Investigating the effects of particle spatial evolutions on the vibration-induced compaction deformation of gap-graded mixtures via DEM models

Abstract

The vibration-induced compaction deformation of gap-graded mixtures is caused by changes in particle spatial distributions. This study utilizes the discrete element method (DEM) to obtain spatial distribution information and verifies the accuracy of DEM models through physical tests. Spatial autocorrelation analysis and neighbor matching tests quantify spatial distributions in terms of particle aggregation. The correlations between mixture deformation and particle spatial distribution are investigated, with discussions on the influences of size ratio (SR) and fine content (FC). Results show a strong correlation between deformation and particle motions in mixtures with SR = 3, while the correlation becomes complex for mixtures with SR ≥ 4.45. Weakened aggregation facilitates pore-filling by fine particles and promotes deformation in mixtures with FC = 10%. Mixtures with 20% ≤ FC ≤ 30% exhibit the smallest deformation due to opposing particle motions and effective pore-filling by dispersed fine particles. Mixtures with FC > 40% experience deformation related to the aggregation state of coarse particles, despite being primarily composed of fine particles. This study sheds light on the vibration-induced deformation mechanism of mixtures through a mesoscopic perspective of particle spatial distributions.