Reinforcing geosynthetics are used for lot of geotechnical works: embankments, bases stability on soft soils, secure a risk of potential sinkholes, retaining walls reinforcements, asphalt reinforcements, reinforcement of load transfer platforms on piles, optimization of road structures. Their utilization permits also to minimize the environmental footprint and construction costs ( reduction of the quantity of soil material used). For these constructions, a long-term design is asked (50 to 100 years). To guarantee the functionality of the geosynthetic during all the life of a construction, safety factors are used in calculations, according to different standards including for instance Eurocode 7, NF P 94270, NFG 38064. Four main partial safety factors are: Creep reduction factor RFCR, Chemical degradation reduction factor RFCH, Installation damage reduction factor RFID, Global geosynthetic reduction factor RFg.