Abstract
When the ground is frozen, some pore water may not be frozen because there is unfrozen water even if the temperature drops to freezing point or below. In the artificial ground freezing technique, it is necessary to understand the temperature drop and freezing speed of the ground as correctly as possible; therefore, thermal analysis in which unfrozen water is taken into account is required. In this paper, we suggest derivation of the unsteady heat conduction analysis method based on difference formulae in which unfrozen water is taken into account and suggest estimation formulae for the amount of unfrozen water. Freezing and thawing experiments were conducted indoors using clay and sand as soil samples and fresh water and salt water as pore water. When the experimental results and analytical
values based on this analysis method were compared, they matched each other well.
