Ariake clays have been widely deposited around Ariake Bay in Japan. The basic characteristics of Ariake clays are very soft yet sensitive. Quantitatively assessing the quality of soil samples and correcting the mechanical properties for sample disturbance is a well-known, but not well understood issue in geotechnical engineering. In this study, the undisturbed Ariake clays are deliberately disturbed to various level of disturbance. Then, a series of consolidation tests are performed to investigate the effect of sample disturbance on the consolidation yield stress. A new yet simple index for providing a quantitative measure of the degree of sample disturbance is proposed in this paper. Further, a new approach of correcting the consolidation yield stress for sample disturbance is also proposed based on the new index of sample disturbance.
Ariake clays have been widely deposited around Ariake Bay, located at the western part of Kyusyu Island, Japan. The basic characteristics of Ariake clays arc very soft and sensitive. The natural water content is generally over 100%. The liquid limit is often greater than the natural water content. In addition, the thickness of the Ariakc clay deposit varies generally 10–30m, with a maximum of about 40m. Hence, the settlement and the stability in the area of such a marine deposit are serious problems in the engineering practice. Accurately assessing the consolidation yield stress is indispensable in the settlement and the stability analyses. Stress release and mechanical disturbance during sampling and handling, however, may lead to a significant difference in the mechanical behavior. In this study, a new yet simple index for providing a quantitative measure of the degree of sample disturbance is proposed, and a new approach of correcting the yield stress for sample disturbance is also proposed based on the nev, index of sample disturbance.