Inter-Particle Pressure as influenced by Physicochemical Parameters on Microscale of Saturated Heavy Clay

Abstract

Determination of inter-particle repulsive pressure in clays is essential in many geotechnical engineering fields, for example, in determination of compressibility and swellability behavior, hydraulic conductivity, shear strength, swelling pressure, and volume change because of changes in matric suction. With respect to heavy clay there are a lot of factors overlapping with each other that control its behavior. This behavior may be companion with great perils on the structures and as a result, complex damages and exorbitant costs are expected. Physicochemical factors such as ion type and concentration play a great role in the properties of such clays. Limited number of past research focused on the effect of ion type and its concentration on such type of soils. This study reports the influence of these two factors on the inter-particle pressure that developed upon saturation of laboratory-prepared heavy clays. A new approach of inter-particle pressure prediction using double layer theory was proposed by investigating the forces within the diffuse double layer of clay particle in saturated state. The experimental results of oedometer tests showed a consistent behavior with the results represented by the double layer theory using special cases of application on micro scale forces. It can be assumed that the forces at macro-scale may be an applicable concept for an assessment of swell characteristics of heavy clay that subjected to saturation.

Keywords: heavy clay, inter-particle pressure, double layer, ion type.