Framework for Thaw Consolidation of Fine-Grained Soils

A framework for thaw consolidation of fine-grained soils is proposed. The development of the framework is based on the general definition of large-strain consolidation and on the general behaviour of soils upon thawing. The residual stress and the residual stress curve are used in the framework to define the initial thawed state. The concept of the residual stress is generalized to ice-rich soils by specifying that the residual stress is the effective stress within the soil elements upon thawing rather than the effective stress in the bulk soil. The framework is formulated in terms of σ'_v - e - k_v relationships. The volume change behaviour of ice-poor soils is described by a semi-logarithmic linear relationship. The slope of the relationship is given by the compression index of the thawed soil. For ice-rich soils, a bilinear relationship is adopted. First, drainage of the excess water occurs with no compression of the soil skeleton. Then, water is drained out of the soil upon compression of the soil skeleton in an ice-poor equivalent manner. The hydraulic conductivity relationship of thawed fine-grained soils is defined by a semi-logarithmic linear curve with a slope defined by the hydraulic conductivity change index of the thawed soil.