The Relationship Between Particle-Void Fabric and Pre-liquefaction Behaviors of Granular Soils

When driven by undrained cyclic shearing, saturated granular soils will experience the increase of excess pore water pressure and the decrease of effective stress. This phenomenon is termed as “cyclic liquefaction” or “cyclic softening”. Revealing the evolution of fabric in accompany with effective stress reduction provides a significant insight into the fundamental mechanism of cyclic liquefaction. In this study, numerical tests were conducted in DEM simulations to explore the cyclic liquefaction of granular packings with different void ratios. With the decrease of mean effective stress p′ during cyclic liquefaction process, the decrease of particle-void descriptor E_d can be observed for all packings. From the micromechanical perspective, large size voids are redistributed and the local void distribution around particle becomes relative uniform. The change of particle-void fabric from consolidated state to initial liquefaction state is irrelevant to density of the packing. A power function is further adopted to describe the negative correlation between E_d and p′.