Control of seismically excited cable-stayed bridge using a resetting semi-active stiffness damper

Cable-stayed bridges are prone to exhibit large amplitude oscillations due to the 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. A resetting semi-active stiffness damper (RSASD) is utilized to control the peak dynamic response of a benchmark problem on cable-stayed bridge subject to earthquakes developed recently by S.J. Dyke et al (2000). The model of the benchmark cable-stayed bridge is based on the actual cable-stayed bridge that is under construction on Cape Girardeau, Missouri, USA. The prime aim of the study is to investigate the application of protective devices, such as semi-active 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, we have investigated the applications of resetting semi-active damper (RSASD) as well as passive viscous and fluid dampers to the benchmark bridge problem. 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 those of the shear and moment at the base of the towers are reduced substantially by installing these protective devices