Which factors can influence the swelling potential of clay soils?

Moisture content and soil structure are key factors that influence the swelling potential of clay soils. Clay minerals possess a unique property known as "expansion," which allows them to absorb water and swell. When the moisture content increases, the water molecules infiltrate the spaces between the clay particles, causing them to push apart and increase in volume. This characteristic swelling can lead to significant changes in the stability of structures built on or within clay soils.

Additionally, soil structure plays a crucial role in determining how much water can be absorbed and retained in the soil. Well-structured soils, with larger aggregates, may have lower swelling potential compared to poorly structured soils, where the particles are more likely to closely pack together and cause greater water retention and subsequent expansion during wet conditions. Thus, both moisture content and soil structure directly impact the extent to which clay soils swell.