Undrained Cyclic Loading of Anisotropically Consolidated Clayey Silts

Abstract

Data are presented from cyclic triaxial tests on anisotropically consolidated kaolin clay and silica silt mixtures prepared in the laboratory. The soil type ranged from a pure silt to a silty clay with 40% clay content. The undrained behavior of clay‐silt soils subjected to anisotropic cyclic loads without shear stress reversal can be adequately described by the average resultant cyclic strain rate provided that the test conditions account for strain rate effects and cross‐sectional area changes during straining. Strain rate effects in cyclic triaxial tests may induce nonuniform pore pressure distribution within the specimen. Nonuniform pore pressure effects are related to the average resultant cyclic strain rate, while the dynamic strength parameters are related to the maximum cyclic strain rate. It has been established that the average resultant cyclic strain rate depends upon the imposed static shear stress, the cyclic stress ratio and clay content. Cyclic frequency, however, did not significantly affect the 20% clay/80% silt mixtures.