The interaction mechanism of geosynthetics-soil interface is complicated and also important for designing the geosynthetics reinforced structure. A series of large scale direct shear tests

using Fujian standard sand and Fiberglass geogrid

are used to investigate the influence of longitudinal and transverse ribs and aperture pattern on the interface shear behavior of soil against geosynthetics. The test results show that both the longitudinal and transverse ribs play an important role in improving the interface strength through different courses of action. The shear force of interface will be shared by passive resistance of transverse ribs and friction resistance of longitudinal ribs when shear displacement is small; while the longitudinal ribs present the role of framework to improve the geogrid stiffness with the increasing of transverse resistance due to the shear displacement increasing. Therefore

coordinate work of longitudinal and transverse ribs will help to advance the interface shear strength.