Slip-joint with filling

Abstract

Slip-joint between a platform (3) and a pile (2), wherein the pile has a first surface area at or near a top end of the pile and the platform has an opening defined at least partly by a second surface area, wherein in the slip joint between the first surface area and the second surface area at least one pad (9) is provided, made at least partly of a flexible material, wherein the at least one pad has a primary surface (33) facing one of the first surface area (6) and the second surface area (7) and an opposite secondary surface (34) facing the other of the first surface area (6) and the second surface area (7), wherein at least the primary surface has a surface profiling (100) allowing compression of part of said profiling

Description

[0001] Title: Slip -joint with filling

[0002] The invention relates to a shp-joint. The invention relates especially to a shp-joint between a pile and a platform. The invention further relates to a method for forming such slip-joint and to filling elements for use for forming such slip -joint.

[0003] A shp-joint is known in the art for forming a connection between a pile and a platform, for example in off-shore and on-shore wind turbine generators, power stations and connectors. A slip joint is traditionally formed between an at least partly truncated conical top end of a pile, such as a foundation pile or tower, and a similarly truncated conical opening in a tower or tower section or transition pile to be mounted on said pile.

[0004] In EP3884111 it is disclosed that a slip joint can be used for mounting a platform to a pile. Providing a platform over an upper end of a pile by a slip joint has the advantage that placing the platform can be accomplished by sliding the platform over the upper end of the pile, the joint being formed substantially by force of gravity. It has however been found that the surfaces of the fitting opening of the platform and the foundation pile that have to meet will not always fit properly. This is an essential difference compared to slip joints that are classically used to connect 2 tubulars that form part of the carrying structure of a wind turbine. In the classical slip joint application, both conical tubulars can deflect freely radially whereby any ovality differences between both conical slip joint tubulars are balanced out due to the ability of said conical tubulars to deflect radially resulting in a proper fit to each other. Production tolerances that can be achieved without excessive costs to manufacturing will lead to surface irregularities, which in case of fitting a platform to a foundation pile prevents said proper fitting due to the inability to deform of the conical tubular that forms part of the platform due to the inherent radial stiffness of said platform. This may lead to instability of said slip joint and to misalignments of the platform and the foundation pile. Moreover this may lead to excessive wear of the surfaces and to excessive local forces and stresses in the materials and to corrosion. Furthermore this may lead to improper positioning of the platform relative to the foundation pile, especially in axial position relative to the upper end of the foundation pile. In other words, the platform may for example come to be sitting too low or too high on the foundation pile, and / or askew.

[0005] EP3443224 discloses a slip-joint between a pile and a transition piece, the transition piece providing for a connection between a tower of a wind turbine generator on the one hand and a foundation pile on the other. In this slip-joint a gasket is provided between the inner surface of the transition piece and the outer surface of the pile. The gasket is formed as a tubular, elongated body, made of an elastomeric material, formfitting a bottom part of the transition piece and an upper part of the pile. The gasket forms a seal between the pile and the transition piece. Moreover, the gasket is used to accommodate for differences in the mating shapes of the opening and pile, for example due to said production tolerances.

[0006] Surprisingly it has been found that although the gaskets known from EP3443224 are made of a polymeric material and are as such relatively flexible, during use the gasket fills the entire gap between the mating surfaces of the transition piece and pile, and the gasket does not overcome the problem of local stresses and high pressures and forces on the surfaces of the pile and of the transition piece. Moreover, these gaskets are hard to handle, both in production and in use.

[0007] It is an aim of the present disclosure to provide for an alternative method for fitting a platform over an upper end of a pile. An aim of the present disclosure is to provide for a method for fitting a platform over an upper end of a pile, overcoming at least one of the problems of the prior art at least partly. An aim of the present disclosure is to provide for a method for placing a platform onto a pile without use of a transition piece. An aim of the present disclosure is to provide a method for mounting a platform onto a pile, wherein a tower of a construction element, such as a wind turbine generator, can be mounted directly onto the pile, above the platform, without a transition piece. It is an aim of the present disclosure to provide for a method for forming a slip joint between a platform and a pile, wherein tolerances in production of the foundation pile and / or the platform can easily be compensated for.

