Dynamic response of bridges under moving vehicles

Two different iteration strategies are developed to solve the problem of bridge-vehicle dynamic interaction in the time domain, taking into account the pavement roughness effects. Separate and decoupled mechanical models for the vehicle and the bridge are adopted. The procedure named WTH iterates on the whole time history, can be easily applied with any commercial code and might deal with slight non linearity. The procedure named STS iterates over the single time-step, relies on an ad hoc developed computer code and can be further developed to include the effects of any non linearity in both the structure and the vehicle. Parametric studies are performed, making use of the WTH procedure, on a 3D model of a reinforced concrete simply supported bridge 30.3 m long, and a travelling vehicle modelled as 7-degrees of freedom (DOFs) sys-tems; the effect of road roughness and speed are investigated. The procedure STS, still under development, has been applied to a 1D model of the same bridge (only beam elements), travelled by a force, a mass and simple 1-axle or 2-axle vehicle models, without accounting for the roughness profile effects.