Rolling supports system with magnetic damping for isolation seismic of highway bridges

Seismic isolation systems are used to uncouple structures from their foundation, reducing the transmission of seismic energy that occurs during an earthquake. In this way, the potential damage is mitigated. Currently, several isolation systems have been developed. Some of them include sliding friction surfaces and high resistant elastic rubbers. In addition to providing lateral flexibility, these devices contain energy dissipation mechanisms. An alternative is rolling isolation system with supplemental energy dissipation. This paper evaluates the performance of the rolling supports system with magnetic damping applied to a highway bridge. First, the equations of motion for a seismic isolation bridge are obtained by using nonlinear two-degree-of- freedom system. Then, the effectiveness of the system is studied through the acceleration response of a highway bridge with rolling supports system under near-field ground motions. To represent the real earthquake records, the analytical pulse model proposed for He and Agrawal (2008) was implemented. Finally, a discussion about effectiveness and feasible of seismic isolation system is presented.