Theory 13/Hysteresis & Memory/Soil mechanics
Compaction Does Not Reverse
The claim
Soil compaction follows a hysteresis loop, so reloading to a stress previously experienced produces almost no further strain, and unloading does not restore structure.
01Mechanism
Particle rearrangement is irreversible; once contacts are reoriented at a given stress, further loading follows a stiffer path.
02Prediction
Compaction should depend on maximum past stress, not current stress.
03Refutation
Strain tracking current stress alone would remove the memory.