Interplay of particle size distribution and relative density in cyclic liquefaction resistance

This study investigates the interplay of particle size distribution and relative density on the cyclic liquefaction resistance of sands using three-dimensional discrete element method simulations. Assemblies with varying coefficients of uniformity (Cu) were prepared at two relative densities and underwent constant volume cyclic shearing at the same cyclic stress ratios until initial liquefaction. Results show a non-monotonic relationship between Cu and liquefaction resistance: an initial increase in resistance with increasing Cu, followed by a decrease beyond a critical Cu value, consistently observed at both relative densities. Micromechanical analyses demonstrate that this trend correlates with the rate of decline of the mechanical coordination number during the pre-liquefaction phase. A power-law relationship is established between the cyclic resistance and the rate of coordination number reduction, providing insight into the underlying fabric evolution mechanisms.