FORMULATION OF STRESS-STRAIN-TIME BEHAVIOR OF SOILS UNDER DEVIATORIC STRESS CONDITION

Although the degrees of time-dependency in soil behavior somewhat differs between sand and clay, every soil expresses viscoelastic, viscoelastoplastic and creep failure characteristics according to the level of applied deviatoric stress. In this study, the fundamental stress-strain-time relationships of soil skeletons including sand and clay caused by the deviatoric stress are theoretically formulated for various stress levels and are simulated by a mechanical model. In the formulation, originations and functions of the elementary properties of the skeletons such as elasticity, elastoplasticity and viscosity are studied from the microscopic point of view. Then applying these fundamental stress-strain-time relationships to the analyses of the creep behaviors, the author presented not only the various relationships previously proposed by some researchers but also obtained some new relationships.