A simplified method to analyze soil-pile-raft interactions

The paper describes a simplified method to analyze soil-pile-raft inte ractions. The settlement of each pile in pile group consists of the compression of the pile and the settlement of the pile toe. The compression of pile can be d etermined by static load test or estimated by Geddes’ method. The settleme nt of pile toe is calculated by layerwise summation method. The stiffness of each pile in pile group is determined by the average of loads acting on piles and the settlement of the pile top. Then the pile is modeled as a elastic spring with t he stiffness of the corresponding pile. The raft is modeled by the Finite Elemen t Method (FEM) with 16-node degenerated elements, to obtain its internal fo rc e and deformation.These elements are particularly suitable to model the raft wit h i rregular thickness and shape. Compared with other methods, the proposed me thod is rather easy and simple to estimate the pile stiffness and to model layered so ils. Its results are more reasonable than those obtained by other methods.At th e end of the paper, a case record is presented to show the effectiveness of this method.