Load-settlement behavior of vertically loaded pile groups in sand

With the fast growth of metropolitan areas and quick industrialization stemming from fast-paced global economics, there has been a need to build heavier and higher buildings on marginal locations, where surface soils are weak and shallow foundations are typically not the ideal design option. The aim of the deep foundation is to transfer a very large load to the layer that can withstand the load, thereby, giving the foundation the tenacity to withstand all load types, such as vertical or lateral, and also minimize the settlement to the required degree. Pile group foundation is one of the deep foundations used widely in civil engineering structures. The pile group foundation is designed based on the ultimate bearing capacity. There are lots of factors that affect the bearing capacity of the pile groups. By controlling these factors, the bearing capacity of group piles will be improved and the cost of the project will be economical. The aim of this study is to show the effect of changing the spacing-diameter ratio, number of pile, and soil relative density of pile group foundation by experimental tests in the laboratory, and validation all of the results by theoretical and finite element analysis methods. Using Plaxis 3D (V20.1) for the analysis of finite element analysis. A total of 36 experiments were performed in the laboratory by using model steel piles embedded in a sand soil in a three different relative density (Dr=10%, Dr=40%, and Dr=65%). The piles of the model have a diameter 10 mm and embedded 330 mm. Three distinct pile-group configurations (3x3, 4x4, and 5x5) of center-center spacing between the 1.5D, 3D, 4.5D, and 6D piles (D is the diameter of the pile) were tested under vertically loaded pile groups. The result of this study shows that the bearing capacity of pile groups will increase and settlement decrease with increasing number of pile and relative density of soil. For the spacing to diameter ratio effect, the bearing capacity will decrease with increasing the spacing between piles under vertically loaded group pile.