Effects of Freezing and Thawing Process on Soil Compressibility

One of the factors affecting soil structure is freezing and thawing process. It could change soil compressibility threshold (bearing capacity or pre-compression stress). For this purpose, the effect of freezing and thawing process on the bearing capacity and energy consumption during soil compression was studied. The soil samples in this study were prepared in two humidity levels of 10% and 15%, with the density of 1.15, 1.265 and 1.39 g/cm3. They were affected by freezing and thawing process and the results were compared with the similar samples without thaw-freeze process. The results showed that soil thawing and freezing process has reduced significantly the bearing capacity and required energy for soil compaction. Although this process improves and modifies soil structure, but any excessive pressure over normal load, not only eliminates the beneficial effects of freezing and thawing on soil structure, but also causes more soil compaction.Therefore, the use of machines and implements on farms must be carefully according to soil physical properties and the factors affecting it.