Modeling of soils using isotropic and anisotropic models

In this study, two behavioral models—unified and multilaminate—are employed to simulate soil behavior. The unified model incorporates a non-associated flow rule along with the critical state concept. Additionally, the sub-loading surface concept is adopted to capture a smooth elastic-plastic transition. For numerical implementation, the implicit Euler method is used. The multilaminate model is based on a ۱۳-plane framework, in which each plane exhibits elastic-plastic behavior. The overall soil response is obtained by integrating the elastic-plastic responses of the individual planes oriented in various directions at a material point. A set of unconventional constitutive equations is applied to each plane. This model captures soil softening behavior more realistically due to the use of a non-classical plasticity approach. Moreover, it accounts for the effect of induced anisotropy. To evaluate the models, four clay samples subjected to monotonic loading—under both drained and undrained conditions—were analyzed using both the unified and multilaminate models and were compared with experimental data. The results demonstrate that the unified model offers a more favorable representation of soil behavior.

کلیدواژه ها:

General dilatancy rule ، Implicit Method ، multilaminate theory ، sub-loading surface ، unified model