In the paper the numerical simulation of two-dimensional flows in problems of interaction of shock waves with layers of dust is performed on the model of two-phase media with regard for the particle collisional dynamics. It shows the development of instabilities of the Richtmyer-Meshkov type and the Kelvin-Helmholtz type on the rough surfaces of layers of particles. Development of the collisional dynamics of particles promotes more intensive dispersion of the layers and damping of the disturbances.