TM 5-852-4/AFM 88-19, Chap. 4
U. S. Army Corps of Engineers
Figure 4-4b. Approximate depth of thaw or freeze vs air thawing or freezing index and n-factor for various homogeneous
soils. In calculations for the curves, thermal conductivities for frozen and thawed states have been averaged together.
Because the actual effective thermal conductivity may not be equal to this average value during either freezing or thawing,
precise agreement between measured and predicted values should not be anticipated. However, deviations due to this
approximation should not exceed those arising from other causes. Curves developed from calculations based on
procedures in TM 5-852-614. (Air freezing index vs depth of freeze.)