What is the volume change that occurs when soil goes from a compacted state to an uncompacted state called?

The volume change that occurs when soil transitions from a compacted state to an uncompacted state is referred to as swell. This term specifically describes the expansion of soil volume when it is loosened, often resulting from the addition of water or the removal of compressive forces that were initially compacting the soil.

Understanding swell is crucial for various engineering and construction applications, especially in earthworks where control of soil volume is necessary for stability and foundation performance. Effective management of swell can prevent issues such as excessive heaving that may compromise the integrity of structures built on or near the soil.

Dilation, while related to the change in volume or structure, typically refers to the change that occurs under the influence of forces that cause soil particles to move apart, but it does not specifically address the transition from a compacted to an uncompacted state in the same way as swell does. Other terms like settlement and consolidation refer to different processes involving soil density and volume changes due to loading and moisture expulsion, respectively.