Discrete element analyses of stiffness distribution of gap-graded soils with particle property disparity

Utilizing the Discrete Element Method, this research studied the stiffness distribution of gap-graded soils by modifying the conventional static method. By acknowledging the inherent particle property disparity between coarser and finer particles, this research differentiates the stiffness distribution of gap-graded soils from the perspective of contact and particle types. Results indicate that particle property disparity significantly influence the small-strain stiffness characteristics, consequently altering the overall stiffness distribution in gap-graded soil specimens. Specifically, with the equivalent coarser particle property, an increase in particle Young's modulus of finer particles results in an augmentation of small-strain stiffness values, alongside an increased stiffness distribution contribution from finer particles. Nevertheless, this study reveals that even with a higher particle Young's modulus of finer particles, the proportion of small-strain stiffness transferred by finer particles remains consistently lower than their volume fraction. Furthermore, the proportion of stiffness transferred by finer particles may fall below their contribution to stress transmission. This investigation accentuates the subtle yet significant effects of particle property variations on small strain stiffness and its subsequent distribution, providing a foundation for advancing the significance of particle property disparities in evaluating soil responses. © 2024 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences