Stress distribution in sandpiles - A variational approach

Two variational closure models are proposed in order to describe stress distribution and arch formation in sandpiles located on a rigid base. The maximum strength and the maximum entropy closures are shown to yield the normal stress minimum below the pile apex. Stress distributions in sandpiles are determined numerically. The force fluctuations in a model regular granular assembly are studied by Monte Carlo simulation method. A dependence of the level of the fluctuations vs. the macroscopic stress state is determined.