Discrete element method modeling of structural clay

Abstract

Structures in clay, found as an important role resulting in the weakness and failure of foundations under disturbance, are mainly caused by the cementation between particles. Existing constitutive models reflect the failure characteristics of clay from the phenomenological aspect, while the mechanism of the clay damage from a microscopic perspective is still unclear. In this study, the discrete element method, together with the bond and cohesive contact model, which were introduced for capturing the cohesion and structure of soft clay, respectively, is used to reproduce the cementation of clay, the numerical models of confined compression test, vane shear test and triaxial test were established, aiming to reveal the influence of structure of clay on its deformation and failure process. The results exhibited that the deformation and stress-strain development were in good agreement with experimental results in macroscopic. Moreover, the relationship between the structural failure and the macroscopic mechanical behavior can be established, which is helpful to better uncover the failure mechanism of structural clay. According to this developed of failure surface under the micro scale, an optimized suggestions were proposed for the conventional shear stress calculation in the vane shear test. The method in this study has the potential to simulate the mechanical behavior of structural clay and how significant implications for the improvement of the constitutive models and engineering design.