A series of model tests were conducted to investigate the bearing capacity and reinforced mechanism of a horizontal-vertical (H-V) geogrid-reinforced foundation. The bearing capacities of the unreinforced foundation, the conventional geogrid, and the H-V geogrid-reinforced foundation were compared. The parameters, including the length of the H-V geogrid, the vertical geogrid height, the depth of the top layer, and the number of H-V geogrid layers, are discussed. Through experiments, it was found that the optimal length of H-V geogrid is around 4B, the optimal vertical geogrid height is approximately 0.6B, and the optimal depth of the top H-V geogrid layer is between 0.33B and 1B. The optimal number of H-V geogrid layers is 2. The result also indicates that the bearing capacity of H-V geogrid is almost 1.7 times greater than that of conventional geogrid. Additionally, the maximum top subsidence of H-V geogrid-reinforced foundation decreased by 13.63% compared to that of conventional geogrid-reinforced foundation. Under the same settlement, the bearing capacity ratio of two H-V geogrid-reinforced foundation layers is 75.28% higher than that of one layer. The results also demonstrate that the vertical elements of H-V geogrid interlock the sand from being displaced under the applied load and redistribute the surcharge over a wider area, thereby increasing the shear strength and improving the bearing capacity of an H-V geogrid-reinforced foundation.
Keywords: bearing capacity; foundation; horizontal–vertical geogrid; reinforced mechanism; strip footing.