Abstract
A multi-belled cast-in-place concrete pile construction method has been developed in order to obtain a high level of bearing capacity with normal pile. The newly developed multi-belled pile has a shape of some bell enlargements at its axial part and consists of high strength materials such as high-strength concrete of Fc60N/mm2 at its maximum. The investigation of actual-size pile digging out after construction was carried out to measure the dimensions and concrete strength of the pile. The results indicated that this method controls high construction quality of the pile. And the case history applied to super-high-rise building foundation was also described.