[0008] At least one of these and other aims is at least in part obtained by a slip-joint or method according to the present disclosure.

[0009] In an aspect of the disclosure a slip-joint between a platform and a pile is formed, wherein the pile has a first surface area at or near a top end of the pile and the platform has an opening defined at least partly by a second surface area. In the slip joint between the first surface area and the second surface area at least one pad or tile is provided, made at least partly of a flexible material. The at least one pad or tile has a primary surface facing one of the first surface area and the second surface area and an opposite secondary surface facing the other of the first surface area and the second surface area, wherein at least the primary surface has a surface profiling allowing compression of part of said profiling.

[0010] The profiling allowing compression of part of said profiling has the advantage that the pad or pads or tile or tiles can easily adapt to the shape of the space between the platform and pile in which they are provided, such that local stresses are reduced or prevented, distributing the force of gravity acting on the platform more evenly over the pad or pads and hence over the outer surface of the pile.

[0011] It has been found that when using gaskets as disclosed in the prior art, filling the said space between the platform and pile, the gasket cannot be compressed or at least not compressed sufficiently to accommodate for any misalignment and / or shape deviations, for example due to manufacturing tolerances. Because these gaskets are fully enclosed and have closed, curved surfaces fitting against the relevant surface areas of the platform and pile there is not sufficient possibility for them to adapt their shape by compression. The gasket is hydrostatically locked in place between the two conical slipjoint surfaces and has no free space for the material to deform for adapting it's shape to facilitate the required deformation. This results in that there are still undesired, excessive stresses on the platform and / or pile and / or misalignments of the platform relative to the pile. By allowing compression according to the disclosure this problem is at least significantly reduced.

[0012] In embodiments according to the disclosure the profiling comprises or is formed by a series of openings in the primary surface. These openings allow material of the pad surrounding these openings to deform into said openings when compressed. Said material can for example bulge into said openings, allowing for the primary surface to adapt to the first or second surface it faces, without excessive stress. The material forced into said openings will reduce the size of the openings, filling said openings at least in part.

[0013] In embodiments at least some of the openings can have a closed end spaced apart for the primary surface, for example at or near the secondary surface. Such closed end can reduce possible undesired deformation of the pad, especially prior to and during adhering the pad to a surface of the pile or platform. Moreover this increases the surface area at the secondary surface suitable for adhering compared to openings extending through the full thickness of the pad.

[0014] In embodiments at least a number of said openings can be substantially truncated conical, a cross sectional size of the openings reducing in a direction away from the primary surface. Such openings can have the effect that the further the pad is compressed at an opening, the more force is required for further compression, improving stability of the pad and improving pressure distribution. By making the openings conical in shape moreover manufacturing can be improved.

[0015] The openings preferably define a significant portion of the surface area of the primary surface, for example more than 20%, such as for example between 20 and 80%. The openings preferably have a relatively large cross section, compared to the thickness of the pad. For example the openings can have a surface area which is equal to nR2, wherein R is between 0,25 and 2 times a thickness of the pad at the relevant opening. This is for example a surface area of a circle with a radius R.

[0016] The openings can for example be provided in but not limited to a regular pattern such as for example in rows and / or columns, such as in a matrix. Such configuration can improve load and stress distribution.

[0017] The openings can be prefabricated, that is can be provided for during manufacturing of the pads or tiles, or can be drilled or cut or stamped or otherwise provided after forming the pads, or can be adjusted after manufacturing of the pad or tile, for example adjusted in size and / or shape, or combinations thereof.

[0018] In the same or alternative embodiments the profiling comprises a series of protrusions with at least one void between said protrusions, formed such that at least part of the protrusions can be compressed by deformation into said at least one void.

