The phase change evolution of pore water was analyzed in the freezing process.Based

on the mechanism of sensible heat and latent heat

the frozen soil was divided into freezing soil and stable frozen soil.According to the physical meaning of latent heat

the specific heat of soil should be stepwisely calculated

namely melting stage

freezing state and frozen state as the temperature gradually drops from a general temperature to a larger negative temperature.In the melting stage

the pore water is always in the liquid phase.In the freezing stage

existing liquid water can be frozen into ice.In the frozen state

there exists no liquid water can be frozen into ice.Thus

the cooling of freezing soil would be accompanied by releasing of sensible heat and latent heat.In frozen soil

the further cooling was accompanied by releasing of sensible heat.Then

based on the weighted superposition of specific heat capacity of mixture

the specific heat of the frozen soil is investigated.A method is developed for calculating the specific heat capacity of frozen soil with consideration of latent heat.