Laboratory study and numerical analysis for pull-out behaviors of geogrids confined by weathered mudstone and sandy soil

Among the pull-out behaviors of geogrids, it is important to note that pull-out resistance tends to increase along with increases in confinement pressure. For semi-rigid geogrids covered by cohesiveless particulate soils, most of the pull-out resistance of the geogrid is provided by passive soil resistance, while the greater portion of the pull-out resistance for geogrids covered by cohesive particulate soils is provided by friction. Using numerical analysis to simulate the conditions of the reinforced soil slope, it was found that sand backfill materials provided excellent results, while a relatively greater amount of weathered mudstone was needed for the same amount of reinforcement. When considering the use of fine grained soil as backfill, if undrainage is present, attention must be given to the grid's anchorage strength as force is exerted on the the soil structure.