Some Physical Properties of Thawy Soils

Studies on characteristics of frost and thawy soils (III)

Abstract

Freeze-thaw action has a large effect on [soil-water] system and the following interesting points were observed in liquid limit, shrinkage and swelling.
1. A tendency of decrease in liquid limit by the freeze-thaw action was indicated.(Figs. 1, 2)
2. The apparent shrinking coefficient of soil mass by drying decreased by the freeze-thaw action.(Figs. 3, 4)
3. Under the same condition, the shrinking behavior of prefrozen soil is completed quicker than unfrozen soil. Also the dehydration rate of prefrozen soil is higher and this tendency is enhanced the lower the freezing temperature.(Figs. 5, 6)
4. Shrinkage of undisturbed soil by drying is much less than that of disturbed soil. Also undisturbed soil does not receive the effect of freeze-thaw action to such an extent.(Figs. 7, 8)
5. When rehydrated after shrinkage has been completed, the swelling amount and water-absorption amount of prefrozen soil are larger than those of unfrozen soil and these tendencies are more marked the lower the freezing temperature. In case of undisturbed soil, however, swelling is not indicated in both unfrozen soil and prefrozen soil.(Table)
6. Observation of the surface of specimens after swelling indicated formation of numerous cracks in prefrozen soil.(Photo.)