water migration|water accumulation|temperature field|phenomenon

In order to quantify the studies on the water migration in undisturbed soil during the freezing and thawing process,under the same experiment conditions,the influence of single factor on water migration is studied by changing the only factor of the initial water content or temperature mode.After freezing and thawing of the pre-set position,the following phenomena are observed: the horizontal and vertical cracks in the unmelt portion,the obvious freezing and thawing boundary,the water accumulation layer and melting layer in different layers,different water freezing temperatures in the soil,and the unevenly distributed water accumulation and ice.Through the studies on the temperature fields during freezing and thawing process and the water contents before and after the freezing and thawing process and the test data,the conclusions are drawn as follows: when the top board temperature of the test case changes,the soil samples with different water contents have the same changing trend at various testing points;when the top board temperature of the test case keeps unchanged,the more the initial water content of the soil samples,the more the water migration and accumulation;the influence of the water migration is obvious under different freezing and thawing temperature modes,and the higher the freezing temperature of the top board of the test cases,the more the water content accumulation at the water accumulation layer.