title: Overshoot effect in the Janssen granular column: a crucial test for granular mechanics.
abstract: We present experimental results on the mechanical behavior of static granular assemblies confined in a vertical column. Our measurements confirm the universal Janssen scaling for the stress saturation curve. We show consequently, in the context of isotropic elasticity, a relation between the Poisson ratio and the granular packing fraction. Moreover, using a systematic study of the overshoot effect created by a top mass equal to the saturation mass, we show behaviors that are reproduced qualitatively by isotropic elastic materials but of a spectacular amplitude in the case of a granular assembly. These experimental results are strong tests for any theory of granular matter.
authors.affiliation: Laboratoire des Milieux Désordonnés et Hétérogènes, CNRS UMR 7603, Université Pierre et Marie Curie, Paris, France.
authors.forename: G
authors.initials: G
authors.lastname: Ovarlez
authors.forename: C
authors.initials: C
authors.lastname: Fond
authors.forename: E
authors.initials: E
authors.lastname: Clément