STUDY OF SOIL-WATER CHARACTERISTICS CURVE AND THERMAL MECHANICAL PARAMETER OF UNSATURATED SOIL

摘要

Soil-water characteristics curve (SWCC) describes mainly the relationship of suction and volumetric water content of non-saturated soil, the thermal mechanical properties present the energy conservation of the non-saturated soil, they are very important for un-saturated soil mechanics. The relationship between SWCC and non-saturated seepage curve has been studied based on theory in this paper, the function of SWCC and of non-saturated seepage curve are established by natural proportional rule, then the characteristics among SWCC and its differential curve, non saturated seepage curve, grain distribution curve are investigated in the physical and mechanics, the scope of constant index of SWCC and of non saturated seepage function is given and their relationship is described. It is necessary for the establishment of the energy conservation equation to research the thermal mechanical properties of unsaturated soil; the determination of two representative parameters (volumetric specific parameter and thermal conductive parameter) of fundamental physical-mechanical is a key factor to obtain the results of the energy conservation equation. The effective thermal conductive coefficients of dry soil grain are analyzed for different composition geo-material, and the thermal mechanical properties of porous media with water and gas are researched, the comparative analyses of different calculation method of thermal conductive coefficient have been conducted, an available calculating method is proposed to determine the thermal mechanical parameters, the results among the proposed method, the volumetric average method, the self consist method, the Hashin--Strikman method have been compared, the proposed method is in the good agreement with the testing result and fit to describe the main properties of thermal mechanical conductivity.