What is the process whereby soils collapse when they are wetted called?

The process whereby soils collapse when they are wetted is termed hydrocompaction. This phenomenon occurs when certain types of soils—particularly loose, dry, and granular materials—experience a significant reduction in volume due to the infiltration of water. When water is introduced, the soil particles lose their cohesive strength, and voids in the soil matrix are filled, leading to a densification.

This process is particularly relevant in arid and semi-arid regions where soils may be dry and subject to sudden saturations, resulting in structural issues, instability, or subsidence. Hydrocompaction is a critical concept in geotechnical engineering, as understanding the behavior of soils under varying moisture conditions is essential for the design and safety of structures.