A series of isotropica1ly consolidated undrained triaxial tests have been performed to under stand the response of an artificially cemented marine clay under static compression loading. The investigation highlights the role played by cementation on the stress-strain curve, failure strain, effective stresspath, undrained strength and Skempton's pore water pressure parameter. The results show that the behaviour of a cemented clay is strongly influenced by consolidation pressure. The paper discusses, in detail, the phenomenon of "phase transformation" and its relation to the existence of bisegmented stress-strain behaviour, typical of the cemented clay.
Marine clays are often encountered with good amount of precipitation compounds like carbonates and iron oxides etc.(Bjerrum, 1973; Lefebvre & La Rochelle, 1974). These compounds induce brittle nature and cause apparent overconsolidation through chemical bonding effect This special feature in marine clays, inherited due to its mode of deposition, makes the deformation phenomenon more complex to understand. As of today, the available information dealing with naturally cemented marine clays is rather scarce and inconclusive mainly due to the non-uniform cementation and disturbances during sampling, particularly when the sample is collected from a considerable depth below the sea bed. A number of researchers, in the past, have attempted to understand the behaviour of the naturally cemented clays through artificially cemented specimens, since it allows greater control over important variables. Tavenas et al.(1973) developed a synthetic material With kaolinite, bentonite, cement and water in order to simulate mechanical properties of Champlain clays. Fischer et al. (1978) studied the simple shear behaviour of Drammen clay introducing calcium carbonate into it as the cementing agent The present study undertakes an experimental programme on an artificially cemented Indian marine clay to bringout the effect of cementation on various aspects of the stress-strain behaviour of soft marine clays under undrained loading conditions.
