Numerical modeling of natural soft soil using a robust rotational hardening law

Abstract

Fundamental features of soft soil behaviour such as anisotropy, inter-particle bonding and destructuration, and strain-rate dependency make the design and construction on soft soils a challenging geotechnical task. To model the effect of fabric anisotropy on the soil behaviour, a number anisotropic elastoplastic soil models have been proposed using inclined yield surfaces. Since the soil fabric orientation varies under plastic strains, these models usually contain a “rotational hardening law” that allows yield surface inclination to change under various loading conditions. Hence such models provide more realistic predictions compared to isotropic models. A latest version of the SANICLAY model, in which the aforementioned features of anisotropy, destructuration and rate-dependency are accounted for, is used in this study to investigate the stress-strain behaviour of natural soft soils. A novel rotational hardening law is applied to the model which guarantees the uniqueness of the critical state line, prevents excessive rotation of yield surface under special loading condition and is particularly simple that makes it very useful for practical applications. To consider strain-rate dependency of the soil behaviour, Perzyna’s overstress theory is employed. The model predictions are then evaluated by exploring its performance against measured data of a test embankment boundary value problem. Numerical modeling of natural soft soil embankments using a robust rotational hardening law (PDF Download Available). Available from: https://www.researchgate.net/publication/305986899_Numerical_modeling_of_natural_soft_soil_embankments_using_a_robust_rotational_hardening_law [accessed Nov 30 2017]