Centrifuge modelling of piled raft foundations on clay

Centrifuge tests of model piled raft foundations were performed to examine the role of a small centred pile group in reducing the settlement of the raft. Particular attention was paid to the differential settlement across the raft and the load transferred to the pile group during unload–reload cycles. The results were compared with those of a fully piled raft designed by a conventional method, where any contribution of raft or pile cap was ignored. The test results showed a high level of consistency despite the small magnitude of settlements observed in the models. It was found that even a small pile group could reduce the differential settlement of the raft significantly, in spite of rather low loads being transferred to the pile group. Loading tests were also performed on single piles with and without small pile caps. The results showed that a small cap could increase the total bearing capacity significantly, because of the transfer of load to the soil through the cap. Des essais ont e menes sur des mod...