  Ripples or corrugations are common phenomena observed in unpaved roads in
less developed countries or regions. They cause several damages in vehicles
leading to increased maintenance and product costs. In this paper, we present a
computational study about the so-called washboard roads. Also, we study grain
segregation on unpaved roads. Our simulations have been performed by the
Discrete Element Method (DEM). In our model, the grains are regarded as soft
disks. The grains are subjected to a gravitational field and both translational
and rotational movements are allowed. The results show that wheels' of
different sizes, weights and moving with different velocities can change
corrugations amplitude and wavelength. Our results also show that some
wavelength values are related to specific wheels' speed intervals. Segregation
has been studied in roads formed by three distinct grain diameters
distribution. We observed that the phenomenon is more evident for higher grain
size dispersion.
