Constitutive Modeling of Normally and Over-Consolidated Clay with a High-Order Yield Function

In this paper, a simple sub-loading yield surface model for both normally consolidated and over-consolidated clay is proposed with emphasis on the effect of shape. Compared modified Cam-clay model, only one additional material parameter introduced to reflect geometry features surface. A higher-order stress–dilatancy relation given in current study, leading new function capable offering an adequate description soil samples p–q plane. By introducing concept unified hardening parameter, can capture main dilatancy strain-softening behavior contraction strain-hardening behavior. The results show that adjusting leads more accurate predictions than model. also reasonably describe its mechanical samples.