An experimental and numerical study on the influence of inherent and induced anisotropy of a fine-grained soil

This study investigates the inherent and induced anisotropy of reconstituted kaolin samples through a series of triaxial tests in both extension and compression under various preloading conditions. Triaxial specimens were extracted from pre-consolidated cylinders either in the vertical or horizontal direction to assess anisotropic behaviour. Additionally, different preshearing steps were applied to examine their influence on inherent anisotropy. Numerical simulations using the modified Cam Clay model and the anisotropic visco-hypoplastic model failed to capture the effects of inherent anisotropy. To address this limitation, the latter model was extended by incorporating a cross-isotropic elastic stiffness formulation. By increasing the number of parameters and model complexity, this study systematically evaluates which parameters and mathematical formulations are essential for accurately describing the stiffness anisotropy of reconstituted fine-grained soils.