Settlement of Piled Rafts with Different Pile Arrangement Schemes via Centrifuge Tests

Abstract

In the design of piled raft foundations, the control of total and differential settlements is crucial. On the basis of centrifuge tests, this study presents the feasibility of a fairly optimal pile arrangement scheme for reducing total and differential settlements. Two models of piled raft foundations having the same flexible raft and number of piles, the uniform pile arrangement model and the concentrated pile arrangement model, and one model having a rigid raft with a concentrated pile arrangement were designed for centrifuge tests. The settlements of three rafts of the piled raft models and the induced bending moments of two flexible rafts were measured during the load application process. The measured results were compared between the tests to illustrate the ability of the concentrated pile arrangement scheme in reducing total and differential settlements, as well as induced bending moment. Moreover, three piled rafts were simulated by the Plaxis 3D Foundation software package to calculate the total and differential settlement, as well as the induced bending moments, after which a comparison was made with the centrifuge tests to verify the reliability of these tests. The results show that the piled raft model with a concentrated pile arrangement can effectively decrease the total and differential settlements in comparison with the pile raft model with a uniform pile arrangement. (C) 2013 American Society of Civil Engineers.