Seismic isolation devices are now commonly implemented in bridges to prevent structural damage during strong earthquakes. Seismic isolation research has focused on structural responses to prove the effectiveness of isolation systems to mitigate seismic effects. However, there is a lack of knowledge on vehicle-seismic isolated bridge interaction (VSIBI). The VSIBI maycontribute significantly to the dynamic behavior of the vehicle and structural systems during a strong earthquake, when heavy trucks, railway locomotives and large impact vehicles are involved. This paper intends to provide a general descriptive approach to the main variables involved in VSIBIdynamics. It includes a review of literature on fundamentals of seismic isolation and on vehicle models and methods of solution. The paper also summarizes the main aspects involved in the VSIBI and concludes with directions for further research. The dynamic behavior of VSIBI systems involves three subsystems: a) the moving vehicle, b) the bridge and c) the isolators. The vehicle and the bridge interact with each other through the contactforces existing between the wheels and pavement or road surfaces. The bridge interacts with the isolators through the method of connection. The dynamics of the interaction of these subsystems is a nonlinear, coupled and time- dependant problem that involves variables such as: vehicle- bridge mass ratio, moving vehicle speed, breaking and acceleration, number of vehicles and crossing of vehicles in opposite directions, pavement roughness and road surface irregularities, effect of tires and suspension systems, excitation characteristics and properties of isolation systems, among others.
Abstract