An extended modified cam clay model for improved accuracy at low and high-end stress levels

Abstract

The Modified Cam Clay (MCC) model is extended based on S-shaped compression so that the quantitative inaccuracies and the qualitative errors of the model associated with both low and high stress levels can be removed. The following modifications are made: (i) a material constant r, the spacing ratio, is introduced; (ii) the yield surface is modified for r ≠ 2; and (iii) the ratio of the elastic compression index to the virgin compression index is assumed to be constant. The compression and shearing behavior of reconstituted clays for p′ < ∝ can be successfully described. Following the same method, the proposed complete S-shaped compression curve can be implemented to many existing models, removing errors of the models at the extremities of stress level and improving the performance of the models for different stress levels with one set of values of the model parameters.

Keywords:

• Compression
• constitutive equations
• high stress
• low stress
• plasticity
• reconstituted clay

Acknowledgement

The last author is grateful to the Thailand Research Fund under the TRF Senior Research Scholar programme Grant No. RTA5980005 and Suranaree University of Technology.