Torsional Shear Behavior of Anisotropically Consolidated Sands: Fid-Bau Portal

Torsional Shear Behavior of Anisotropically Consolidated Sands

Georgiannou, V. N. / Konstadinou, M.

Abstract

This study addresses the effects of anisotropic consolidation on sand behavior by comparing the detailed response of undrained torsional shearing of two sands isotropically and anisotropically consolidated to a range of consolidation stresses and relative densities. Anisotropic consolidation does not appear to alter the mobilized angle of shearing resistance at failure and phase transformation during torsional loading. However, anisotropic consolidation greatly affects the response of the two sands; flow deformation was observed for anisotropically consolidated loose specimens in contrast with limited flow deformation exhibited by their isotropically consolidated counterparts. For the specimens exhibiting brittleness, the instability line is well defined for both isotropically and anisotropically consolidated specimens and it appears to have the same slope in a Mohr-Coulomb diagram independent of the consolidation path followed. However, differences are observed in the peak strength, strength at phase transformation, and peak stress ratio. A stress level dependency of the stress paths and stress-strain curves is observed for both sands, which is exacerbated at higher consolidation stress levels for anisotropically consolidated specimens. Finally, the stiffness variation for both isotropically and anisotropically consolidated specimens over a range of strains is presented herein.