Primary and secondary compression behavior of dredged clay at low effective stresses

Abstract

This study presents an experimental investigation on the time-dependent compression behavior of dredged clay samples at high initial water contents under lower effective stress. A series of laboratory one-dimensional consolidation tests with or without aging were conducted on dredged clay samples with various initial water contents. Test results showed that initial water content has a significant effect on the primary compression of dredged clay specimen. All dredged clay specimens follow the same decreasing trend in void ratio with time. Compared with the significant decrease in void ratio in the primary consolidation stage, void ratio decreases less significantly with time in the secondary consolidation stage and tends to level off. The aging strain will not continue increasing as the increase in initial water content more than two times the liquid limit. Aging strain of specimens at different initial water contents consistently increase linearly with the increasing time. The value of secondary compression index is influenced by both aging time and initial water content. It consistently reduces with increasing aging time yet increases with increasing initial water content. We should fully consider the effect of initial water content and aging time on the secondary compression index to predict the secondary compression settlement.