Advances in Computed Tomography for Geomaterials: GeoX 2010

Sand Deformation at the Grain Scale Quantified Through X-ray Imaging

G. Viggiani — P. Bésuelle — S. A. Hall — J. Desrues

Laboratoire 3S-RUniversity of Grenoble – CNRS38041 [e-mail]

ABSTRACT. This paper presents a study of localized deformation processes in sand with grain-scale resolution. Our approach combines state-of-the-art x-ray micro tomography imaging with 3D Volumetric Digital Image Correlation (3D V-DIC) techniques. While x-ray imaging and DIC have in the past been applied individually to study sand deformation, the combination of these two methods to study the kinematics of shear band formation at the scale of the grains is the first novel aspect of this work. Moreover, we have developed an original grain-scale V-DIC method that enables the characterization of the full kinematics (i.e. 3D displacements and rotations) of all the individual sand grains in a specimen. We present results obtained with both “continuum” and “discrete” DIC on Hostun sand, and a few preliminary results (continuum DIC only) recently obtained on ooid materials, which are characterized by spheroidal, layered grains.

 

KEYWORDS: strain localization, granular media, in-situ x-ray tomography, 3D volumetric digital image correlation

1. Introduction

Shear banding, the localization of deformation into thin zones of intense shearing, is a phenomenon commonly observed in sand and ...