Theory 05/Earthquake Engineering
Liquefaction Is a Cyclic Ratio
The claim
Liquefaction triggering is set by the ratio of cyclic stress to effective confining stress rather than by the number of cycles.
01Mechanism
Pore pressure builds when cyclic shear exceeds the soil's resistance; the ratio determines how many cycles are needed to reach zero effective stress.
02Predictions
- P1Triggering should collapse onto the ratio.
- P2Cycle count alone should mispredict.
03Refutation
Triggering tracking cycles would remove the stress ratio.