Influence of Water Content on Elastic Properties of Expansive Soil

Shrink-swell characteristics of expansive soils cause differential settlement beneath foundations, and the volume shift in the soil can cause serious structural damage, the elastic properties of the soil are one of the elements that are affected at the same time. These properties are also required for studying such soils using FEM modeling or software techniques. In the present investigation, an attempt has been made to establish a correlation between the elastic properties of expansive soil and the variation in its water content, which may be used directly for analytical studies. The stress–strain curve obtained from the triaxial test is used to compute the initial tangent modulus and secant modulus, while Poisson's ratio of soil is derived using unconfined compression tests at various strain values. The findings were compared to those of earlier studies. The R² (strength of association) value was well above 0.92 for the obtained correlation for water content and Poisson's ratio. The values of tangent and secant modulus were observed to increase until the optimum moisture content was exceeded by 2–4 percent, after which they decreased.