SETTLING BEHAVIOUR AND CLAY MINERALOGY

 A. SRIDHARANl and K PRAKASH

 ABSTRACT Sedimentary soils are formed due to the process of settling of soil particles in suspension. The settling process is physico-chemical in nature as the soil contains chemically active clay minerals. The extent to which the clay mineralogy affects the settling process depends upon the initial water content of the soil-water suspension. For montmorillonitic soils, the limiting water content at which the nature of settling changes from a discrete free type to a flocculated free type increases with an increase in the soil plasticity and decreases with an increase in the soil plasticity for kaolinitic soils. While the diffuse double layer repulsion controls this kind of behaviour of montmorillonitic soils, the behaviour of kaolinitic soils can be attributed to the fabric effect.

Key words: clays, fabric/structure of soils, mineralogy, sedimentation (IGC: D2/D5)