Settlement and Mobilized Bearing Capacity of Circular Footings on Geosynthetic-Reinforced Sand: Experimental and Numerical Study

Abstract Circular footings are common in towers and tanks but their performance on geosynthetic-reinforced sands remains underexplored. We present an integrated experimental–numerical–analytical study using large-scale plate tests on geogrid-reinforced sand and validated 3D simulations extended to geocell reinforcement. The work delivers settlement-dependent performance maps and a bounded predictor for design. Geogrid tests show bearing improvement factors up to I f = 1.82 (for s/D > 5%) and PRS reductions up to 25%. Optimum ranges are u/D≈0.10–0.25, WD ≤ 1.5 (≈WD < 445 mm for D = 300 mm), with diminishing gains for N > 2. Numerical analyses reproduce experiments within ≈10% and reveal deeper mobilization of soil mass with geocells, explaining plateaus observed at large WD and depth. A settlement-dependent empirical equation is proposed with stated validity ranges and external validation (MAE ≤ 10–15%). The results provide mechanistic insight and practical guidance for circular foundations reinforced by geosynthetics, emphasizing when reinforcement is most effective and when densification or fewer layers suffice. This integrated approach advances understanding of soil–footing–reinforcement interaction and offers practical design guidance for circular foundations on granular soils.