The use of a quasi-static cone penetrometer to determine index properties of fine-grained soils

Abstract

This paper describes the use of a soil mini-penetrometer (SMP) to determine the strength and index properties of fine-grained soils. The SMP has been developed to allow both fall cone and quasi-static penetration tests to be performed. Displacement controlled quasi-static penetration tests can be used for the direct measurement of undrained sheer strength, both for remoulded and undisturbed samples. In addition the quasi static penetration test can be used to define an additional lower 'plastic' limit parameter, the PL100, which represents the moisture content of a fine-grained soil with an undrained strength 100 times that at the liquid limit. This approach offers the advantage that removal of the coarse fraction is not required to eliminate the PL100.