Secondary Consolidation and Strength of a Clay

The undrained strength and stress path of a soft marine clay subjected to different periods of secondary consolidation under isotropic stress was examined. The phenomenon of buildup of pore-water pressure has been shown to be due to the arresting of secondary compression. The effect of this phenomenon on the undrained strength and stress path was also studied. The results have been explained using the Cam-clay model. It is concluded that secondary compression would cause increase in undrained strength and stiffening of the stress-strain characteristics of bay mud, while the effect of the pore-water pressure buildup was to produce steeper undrained stress paths at small strains only.