Research on the characteristics of swelling force of unsaturated swelling rock & soil

Swelling force is one of the most important parameters of study on swelling rock and soil. The factors in influencing swelling force: initial water absorption, dry density and time effect, are further researched. Swelling force increases with dry density, but decreases with increasing initial water absorption, which are both expressed by exponential function. The relationship between swelling force and time is described by piecewise exponential function. The computing formula of swelling force is established, taking initial water absorption, dry density and test time effect as independent variables. The study lays a theoretical foundation for the research on shear strength of swelling rock and soil.