The Frost Heave of Stones in the Active Layer Above Permafrost with Downward and Upward Freezing

Abstract

The frost heave of stones in the active layer above permafrost by downward freezing is well known. The phenomenon is usually explained by either the frost-pull or the frost-push theory. However, if the active layer also freezes upward from the late summer frost table, neither the frost-pull nor the frost-push theory can be applied by reversing all of the directions associated with downward freezing, because the direction of thaw and of gravity cannot be reversed. Laboratory experiments have been carried out to study frost heave with both downward and upward freezing. The laboratory evidence demonstrates that ice lenses can grow on the cold (freezing) side of many stones provided water can migrate from the warm (unfrozen) side of the stones, irrespective of whether the freezing direction is downward or upward. The experiments show that some stones, like some soils, are frost-susceptible. Therefore, the frost-susceptibility of a stone is a factor that must be considered in the study of frost heave irrespective of the direction of freezing.