Expansive soils are soils that have the ability to expand significantly when they absorb water, and then shrink when they dry out. They are commonly found in regions with clay-rich soils, such as the western and southern regions of the United States.
The expansion and contraction of these soils can cause significant damage to buildings and other structures that are built on top of them. This is because the soil movements can create pressure against the foundation of the structure, causing it to shift or even crack. Expansive soils can also damage roads, sidewalks, and other infrastructure.
The expansion of expansive soils can be caused by a variety of factors, including changes in the moisture content of the soil, temperature fluctuations, and chemical reactions. Proper soil testing and site evaluation can help identify the presence of expansive soils and guide the design and construction of structures in these areas. Building techniques that accommodate soil movement, such as installing flexible foundations, can help minimize damage from expansive soils.