Shear Banding in Cross-Anisotropic Sand Tests with Stress Rotation

Abstract

Shear banding in Santa Monica Beach sand deposited by dry pluviation in hollow cylinder specimens is studied in drained torsion shear tests with rotation of principal stress directions. Each test was conducted with the same, constant inside and outside confining pressure, σr, thus tying the value of \(b = ({\sigma }_{\mathit{2}} - {\sigma }_{\mathit{3}})/({\sigma }_{\mathit{1}} - {\sigma }_{\mathit{3}})\) to the inclination, β, of the major principal stress. Shear bands can develop freely without significant restraint for soft rubber membranes. Strain localization and shear banding were observed in the hollow cylinder specimens, and this created failure conditions in plane strain and in tests with higher b-values. The results indicate the influence of the cross-anisotropic fabric on the stress-strain behavior, on the shear band inclination and on the shape of the failure surface.