MECHANICAL AND HYDRAULIC BEHAVIOR OF A SOFT INORGANIC CLAY TREATED WITH LIME

A comprehensive series of laboratory tests was conducted on an inorgan ic clayey sediment in order to predict the mechanical behaviour of dre dged sediments used in reclamation projects. The soil used was a Louis eville clay, which was mixed with various quantities of lime (0-10%) a nd had a varied water content (122-650%). Tests were carried out with special large cells and standard oedometers to look at both the compre ssibility and the hydraulic conductivity. Once pozzolanic reactions ar e begun, for a given curing time, a linear relationship between precon solidation pressure and lime concentration is observed. Compressibilit y results indicate that it is possible to define a separate compressio n curve for each lime concentration and curing time. Adding lime will influence the hydraulic conductivity both by flocculation and by the f ormation of secondary minerals. If only flocculation occurs, an increa se in hydraulic conductivity follows. If enough lime is added, the res ulting secondary minerals will create major changes in the micropore n etwork and this will decrease the hydraulic conductivity by up to one order of magnitude. The development of a secondary micropore network a long with the cementation of large flocs induce significant increases in both the liquid and plastic limits. This results in a significant i ncrease in the water sorption potential and higher Atterberg limits.