Cataloguing stiffness anisotropy of natural sedimentary soils – From clays to intermediate soils

抄録

Natural sedimentary soils often exhibit marked anisotropy from early stages of deformation, in some cases manifesting even a few times greater stiffness in one direction than in another. Capturing this characteristic will lead to more accurate prediction and rational interpretation of ground movements in 2D and 3D problems. However, rigorous assessment of the 'effective-stress-based' stiffness anisotropy in laboratory tests requires considerable skill and expertise, particularly for fine-grained soils, which require slow, stable loading and measuring capabilities allowing full drainage. This study set out to catalogue and demonstrate general typologies of small-strain anisotropy found in naturally sedimented fine-grained soils to offer geotechnical designers a rough guide to stiffness estimation. A mechanical framework and experimental/interpretative innovations to facilitate the above are summarised.