Shear Band Characterization of Triaxial Sand Specimens Using Computed Tomography
Batiste, SN
Laboratory for Atmospheric & Space Physics (LASP), 1234 Innovation Drive, University of Colorado at Boulder, Boulder, CO 80303

Alshibli, KA
Department of Civil and Environmental Engineering, 3505C CEBA Building, Louisiana State University and Southern University, Baton Rouge, LA 70803

Sture, S
Campus Box 428, University of Colorado at Boulder, Boulder, CO 80309-0428

Lankton, M
Laboratory for Atmospheric & Space Physics (LASP), 1234 Innovation Drive, University of Colorado at Boulder, Boulder, CO 80303

(Received 7 July 2003; accepted 11 May 2004)

Abstract
A thorough quantitative analysis of the internal density distribution and strain localization of axisymmetric triaxial sand specimens is presented. Computed tomography technique was used to acquire detailed three-dimensional images of a series of Ottawa sand specimens subjected to Conventional Triaxial Compression (CTC) conditions at very low effective stresses in microgravity and terrestrial laboratories. Analysis tools were developed to quantify the distribution of local void ratio, track the onset, propagation, thickness, and inclination angle of shear bands, and calculate the variation of void ratio within and outside shear bands. It has been found that shear bands initiate in the post-peak strength regime in CTC specimens, where a rather complex pattern of shear bands develops such that behavior is highly influenced by large-scale kinematics of the specimen. Four main deformation patterns were identified and their contribution to the overall volume change of the specimens was quantified.

Keywords:
computed tomography, granular materials, instability, localization, sand, shear band inclination (orientation) angle, shear band thickness, triaxial compression, void ratio

Paper ID: GTJ12080
DOI: 10.1520/GTJ12080

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Author Batiste, SN Affiliation Laboratory for Atmospheric & Space Physics (LASP), 1234 Innovation Drive, University of Colorado at Boulder, Boulder, CO 80303 Author Alshibli, KA Affiliation Department of Civil and Environmental Engineering, 3505C CEBA Building, Louisiana State University and Southern University, Baton Rouge, LA 70803 Author Sture, S Affiliation Campus Box 428, University of Colorado at Boulder, Boulder, CO 80309-0428 Author Lankton, M Affiliation Laboratory for Atmospheric & Space Physics (LASP), 1234 Innovation Drive, University of Colorado at Boulder, Boulder, CO 80303 Author Batiste SN, Alshibli KA, Sture S, Lankton M Title Shear Band Characterization of Triaxial Sand Specimens Using Computed Tomography Symposium , Committee on