A new criterion for vapour induced ice lens initiation in coarse-grained soils

Abstract

Vapour migration and condensation into ice have been found to be the main reasons for frost heave in coarse-grained soils. The mechanism of this kind of frost heave is less understood than the traditional one due to condensation of liquid water. In particular, an accurate mathematical criterion is required to explain when and where the ice lens will form in coarse-grained soils. This study focuses on the migration of vapour from a mesoscale point of view. Mechanical equilibrium on the vapour-ice interface is discussed, and the rate of frost heave is acquired theoretically. A new criterion for ice lens initiation is proposed by analysing the forces acting at the vapour-ice interface. The influence of the overburden pressure and temperature gradient on the heaving rate is discussed. The new criterion provides a theoretical basis to understand frost heave in coarse-grained soils and can be used in numerical models for simulating frost damage in cold regions.