Geosynthetics are widely used on slopes in several civil engineering structures such as waste facilities and hydraulic works, generally named geostructures, in particular to assure the water-proofness of these works. Generally, several geosynthetics are associated to meet the various expected functions (waterproofness, drainage, anti-puncturing…), so the stability of materials implemented over these geosynthetics systems is widely dependent on characteristics of the geosynthetics interfaces be-tween them or in the contact with grounds surrounding the system and on the geosynthetics internal sta-bility especially in the case of geocomposites. On the basis of these characteristics, different methods of calculation are used to justify the stability of these works.
The present communication approaches the various aspects of the justification of the stability of these works. A first part is dedicated to the calculation of stability for the thin layers on slope on a geomem-brane lining system of dam or waste disposal which can be realized on the basis of the standard NF G 38-067 (AFNOR 2017). But in numerous situations, this approach presents limits and questions remain open on the hypotheses and the consideration of the behavior of materials.
In a second part, we propose answers, on one hand, we have therefore developed a numerical approach based on the use of the FLAC software which enables to realistically model the behavior of geosynthetics taking into account the mechanical nonlinearities of the materials and interface constitutive laws; on the other hand we lead works for the determination of interfaces and internal shear resistance of geosynthetics ; new proposals of operating procedures are made to overcome the limits of the current standards.