ABSTRACT
The behaviour of natural sedimentary clay is different from the comparative behaviour of a reconstituted sample due primarily to in-situ ageing. In this paper, the metastability of Holocene clays from six nations was examined by performing a series of undrained triaxial tests on each pair of natural and reconstituted samples. The undrained shear strength cu of the source ground was obtained by shearing each natural sample subjected to anisotropic consolidation with in-situ effective overburden pressure. The cu value of the natural samples reflecting ageing effects was examined with respect to the metastability index, MI(G), proposed by Shibuya (2000). A method for distinguishing the primary source of clay ageing; i.e., secondary compression or interparticle bonding, is also proposed.
