Affiliation:
1. Department of Civil & Environmental Engineering, Hong Kong University of Science & Technology Clear Water Bay, Hong Kong 999077, China, State Key Lab. of Disaster Reduction in Civil Engineering, Tongji University College of Civil Engineering, Tongji University 1239 Siping Rd, Shanghai 200092, China
Abstract
This research pioneers a stochastic discrete element method (DEM) by integrating the probability density evolution method (PDEM), offering a novel approach to connect particle-scale property uncertainties, specifically inter-particle friction coefficient (μ) and particle shear modulus (G_p), with macroscale soil behavior. Through 1,100 DEM simulations, this study reveals that, for uniform particle size distribution, the uncertainty in μ substantially affects large strain soil behaviour, with its effect being associated with packing density and soil state. The uncertainty effect of μ remains pronounced at the critical state, while the packing density effect diminishes. Stress distribution appears insensitive to uncertainty of μ, rather suggesting a predominant influence of particle size distributions. In contrast, uncertainty effect of μ becomes negligible on small strain behaviour, demonstrating limited effect on small strain stiffness. Uncertainty in G_p presents limited effects on large strain behaviour, including stress ratios and dilatancy. At small strains, G_p shows a significant impact on stiffness, diverging from minimal influence identified for μ. This study presents a framework that integrates experimental techniques to study particle-scale uncertainty propagation, enhancing predictions of macro-scale soil behavior. This approach could be beneficial for precise multi-scale simulations, incorporating particle-level uncertainties in engineering-scale models, thus improving geotechnical practice predictability.