Incorporation of void ratio as a state variable into constitutive models allows, in principle, to use a single set of material parameters for soils with different degrees of overconsolidation. p constant experiments by Hattab and Hicher (2004) on soils with overconsolidation ratios (OCR) ranging from I to 50 are used for evaluation of three constitutive models of different complexity. It is demonstrated by means of a scalar error measure and stress-strain diagrams that at least two sets of parameters for different OCR intervals should be used.
Further, advanced models perform significantly better than the Modified Cam clay model and a hypoplastic model for clays leads to better predictions than elasto-plastic three surface kinematic hardening model.