One-Dimensional Viscous Behavior of Clay and Its Constitutive Modeling.

One-dimensional viscous behavior of clay was evaluated by performing drained one-dimensional compression tests, and drained triaxial compression tests. In both types of tests, the strain rate was changed stepwise many times and creep tests were performed several times during otherwise monotonic primary loading, unloading, and reloading. The specimens were: (1) saturated specimens of undisturbed clays; (2) normally consolidated saturated clay specimens reconstituted by consolidating slurry of clay chips from undisturbed samples and clay powder; and (3) specimens prepared by compacting wet, air-dried, and oven-dried powder of several different clay types. One-dimensional viscous behavior, which can be described with β value of clay, is significant in all types of clay specimens. The observed viscous behavior of clay specimens is successfully simulated by a nonlinear three-component rheology model of the isotach type. [ABSTRACT FROM AUTHOR]