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 parameters. 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 method 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.