A Predictive Model for Pullout Bearing Resistance of Geogrids Embedded in a Granular Soil

Currently, Geosynthetic-Reinforced Soil (GRS) structures represent one of the most sustainable solutions capable to improve the protection of the territory, guaranteeing high performance (especially in seismic field) with construction costs that are lower than those required for the more traditional Civil and Environmental engineering works. To design such types of structures the knowledge of soil-geosynthetic interface parameters is necessary, and their prediction is very complex due to the elementary interaction mechanisms affecting the pullout resistance of geogrids embedded in soils that are mainly the skin friction between soil and the reinforcement’s solid surface, and the bearing resistance developing on transverse elements. When the spacing between the geogrid’s transverse elements is below a threshold value, the interference mechanism develops and it can affect the bearing resistance, as the passive surfaces cannot be entirely mobilised on bearing members. In order to model the peak pullout resistance of extruded geogrids embedded in a compacted granular soil, the paper deals with a new experimental validation of a theoretical method taking into account the interference mechanism.