The effect of transverse elements added to geogrid on pullout resistance and load bearing performance

The utilization of geosynthetics is a widely adopted practice to improve the strength of soils. Among geosynthetics, geogrids stand out due to their cellular structure, high strength, cost effective and environmentally friendly characteristics. The internal failure mechanisms of geogrid primarily involve rupture due to tensile stress and pullout from the soil. This study aimed to increase the interaction between the geogrid and the soil, thereby enhancing pullout resistance thanks to the adopting of vertical geomembrane barriers in front of the geogrid's transverse ribs. Furthermore, the study investigated the impact of adding geogrid barriers at various distance of intervals. The effectiveness of geomembrane barriers was assessed through pullout experiments conducted in silty gravel with sand type of soil (GM) with a 99.13% compaction ratio. Results from experiments conducted under three different normal stresses highlighted the positive contribution of geomembrane barriers to pullout resistance. Additionally, reducing the distance between barriers strengthened soil-reinforcement interaction. The added barriers caused deformations in the geogrid longitudinal rib to concentrate more in the section where pullout force was applied. Beyond pullout experiments, the study examined the impact of barriers through load-bearing tests by constructing a 1.00 m high mechanically stabilized earth wall with modular block facing subjected to strip footing loading. The beneficial effects of geomembrane barriers were clearly observed concerning both loadbearing capacity and facing displacement.