Backfill-geogrid interaction: insights from pullout tests and numerical simulation

Abstract The study investigates the interaction between geogrids and two distinct granular backfill materials, Yamuna sand and coal mine overburden through a combination of laboratory experiments and numerical simulations. It evaluates the physical and mechanical properties of coalmine overburden and Yamuna sand, and the pullout performance of geogrid embedded in both materials. A large-scale pullout box was utilised to conduct the experiments, and the results showed that coalmine overburden offers higher pullout resistance than Yamuna sand. The effect of physical parameters such as elasticity of geogrid, geogrid geometry and angle of inclination were analysed using the discrete element method. The pullout resistance of geogrids mainly depends on the elastic properties of the material. The study also shows the existence of an optimum spacing between longitudinal and transverse ribs.