Frost heaving pressure characteristics of frozen soils in Korea - A laboratory test

Most of land reclamation projects are being implemented along the south and west coastal lines of the Korean Peninsula. The earth structures and in-ground LNG tank, and buildings can be constructed using artificial freezing method on the reclaimed land to control the uplift pressure due to capillary forces. In this study, upon freezing a saturated soil in a closed-system from the top, a considerable frost heaving pressure was developed. Decomposed granite soils, silty soil, and sandy soil were used in the laboratory test which sometimes subjected to thermal gradients under closed-systems. A major concern has been the ability to predict the frost heaving pressure over the results of relatively short-term laboratory tests. The frost heaving pressure arising within the soil samples and the temperature of the samples inside were monitored with elapsed time. The degree of saturation versus heaving pressure curve is presented for each soil sample and the maximum pressure is closely related to this curve. TDR (time domain reflectometry) apparatus was used to measure the volumetric water content by the measurement of unfrozen water contents of frozen soils. Unfrozen water has been shown to be true for soils containing a high percentage of fine-grained particles. Fine-grained soils with strong attractive forces between soil grains and water molecules, and additional water is attracted into the pores leading to further volume changes and ice segregation.