Mechanisms discussion of frost heave and test verifications of moisture migration

摘要

Herein we review research on the structure of the frozen fringe and one of its key characteristics(unfrozen water content),and compare its current measurement methods,including pulsed nuclear magnetic resonance(NMR),time-domain reflectometry(TDR),calorimetry,thermometry,the sublimation method,and CT imagery.A freeze-thaw cycle experiment with remolded soil was conducted inside to verify the mechanism of frost heave,measuring such variables as soil-water potential,temperature,water supplement,and the position of the freezing front.Conclusions from the analysis of the experiment data are:(1) The soil-water potential,the water supplement,and the position of the freezing front vary with temperature; and(2) the temperature gradient induces the soil-water potential,which in turn provides a stable driving force for moisture migration.