Influence of particle-size disparity on cyclic liquefaction resistance of silty sands

Liquefaction of silty sands remains puzzling due to the complexity involved in the interaction between coarse and fine particles during loading. This paper presents first-hand experimental data from a series of cyclic triaxial tests under controlled particle characteristics, with the aim to elucidate the influence of particle-size disparity on the liquefaction resistance of sand-fines mixtures. A detailed analysis of the test results and an experimental database compiled from the literature reveal that the particle-size disparity, defined as the ratio between the characteristic sizes of the base sand and the fines, is a major and rational factor controlling the reduction of cyclic resistance of sand-fines mixtures as compared with factors such as the grading and shape of the base sand. A simple, explicit expression is further proposed to properly account for the reduction of cyclic resistance of sand due to fines.