Modeling Strain-Rate Dependent Behavior of KR0-Consolidated Soft Clays

An anisotropic elastic-viscoplastic constitutive model is developed for K0-consolidated soft clays in general stress space. Two surfaces are assumed to exist for any loading stress as the loading surface and the reference surface. The scalar multiplier is established by the viscoplastic volumetric strain rate under a one-dimensional straining condition. This model can adequately simulate the stress–strain behavior of undrained triaxial constant strain rate shear tests and undrained creep tests for K0-consolidated clays. The strain-rate dependencies of preconsolidation pressure and undrained shear strength are investigated in analytical formulations, and the similarities and differences of their corresponding strain-rate parameters are examined.