Application Study of New Elasticity-Damping Composite Device on Zhuankou Yangtze River Highway Bridge

Abstract

Long-span cable-stayed bridges usually adopt a semifloating system scheme to reduce the internal force of seismic response. However, the seismic measures based on conventional fluid viscous dampers (FVDs) cannot prevent excessive displacements in the beam-ends as well as adverse stress in the members under both dynamic and static cases, especially when the damping is comparatively lower or the beam-ends accumulate displacements due to the configuration of the dampers. To address this issue within reasonable cost, a new type of elasticity-damping composite device was developed for the Zhuankou Yangtze River Highway Bridge in Wuhan, China. This paper presents the merits of the device by introducing its constitution, installation, and working mechanism, as well as mechanical studies in the design process. The device, combining a damping system and a disk spring system, was designed to have restorable elasticity in a specific mechanism. The mechanical model of the device was conceived by estimation of a reasonable connection between the pylon and the deck. Then, the parameters of the model are determined mainly by comparison and parametric studies for a rational combination of strength, stiffness, and damping of the structure. Static finite-element (FE) and nonlinear time history (NTH) analyses are performed in the studies to satisfy the static and seismic demands, respectively. The procedure reveals a comprehensive advantage of the device in framework, damping effects, and static behaviors, followed by the validation analysis in more general cases.