Experimental evaluation of consolidation behavior of stiff clay lumps in reclamation fill

Abstract

When stiff clay dredged from the seabed is deposited by barge as fill material, large voids exist between the stiff clay lumps in the reclamation fill. One major concern is that the voids may close up upon loading, resulting in a large and sudden increase in the fill settlement. In the present study, an experimental investigation is carried out to examine the behavior of fill made up of dredged stiff clay lumps using a large one-dimensional compression apparatus and a centrifuge modeling technique. The results revealed that much of the inter-lump voids close up during the preloading stage. In addition, the rate of consolidation of the lumpy fill is significantly faster than that of homogeneous clay with the difference in consolidation rate diminishing with increase in loading pressure. The effects of lump shape and size, and original shear strength of in situ clay on the performance of lumpy fill, are also investigated.