Evaluation of Optimal Design Parameters of the Geogrid Reinforced Foundation with Wraparound Ends Using Adaptive FEM

This paper presents the numerical study based on the adaptive finite element analysis of the bearing capacity of a strip footing on reinforced soil mass. A parametric study has been conducted to estimate the ultimate load-bearing capacity of footing having a width, B resting over reinforced soil mass (q_{ult, R}) using wraparound ends configuration of geogrids. Based on the load-settlement response, the bearing capacity ratio (BCR) for all the studied wraparound ends configurations are evaluated, and their potential failure envelopes have been discussed. From the study, the optimum values of the wraparound end reinforcement geometrical configuration are noted as normalized width of reinforcement (b/B) = 3; depth of the first layer of reinforcing layer from the bottom of the footing to the width of footing ratio (u/B) = 0.25; normalized vertical spacing between successive layers of reinforcement (h/B) = 0.30; normalized vertical length of the wrapping ends (d/B) = 0.20; and the normalized lap length of wrapping ends of geogrid (l/B) = 0.50. The results noted from the study indicates that the axial elastic stiffness of the geogrid (EA) governs the ultimate bearing capacity of footing and the q_{ult, R} is improved by almost 62% for settlement ratio (s/B) = 10%, upon reinforcing the soil mass with wraparound ends technique at EA = 5000 kN/m. This study also focuses on the normalized vertical stress (σ_yy/q_u) and normalized vertical strain (ε_yy/q_u) of the soil mass beneath the footing to investigate the influence of reinforcement on the soil mass beneath the footing.