Anisotropic behaviour of a saturated clayey loess

Abstract

Anisotropic behaviour of a saturated clayey loess has been investigated by means of triaxials and oedometers. It was found that the vertically cored samples reached well-defined gross yield points outside the horizontally cored samples in oedometer and isotropic compression. The undrained and drained shear stress of vertically cored samples increases more quickly than that of horizontally cored samples though they finally reach the same values. In the volumetric plane, the critical state lines (CSLs) for vertically and horizontally cored samples were obviously distinguished. For the horizontally cored samples, the CSL is with horizontal asymptotes at low stress levels and is distinctly lower than that of vertically cored samples. At high stress levels they converge due to the elimination of anisotropy. The anisotropic effects identified for soils retrieved from different depths are similar but slowly decrease as the depth increases. Through normalising the stress paths with a reference of intrinsic behaviour of the clayey loess, vertically and horizontally cored samples show a significant difference.