Cyclic Strength of Underconsolidated Clay

ABSTRACT The effect of preconsolidation period on cyclic strength of a reconstituted clay was investigated using cyclic triaxial tests. It was indicated from the test results that cyclic strength of underconsolidated clay was more uniquely defined by the degree of consolidation in terms of effective stress than volumetric strain. Further, by using undrained static strength instead of effective stress in normalizing cyclic shear stress, we obtained a very unique relation between the cyclic shear stress and the number of load cycles which is not influenced by the consolidation time. This is because the undrained strength is directly proportional to the magnitude of effective stress developed during consolidation. Thus, a new cyclic stress ratio using undrained static strength instead of effective confining pressure was proposed to define the cyclic strength of clay.