Piled raft foundation design: A method to consider interaction effects

Abstract

Pile-soil-raft interactions are important factors that control the piled-raft foundation behavior. This paper presents a method to consider these interactions in the design of piled-raft foundations. The piles and the soil were modeled as springs supporting the raft, which was modeled as a plate. The interactions were taken into account by interaction factors due to the spring spacing. The ultimate load capacity of the piles was also considered when the foundation was subjected to large vertical loads. In addition, this method estimates the nonlinear behavior of the piled-raft foundation by using the nonlinear behavior of its piles. A 16- pile raft and a 9-pile raft with different pile lengths resting on homogeneous silica sand are used to illustrate the application of the method. Centrifuge models of these foundations were tested in order to verify the results of the numerical method. A good agreement between centrifuge modeling and the proposed method was obtained.