A Numerical Study of Load Distribution of Pile Group Foundation by 2D Model

Studies about pile group foundation have been rapidly increasing in number over the past years. However, past research works focused on pile settlement with consideration of a purely vertical load for pile groups or pile raft foundations. There were few studies with an emphasis on pile load distribution of pile group foundations together with a combined vertical load and a large overturning moment. For example, the foundation of a wind turbine carries a large overturning moment and vertical forces at the base of the structure. This paper presents a numerical study of load distribution of pile group foundations. A 2D numerical model using finite element software, PLAXIS 2D, has been employed to analyze the behavior of the pile group foundation. In the scope of analysis, pile group foundation consisting of large numbers of regular grid piles with a cross section of the strip of the pile row can be analyzed with a 2D model. For structural modeling, each pile is modeled as the embedded pile row. Modeling of pile group foundation is achieved by creation of a small gap between the plate element of the pile cap and the underlying soil, while the pile cap is rigidly connected with a small vertical plate segment which is hinged at the top of the embedded pile row. Several parametric studies, including numbers of piles, overturning moment ratios, stiffness of pile cap, and pile spacing, are also presented in this paper.