Laboratory Large-Scale Pullout Tests for Evaluation of the Application of Waste Plastic Bottles as Transverse Members on Geogrid Reinforcement

In recent years, the application of geogrid in reinforced soil structures, including mechanically stabilized earth walls, has remarkably increased. In earthen structures reinforced with geosynthetics, the interaction between soil and geogrid is an important criterion for designing and controlling stability. Accordingly, finding solutions to improve and strengthen the parameters of the soil–geogrid interaction is demanding. The purpose of this study is to examine the effect of using recycled bottles as transverse members on geogrid by large-scale pullout tests; the new system is called Geogrid-Bottle (GG-B). The pullout tests results have shown that sand-filled recycled bottles can provide reasonable strength in the third dimension of the reinforcement and can increase the reinforcement resistance against the pullout force. The results showed that the GG-B system increased the pullout force by more than about 69% compared to geogrid alone. In addition, it was proved that the appropriate distance between the transverse bottles attached to the geogrid was four times as large as the bottle diameter (D) under different vertical stresses. Furthermore, results showed that displacements at the geogrid end decreased with increasing the number of bottles.