Bearing capacity of Multi-Edge shallow foundations on geogrid reinforced sand

Increase in bearing capacity of shallow footing is one of the most important issues in geotechnical engineering. For this purpose, various methods exist such as geometry improvement, interference effect, soil improvement and soil reinforcement by materials such as using Geosynthetics .This paper aims to investigate the increase in the bearing capacity of shallow foundations constructed on sand using geogrid reinforcement layers. The foundation is assumed to be plus shape. For carrying out analyses, three dimensional modeling has been used to simulate soil-foundation-reinforcement layers using Flac3D.The failure stage in the sand was controlled using the Mohr–Coulomb failure criterion. Numerical results were compared with those obtained from other experiments and were found to be in good agreement. The study highlights the effect of the footing size, number of reinforcing layers, reinforcement placement within the soil, bond length and the relative density of the soil on the load-settlement characteristics of the footings. The Influence of all these parameters on the bearing capacity improvement of multi-edge footing is studied by comparing with the square footing shape on unreinforced sand. In short, the results showed that the bearing capacity of multi-edge footings increases with the use of geogrid layers, depending on multi-edge footings size. The best geometry of multi-edge footings and orientation of the geogrid layers were determined to achieve the maximum bearing capacity. The results show that the ultimate bearing capacity of multi-edge foundations on the reinforced sand is generally greater than that of square shaped foundation of the same width.

Keywords:

foundation , Bearing capacity , Sand , Soil reinforcement