Influence of Consolidation Pressure on Cyclic and Post-cyclic Response of Fine-Grained Soils with Varying Mineralogical Compositions and Plasticity Characteristics

In this study, nine different soil samples with varying mineralogical compositions with a wide range of plasticity characteristics were consolidated to five different normal stresses prior to testing in the cyclic simple shear apparatus, where cyclic loading in the form of a sinusoidal wave form with a frequency of loading of 0.5 Hz and varying amplitudes was applied. The shear strength of the samples immediately after cyclic loading were also determined and compared to the static shear strength to determine the reduction in shear strength resulting from the cyclic loading. The results were used to determine the cyclic strength curves for each sample at 2.5%, 5%, and 10% double amplitude shear strain. These curves demonstrated that an increase in the consolidation pressure corresponded to an increase in the cyclic resistance. The post-cyclic undrained shear strength measurements suggested that an increase in the consolidation pressure would cause a lower reduction in undrained shear strength as a result of cyclic loading.