Abstract: The invention relates to a base structure for an off-shore wind power installation having a plurality of base piles wherein each base pile has a driving pile which is guided in its interior at least portion-wise for anchoring in the seabed, and at least one support structure for mounting a pylon of a wind power installation, wherein the support structure connects the upper ends of the base piles together. Furthermore the base pile and the driving pile have a region of an overlap on a predetermined lengthwise portion, wherein in the overlap region of the piles the gap between the piles and in part beneath and above the overlap region the free internal cross-section of the piles are filled with a hardening filling material. The invention also relates to a method of erecting a base structure for an off-shore wind power installation and an aligning tool.

Abstract: The invention relates to a base structure (1) for an off-shore wind power installation having at least a plurality of, in particular three, bases piles (2, 3,, 4), and a support structure (5) connecting the upper ends of the base piles (2, 3, 4) for the pylon of the wind power installation. Furthermore each base pile (2, 3, 4) has a wall comprising a plurality of layers (19, 20, 21) of differing material substantially over its entire length, wherein the wall is formed from at least one surface portion, having an inner layer (19) and an outer layer (20) and wherein a core material is arranged between the inner layer (19) and the outer layer (20) as an intermediate layer (21).