Consolidation of Soft Sediments Using Artificial Ground Freezing

Abstract: Freeze-thaw cycling is investigated as a possible method for consolidation of fine grained soils. The method relies mainly on phenomena of thaw consolidation. While the soil is subjected to multiple freeze-thaw cycles the water is pressed out of the material as the excess pore pressure dissipates. To prove that this phenomenon can be used to consolidate fine grained soils several laboratory tests are conducted. Oedometer test are conducted with alternating freeze-thaw cycles at different load. Unconfined soil specimens are also frozen to assess the effect of freeze-thaw cycling on plastic and liquid limit and also to determine how much free water is produced in the process. A larger scale test is conducted to provide a better understanding about how the method could work in reality. It is proven that it is possible to significantly lower the water content of the tested material by using freeze-thaw cycles. It is concluded that liquid and plastic limits as well as the void ratio of the material decrease with increasing number of freeze-thaw cycles.