[0019] In such embodiments the secondary surface of the or each pad or tile is placed against one of the first and second surface areas of the platform and pile, whereas an apex or apexes of the at least one protrusion of the at least one pad or tile is or are pressed against the other of the first and second surface areas of the platform and pile. By pressing against the apex of a protrusion the protrusion will be compressed, bulging out into the at least one void provided next to the protrusion, allowing for compression of the protrusion without excessive stress. Thus the at least one pad or tile can easily adapt the shape to the adjacent surface areas of the pile and platform. In embodiments the primary surface can comprise a series of ribs forming at least part of the profiling. Voids can be provided between the ribs, into which the ribs can bulge out. The ribs can for example extend substantially parallel to each other. In embodiments the ribs have a general longitudinal direction, wherein of at least a series of said ribs and preferably all of said ribs said general longitudinal axis extends in a plane comprising a longitudinal axis of the pile. In such embodiments the longitudinal axes of the ribs extend generally in a direction from a bottom end of the pile towards a top end of the pile, such that they can bulge out substantially sideways into voids there between. Said direction of the longitudinal axis is further referred to further also as a generally upward direction. By providing the ribs in said generally upward direction the risk of dislodging and / or damaging pads or ribs thereof during lowering of the platform onto the pile is reduced significantly. Moreover during such lowering of the platform the ribs can guide the platform.

[0020] In the same or alternative embodiments the primary surface comprises a plurality of studs extending in a direction away from the secondary surface, said protrusions forming part of the profiling. The studs can for example be pyramid shaped or semi-spherically or ovoid shaped, or similar shapes having an apex and a base, the base being closer to the secondary surface than the apex. In such embodiments preferably each stud is surrounded by the at least one void, such that the stud can bulge out into said void or voids in all directions parallel to the secondary surface at the stud when a force is exerted on the apex towards the secondary surface.

[0021] In embodiments the protrusions can be formed having a convex outer surface, such as spherical or semi spherical, such as for example but not limited to half a sphere. Preferably voids in between such convex protrusions have a concave bottom, preferably such that in a cross section through the apexes of adjacent protrusions the protrusions and voids define a substantially sinusoidal or semi sinusoidal profile. The studs can for example be provided in a matrix, for example a regular matrix of rows and columns of the same or similar studs. Such configuration can improve load and stress distribution.

[0022] In embodiments the primary surface can comprise a combination of openings and protrusions, such as openings and ribs, openings and studs, openings, ribs and studs, or ribs and studs.

[0023] In an aspect of the disclosure the secondary surface is provided with indentations. Such indentations can further improve compressibility of the pad. Preferably said indentations are provided such that at least some of the protrusions, such as for example ribs and / or studs, are hollow. The hollow protrusions in embodiments can be open towards the secondary surface. In embodiments the hollow protrusions can be closed off at the side of the secondary surface, for example such that a volume of gas is trapped inside said hollow protrusion.

[0024] The at least one pad or tile preferably is made using a polymeric material. The at least one pad or tile is more preferably made using polyurethane.

[0025] In an aspect of the present disclosure a series of pads or tiles is provided between the first surface area and the second surface area. By providing a series of pads or tiles the pads or tiles can be relatively small and compact, making handling easy. Moreover such pads or tiles can more easily be adapted to a specific position between the platform and pile, for example in thickness. Preferably at least a number of said pads or tiles is spaced apart from neighboring pads or tiles. In such embodiments grooves or channels can be provided between the pads or tiles, allowing for a camera, such as for example but not limited to an endoscope, to pass between the pads or tiles and first and second surface area, for inspection purposes. Such channels also allow fluids such as water and / or gas such as air to pass between the facing first and second surface areas. For example a matrix of pads or tiles can be provided between the first surface area and the second surface area.

[0026] In advantageous embodiments the at least one pad or tile has been adhered to the second surface area, by the secondary surface, the surface profiling facing the first surface area. Thus the pad or pads, tile or tiles can be moved and, especially, placed by moving the platform, wherein the platform protects the pad or pads, tile or tiles for example during transport and storage. Moreover in such embodiment the pad or pads, tile or tiles can be adhered to the platform in a controlled environment, for example a manufacturing facility, instead of in the open air, such as for example offshore, onto a pile.

[0027] The disclosure further relates to a pad for forming a slip-joint according to the disclosure, between a platform and a pile.

