effect of the cylindrical reinforcing element’s filling materials on the soil’s resistance

in this paper a laboratory study has been carried out on the effect of changing the type of soil filling cylindrical reinforcing elements from sm to gm on behavior of sandy soil. in this study the primary tests for evaluation of the impact of reinforced sand and gravel columns with diameters of 5 cm and heights of 15 cm subjected to vertical stresses of 50, 100, and 150 kpa were carried out in a large-scale direct shear apparatus (300×300×150 mm). results showed that the shear stress and settlement of the reinforced sample with geogrid and a gravel column increases by 45.4% and decreases by 23.9% respectively compared to the non-reinforced sample.