Strength and dilatancy of silty sand

Fines content can have a great influence on the mechanical behavior of sand. The effect of fines content has not been taken into account in most of the strength-dilatancy relationships for sand. An attempt was made in this paper to account for the influence of fines content on the strength-dilatancy relationship of silty sands. The test data on Ottawa sands with nonplastic fines were reanalyzed to examine the strength and dilatancy relationship for silty sand with different fines contents. The ratio of excess angle (which is the difference between the peak friction angle and the critical state friction angle) to the relative dilatancy index was found to be a function of fines content. Furthermore, a strengthdilatancy relationship was also modified to account for the influence of confining pressure on the strength-dilatancy relationship of silt sands.