Memories in sand: Experimental tests of construction history on stress distributions under sandpiles

We report experiments on piles of cohesionless granular materials showing t he effect of construction history on static stress distributions. Stresses under piles are monitored by sensitive capacitive techniques. The piles are formed either by pouring granular material from a funnel with a small outl et (localized source), or from a large sieve (homogeneous rain). Localized sources yield stress profiles with a clear stress dip near the center of th e pile; the homogeneous rain profiles have no stress dip. We show that the stress profiles scale linearly with the pile height. Experiments on wedge-s haped piles show similar but weaker effects. [S1063-651X(99)51410-4].