The use of geosynthetics in geotechnical construction is growing up intensively on the last years, which make the study on interface strength more important and necessary to its application on projects and construction. Particularly, these studies should watch out field and laboratory tests in order to obtain strength parameters (adhesion and friction angle). Laboratory tests are more frequently used, due to their accessibility and easy execution. Field tests reproduce construction condition in a directly way, but have as disadvantages high cost and hard execution condition. The current research have as objectives present the test equipment used and analyze software results obtained for soil and geosynthetic interfaces. The experimental program involved ramp tests, conventional direct shear test and inclined direct shear test. This program was carried out on gravel soil in contact with two different types of geosynthetics (geomembrane and geogrids). Results were analyzed based on the influence of confining pressure and the introduction of geosynthetics, and comparing the different materials and test techniques. The confining pressure influence/importance was studied based on three different low magnitude confining pressures (1,0; 1,7 e 2,4kPa). The confining pressure increases resulted in an increase of both displacements until the failure and interface strength. This behavior could be explained due to the possibility of interlocking e between the gravel grains. Considering the geosynthetic type, gravel-geogrid interface presented higher strength than gravel- geomembrane interface. This could be explained by the structure of the geosynthetic; geomembrane has low strength due to its smooth surface, which benefits the slide. Geogrid instead, counts with the soil interlocking; effects in the mesh holes.