The ASTM D4546-21 standard provides the standardized framework for measuring both of these potentially hazardous soil behaviors.
The amount of pressure required to prevent a soil from expanding.
The minimum vertical stress required to prevent a soil from expanding when wetted. Astm D4546-21 Pdf
Design deep foundations, moisture barriers, or soil modification strategies to mitigate risk.
Buying the individual standard or a volume subscription from ASTM International. What’s New in the "-21" Revision
The decrease in soil height that occurs when certain unsaturated soils are wetted under a constant load. What’s New in the "-21" Revision?
The standard outlines three main laboratory testing methods, usually conducted in a consolidation apparatus (oedometer). Method A (Free Swell or Hydrocompression) Design deep foundations
It is vital to allow primary swell or collapse to complete entirely (typically measured by the square root of time method) before proceeding to the next loading phase.
Only undisturbed or compacted specimens representing field conditions should be used.