[0028] In advantageous embodiments the pad has a primary surface which has a profiled surface, for example a substantially undulating surface, such as for example provided with ribs and / or studs, and / or has openings, such as indentations, and an opposite secondary surface which is substantially flat or curved. In the curved embodiment the curvature preferably is similar to or corresponds to the curvature of the surface area against which the secondary surface is to be mounted. The undulating surface can for example be formed by alternating ribs and valleys between such ribs, by studs and / or openings or combinations thereof.

[0029] In alternative embodiments the pad has a primary surface comprising an array of studs, preferably a matrix of spaced apart studs, and / or openings, preferably a matrix of openings, preferably as discussed previously.

[0030] In an aspect of the present disclosure the pad has a length direction, which during use extends in a vertical plane comprising a longitudinal axis of a pile with which it is used, and a width direction, perpendicular to the length direction, a primary surface at a side of the pad and a secondary surface at an opposite side of the pad, wherein the pad has a cross section seen in said longitudinal direction, said cross section comprising alternating peaks and valleys forming the primary surface.

[0031] The disclosure is further directed to a set of at least a first pad and at least a second pad, wherein the first pad has the profiling, such as but not limited to protrusions as discussed, whereas the second pad has opposing primary and secondary surfaces which are both substantially free of such profiling.

[0032] The disclosure is further directed to a tile, the tile having a profiled primary surface and a substantially flat opposite secondary surface, wherein the profiling comprises rows of protrusions and voids between the protrusions, wherein the protrusions have a convex surface, and are preferably spherical or semi-spherical and wherein the voids between the protrusions have a concave bottom, wherein preferably central to the tile at least one substantially flat primary surface portion is provided.

[0033] A tile as disclosed can be manufactured and placed easily, and will allow for sufficient deformation of the protrusions for proper support, whereas the at least one substantially flat primary surface area will provide for a stop to avoid too much deformation of the protrusions, for example to avoid damage through shear forces.

[0034] In this disclosure a tile can be formed as a series of pads interconnected, especially a series of first pads and at least one second pad.

[0035] The present disclosure is further directed to a method for fitting a platform on a pile by a slip joint formed between an internal surface area of the platform and an external surface area of the pile. At least one of the platform and the pile is provided with at least one pad or tile having a primary surface at a first side of the pad or tile and a secondary surface at an opposite second side, wherein the primary surface has ribs and / or studs and / or openings forming at least part of said primary surface. The platform is slid over an upper end of the pile, such that the said internal surface of the platform is brought adjacent the said external surface of the pile, the at least one pad or tile being positioned in between said external and said internal surface. At least part of the ribs and / or studs and / or material surrounding openings is deformed by compression by the weight of the platform.

[0036] In embodiments according to the disclosure pads or tiles can be used which are ring shaped or form part of a ring, such that a number of such pads or tiles together can form a ring shaped filling system fully enclosing an upper end portion of a pile. In alternative embodiments pads or tiles are used which have small dimensions, i.e. small length and width dimensions compared to the cross section of the pile and opening in the platform, such that a large number of such pads can be placed along the circumference of the pile, some or all of said pads spaced apart from a neighboring pad.

[0037] By individually placing the filling elements they can be chosen and / or shaped in a relatively easy manner to fit a specific location. Such filling elements can be handled relatively easily, and can for example be replaced if needed individually. As indicated said filling elements can be pads or tiles or combinations thereof.

[0038] By using individual filling elements a further advantage can be obtained in that individual filling elements can be replaced easily, for example when damaged or when it is found that for example the thickness of a filling element in a specific position is incorrect. Moreover, if one of the filling elements during use is damaged, for example by overpressure due to for example contamination or misalignment, this will not significantly influence the support offered by the slip joint formed between the platform and the pile. Neighboring filling elements will easily correct for the loss of said filling element.

