68th Canadian Geotechnical Conference and 7th Canadian Permafrost Conference

FROST HEAVE BEHAVIOR OF UNSATURATED SOILS UNDER LOW OVERBURDEN PRESSURE AND ITS ESTIMATION

Session: Laboratory Testing in Cold Regions / Essais en laboratoire en ingénierie nordique

Tatsuya Ishikawa, Hokkaido University (Japan)
Tetsuya Tokoro, Tomakomai National College of Technology (Japan)
Satoshi Akagawa, Cryosphere Engineering Laboratory (Japan)

This study proposes two kinds of estimation methods for the frost heave ratio of unsaturated frost-susceptible soils under low overburden pressure such as subgrade soils at the pavement structure in cold regions. One is the modified Takashi’s equation in contemplation of matric suction of soils under low overburden pressure. The other is the simple frost heave model which evaluates the effects of initial water content, Bishop’s effective stress and water absorption during freezing on the frost heave ratio. In addition, the applicability and the usefulness of both methods were discussed based on the results of frost susceptibility tests. As the results, it was revealed that the estimation methods proposed in this study have an excellent applicability to the precise prediction for the frost-heave phenomenon of unsaturated subsurface ground in cold regions.