ABSTRACT
Oh et al. (2009) proposed a semi-empirical model using the stress versus displacement relationships from model footing tests performed on different sands under unsaturated conditions for predicting the variation of modulus of elasticity with respect to matric suction using the SWCC and the modu-
1 INTRODUCTION
The modulus of elasticity of soils is a fundamental property in understanding and estimating the swelling and shrinkage behaviour of expansive soils associated with variations of environmental conditions. Terzaghi’s (1925, 1926, 1931) pioneering modeling and experimental studies showed that clay swelling and shrinkage are essentially elastic deformations caused by the clay’s affinity for water. Terzaghi (1925, 1931) suggested that the swelling of the soil produced by eliminating the surface tension of the capillary water is identical with the expansion produced by the removal of the external load. It was explained that any soil which is capable of swelling contains a solid phase under a pressure equal to the tension in the liquid phase. This indicates that the swelling capacity of soil is dependent on the elastic properties of the solid phase. The physiochemical reactions between the solid and the liquid phase (formation of adsorption compounds within the system) can at best only play a minor role (Vanapalli & Adem 2013).
