Gasparre, A: Advanced laboratory characterisation of London

This work aims at finding a framework for the London Clay relating the engineering proprieties of this material to its geological features. Results of tests on samples from different depths in their intact and reconstituted states using oedometer and advanced triaxial apparatus are presented. The structure and the nature of the clay from different strata are investigated and correlated with its large and small strain mechanical response. Shallower units show a more open structure and higher clay content than deeper units. Samples from the same units appear to have the same mechanical behaviour and engineering parameters, but differences are found between the different units, which reflect the differences in the nature and structure of clay from each stratum. The behaviour in both compression and shearing seems to be dominated by the structure of the clay as well as by its nature, so that clay from units having a more packed and orientated structure show a stiffer response and higher strengths than the clay from units with a more open structure. The stiffness behaviour of the clay at small and large strains is also presented.