Effects of transient temperature gradient on frost heave of saturated silty clay in an open system

Frost heave in seasonally frozen regions is a one-dimensional process that could severely damage infrastructure subgrades. Stress state, temperature and water migration are important factors for frost heave. This work investigated the effects of soil temperature and volumetric water content on the transient frost heave ratio during the freezing of saturated silty clay in an open system and analyzed the relationships between the transient frost heave ratio and freezing rate and between temperature gradient and frost heave rate. The results show that the frost heave ratio, frost heave rate, and freezing rate are positively correlated with the temperature gradient since the temperature gradient drives the water migration during freezing, indicating the transient temperature gradient could be used to evaluate the frost heave of saturated silty clay. The transient freezing rate and transient frost heave ratio are logarithmically related to the transient frost heave ratio and transient temperature gradient, respectively. The effects of transient temperature gradient on frost heave are the principal mechanism responsible for different frost heave characteristics and uneven frost heave along a subgrade of the same soil type.