Influence of pore fluid composition on the mechanical behaviour of a marine plastic clay

This paper describes the results of mechanical tests on an active clay of marine origin. Two sets of triaxial tests were performed on undisturbed samples. Each of them was divided into two parts, the first being immediately tested according to CIU triaxial tests (using distilled water in contact with the specimen). The latter was exposed to a potassium chloride solution (KCl 1M) for different time ranges. At the end of the exposure time also these specimens were forced to failure in conventional CIU tests. The results show that the ion diffusion inside pore water induced a large increase in peak shear strength associated to an appreciable decrease in liquid limit, while water content variation was negligible. Other tests on reconstituted clay have been carried out to evaluate volume change due to ion diffusion through pore water