On the influence of nonplastic fines on residual strength

Toyoura sand was milled into a nonplastic silt and then the series of mixtures was made from the two materials, with the increasing content of silt, from 0% to 100%. The specimens were prepared into the loosest state using three methods of preparation. In dry state, with an increase in the silt content, the maximum void ratio increased, the peak and residual strength decreased and the quasi-steady state line in the logp', e space moved downwards with the increase in the silt content up to 30%. With further increase in the silt content, contractiveness decreased, strength increased and the quasi-steady state line moved upwards. These results show that some values of silt content are extremely dangerous.