Influence of Osmotic Suction on the Soil-Water Characteristic Curves of Compacted Expansive Clay

Thyagaraj, T and Rao, Sudhakar M (2010) Influence of Osmotic Suction on the Soil-Water Characteristic Curves of Compacted Expansive Clay. In: Journal of Geotechnical and Geoenvironmental Engineering, 136 (12). pp. 1695-1702.

PDF Osmotic.pdf - Published Version Restricted to Registered users only Download (479kB) | Request a copy

Abstract

Unsaturated clays are subject to osmotic suction gradients in geoenvironmental engineering applications and it therefore becomes important to understand the effect of these chemical concentration gradients on soil-water characteristic curves (SWCCs). This paper brings out the influence of induced osmotic suction gradient on the wetting SWCCs of compacted clay specimens inundated with sodium chloride solutions/distilled water at vertical stress of 6.25 kPa in oedometer cells. The experimental results illustrate that variations in initial osmotic suction difference induce different magnitudes of osmotic induced consolidation and osmotic consolidation strains thereby impacting the wetting SWCCs and equilibrium water contents of identically compacted clay specimens. Osmotic suction induced by chemical concentration gradients between reservoir salt solution and soil-water can be treated as an equivalent net stress component, (p(pi)) that decreases the swelling strains of unsaturated specimens from reduction in microstructural and macrostructural swelling components. The direction of osmotic flow affects the matric SWCCs. Unsaturated specimens experiencing osmotic induced consolidation and osmotic consolidation develop lower equilibrium water content than specimens experiencing osmotic swelling during the wetting path. The findings of the study illustrate the need to incorporate the influence of osmotic suction in determination of the matric SWCCs.

Item Type:	Journal Article
Publication:	Journal of Geotechnical and Geoenvironmental Engineering
Publisher:	American Society of Civil Engineers
Additional Information:	Copyright of this article belongs to American Society of Civil Engineers.
Keywords:	Clays; Unsaturated soils; Suction; Laboratory tests; Expansive soils
Department/Centre:	Division of Mechanical Sciences > Civil Engineering
Date Deposited:	13 Dec 2010 09:07
Last Modified:	13 Dec 2010 09:07
URI:	http://eprints.iisc.ac.in/id/eprint/34452

Actions (login required)

View Item