On the Comparison Between the Approximate And Precise Methods of Piled Raft Foundation Analysis

Use of raft foundation to support heavy and tall building may provide the overall safety factor against design loads but the average and differential settlement could exceed the allowable value. On the other hand, utilizing pile group may be an expensive option. In this situation, use of composite pile group and raft foundation that called “Piled Raft Foundation” seems a suitable choice. This foundation is a composite geotechnical system of three bearing components: raft, pile group and soil. The applied load on the raft is transferred to the underlying soil by the contribution of raft and piles. Therefore, considering the interaction effect between the components is essential. It causes some complexities in predicting the behavior of piled rafts. Thus, on this basis, so many different methods were developed. In this study, a comparison between these different methods including approximate and precise methods are presented. Based on the results, a three-dimensional finite element analysis gives perfectly satisfactory results in the prediction of bearing and settlement behavior of piled rafts.