Shear mechanical behavior of model materials samples by experimental triaxial tests: case study of 4 mm diameter glass beads
Résumé
This paper aims at studying the shear behavior of glass beads samples through experimental triaxial tests as regards the case of 4 mm diameter glass beads. Repeated tests are systematically carried out, together with the evaluation of the repeatability. Study of numerous experimental conditions is performed: compactness state (high/medium density), variable effective confining pressure (p0′ = 50–200 kPa), saturation state (saturated/dry) and surface state (rough/smooth). Specifically, the influence of these parameters on the stick-slip phenomenon is reported. Equivalent study of perturbation on the mechanical response by larger size spherical inclusions is also performed. The experimental findings received from drained triaxial tests classically throw light on the shear behavior of granular media directly dependent on compactness, in addition to the application of effective confining pressure, with a more dilatant behavior with the decrease of the confining pressure. The Rowe’s law is truly verified in experiments. The modification of the surface state of glass beads results into observably different responses on both the deviatoric and the volumetric aspects. It is quite evident that the intensity of stick-slip phenomenon experienced increase with the application of confining pressure and depends on the surface roughness. No noteworthy impact on the mechanical response is taken into observation between the states of entire saturation and dry. Calculation of friction and dilatancy angles are made as well as reported in respect of different experimental configurations. © 2017, Springer-Verlag GmbH Germany.