PARTIAL-PRESSURE SUPPORTED BY GRANULOMETR IC CLASSES IN A POLYDISPERSE PACKING

A packing of particles subjected to an oedometric compression displays a large distribution of interparticle contact forces. The latter are correlated with the particle size. Using the principle of virtual work , we relate the 'partial' pressure supported by a granulometric class of particles to a purely geometrical problem, namely the compacity of a polydisperse granular medium as a function of its granulometry We ap ply this result in particular to the case of bi-modal packings and we show that the partial pressures are larger for small particles in thre e dimensions, whereas size independence is predicted in two dimensions . Numerical simulations in two dimensions confirm this result.