[0039] In an aspect of the disclosure the filling elements, which advantageously can be tiles, have a length dimension, a width dimension and a thickness, wherein the length dimension and the width dimension are substantially larger that the thickness. The filling elements can have any suitable shape, and are for example rectangular or square with a length and width substantially smaller than a height of the opening, measured along the inner surface between the upper side of the platform and the lower side of the platform at said opening, and substantially smaller than the smallest diameter of said opening, such that for example at least one hundred filling elements or more, for example at least one thousand filling elements or more can be positioned between said surfaces, with channels extending between adjacent filling elements, both alongside the length direction and the width directions of the filling elements. By way of example, the filling elements can have, but are not limited to, a length and width of between 10 and 60 centimeters, for example between 10 and 30 centimeters, or when formed as tiles for example a length and width of between 30 and 100 cm, for example between 40 and 80 cm, such as for example about 60 cm, whereas the channels can have a width, measured as a shortest distance between adjacent filling elements, of between 1 and 15 centimeters, such as for example between 1 and 10 centimeters, for example between 1 and 5 centimeters, for mounting a platform on a pile in which the platform for example has a height of the opening of more than 0.5 m, for example between 0,5 - 3 meter and a smallest diameter, measured at a top end of the opening, of for example between 3 and 15 meters. The filling elements preferably have a thickness which is smaller than the length and width thereof, for example at most one-third ( l / 3rd) or less of the smallest of the length and width, for example at most one-fifth (l / 5th), such as for example at most one-eight (l / 8th). The filling elements for example have a thickness of between 0,5 and 5 cm.

[0040] The dimensions of the filling elements can be chosen for example based on the diameters of the pile and the opening at the level of the filling elements. For example the length and width of the filling elements can be larger with increasing diameters. For example, but not limited to, the dimensions of the filling elements, especially a width dimension extending during use substantially parallel to the curvature of the surface, can be chosen such that, when using flat filling elements, in order to adhere them to the relevant surface the filling elements only have to be bent to a very small degree. For example a width to diameter ratio can be chosen to be between 0,02 and 0,04, although also other ratios can be used, depending inter alia on bending resistance of the filling element in the bending direction. The filling elements can cover for example less than 90 % of the said surface area of the opening, the further surface area being exposed in said channels.

[0041] In an aspect of the disclosure filling elements can be provided having different thicknesses, wherein each filling element preferably has a coding depending on said thickness. The coding can for example be a coloring of the filling element or a part thereof, such that based on said coding, especially said color, it can directly be ascertained what thickness said filling element has.

[0042] In this description wording like substantially and about should be understood as meaning that small deviations of sizes, numbers or dimensions or shapes are allowed, for example deviations of 15% or less, such as for example 10% or less, for example 5% or less.

[0043] The invention will be further elucidated on the basis of exemplary embodiments which are represented in the drawings. The exemplary embodiments are given by way of non-limitative illustration of the invention. In the drawings:

[0044] Fig. 1 shows a schematic top view of a platform mounted over an upper end of a foundation pile;

[0045] Fig. 2 shows schematically a platform in a cross sectional side view along the line II - II in fig. 1 mounted over an upper end of a foundation pile; Fig. 2A and 2B schematically part of a pile and platform, in alternative embodiment;

[0046] Fig. 3 shows schematically in isometric view an inner surface of an opening of a platform and a surface area part of an outer surface portion of the upper end of a foundation pile, transparently shown, showing a series of filling elements arranged between said surfaces;

[0047] Fig. 4 shows schematically part of the inner surface of an opening of a platform, with a series of filling elements provided thereon;

[0048] Fig. 4A shows schematically a number of filing elements as shown, for example in any one of fig. 1 - 4, with inscribed some possible dimensions and mutual relationship of such filling elements;

[0049] Fig. 4B, C and D show schematically and by way of examples only, different possible contours of surface portions between which filling elements are positioned, here shown in vertical cross sectional views;

[0050] Fig. 4E shows schematically and by way of example only, a possible contour of surface portions between which filling elements are positioned, here shown in horizontal cross sectional view;

[0051] Fig. 5 shows schematically an embodiment of a filling element, in a frontal view;

[0052] Fig. 5A shows schematically a filling element of fig. 5, in cross section along to the line VA - VA;

