The captain pile method is a method of semi-fixing the pile head for cast-in-place piles in which a precast concrete ring (PC ring) is placed over the pile head to connect the pile to the foundation.

Left: Pile bending moment distribution/Right: Captain pile method
Pile head delivery is simple and there is no pile anchorage rebar, making installation fast and easy.
The bending moment of the pile head can be reduced, and the damage to the pile material is less than with conventional construction methods, thus improving seismic resistance.
The reduction of the pile head moment allows for smaller foundation beams and pile cross-sections, which can significantly reduce the amount of concrete and reinforcing steel needed.
This is an environmentally friendly method that reduces the amount of soil exhausted.
Applicable to cast-in-place concrete piles (φ800~φ3,000), including steel pipe piles.
Need to negotiate for φ2,500 or more.
This method may be used by companies other than members of the Institute, as long as they obtain permission from the Institute.
The Institute will provide guidance on design and construction for use. (Pile diameters: φ800 to φ2,500)
Received an evaluation (BCJ-FD0230-01) from the Building Center of Japan in December 2005 and renewed (BCJ-FD0230-04) in December 2020. (Jointly developed by 10 companies, including Neturen)
ULBON spirals are used for shear reinforcement of pile heads.
Received an evaluation (BCJ Evaluation - FD0157-05) from the Building Center of Japan for "Construction method using ULBON as shear reinforcement for cast-in-place concrete piles."