Influence of particle size on the drained shear behavior of a dense fluvial sand

Particle morphology, including particle shape and particle size, has significant influence on the shear behavior of granular soils. The effect of particle shape has been investigated in several studies. However, the effect of particle size has not yet been paid much attention. In this study, the effect of particle size on the shear strength and the stress-dilatancy behavior of sands was assessed through a series of drained triaxial compression tests on dense uniform silica sands. The effect of particle size was analyzed on various aspects of mechanical behavior: the stress-strain response, the shear band formation, the peak-stress axial strain, the peak dilation angle, the peak friction angle, the critical-state friction angle, and the stress-dilatancy relations. Furthermore, we noticed that the particle shape of silica sands usually varies with particle size. The effect of this morphologic characteristic on mechanical behavior was also discussed by comparing the experimental results on silica sands with those reported on glass beads and Peribonka sand (Harehdasht et al. in Int J Geomech 17:04017077, 2017). The results show that particle size significantly influences the peak friction angle, the peak dilation angle and the stress-dilatancy behavior. The underlying mechanism for the effect of particle size was discussed from the perspective of kinematic movement at particle level.