Gravitational Sedimentation Behavior of Sensitive Marine Ariake Clays

Abstract

It has been well documented that natural marine Ariake clays are sensitive clays. In this study, extensive data of marine Ariake clays are obtained to investigate the gravitational compression behavior for sensitive clays. Analysis results indicate that the compression behavior of remolded Ariake clays is not different from that of other remolded=reconstituted soils. But natural Ariake clays do not follow the gravitational compression pattern reported by Skempton (1970) for natural sedimentary soils. At a given value of effective overburden pressure, the void ratios of natural Ariake clays are almost independent of liquid limits. Most natural Ariake clays lie above the sedimentation compression line proposed by Burland (1990). When the liquid limit is larger than 90% and the ratio of natural water content over liquid limit ranges 0.8-1.1, the natural Ariake clays lie around the sedimentation compression line. In addition, the natural Ariake clay with higher value of the ratio of natural water content over liquid limit lies above the natural Ariake clay with lower value of the ratio of natural water content over liquid limit. Salt removal is the most probable cause for such a phenomenon.

Strength Sensitivity of Marine Ariake Clays

“…Marine Ariake clays have been widely deposited around Ariake Bay with an area of several hundreds of square kilometers . It has been well documented that the sensitivity of Ariake clays is very high (Ariake Bay Research Group 1965;Ohtsubo et al 1982;Hong et al 2004), typically larger than 16, with the maximum over 100 (Torrance and Ohtsubo 1995). Salt removal has been reported to be an important factor causing high sensitivity for marine Ariake clays (Torrance and Ohtsubo 1995;Ohtsubo et al 1995;Hong et al 2003).…”