A Technique to Reduce Moisture Content Using Freeze-Thaw Action in Cold Climatic Conditions

Ice lenses are known to form when ground cools and the soil surface begins to freeze, thereby causing water in unfrozen soil to move upward toward the freezing front (Japanese Geotechnical Society, 1994). In this process, moisture content in unfrozen soil decreases as water moves out. Based on this principle, the ability to leverage Hokkaido's cold winter climate to reduce the moisture content of dredged soil would significantly reduce costs compared to those incurred in general soil improvement methods (i.e., expenses related to aeration desiccation, mechanical stabilization and solidifier application). Against this background, in order to investigate the feasibility of using the dehydration method based on cold-climate conditions, an experiment was conducted using large sandbags in place of outdoor earth tanks to determine whether moisture content would be reduced as a result of soil freezing. The outcomes indicated that dehydration could be realized simply and economically using large sandbags in a cold climate. It was also revealed that specific soil components could be extracted through freezing-induced dehydration.