Three‐Dimensional Behavior of Sand with Anisotropic Fabric

Abstract

The three‐dimensional, drained stress‐strain and strength behavior of Cambria Sand prepared in cubical specimens with cross‐anisotropic fabric was studied using triaxial compression, plane strain, and cubical triaxial tests with independent control of the three principal stresses. All specimens were loaded under conditions of principal stress directions fixed and aligned with the directions of the material axes. For comparable test conditions, the major principal strain was smallest and the rate of dilation was highest when the major principal stress acted perpendicular to the long axes of the sand grains. The opposite extremes were obtained when the major principal stress acted parallel to the long grain axes. The effects of initial cross‐anisotropic fabric were mainly observed in the prefailure stress‐strain behavior, whereas sufficient changes in the fabric had occurred at large strains to produce failure conditions which resembled those observed for isotropic sands. The three‐dimensional failure surface could for practical purposes be modeled by an isotropic failure criterion.