Factors Affecting Small-Strain Shear Modulus of Sand-Silt Mixture Considering Different Moisture Contents

The factors affecting the small-strain shear modulus of sand-silt mixture in the saturated or dry state have been studied in the last two decades. The present work investigated the effect of moisture content on the dependence of small-strain shear modulus on the fine content, void ratio and confining pressure for a poorly graded sand mixed with the non-plastic fines. For this purpose, using the triaxial apparatus equipped with the bender element device, the isotropically consolidated samples were first subjected to shear wave and then sheared monotonically by applying a constant rate of axial strain. The results of tests indicated that the small-strain shear modulus follows an increasing-decreasing trend, while the moisture content increases. The change in small-strain shear modulus in terms of fine content is significantly affected by the moisture content. In this way, contrary to the dry state, an increasing trend was developed with increasing the moisture content when the silt content increases. The application of equivalent intergranular void ratio leads to the further concentration of data about the trend curve of small-strain shear modulus.