Large-Strain Damping of Sands: Parameter Effects

Abstract

A recently developed damping calculation method for undrained load-controlled cyclic tests was implemented on some 70 cyclic triaxial and direct simple shear tests conducted by various researchers on a range of different sands for a correct understanding of the high-strain (0.1%–4%) damping behavior of sands. The effect of various controlling parameters was investigated, including the shear strain, confining stress, number of cycles, void ratio, gradation, nonplastic fines content, and overconsolidation ratio. The data analysis shows that general trends at high strains are in good agreement with the damping behavior of sands at small strains. The results also indicate a direct correlation between the damping behavior of sands and cyclic strength. The recently proposed guideline on load-controlled damping ratio bounds for clean sands at high strains was also in good agreement with the damping behavior of sands with nonplastic fines content up to 25%.