ABSTRACT
The shear behavior of sandy soils containing gravel particles has been investigated by many researchers. Mixtures with 40% and 60% gravel contents were prepared to investigate the effect of gravel size on the shear behavior in higher gravel contents. The contact forces between particles are more for larger gravel grains compared to the smaller ones due to the more contact surface that leads to higher shear strength. A regular set of direct shear tests performed on mixtures of sand and different types of gravel grains to investigate the effects of gravel grain shape and size on the shear behavior of sand-gravel mixtures. The effect of gravel grain angularity is more obvious in higher gravel contents. The friction angles of the mixtures containing different amounts of gravel content were also studied and it was understood that the increase in gravel content results in more friction angle.
