Stability of Loaded Footings on Reinforced Soil

Results are presented of laboratory-scale bearing capacity tests using a 4 in. (100 mm.) square footing on sand reinforced with strips of a rope fiber material. Each layer of reinforcement was arranged in horizontal square grids. The addition of reinforcements increased the bearing capacity of the footing on the unreinforced soil by a factor which depended on the following: the horizontal spacings between strips on each layer, the vertical spacings between layers of reinforcement, the depths above the first layer of the footing, and the number of layers. Depending on the strip arrangement, the ultimate bearing capacity improvement could be up to three times that of the unreinforced earth.