Improvement of the modified Cam-Clay model for overconsolidated soils

For the heavily overconsolidated clays the important rise in deviator stress to a peak predicted by the modified Cam-clay model is contestable. In this study this model has been improved by reducing the evaluation of the rise in deviator stress. This article presents the mathematical procedure of the improvement by replacing the yield surface for overconsolidation of the model by a quadratic function. Numerical tests have been made on Cam-clay samples.