Method for determining content of unfrozen water in soil freezing process by using specific heat calculation

The invention provides a method for determining the content of unfrozen water in a soil freezing process by using specific heat calculation. The method comprises the following steps: adopting the total heat of one temperature measuring point as the sum of soil particle heat, pore water heat, pore ice heat and heat released by phase change of water in soil; determining the physical properties of a soil sample by using indoor geotechnical test, and determining the phase change temperature range of the soil sample through freezing test; determining the specific heat of frozen heat at the corresponding temperature measuring point by using a calorimeter through mixed calorimetry; and expressing the four heats and the total heat by using the specific heat, deriving the unfrozen water content-specific heat function relation, and calculating to obtain the content of the unfrozen water at every temperature measuring point. The method for measuring the content of the unfrozen water has the advantages of simple operation and small test result error. General labs and construction units can use a simple calorimeter to measure and calculate the content of the unfrozen water.