[0053] Fig. 5B shows schematically a filling element of fig. 5 in an alternative embodiment, again in cross section along to the line VA - VA;

[0054] Fig. 6 shows schematically an alternative embodiment of a filling element, in a frontal view;

[0055] Fig. 6A shows schematically a filling element of fig. 6, in cross section along to the line VIA - VIA;

[0056] Fig. 6B shows schematically a filling element of fig. 6 in an alternative embodiment, again in cross section along to the line VIA - VIA; Fig. 6C shows schematically a filling element of fig. 6 in a still further alternative embodiment, again in cross section along to the line VIA - VIA;

[0057] Fig. 7 shows, schematically, an embodiment of a filling element similar to that of fig. 6, but with staggered rows of openings and / or protrusions such as studs;

[0058] Fig. 8 shows schematically a further embodiment of a filling element, in a frontal view, comprising studs;

[0059] Fig. 8A shows schematically a filling element of fig. 8, in side view;

[0060] Fig. 9 shows schematically another embodiment of a filling element, in a frontal view, comprising ribs;

[0061] Fig. 9A shows schematically a further embodiment of a filling element, in a frontal view;

[0062] Fig. 10 shows schematically another embodiment of a filling element, in a frontal view, comprising studs;

[0063] Fig. 11 shows schematically a further embodiment of a filling element, in a frontal view, provided with studs and openings;

[0064] Fig. 11A shows schematically, in cross section along the line XIA - XIA a filling element of fig. 11;

[0065] Fig. 12A schematically shows part of a filling element between a first and second surface of a pile and a platform respectively, for example during placement of the platform onto the pile, the said part of the filling element being undeformed;

[0066] Fig. 12B schematically shows part of the filling element of fig. 12A, partly deformed by compression between the first and second surface;

[0067] Fig. 13A schematically shows part of an alternative filling element between a first and second surface of a pile and a platform respectively, for example during placement of the platform onto the pile, the said part of the filling element being undeformed; Fig. 13B schematically shows the part of the filhng element of fig. 13A, partly deformed by compression between the first and second surface;

[0068] Fig. 14 schematically shows a further embodiment of a filhng element, with ribs and studs and / or openings;

[0069] Fig. 14A schematically shows in cross section along the line XIVA - XIVA a filling element of fig. 14; and

[0070] Fig. 14B shows schematically in cross section a filling element with protrusions at a first side, such as ribs and / or studs, and openings, such as indentations, at an opposite second side;

[0071] Fig. 15 shows schematically a system for scanning surface portions of a surface of an upper end of a foundation pile and of a peripheral inner surface of an opening of a platform;

[0072] Fig. 16 shows schematically in top view part of a platform mounted over the upper end of a foundation pile, wherein the pile has a deviation from circular, for example at a welding seam, wherein filhng elements are provided between the platform and the pile, compensating for the deviation;

[0073] Fig. 17 shows schematically in cross section side view part of a platform and or an upper end of a foundation pile, wherein an actual interspace is shown next with in striped line a surface of the pile as desired, wherein a filling element is shown filling said interspace, adapted to fit the actual interspace, without specifically showing openings and / or ribs and / or studs as discussed;

[0074] Fig. 18A and B show schematically in cross sectional side view respectively in cross sectional side view a standard filling element from which the filling element according to fig. 18B is made as a filling element, adapted based on scan data from opposite surface portions of a foundation pile and a platform;

[0075] Fig. 19 schematically shows an alternative positioning of filling elements; Fig. 20 schematically shows a further positioning of filling elements;

[0076] Fig. 21 shown a frontal view of an embodiment a first type of pad according to the disclosure, and a cross section thereof along the line A - A in fig. 21;

[0077] Fig. 21A shows a perspective image of a series of first type of pads comprising protrusions with a convex surface;

[0078] Fig. 22 shows a frontal view of an embodiment a second type of pad according to the disclosure, and a cross section thereof along the line B - B in fig. 22;

[0079] Fig. 22A and 22B show examples of arrangement of pads, including first and second pads;

