title: Influence of fine particles on the stability of a humid granular pile.
abstract: We have investigated by rotating drum experiments the influence of a small amount of fine particles on the stability of a granular heap. The fine particles are shown to have a strong and ambivalent influence. For low fine particle content, the heap destabilizes by avalanches, and the fine particles tend to fluidize the heap. In contrast, for high fine particle content, they increase the cohesion of the heap, which destabilizes through stick-slip at the drum wall. We interpret and model the fluidification in the avalanching regime, which we show is independent of humidity, by granular lubrication considerations, whereas the stick-slip behavior, highly dependent on humidity, is understood by a solid friction model.
authors.affiliation: Laboratoire de Tribologie et Dynamique des Systèmes, Université de Lyon, École Centrale de Lyon, CNRS UMR 5513, 36 avenue Guy de Collongue, F-69134 Écully, France and Institut Lumière Matière, Université de Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5306, Domaine scientifique de la Doua, F-69622 Villeurbanne, France.
authors.forename: Xixi
authors.initials: X
authors.lastname: Huang
authors.affiliation: Laboratoire de Tribologie et Dynamique des Systèmes, Université de Lyon, École Centrale de Lyon, CNRS UMR 5513, 36 avenue Guy de Collongue, F-69134 Écully, France.
authors.forename: Sandrine
authors.initials: S
authors.lastname: Bec
authors.affiliation: Institut Lumière Matière, Université de Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5306, Domaine scientifique de la Doua, F-69622 Villeurbanne, France.
authors.forename: Jean
authors.initials: J
authors.lastname: Colombani