Particle-void fabric and effective stress reduction in cyclic liquefaction of granular soils

Abstract

During undrained cyclic loading, granular soils undergo the reduction of effective stress in the constant volume condition. Revealing the evolution of particle-void 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 particle size distributions and void ratios. With the decrease of mean effective stress p' during cyclic liquefaction process, the decrease of particle-void descriptor Ed can be observed for all packings. From micromechanical perspective, large size voids are redistributed and 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 positive correlation between Ed and p'.