<p>This paper aims to determine the impact of sand-clay bond in geo-grid and geo-textile on bearing capacity. In doing so, we examined clay-geo-synthetics, sand-geo-synthetics and clay-sand-geo-synthetics samples using direct shear tests. The friction between clay and reinforcement was provided by encapsulated-sand system.</p><p>This method is used to transfer the tensile force mobilized in geo-synthetics from sand to clay and improve the strength parameters of clay. This study indicated that the provision of a thin layer of sand at both sides of the reinforcement significantly improved the shear strength of clay soil.</p>Bond coefficient computations indicated that the shear strength of clay-geo-synthetics samples was higher than non-reinforced clay. The increased strength was due to the impact of open meshes of geo-synthetics which provided some degree of resistance bearing. To determine the share of resistance bearing provided by geo-synthetic transverse members in the entire direct shear strength, we conducted a series of tests on geo-synthetics-reinforced samples with and without transverse members. The resistance bearing provided by geo-synthetic transverse members was almost 10% of total shear strength. The results indicated that encapsulated geo-grid and geo-textile sand system increased the bearing capacity of clay, with geo-grid being more efficient than geo-textile.