A multi-component model for expansive soils with different mineral compositions

The accurate prediction of swelling deformation and(or) swelling pressure if confined for expansive soils is essential for a better design and construction of a geotechnical structure that is built on or in an expansive soil. In this paper, we proposed a new method to quantify the swelling strain and(or) swelling pressure of expansive soils by considering the mineralogical components and their different swelling properties. The proposed multi-component model employs a tandem combination of different sub-molecular oedometers for different minerals, and the total swelling strain of soil was calculated by integrating the swelling strain of each mineral. A linear relationship between potential energy and swelling strain is identified based on molecular dynamics’ simulation, which is then incorporated into the diffuse double-layer theory to calculate the relationship between confining pressure and swelling strain for each mineral. The numerical model was then validated by experimental results from the literature, which shows a good agreement with the experimental data in the literature. This model provides a cost-effective way to estimate the swelling behavior of expansive soil.