Micromechanical Effects of Shape‐Induced Fabric on Cyclic Liquefaction of Saturated Sand: A CFD‐DEM Study

The liquefaction susceptibility of saturated sands is commonly evaluated using macroscopic indices such as relative density and confining pressure, whereas the role of particle morphology remains less well understood. In this study, a coupled computational fluid dynamics‐discrete element method (CFD‐DEM) framework is used to investigate particle‐shape effects on liquefaction under a unified deposition and cyclic loading protocol. Three idealized assemblies composed of 1‐sphere, 2‐sphere, and 3‐sphere particles are compared. The results show that particle shape affects packing state, permeability, depositional fabric, and load‐bearing skeleton stability. Although the 2‐sphere assembly has the densest initial packing, it exhibits the fastest excess pore‐pressure buildup and the lowest liquefaction resistance. The 1‐sphere assembly shows the slowest pore‐pressure accumulation and the highest liquefaction resistance, while the 3‐sphere assembly exhibits an intermediate response. The higher permeability of the 1‐sphere assembly may partly promote pore‐pressure dissipation, but the similar permeabilities of the 2‐sphere and 3‐sphere assemblies cannot explain their markedly different liquefaction responses. Micromechanical analyses show that the 2‐sphere assembly undergoes more rapid fabric and contact‐network degradation, whereas the 3‐sphere assembly maintains greater stability through stronger geometric interlocking. These results indicate that liquefaction resistance is governed by the coupled effects of hydraulic characteristics and shape‐induced microstructural evolution rather than by packing density or permeability alone.