Influence of Geogrid-Axial Stiffness on Bearing Capacity of Geogrid-Reinforced Fine Sand

Geosynthetics are man-made materials used to increase the tension, compression, and shear characteristics of soil. Geogrid-reinforced material is regarded as one of the most widely used soil reinforcements. The Abaqus software (Ver. 2017) is used to simulate a 3-D fine sand model. The load-carrying capacity is investigated for both unreinforced and geogrid-reinforced fine sand supporting a 2.0m x 2.0m square footing. The relative density (Dr) of un-reinforced fine sand is 40%, the geogrid axial stiffness (J) used in the analysis varies at 250 kN/m, 500 kN/m and 1000 kN/m. The bearing capacity ratio (BCR) of geogrid-reinforced fine sand is influenced by the use of geogrid-layers with different axial stiffnesses (J). The influence of geogrid axial stiffness is evaluated using four investigated parameters: geogrid-layers number (N), vertical spacing (h/B), geogrid width/length (b/B), and first geogrid-layer depth (u/B). The results show that the numerical model validation agrees with the experimental results of Hotti and Gupta with an agreement ratio of 98% and 93%, respectively. The geogrid-reinforced fine sand with appropriate dimensions and proper geogrid-layers number has significantly increased the square footing bearing capacity. The load-bearing capacity of geogrid-reinforced fine sand increases with geogrid axial stiffness. The bearing capacity ratio is 1.45 and 2.13 when the geogrid axial stiffness increases from 250 kN/m to 500 kN/m and from 250 kN/m to 1000 kN/m, respectively. The most efficient and economical values of (u/B), (b/B), (h/B) and (N) are 0.30, 3.0, 0.15 and 3.0 for all values of geogrid axial stiffness, respectively.