In projects of geosynthetically reinforced soil, the design tension values are obtained by considering a global reduction factor on the standard strength value for the reinforcement. This reduction factor is usually subdivided in partial factors, so they may take into account the independent effects of mechanical damage, biological degradation and creep deformations. In reinforced masses, the reduction factor due to mechanical damage is most important and may contribute for a significant reduction of the material’s ultimate strength. This paper presents results of pullout tests carried on with mechanically damaged geogrids. Two different geogrids were used in this experimental program. Damage was imposed artificially by physically rupturing a few selected grid elements. The objective of these tests consisted in the influence study of the mechanical damage in the geogrids behavior. The pullout tests were executed under different conditions of relative density. The results indicat that the influence of the damage increases with the relative density of the soil, and suggest that the damage should be investigated from confined tests, taking into consideration the soil-geogrid interaction.
Mechanical damage; geogrids; reinforced soil
