Background This experimental study examines the performance of ring footing on geogrid-reinforced sandy soil under the combination of eccentrically inclined loading, which is a case that is commonly encountered in structures such as tower foundations, silos, tanks, and offshore supports. Methods An experimental laboratory program was conducted to evaluate three parameters: reinforcement length ratio (L/B), spacing ratio between layers (Z/B), and number of geogrid layers (N). Tests were performed under eccentricity ratios e/B = 0, 0.04, 0.08, and 0.16, and load inclination angles α = 0°, 5°, 10°, and 15°. Results The outcomes showed that the optimal values of the parameters that achieving substantial improvement in both bearing capacity and tilting resistance were identified as L/B = 5, Z/B = 0.50, and N = 4 layers, which increased the bearing capacity by approximately 200% and enhanced tilting resistance by up to 1.52 under the most critical values of (e/B = 0.16, α = 15°). On the other hand, spacing ratios of (Z/B = 0.25 and 1.25), which are too small or too large, and the addition of layers beyond N = 4 resulted in minimal benefit due to ineffective stress transfer and reduced soil-reinforcement interaction. Conclusions The study outcomes offer recommendations for the optimal values of reinforcement parameters that optimize ring footing performance while maintaining cost-effectiveness under complex loading conditions of eccentrically inclined loads.
J.Y.M et al. (Sat,) studied this question.