Laboratory Investigation of the Resistance of Tailings and Natural Sediments to Cyclic Loading

A number of cyclic triaxial tests were carried out on mine tailings and natural sediment samples under undrained conditions to investigate their resistance to cyclic loading. The tests were performed on more than 100 samples with a cyclic shear stress ratio ranging from 0.10 to 0.40 under varying void ratio and the same confining pressure. It was observed that the axial strain and excess pore water pressure increased with the number of loading cycles while the effective stress decreased with increasing number of loading cycles. The liquefaction resistance of the tailings was also observed to be higher than that of natural soils with similar particle size distribution, void ratio and plasticity index. It was observed that the influence of specific gravity on the cyclic strength of mine tailings is significant. The results showed that the cyclic resistance of the tailings was not strongly influenced by plasticity index for low plasticity tailings. A boundary relationship between void ratio and normalized cyclic resistance ratio was established based on the results.