Liquid limit as a predictor of shear modulus degradation in high-plasticity soils with and without diatoms

This research compares the effect of diatoms and high-plasticity clays on the shear modulus degradation curve. For this purpose, the degradation curve of the shear modulus was measured in different mixtures based on kaolin and bentonite or kaolin and diatoms. A hyperbolic model was used to fit the experimental data for these two types of mixtures. The results suggest that the reference strain of the model can be better described in terms of the liquid limit rather than the classical plasticity index approach. Surprisingly, despite the very different mechanisms for increasing soil plasticity given by high-plasticity clays or diatoms, the effect of both types of particles can be described by the same phenomenological approach when considering the liquid limit as a descriptor.