Analysis of Undrained Cyclic Behavior of Sand under Anisotropic Consolidation

Abstract

In order to examine the capability of a cyclic mobility model consisting of multiple shear mechanism defined in strain space (Iai et al., 1992), cyclic behavior of anisotropically consolidated sand is analyzed under an undrained and simple shear condition. This behavior of sand, though commonly encountered in earthquake engineering, was not easy to analyze with the conventional plasticity models because it involves effects of rotation of principal stress axis directions. Two analyses are conducted in the present study; one is cyclic simple shearing with constraining lateral normal strain as in the level ground, the other is without the constraint on the lateral strain but keeping the axial stress difference unchanged. The former analysis indicates that cyclic behavior of sand is not affected by initial anisotropic consolidation conditions if initial mean effective stress is kept the same. The latter indicates gradual growth in the axial strain difference causing gradual settlement with lateral bulging. Both of these results are consistent with the previous laboratory findings, suggesting reasonable applicability of the cyclic mobility model.