title: Avalanches in compressed porous SiO(2)-based materials.
abstract: The failure dynamics in SiO(2)-based porous materials under compression, namely the synthetic glass Gelsil and three natural sandstones, has been studied for slowly increasing compressive uniaxial stress with rates between 0.2 and 2.8 kPa/s. The measured collapsed dynamics is similar to Vycor, which is another synthetic porous SiO(2) glass similar to Gelsil but with a different porous mesostructure. Compression occurs by jerks of strain release and a major collapse at the failure point. The acoustic emission and shrinking of the samples during jerks are measured and analyzed. The energy of acoustic emission events, its duration, and waiting times between events show that the failure process follows avalanche criticality with power law statistics over ca. 4 decades with a power law exponent ɛ≃ 1.4 for the energy distribution. This exponent is consistent with the mean-field value for the collapse of granular media. Besides the absence of length, energy, and time scales, we demonstrate the existence of aftershock correlations during the failure process.
authors.affiliation: Departament d'Estructura i Constituents de la Matèria, Facultat de Física, Universitat de Barcelona, Diagonal 647, E-08028 Barcelona, Catalonia, and INP Grenoble, 38031 Grenoble Cedex 1, France.
authors.forename: Guillaume F
authors.initials: GF
authors.lastname: Nataf
authors.affiliation: Departament d'Estructura i Constituents de la Matèria, Facultat de Física, Universitat de Barcelona, Diagonal 647, E-08028 Barcelona, Catalonia.
authors.forename: Pedro O
authors.initials: PO
authors.lastname: Castillo-Villa
authors.affiliation: Departament d'Estructura i Constituents de la Matèria, Facultat de Física, Universitat de Barcelona, Diagonal 647, E-08028 Barcelona, Catalonia.
authors.forename: Jordi
authors.initials: J
authors.lastname: Baró
authors.affiliation: Departament d'Estructura i Constituents de la Matèria, Facultat de Física, Universitat de Barcelona, Diagonal 647, E-08028 Barcelona, Catalonia.
authors.forename: Xavier
authors.initials: X
authors.lastname: Illa
authors.affiliation: Departament d'Estructura i Constituents de la Matèria, Facultat de Física, Universitat de Barcelona, Diagonal 647, E-08028 Barcelona, Catalonia.
authors.forename: Eduard
authors.initials: E
authors.lastname: Vives
authors.affiliation: Departament d'Estructura i Constituents de la Matèria, Facultat de Física, Universitat de Barcelona, Diagonal 647, E-08028 Barcelona, Catalonia.
authors.forename: Antoni
authors.initials: A
authors.lastname: Planes
authors.affiliation: Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, United Kingdom.
authors.forename: Ekhard K H
authors.initials: EK
authors.lastname: Salje
mesh_terms: D000162:Acoustics; D005898:Glass; D008962:Models, Theoretical; D055585:Physical Phenomena; D016062:Porosity; D012822:Silicon Dioxide
chemical_list: D012822:Silicon Dioxide