STRAIN-SPACE CONSTITUTIVE MODEL FOR CLAY SOILS.

A simple constitutive model for clays is presented. The model is formulated in strain space rather than in stress space, providing advantages from both an analytical and computational point of view. The model is developed from simple physical concepts of soil behavior obtained from conventional soil experiments. For simplicity, only a few common material constants are employed, namely, the slope of the normal consolidation and recompression lines in the semi-log plane and the slope of the critical state line in the Cambridge triaxial stress space. The model is generalized to handle load reversal by using Masing's rule. The model is calibrated using undrained monotonic triaxial tests. It is then used to predict response behavior for a broader class of loading histories. These predictions are found to compare favorably with experimental data for both normally-consolidated and overconsolidated clays under monotonic as well as cyclic loading conditions.