A Comprehensive Investigation of Particle Gradation Effects on Limiting Void Ratios and Pore Structures of Granular Soils

ABSTRACT The limiting void ratios (i.e., maximum and minimum void ratios, e max and e min ) and pore structures of granular soils critically influence their compactness, permeability, and deformation behavior. However, the effects of particle gradation on both macroscopic limiting void ratios and microscopic pore structures remain inadequately quantified. In this study, DEM simulations of the loosest and densest packings of ideal spheres are conducted to isolate gradation effects from particle shape. The combined influences of the coefficient of uniformity ( C u ) and coefficient of curvature ( C c ) on limiting void ratios are systematically investigated, and predictive models are developed to accurately capture these effects, with both interpolation accuracy and extrapolation capability validated. Additionally, particle gradation effects on three‐dimensional pore structures are analyzed, revealing that pore size distributions are well described by the Weibull distribution. Predictive models linking Weibull parameters to gradation parameters are also proposed, demonstrating high accuracy across a wide range of gradations. These findings provide quantitative tools for predicting both macroscopic limiting void ratios and pore‐scale properties from particle gradation, offering valuable insights for geotechnical design and optimization.