The Influence of Depth of Frost Penetration on the Frost Susceptibility of Soils

Abstract

Research on heaving pressures associated with the formation of ice lenses in soils indicates that the magnitude of the heaving pressure in silt soils is governed by the geometry of the ice-water interface. This geometry involves a double curvature of the ice front, into the voids and around the adjacent particles, and thus depends on both particle and pore size distribution. A theory for predicting frost heaving pressures, which takes into account the geometry of the ice-water interface, is described and it predicts greater heaving pressures for decreasing particle and pore sizes. Supporting experimental results are given.The formation of ice lenses in a freezing soil can be arrested if the frost heaving pressure is counteracted by an equal or greater external pressure, such as overburden pressure. From the theory, the frost heaving pressure for a given particle and pore size distribution can be obtained. If this pressure is equal to the pressure of the frozen overburden, a state of equilibrium will exist and ice lenses will not form. Thus, a critical particle and pore size for a given depth of frost penetration can be predicted for which a soil will be non-frost-susceptible.