THE INFLUENCE OF TEMPERATURE AND WATER CONTENT ON THE BEHAVIOR OF SOILS

The most widely used construction material for various civil infrastructures is the naturally available, compacted or modified soils. The behavior of these soils is significantly influenced by environmental factors such as the precipitation, evaporation and variations associated with the natural ground water table. The stability and deformation behavior are two key criteria that govern the design of these infrastructures. Soil is a complex material with different phases in unfrozen and frozen conditions. The water content within the unfrozen and frozen soils is influenced by a wide range of negative and positive temperatures. The soil can be in a frozen or thawed, saturated or unsaturated condition or combinations of them due to the variations in temperature and water content. In other words, the hydro-mechanical behavior of soils is significantly influenced by freezing/thawing and wetting/drying processes. In this paper, the influence of variation of temperature and water content on the soil behavior is explained using the soil-water characteristic curve (SWCC) and soil-freezing characteristic curve (SFCC). The SWCC and SFCC are respectively used as tools in the prediction and interpretation of the behavior of unfrozen unsaturated soils and frozen soils. The focus of this paper is directed to understand the influence of wetting/drying, freezing, and freeze-thaw cycles on soil properties such as void ratio, hydraulic conductivity, shear strength, microstructure change and swelling behavior of expansive soils. Finally, the influence of temperature and moisture on the design of pile foundations in expansive soils is succinctly highlighted.