Field tests for the identification of silts

Abstract

Accurately identifying soil texture and understanding soil behaviour in terms of plasticity is a crucial initial step in properly characterizing a site, which in turn facilitates appropriate sampling and scheduling of laboratory tests. Soil identification techniques in literature are effective at assessing pure clays and silt–clay mixtures. This paper presents a comparative study between field tests, soil plasticity classifications, Atterberg limits, mineralogical and chemical data, SEM imagery, and stereographical microscopy. Natural residual soils comprising varying quantities of clays, silts, and sands were used and subjected to the same field and laboratory protocols. The findings of this study demonstrate that a series of field tests can effectively characterize and classify soils ranging from coarse soils to fine soils exhibiting non- to highly plastic indices with particle sizes less than 2.00 mm. By employing a single list of field tests that only necessitate water and commonly available stationery materials on-site, the researchers have presented a valuable tool for on-site determination of soil texture and inference of the Unified Soil Classification System (USCS). This approach streamlines the process and provides professionals with an efficient means of assessing soil properties and determining problem soils at an early stage of the investigation and during construction of high fills.