Frost heave in an instrumented soil column

Abstract

Thermocouples, electrical resistivity gages and tensiometers were installed at various depths in a column of Fairbanks silt 100 cm long and about 14 cm in diameter. The water level was maintained at a depth of 45 cm below the surface and the volume of water taken up during the freezing process was monitored. Three freezing tests were conducted, two with a surcharge equivalent to about 35 cm of water pressure and one with a surcharge equivalent to about 350 cm of water. The upper 15 cm of soil was frozen at a rate of about 1 cm/day. The soil moisture tension increased (became more negative) throughout the length of the sample when the first ice was nucleated. All three samples exhibited a similar behavior. The amount of frost heave at the end of the tests was 6.0 and 2.1 cm for the two samples with the small surcharge and 3.2 cm for the sample with the higher surcharge. During freezing the two samples with the small surcharge took up 615 and 410 cm 3 of water while the sample with the larger surcharge took up 490 cm 3 of water.