Strain localization in sand: an overview of the experimental results obtained in Grenoble using stereophotogrammetry

TLDR

Systematic stereophotogrammetric analysis of photographs during drained plane‑strain compression tests enabled precise measurement of deformation and strain fields before, during, and after strain localization, with detailed discussion of the method’s principles, accuracy, and suitability for depicting deformation patterns. The tests revealed that strain localization initiates and evolves with specific shear‑band orientations and thicknesses, exhibits temporary and persistent complex patterns, and alters volumetric behavior within bands, while being influenced by the sand’s initial effective stress, relative density, specimen size, slenderness, and grain size. © 2004 John Wiley & Sons, Ltd.

Abstract

Abstract Experimental results are presented from the extensive program of drained plane strain compression tests on sand carried out in Grenoble over the last two decades. Systematic analysis of photographs of the deforming specimen allowed for measuring deformations and determining strain fields throughout the test, that is: prior to, at, and after the onset of strain localization. The principles, details and accuracy of the procedure are described, as well as its suitability to properly depict the patterns of deformation. Findings concerning the occurrence and progression of strain localization are discussed. The issues of shear band orientation and thickness are addressed, as well as temporary and persistent complex localization patterns, and the volumetric behaviour inside a band after its formation. The influence of such variables as initial state of the sand (effective stress and relative density), specimen size and slenderness, as well as grain size, is discussed. Copyright © 2004 John Wiley & Sons, Ltd