An experimentally based "bubble' model for clay

In order to extend the Cam clay model an inner kinematically hardening bubble is added in order to match experimentally observed hysteretic response. The new model is found to be quite successful in reproducing patterns of response observed in slow cyclic oedometer and triaxial tests. -from Authors

The influence of water-miscible solvents on the permeability of clay

Centrifuge tests were carried out to determine the effect of 5 different water-soluble chemicals on a thin consolidated disc of clay. The evolution of changes in the clay permeability with time was investigated and other structural changes due to chemical attack were monitored. The findings presented here demonstrate that the permeability of the clay appear to be generally related to the polarity of the chemicals and the dielectric constant, with the exception of Butanol. In the case of Butanol at low flow rate and low stress level, the action of the chemical caused the clay to crack, with a consequent large increase in flow.