Bearing capacity of two asymmetric differently loaded concrete footings seated on geocell-reinforced sand slopes

Abstract

In practical scenarios, it is common to encounter adjacent reinforced concrete (RC) footings that have different loads and shapes near the top of a stabilized slope. The proximity of these footings, along with the reinforcement and slope characteristics, can influence the bearing pressure and failure mechanisms. Surprisingly, the existing literature has not adequately addressed the behavior of closely spaced non-identical footings with varying loads on reinforced soil. To fill this knowledge gap, our study focused on modeling two non-identical RC footings on both unreinforced and geocell-reinforced sand (GRS) slopes. These footings were subjected to different gravity loads from buildings of various sizes. For this purpose, a series of large-scale experiments and carefully selected relevant case studies involving sand were conducted. By considering optimal values for the embedment depth and geometry of geocell reinforcement, the combined effects of footing asymmetry, material properties, load intensity, and geocell reinforcement on the bearing pressure of the RC footings were investigated. The impact of the spacing ratio between footings and their distance from the edge of the slope on the overall performance and efficiency of the RC footing systems was also explored. Results were presented using non-dimensional efficiency factors and bearing capacity improvement parameters. Findings conclusively demonstrated that the inclusion of geocell reinforcement, combined with the interference effect between footings, significantly enhanced the load-carrying capacity of the non-identical RC footing systems on slope surfaces, resulting in a remarkable improvement exceeding 300%. Additionally, broader footings exhibited higher levels of efficiency and improvement, with variations based on the distance of the footings from the slope crest and the disparity in load intensity.