Expansive soils are characterized by their high plasticity index, which indicates a high potential for swelling and shrinkage. When these soils come into contact with water, the clay particles absorb the water and swell, causing the soil to expand. Conversely, when the soil dries out, the clay particles shrink, leading to a decrease in soil volume. This cyclical process of swelling and shrinkage can cause foundations to shift, crack, and even collapse.
https://www.sciencedirect.com/science/article/pii/B9780128132081000265 foundations on expansive soils chen pdf
F.H. Chen's Foundations on Expansive Soils is a cornerstone text for geotechnical engineers, bridging the gap between theoretical soil mechanics and practical field solutions. Expansive soils, often referred to as "the cancer of soil mechanics" by Chen, cause massive global structural damage—frequently exceeding that of floods and earthquakes combined. Core Principles from Chen’s Work Expansive soils are characterized by their high plasticity