On the Influence of Physico-Chemical Phenomena on Shear Strength of Consolidated Kaolinite: Fid-Bau Portal

On the Influence of Physico-Chemical Phenomena on Shear Strength of Consolidated Kaolinite

Jaradat, Karam A. / Wei, Shijun / Abdelaziz, Sherif L.

At the same effective stress, shear strength of consolidated clays is a function of the stress history. Normally consolidated clay specimens tend to contract upon shearing while overconsolidated clays tend to dilate. Moreover, overconsolidated clays have a peak shear strength while normally consolidated clays plateau to their critical state. In this study, two-dimensional (2D) discrete element method (DEM) simulations for kaolinite at different stress histories are presented. Clay particles are modelled as rigid rods (clumps) in a two-dimensional framework, with different sizes replicating the actual particle size distribution of the kaolinite used later for model validation. The nonlinear nature of contact between clay particles is simplified by introducing linear springs at the particles’ contact to simulate van der Waals attractive and double layer repulsive forces. A series of numerical simulations at different stress histories and effective stresses is presented. The observed shearing behavior at different stress histories is discussed in light of microstructural changes before shearing. Results suggest particle orientations, and therefore the physico-chemical forces prior to shearing might have minimal impact on shear strength, while the void ratio is the main factor controlling the shearing behavior.