Lateral Isolation System of a Long-Span Cable-Stayed Bridge with Heavyweight Concrete Girder in a High Seismic Region

Abstract

AbstractThis paper primarily introduces a new lateral isolation system proposed for the seismic control of a long-span cable-stayed bridge, namely, the Yongning Yellow River Bridge, with high seismic activity and a heavyweight concrete girder. Elastic cables (used in pairs to provide a uniaxial tension/compression constraint) in association with a fluid viscous damper (FVD) for supplemental energy dissipation were employed to form a new lateral isolation system at the girder–tower connections. The cable pairs provided the essential lateral stiffness in service conditions, the desired flexibility and sufficient deformation capacity for seismic isolation, and the ability to recenter the girder following an earthquake. At the pier locations, buckling restrained braces (BRBs) were used for lateral isolation of the piers. A three-dimensional nonlinear finite-element model was developed, and three lateral earthquake-resisting systems (i.e., the traditional fixed system, an isolation system using steel dampers, ...