K0 consolidation of undisturbed clays by means of triaxial cell

Abstract

It is well realized that the in-situ K0 stress condition of undisturbed soil samples should be reproduced in the laboratory test in order to inspect the mechanical properties of soil properly. In this study, an automatic triaxial testing system was newly developed, in which triaxial tests on undisturbed clay samples after reproducing the in-situ K0 stress condition can be carried out in a practical manner. According to the results of the tests with this system, it was made clear that the measured K0-value was largely affected by the compressibility of side drain paper and that the correction was necessary in order to reproduce the in-situ stress condition with the proper K0-value. The initial isotropic consolidation pressure at which the control of K0 condition started also had an important effect on the final K0-value. It is recommended that one sixth or one eighth of the preconsolidation pressure should be used as the initial isotropic consolidation pressure.