Book contents
- Frontmatter
- Contents
- Editor's note
- Acknowledgements
- Notes on translations and definitions
- Abstract
- Preface
- Introduction
- I Thermal-physical, physico-chemical and mechanical processes in freezing, frozen and thawing ground and their manifestation in the permafrost regions
- 1 Thermal-physical processes in freezing and thawing ground
- 2 Water transfer and ice formation in soils
- 3 Physico-chemical and mechanical processes in freezing and thawing ground
- 4 Structure and texture of freezing and thawing soils
- 5 Cryogenic geological processes and phenomena
- II Composition, cryogenic structure and properties of frozen rocks
- III Principles of the formation and development of the frozen strata and layers of seasonal freezing and thawing
- IV Regional features and evolution of permafrost
- V Rational use of frozen ground and environmental protection in the course of economic development of the permafrost regions
- References
- Index
2 - Water transfer and ice formation in soils
Published online by Cambridge University Press: 03 November 2009
- Frontmatter
- Contents
- Editor's note
- Acknowledgements
- Notes on translations and definitions
- Abstract
- Preface
- Introduction
- I Thermal-physical, physico-chemical and mechanical processes in freezing, frozen and thawing ground and their manifestation in the permafrost regions
- 1 Thermal-physical processes in freezing and thawing ground
- 2 Water transfer and ice formation in soils
- 3 Physico-chemical and mechanical processes in freezing and thawing ground
- 4 Structure and texture of freezing and thawing soils
- 5 Cryogenic geological processes and phenomena
- II Composition, cryogenic structure and properties of frozen rocks
- III Principles of the formation and development of the frozen strata and layers of seasonal freezing and thawing
- IV Regional features and evolution of permafrost
- V Rational use of frozen ground and environmental protection in the course of economic development of the permafrost regions
- References
- Index
Summary
Nature and mechanism of moisture migration in soils
Water migration in unsaturated soils is due to a complex mass transfer mechanism and a variety of water exchange driving forces. For geocryological problems the most interesting is the migration of bound and capillary water and vapour. Seepage (movement of free or gravitational water) in fine-grained materials is of minor significance and will not be discussed further. Water migration and vapour transfer in soils are related to the solution of many problems in earth science, engineering geology, pedology and geocryology (absorption and evaporation of water from the soil surface, its resorption by surrounding soil layers, capillary replenishment of soil, water migration towards the front of freezing and cooling, etc.). Thermodynamically, water and vapour migration in soil follow from the disequilibrium of the soil-water system caused by change in time and space of thermodynamic parameters (temperature, pressure, ion concentration, humidity, electrical, magnetic and gravitational potentials, etc.). It is usually impossible to measure directly the driving force of each mechanism separately. This is the reason to find a uniform (generalized) force comprising more or less fully all component forces. All this has resulted in an energy (thermodynamic) approach to mass transfer in colloidal and capillary porous bodies including the soil system.
All the water in soils, with the exception of free (gravitational) water, is held due to the free surface energy of the mineral soil skeleton Es.
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- General Geocryology , pp. 93 - 119Publisher: Cambridge University PressPrint publication year: 1998