Strain-Dependent Dynamic Properties of Remolded Sand-Clay Mixtures

Abstract

A series of undrained cyclic torsional simple shear tests using hollow cylindrical torsional shear apparatus was carried out to investigate the dynamic shear moduli and damping properties of clayey specimens with various sand contents and plasticity indices. The clayey soils used were collected from various sites along the coast of west Japan. Among these clayey soils, a clay sample with intermediate plasticity and another with high plasticity were mixed with silica sand at different proportions in order to examine the dynamic properties of sand-clay mixtures. In addition, experiments were carried out on undisturbed and remolded natural clay specimens with various plasticities. The effects of plasticity, loading frequency and confining pressure on the strain dependent normalized shear modulus and damping ratio were examined. Based on the results, empirical correlations for predicting the normalized shear modulus and damping ratio of remolded sand-clay mixtures at various shear strain levels were proposed.