Field studies carried out mainly since 1975 in permafrost areas of Alaska, Canada, China, and the Soviet Union have been combined with the results of laboratory investigations to show that in summe...

Downward water movement into frozen ground, western arctic coast, Canada

A one-dimensional model for water transport and ice lensing in incompressible saturated and solute-free soil specimens is proposed for the simulation of small-scale frost heave tests in the laboratory. The model considers (1) open-system freezing in which the variables T and Pw are independent, (2) an ice lens that continues to grow as long as enough energy is available in the frozen fringe to produce the work required for mass transfer to the ice lens, and (3) a new ice lens that forms when the vertical strain in the frozen soil reaches the instantaneous tensile failure strain. The proposed frost heave model is amenable to computer simulation procedures which provide predictions of rate of frost heave and rate of pore freezing front penetration as functions of applied load, thermal and water flow regimes, and soil properties. Position, time of initiation, and ultimate thickness of individual ice lenses emerge also as a part of the solution. A quantitative comparison of observed and simulated responses for various boundary conditions is shown for a reference soil known as Devon silt. The model was found to exhibit many of the characteristics observed in frost heave tests on Devon silt and predicted the effects of overburden pressure on frost heave rate.

A model for water transport and ice lensing in freezing soils

The formation of rhythmic lenses of ice in freezing soils is an intriguing geophysical phenomenon that is not fully understood, despite much experimental and theoretical work over the past century. We review proposed mathematical models of ice lens growth and frost heave, from early capillary theories and models based on the concept of a frozen fringe, to more recent advances that have revitalised the capillary model. In addition we identify several key experimental and theoretical challenges that are still to be resolved.

/pdf/the-physics-of-frost-heave-and-ice-lens-growth-3edtqrw2jb.pdf

The Physics of Frost Heave and Ice-Lens Growth

The analysis of frost-heave data on several soils confirmed that segregation potential, hence frost susceptibility, of saturated soils was best related to the average size of the fines fraction, the specific surface area of the fines fraction, and the ratio of the material's water content to its liquid limit. The influence of overburden pressure can also be accounted for by an empirical relationship between the segregation potential, the average size of the fines fraction, and the compressibility index of the soil. The segregation potential was also proportional to the relative fines content in soils where the fines do not completely fill the voids of the coarser fraction. This study led to the development of a new frost-susceptibility assessment methodology based on simple geotechnical routine soil index testing that was validated on a highway site on frost-susceptible subgrade till.Key words: frost heave, index properties, criteria, soil, segregation potential.

Frost susceptibility related to soil index properties

The frost heave response of quarry fines from several locations in the Province of Quebec was studied in the laboratory using one-dimensional step-freezing tests with free access to water. Comparis...

L.E. Goodrich

Papers

Location of segregated ice in frost-susceptible soil