An Experimental Study on the Influences of Particle Size on Small-Strain Shear Modulus of Granular Soils

Under small strains, the shear-wave velocity (Vs) and its resultant maximum shear modulus (Gmax) are important parameters in geotechnical engineering soil dynamics analyses. In this regard, the evaluation of the influences of soil particle size on the dynamic behavior of soils during wave propagation has been an important issue in geotechnical engineering. According to the relevant literature, the influences of grain size on shear wave velocity of soil were completely different in various research studies. This research aims to experimentally examine the effects of a wider range of particle sizes, on maximum shear modulus in dry sandy soils, using a bender element apparatus embedded in a triaxial cell. The results indicated that maximum shear modulus of sand was considerably affected by changes in grain size so that in a particular range of grain size, shear modulus increased as the diameter of soil grains rose, while, in the other range, maximum shear modulus diminished with increasing grain diameter.