Experimental study of the shear resistance of granular material: influence of initial state

The shear strength of sand and its mechanical properties can be affected by numerous para-
meters. This work presents an experimental investigation which aims to study the influence
of the fines content, the depositional method and the grain size on the shear strength of
Chlef sand. Tests were conducted with the shear box on two types of soil, the natural sand
and the clean sand-silt mixture. Dense samples (Dr = 88%) were reconstituted through dry
deposition for each type of the material. An additional series of tests was carried out on
a medium dense natural sand (Dr = 52%) prepared by dry and wet (w = 3%) deposition
methods. All specimens were subjected to normal stresses of 100 kPa, 200 kPa and 300 kPa
and there was no immersion of water. The tests results show that the behavior of sand can be
affected by three parameters, the fines content, the deposition method and the particle size.
The maximum shear stress and the friction angle decrease as the fines content increases, the
initial water content increases, the effective grain size diameter decreases and the uniformity
coefficient increases. The cohesion intercept increases with the increasing fines content and
decreasing initial water content. Overall, the samples prepared by the dry deposition me-
thod show more resistance than those prepared by the wet deposition method. The results
obtained are generally in agreement with the previous research on drained and undrained
saturated sand in the literature.