Geotechnical Engineering in Cold Regions

What is unique about geotechnical engineering in cold regions? Principles of soil mechanics for temperate climates have been largely well-understood and practiced for decades. However, these are based on soil temperatures above freezing. In cold regions, heat flow becomes important in relation to freezing and thawing (seasonal frost), but also in relation to permafrost and its resistance to thawing and consequences of thawing. Soil moisture experiences a change of phase and this can cause a dramatic change in physical properties of the soil. In addition, porewater migrates in certain soils during freezing and this can cause dramatic heaving, well in excess of that which would be caused by phase change alone. Based on an illustrated "white paper" recently prepared for colleagues practicing geotechnical engineering in temperate areas, the authors summarize these fundamental phenomena, providing examples of practical design approaches which have been successfully used for building foundations and for roads in seasonal frost and permafrost areas. The paper concludes with a list of relevant references for readers interested in geotechnical design criteria and more-specialized cold regions engineering topics.