[0080] Fig. 23 shows a frontal view of a tile according to the disclosure, with spherical protrusions and a substantially flat primary surface area;

[0081] Fig. 23A and 23B show cross sections of a tile along the line A - A and B - B in fig. 23;

[0082] Fig. 23C shows in cross section part of a profile of a sinusoidal or semi sinusoidal surface of the protrusions and voids;

[0083] Fig. 24 shows in perspective view an embodiment of tile of the disclosure;

[0084] Fig. 25 shows a multitude of tiles mounted to a surface of a platform opening or to a pile;

[0085] Fig. 26 shows in cross section a tile between opposing surfaces of a pile and a platform opening, during forming of a slip joint; and

[0086] Fig. 27 shows a tile compressed between the surfaces of the pile and platform.

[0087] In this description embodiments of the invention will be described with reference to the drawings by way of example only. These embodiments should by no means be understood as limiting the scope of the disclosure. At least all combinations of aspects, elements and features of the embodiments shown and discussed are also considered to have been disclosed herein. In this description the same or similar elements and features will be referred to by the same or similar reference signs. The drawings are not to scale, and can show exaggerations in order to more clearly show features of the claimed invention.

[0088] In this description expressions of orientation such as top, bottom, vertical etcetera are used for convenience only and refer to the orientation of the foundation pile as seen in the accompanying drawings, especially fig. 1 and 2, the pile being placed vertically in the ground, off shore or on shore.

[0089] In this description wording like substantially and generally should be understood as meaning that relatively small deviations from the feature or value they refer to are also considered to be covered, for example deviations of 20% or less, such as 15% or less or 10% or less.

[0090] In this description embodiments of a foundation pile are disclosed supporting a platform, wherein a wind turbine generator (WTG) is or is to be supported on the foundation pile, directly or indirectly, preferably free of a transition piece.

[0091] In this description a foundation pile is a pile supported in and / or on the earth, for example by driving the foundation pile into a water bedding such as a sea bedding, offshore, or into the ground onshore. The foundation pile is disclosed in the drawings as a monopile, for example made of metal, but could also be a pile made of different segments, and could be made of different materials, such as but not limited to concrete, or combination of materials, such as but not limited to concrete and metal. The foundation pile is preferably substantially hollow, at least over most of its height. A foundation pile can have a circular cross section, seen in top view, perpendicular to a longitudinal axis thereof, as shown by way of example for example in fig. 1, but could also have a different shape in cross section, for example polygonal, oval or the like, or combinations thereof. A foundation pile can have a diameter of several meters to more than ten meters, for example up to or above fifteen meters at its lower end, can be cylindrical with a constant diameter of with a diameter declining in the upward direction of the pile, and can have a wall thickness, if made of metal, of centimeters, for example more than 4 centimeters, such as for example 8 to 10 centimeters or more. The pile will have a conical top end, as will be discussed. These sizes are only given by way of example and should not be considered to limit the disclosure.

[0092] In this disclosure the platform can be made of any suitable material or combination of materials. The platform can for example be, but is not limited to, made of concrete or concrete and metal or metal and / or other materials. The platform can for example have, but is not limited to a substantially circular shape, as shown for example in fig. 1, or an elongated shape, for example substantially oval or rectangular, with an opening extending through the platform, for example a central opening or an opening provided off center. The opening can for example have a central longitudinal axis parallel to and preferably during use extending coaxial with the longitudinal axis of the foundation pile. The opening can have a substantially circular cross section, seen in top view, as for example shown in fig. 1, with a downward increasing diameter, as will be explained. The opening can also have a different shape, depending primarily on the shape and dimensions of the upper end of the foundation pile, as will be discussed.

[0093] In this disclosure the filling elements as will be discussed are preferably made of a plastic material, such as but not limited to polyurethane (PU), for example high density PU, which can also be referred to as PUR. The material of the filling elements may be more pliable than the material of the platform and more pliable than the material of the foundation pile. The filling elements can alternatively be made of a different plastic material, such as for example but not limited to PE, such as for example HDPE, which plastic material is preferably at least water resistant, especially salt-water resistant, or any other suitable material and construction. The plastic material preferably is substantially free of cells. In this description filling elements will also be referred to as pads or tiles, especially but not exclusively when the filling elements have a width W9 and a length L9 which are relatively small compared to a diameter DPiieof the pile, which is preferably measured at a lower end of a truncated conical upper end 5 of the pile 2.

