replacement device was designed for the Runyang Suspension Bridge after studying the configuration of a fire-damaged suspender anchorage structure. The proposed suspender replacement technology removed the damaged suspender with the pin shaft under zero stress instead of the traditional method with the suspender under zero stress. A finite element (FE) model was established to simulate the behavior of the suspension bridge during the suspender replacement process. The change rules for typical and key parameters, such as the temporary suspender force, replaced suspender force, and vertical displacement of the main cables and stiffening girders, are presented. Furthermore, the force monitoring data on the temporary and replaced suspender were recorded during the entire construction process without interrupting traffic. The results show that the changing trend between the FE analysis results and the measured results is consistent, and the method is safe and of little influence to the bridge.