Tp-free monopile and method for forming the same

Offshore structure according to any one of the previous claims, wherein the platform (16) is designed such that it extends all around the upper end (5, 9) of the pile (2) when mounted, and can be lifted over the upper end (5, 9) of the pile (2) and, if provided, a flange (130) mounted on or formed at the upper end (5, 9) of the pile (2), for forming the slip joint (11) with the upper end (5, 9) of the pile (2).

Offshore structure according to any one of the previous claims, wherein the upper end (5, 9) of the pile (2) is truncated cone shaped, wherein the height of the truncated end (5, 9) is preferably about the same as or smaller than the maximum diameter of the truncated end (5, 9), wherein the truncated end (5, 9) preferably has an outer surface (13) at an angle (α) relative to a longitudinal axis (X-X) of the pile (2) between 1 and 45 degrees, more preferably between 2 and 40 degrees, such as for example between 2 and 30 degrees.

Offshore structure according to any one of the previous claims, wherein between an inner surface (12) of a mounting part (19) of the platform (16) and an outer surface (13) of the pile (2):

• a coating (14), especially an anti-fouling coating is provided, increasing friction between the said two surfaces (12, 13) and/or preventing corrosion of one or both of said surfaces (12, 13) and/or
• at least two spaced apart areas (101, 102) are provided with a substance (14A), forming a seal (107, 108) between the said outer surface (13) and the said inner surface (12), near an upper end (5, 9) of the pile and the mounting part (19) of the platform (16) and between a lower end (8) of the mounting part (19) of the platform (16) and the pile (2).

Offshore structure according to any one of the previous claims, wherein the said substance (14A) forming a seal (107, 108) is a substantially visco-elastic material of compound of materials, and/or, wherein the substance (14A) is formed by a mouldable, self-adhesive material, which material preferably is watertight and gastight according to NEN 2768 qualifications, and/or wherein said material extends at least partly over a lower end (8) of the offshore element (7) and/or an upper end (5, 9) of the pile (2), and/or wherein the substance forms an upper (108) and a lower (107) seal between the mounting part (19) of the platform (16) and the pile (2), wherein between said seals (107, 108) a space (109) is enclosed between the mounting part (19) and the pile (2), and/or wherein the substance (14A) is provided between opposing sloping surfaces (12, 13) of the mounting part (19) and the pile (2).

Offshore structure according to any one of the previous claims, wherein the coating (14) and/or the substance (14A) is provided as a foil, preferably an adhesive foil, more preferably a self-adhesive coating.

Offshore structure according to any one of the previous claims, wherein the coating (14) comprises a layer (14) comprising fibers on a carrier foil, wherein the fibers are embedded in a resin, wherein the resin preferably is a cured acrylic.

Offshore structure according to any one of the previous claims, wherein the coating (14) and/or substance (14A) is applied on the outer surface (13) of the pile (2), especially on a truncated conical part of the pile (2) and/or wherein the coating (14) and/or substance (14A) is applied to the inner surface (12) of the offshore element (7).

Offshore structure according to any one of the previous claims, wherein the coating (14) and/or substance (14A) is free of organotin compounds.

Offshore structure according to any one of the previous claims, wherein the offshore element (7) is founded on the pile (2) by force of gravity.

Offshore structure according to any one of the previous claims, wherein the coating (14) has a surface roughness higher than the surface roughness of the relevant part of the inner surface (12) of the offshore element (7) and/or of the outer surface (13) of the pile (2).

Offshore structure according to any one of the previous claims, wherein a filler is provided between at least part of a surface (15) of the coating (14) and an adjacent surface.

Offshore structure according to any of the preceding claims, wherein the bolt based mounting provision includes at least one bolt (131) having a center line that extends substantially in parallel with a center line of the pile (2) and/of the tower (7).

Offshore structure according to any of the preceding claims, wherein the tower (7) has a substantially transversally extending mounting surface that is supported by a substantially transversally extending supporting surface of the pile (2), said substantially transversally extending surfaces of the tower and pile in particular being horizontally extending surfaces when the offshore structure has been placed in a respective vertical position offshore.

Offshore foundation pile (2), comprising a top end portion (5, 9) provided with an anti-fouling coating (14) and/or with an area (101) spaced apart from a top end of the pile (2), provided with a substance (14A) for forming a seal (107), wherein said top end portion (5, 9) is truncated cone shaped and is provided with a bolt provision (B), preferably at least a flange (130), for mounting a tower (7) to said top end portion (5, 9).

Method for mounting a tower (7) to a foundation pile (2), wherein the tower (7) is bolted to an upper end (5, 9) of the pile (2), comprising the step of fitting a mounting part (19) of a platform (16) over the top end (5, 9) at an offshore foundation pile (2), forming a slip joint (11) with the upper end (5, 9) of the pile (2), which upper end (5, 9) is truncated, whereafter said tower (7) is bolted to the pile (2) and/or to a flange (130) provided at or by said top end, wherein an operator (120), standing on said platform (16) or standing within the tower on the pile (2), bolts the tower (7) to the pile (2).