Soils behavior are naturally complex and it can be said that soil reveals the most unknown behavior among all the materials found in nature; therefore, separate interpretations of soil behavior should be linked to interpret and predict the exact behavior and thereby the basis for stating soil behavior emerge. Elastoplastic behavior models that are expanded widely in recent years and they are presented in the framework of critical state model (CSM), provided this possibility. In fact, A constitutive model describes the soils behavior as simple and ideal. When the possibility of soil tests to identify and characterize the site does not exist, or when we have to predict soil behavior in response to changes in loading, in this case, CSM provides a tool for estimating soil response. In the literature, several constitutive models for soils are presented until now in them the critical state is considered as the initial basis. Three cases of old and new constitutive models to simulate the behavior of clay soils are proposed which include S-Clay1, MCC and SANICLAY. In this paper it is tried to investigate the differences in the formulation of these models by introduction of the formulation and basic foundations of critical state model; then, by modeling of MCC model with a computer program, it will be used for simulation the mechanical behavior of a clay soil. Finally, by examining the results of the simulations, it was indicated that this behavior model has relatively acceptable ability to simulate the mechanical behavior of clays and then weaknesses and strengths of this model are fully described.

Full text: IJEIR-1273_final.pdf