Road Roughness and Its Effects on the Infrastructure Caused by Dynamic Wheel Loads

The intention of this paper is to shed light on the interaction between road roughness and the resulting road damage caused by static and dynamic wheel forces. For this purpose several trucks have been mathematically modeled as multi-body systems in great detail. The models are based on actual data of the truck industry, taking concern of geometric details as well as non-linear behavior, such as Coulomb damping in leaf springs and characteristic curves of springs and dampers. In order to describe the relation between road roughness and its effects on road damage in a mathematical manner, the first chapter of this paper deals with the description of the road in terms of the power spectral density. The basis of this mathematical approach is the longitudinal profile of both the left and right wheel track. Three spectral quantities are used to describe the road: the amplitude characteristic, the frequency characteristic and the coherence between the left and right wheel track. Assuming that road damage depends on the fourth power of the instantaneous wheel force and the wheel force itself is distributed Gaussian, a relationship to the road roughness can be found. The contribution of this paper to pavement management is that based on this mathematical approach an easy-to-use formula has been deduced that allows to relate road roughness and vehicle dynamics data to road damage by even considering additional and distinct periodic phenomena contained in the road profiles.