FROST ACTION IN SOILS-A SYMPOSIUM ANALYSIS

PAPERS PRESENTED AT THE SYMPOSIUM DISCUSS THE MECHANISM OF FROST ACTION, THE EXTENT TO WHICH TEMPERATURES IN THE GROUND CAN BE RELATED TO WEATHER CONDITIONS, AND THE INFLUENCE OF SOIL TYPE ON FROST ACTION. A BACKGROUND OF INFORMATION IS PRESENTED TO ASSIST IN ASSESSING THE POSSIBILITY & SEVERITY OF DETRIMENTAL FROST ACTION IN A PARTICULAR REGION. CAREFULLY CONTROLLED LABORATORY EXPERIMENTS ON THE MECHANISM OF FROST LENSING HAS PROVIDED SOME IMPORTANT CONCEPTS, INCLUDING: (1) A BETTER UNDERSTANDING OF THE INFLUENCE OF PORE SIZE, & INDIRECTLY THE GRAIN SIZE, ON ICE LENSING, (2) THE SECONDARY EFFECTS OF DENSITY, HOMOGENEITY AND WATER SUPPLY, (3) THE DEPENDENCE OF FROST HEAVE ON OVERBURDEN PRESSURE, (4) THE PROBABLE RELATIONSHIP BETWEEN RATE OF HEAVE AND RATE OF HEAT EXTRACTION, (5) THE DEPENDENCE OF NUMBER AND THICKNESS OF ICE LENSES ON RATE OF CRYSTALLIZATION AND SOIL WATER PROPERTIES, (6) THE NECESSITY OF CONSIDERING UNSATURATED PERMEABILITY FACTORS IN FROST HEAVING CONSIDERATIONS, AND (7) THE PROBABLE EFFECT OF CHEMICAL STABILIZERS ON THE MECHANISM OF ICE LENSING IN SOILS. METHODS OF PREDICTING FROST PENETRATION IN SOILS ARE REVIEWED.