Evaluating different yield surface assumptions in representing constant axial load tests which follow anisotropic consolidation

The present study utilizes a series of anisotropic consolidation tests followed by a decrease of the mean stress under constant axial load to define the yield locus of anisotropically consolidated soil samples and to evaluate the ability of different yield surface shapes in accommodating the observed behaviour. Nine different axial load tests are used, including three different water contents and three different consolidation stress obliquities. For each test, the “end of compression” and the “failure initiation” stress states are assumed to define the yield locus. Two isotropic and two anisotropic ellipsoids are used to describe the experimentally determined yield points. It proves that a distorted ellipsoid is superior in capturing the behaviour, provided that its aspect ratio is handled as an independent variable.