Abstract
In order to construct a controlled waste disposal site on sandy seabed, bottom sealing by laying artificial sealing geomaterial made of marine clay has been developed. The method to give some necessary shear strength to the sealing material by adding “a small amount of cement” was studied. The conventional cement-treated soil was cracked due to the shear deformation and the hydraulic conductivity was increased. On the other hand, the hydraulic conductivity of clay with addition of a small amount of cement did not change even when subjected to shear deformation more than 20%. However, it should be careful that, with addition of small amount of cement, the hydraulic conductivity became lager than that of clay with no cement, because the void ratio became larger to the same consolidation pressure due to the bonding structure.