Traffic vibration damping: the influence of pavement materials constitutive models

Traffic-induced vibrations are a common source of environmental nuisance: they may cause discomfort to people, malfunction of sensitive equipment and damage to buildings. Interaction between vehicle wheels and road surface causes a dynamic excitation which generates waves that propagate in the soil and break up on the foundations of nearby structures. The study of traffic-induced wave’s propagation is very complex due to the number of variables involved and to the complexity of their relationships. Computer simulation is a possibility of a low cost “trial and error” approach; in this context it becomes a good answer to the question. Many wave propagation problems can be solved using the widespread elastic material model, which is based on a linear and path-independent stress-strain law. However pavement materials have a much more complex behaviour, characterized by plasticity and viscosity features. So the search of reliable road pavement material models, easy to be defined and calibrated, becomes very important. In this paper, by means of a finite differences technique, the authors developed a numerical analysis in order to evaluate the effectiveness of some pavement materials constitutive models in traffic-induced vibrations simulation. Their features have been determined, at the first step, by means of lab tests modelling, comparing numerical results and experimental data, and then by simulating a half-space containing the road pavement and the subgrade.