Bearing Capacity of Strip Foundations in Reinforced Soils

A method is proposed to determine the ultimate bearing capacity of a strip footing placed over granular and cohesive-frictional soils that are reinforced with horizontal layers of reinforcements. The reinforcement sheet is assumed to resist axial tension but not bending moment. The analysis was performed by using the lower bound theorem of the limit analysis in combination with finite elements. A single layer and a group of two layers of reinforcements were considered. The efficiency factors ${\eta }_{\gamma }$ and ${\eta }_c$ that need to be multiplied with the respective bearing capacity factor $N_{\gamma }$ and $N_c$ to account for the inclusion of the reinforcements were established. The results were obtained for different values of the soil internal friction angle ($\varphi$). The critical positions of the reinforcements, which would result in a maximum increase in the bearing capacity, were established. The required tensile strength of the reinforcement to avoid its breakage during the loading of the foundation was also computed. The results from the analysis were compared with those available in the literature.