A method for forming an elongate support structure having a central hollow portion is disclosed including arranging an elongate core member to extend horizontally and then forming a core assembly by locating a first tensioning member at a first end where the first tensioning member including tensioning elements extending from the first end of the core member along the outside of the core member to a second tensioning member located at the second end of the core member. An external mold assembly is attacked to the core assembly between the first and second tensioning members to form a combined mold and core assembly and to also form a cavity extending around and along the central core member through which the plurality of tensioning elements extend. The tensioning elements are then tensioned and the combined mold and core assembly is then positioned in an upright orientation and concrete injected into the cavity formed between the elongate core member and the external mold assembly.

A method for forming an elongate support structure having a central hollow portion is disclosed including arranging an elongate core member to extend horizontally and then forming a core assembly by locating a first tensioning member at a first end where the first tensioning member including tensioning elements extending from the first end of the core member along the outside of the core member to a second tensioning member located at the second end of the core member. An external mold assembly is attacked to the core assembly between the first and second tensioning members to form a combined mold and core assembly and to also form a cavity extending around and along the central core member through which the plurality of tensioning elements extend. The tensioning elements are then tensioned and the combined mold and core assembly is then positioned in an upright orientation and concrete injected into the cavity formed between the elongate core member and the external mold assembly.

A manufacturing method of a concrete pile is shown. The method includes the following, that is, pouring concrete in the pile molding space, reducing the pile molding space to compress and mold the concrete, draining water drained from the concrete by compression and molding outside of the formwork from the drainage hole, and holding the concrete a predetermined amount of time to harden the concrete. The formwork includes an outer formwork that molds an outer wall surface of the concrete pile, an inner formwork that molds an inner wall surface of a hollow space of the concrete pile, and a pair of end formwork that mold upper and lower end surfaces of the concrete pile. The drainage hole is a gap between adjacent components when the mold is tightened, and the gap is configured to be capable of being opened larger during cleaning than when the mold is tightened.

A manufacturing method of a concrete pile is shown. The method includes the following, that is, pouring concrete in the pile molding space, reducing the pile molding space to compress and mold the concrete, draining water drained from the concrete by compression and molding outside of the formwork from the drainage hole, and holding the concrete a predetermined amount of time to harden the concrete. The formwork includes an outer formwork that molds an outer wall surface of the concrete pile, an inner formwork that molds an inner wall surface of a hollow space of the concrete pile, and a pair of end formwork that mold upper and lower end surfaces of the concrete pile. The drainage hole is a gap between adjacent components when the mold is tightened, and the gap is configured to be capable of being opened larger during cleaning than when the mold is tightened.