Thaw Behavior of Frozen Ground

Abstract

Frozen ground contains ice in several forms, ranging from coatings on soil particles and individual ice inclusions to ice with soil inclusions. On thawing, the ice will disappear and for existing overburden pressures the soil skeleton must now adapt itself to a new equilibrium void ratio. The resulting thaw settlement phenomenon is important to the design of frozen ground support systems, design of building foundations and embankments on permafrost where thaw is permitted, design of buried pipelines, and road and highway design on seasonally and perennially frozen ground. Thaw settlement due to melting of ice-rich permafrost is illustrated in Fig. 4-1. The settlement appears to follow a polygon shape, suggesting melting of ice wedges. In this chapter we introduce concepts relative to thaw settlement, thaw consolidation, and thaw behavior in layered soil systems.