Characteristics of Soils with Low Plasticity: Intermediate Soil from Ishinomaki, Japan and Lean Clay From Drammen, Norway

• Published in: SOILS AND FOUNDATIONS Vol. 41; no. 1; pp. 83 - 96
• Main Authors: Tanaka, Hiroyuki, Tanaka, Masanori, Shiwakoti, Dinesh R.
• Format: Journal Article
• Language: English
• Published: Tokyo Elsevier B.V 01.02.2001; The Japanese Geotechnical Society; Japanese Geotechnical Society
• Subjects: Applied sciences; Buildings. Public works; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Engineering geology; Exact sciences and technology; Geotechnics; in-situ tests; intermediate soil; low plasticity; residual effective stress; sample quality; Soil investigations. Testing; Soil mechanics. Rocks mechanics; unconfined compression strength; undrained shear strength (IGC: C6); residual effective stress; intermediate soil; sample quality; in-situ tests; low plasticity; undrained shear strength (IGC: C6); unconfined compression strength; Shear strength; Clay soil; Compressive strength; Soil investigation; Particle size distribution; Effective stress; Pore pressure; Undrained soil test; Plasticity; Water content; Test method; Soil consolidation; Sampling; Residual stress; Physicochemical properties; Field study
• ISSN: 0038-0806; 1341-7452
• DOI: 10.3208/sandf.41.83

Two soils with low plasticity are investigated; intermediate soil from Ishinomaki, Japan and lean clay from Dram- men, Norway. Since both the soils were retrieved using the Japanese sampling method, the test results from these samples are comparable. Though they have the same order of plasticity index (Ip), there is a significant difference in the grain size distribution characteristics between these soils. Ishinomaki intermediate soil contains a lot of sand or silt sized particles, its Ip value being nearly proportional to its clay content. On the other hand, Drammen clay consists of a large proportion of rock flour, which contains little clay mineral. The study shows that the unconfined compression test significantly underestimates the undrained shear strength for both soils, and their residual effective stress (p'r) is also very low. It has been found that to compensate for loss of p'r, recompression tests are useful methods to evaluate the strength of such soils.