Abstract: To study the effect of freeze-thaw cycles on the mechanical properties of compacted soils under open atmosphere conditions, the levee backfill soil samples filling soil taken from the Songhua River levee project were investigated. The laboratory freeze-thaw tests and triaxial compression tests were conducted on specimens with different initial states under open atmosphere conditions. Results show that the water supply during the freezing process can accelerate the development of stable state in the failure strength and the elastic modulus of soil samples. Further, the reduction rates in the failure strength and elastic modulus reach 85% and 92% after 7 F-T cycles, respectively. The degradation effect of freeze-thaw cycles on the mechanical property of the backfill soil can be reduced by enhancing the dry density or by moderately raising the moisture content of soil.

Key words: Open Atmosphere Conditions, Freeze-Thaw Cycles, Compacted Soil, Failure Strength, Prediction Model