Abstract
In cold regions, ground freezing and thawing is repeated several times at winter season. Recently many studies on soil water migration during ground freezing have been done, but studies on soil water migration during ground thawing is not sufficient now. So laboratory test of unsaturated sandy soil freezing and thawing under closed system condition is treated and soil water migration is observed with γ ray moisture content meter. It became clear that soil water migrated to freezing zone during freezing and thawing, and water flow rapidly to ground surface from subsurface. A numerical analysis is developed to estimate the soil water migration during freezing and thawing using the coupled heat and water flow movement. This methed is useful to predict ground water flow at cold regions.
