Ultimate bearing capacity analysis of strip footings on reinforced soil foundation

Reinforced soil foundations (RSFs) have been employed in engineering practice to increase the soil bearing capacity and to reduce the potential footing settlement. The aim of this study is to develop analytical solutions for estimating the ultimate bearing capacity of strip footings on RSFs. A general failure mode for RSFs was first proposed based on previous studies conducted by the authors and test results from literature study. A limit equilibrium stability analysis of RSFs was performed based on the proposed failure mechanism. New bearing capacity formulas, which consider both the confinement and the membrane effects of reinforcements on the increase in ultimate bearing capacity, were then developed for strip footings on RSFs. Several special cases of RSFs were presented and discussed. The proposed model was verified by the experimental data reported in the published literature. The predicted ultimate bearing capacity was in good agreement with the results of model tests reported in the literature. The study showed that the depth of the punching shear failure zone (DP) depends on the relative strength of the reinforced soil layer and the underlying unreinforced soil layer, and is directly related to the reinforced ratio (Rr).