Analysis of Plie Raft Interaction in Sand With Centrifuge Tests

In the conventional design for piled rafts, the load capacity of the raft is not in general taken into account and the load capacity of piles is only considered for the estimation of the total load carrying capacity of the piled rafts. As a consequence, piled rafts are often designed with excessively conservative safety margin, raising a need of further investigation of the load capacity mechanism of piled rafts. In this study, a series of centrifuge load tests using model group piles and piled rafts are conducted and used to compare the axial load carrying behaviors of group piles and piled rafts for different soil conditions. Instrumented model piles and rafts are manufactured and introduced into the centrifuge tests. Different density conditions of test sands were considered in the tests. From the test results, it is revealed that the load carrying capacity increase for piled rafts differ for different soil conditions. The load capacity of piled rafts is greater than those of the group piles by 13% for dense sand cases and by 22% for loose sand cases