Control of Seismically Excited Cable-Stayed Bridge Using Resetting Semiactive Stiffness Dampers

Abstract

Cable-stayed bridges are prone to exhibit large amplitude oscillations because of their large flexibility, small mass, and small inherent damping. Hence, the reduction of seismic or wind-induced vibration of cable-stayed bridges is vital for their safety and serviceability. In this paper, a resetting semiactive stiffness damper (RSASD) is used to control the peak dynamic response of a recently developed benchmark problem on a cable-stayed bridge subject to earthquakes. The model of the benchmark cable-stayed bridge is based on the actual cable-stayed bridge that is under construction on Cape Girardeau, Mo. The prime aim of this study is to investigate the application of protective devices, such as semiactive and passive dampers, in reducing the displacement of the deck as well as base shear and moments at the base of the towers. In this research, the applications of the RSASD as well as passive viscous and fluid dampers to the benchmark bridge problem have been investigated. Numerical simulations are conducted by installing RSASD devices as well as passive viscous and friction dampers between the pier and the deck of the bridge. Numerical results clearly indicate that the displacement of the deck, and shear and moments at the base of the towers, are reduced substantially by installing these protective devices. In particular, energy dissipating capabilities and performance of the RSASD are quite remarkable. It is shown that the RSASD is quite effective in reducing peak response quantities of the bridge to a level similar to that of the sample active controller. A further reduction in response quantities can be achieved by using the RSASD in a combination of passive viscous dampers.