Detailed observations on the nature of frost heaving at a field scale
Observations made using a system of ring magnets have provided a detailed picture of differential soil strain associated with frost heaving at a field scale. The results reveal the evolution of heave as freezing advances through the soil and the variation of soil strain with depth and time, and with soil temperature conditions. The results indicate that soil strain characteristically continues within frozen soil, sustained, it is proposed, by continuing water migration into the frozen soil. Consequently a considerable thickness of frozen soil appears to be actively involved with moisture movement and ice accumulation during frost heaving. The observations support the view that frost heave generally depends in a complex manner on the thermodynamic conditions of temperature and water and ice pressures as they are modified by the rheological properties of the soil. Key words: frost heave, differential soil strain, frost heave measurement.