Novel anisotropic elastoplastic modeling of <i>K</i> ₀ -consolidated sands

Accurately defining the yield surface is a cornerstone of constitutive modeling for sands, as it governs the onset and evolution of plastic deformation under various stress paths. This study proposes and compares some new anisotropic yield functions for K 0 -consolidated sands by introducing two shape parameters ( n and χ) and one anisotropic state variable ( α). For the proposed yield surfaces, the elastoplastic constitutive model is developed within a bounding surface plasticity framework, using a simplified form of the yield function as the plastic potential. Both inherent and induced anisotropy are captured through kinematic hardening and rotational evolution mechanisms. The performance of the proposed yield surfaces is evaluated through two complementary studies. First, the effects of degradation in n, χ, and α on model performance are systematically investigated. Second, a parameter sensitivity analysis is conducted to assess the influence of key model parameters. Results show that with increasing anisotropic consolidation, the proposed model, characterized by flexible shape control and anisotropic state representation, achieves significantly improved predictive accuracy compared to existing models.