Aiming for accurate evaluation of bearing capacity and settlement behavior of multi-belled cast-in-place piles in sand, the characteristics of load-settlement relations and the effect of bell spacing on bearing capacity were investigated by experimental techniques. The findings are summarized as follows: 1) The average curves of the load-settlement relations of intermediate bells based on six full-scale load tests showed larger initial stiffness and curvature than the recommended curve for a pile tip by AIJ. 2) The results of centrifuge modelling tests indicated that smaller bell spacing brought lower resistance of an intermediate bell and the change of ground failure mechanism.