[0094] In embodiments the foundation pile is provided as a monopile made substantially of metal, the platform is made substantially of concrete or using metal, such as sheet metal forming a substantially hollow construction, and the filling elements are made substantially of PU.

[0095] Use of filling elements 9 made of a plastic material, such as but not limited to PU, has the additional advantage that the elements 9 protect the relevant surfaces of the pile 2 and the opening 4 during mounting of the platform onto the pile, especially any coating provided on such surface, such as for example but not limited to paint or anti corrosion coating, sealant and the like.

[0096] The drawings generally show an assembly 1 of a foundation pile 2 and a platform 3 mounted with an opening 4 over an upper end 5 of said foundation pile 2. A further structure can be mounted on and / or over the upper end 5, such as for example a tower of a wind turbine generator 50, which can be mounted to the foundation pile 2 in any suitable way, such as for example by a slip joint or a bolted connection, preferably without a transition piece. The upper end 5 of said foundation pile 2 has a truncated conical outer surface portion 6. Said opening 4 of the platform 3 has a truncated conical inner surface portion 7, which is formed substantially complementary to the outer surface portion 6 of the foundation pile 2. When the platform 3 is provided at a predetermined position relative to the foundation pile 2, a peripheral interspace 8 is provided between the said surface portion 6 of the foundation pile 2 and the said surface portion 7 of the opening 4 of the platform 3. The surface or surface portion 6 of the pile 2 can also be referred to as first surface 6, whereas the surface or surface portion 7 of the opening 4 can also be referred to as second surface 7, or vice versa. The predetermined position can be a predetermined axial position, i.e. for example a predetermined height hi of a lower surface 10 of the platform 3 above the lower end 11 of the truncated conical upper end 5 of the foundation pile 2 or a predetermined distance I12 of an upper surface 12 of the platform below the upper end surface 13 of the upper end 5 of the foundation pile 2. In fig. 3 by way of example a schematic representation of such peripheral interspace 8 is shown, for an embodiment in which the upper end 5 of the foundation pile 2 and the opening 4 have a substantially circular cross section. It will be directly clear to the skilled person how such interspace would be shaped if the upper end 5 and opening 4 have a different cross sectional shape.

[0097] In the peripheral interspace 8 filling elements 9 are provided, between and in contact with said surfaces 6, 7. Preferably a series of filling elements 9 is provided in said interspace 8, more preferably in rows 60 and columns 61, as shown in e.g. fig. 3, 4 and 4A - E, 19 and 20. According to the disclosure the filling elements 9 can be individually selected and / or individually formed and / or amended in shape and / or dimensions, as will be discussed further, for fitting in a specific position between the said surface 6 of the upper end 5 of the foundation pile 2 and the relevant platform surface 7. The filling elements 9 are preferably provided as pads or tiles, having relatively small length L9 and width dimensions W9 compared to a cross- sectional diameter DPiieof the pile 2.

[0098] As can be seen by way of example in fig. 3, the desired, ideal peripheral interspace 8 can be represented by a model showing a hollow truncated conical shape, defined by an ideal representation of the peripheral surface 7 of the opening 4 and the ideal representation of the surface portion 6 of the upper end 5 of the foundation pile 2. The upper and lower ends of the interspace 8 are then formed by two imaginary rings 44A, 44B. Such model can for example be represented by a computer model, using calculated surfaces 6, 7 (also referred to as 6son and 7sou) as they should ideally be when all measurements are met exactly for said surfaces 6, 7 when fabricating said foundation pile 2 and platform 3.

[0099] For fitting a platform 3 over an upper end 5 of a foundation pile 2, wherein said upper end 5 has a truncated conical outer surface 6, and wherein the platform 3 has an opening 4 fitting over said upper end 5 of the pile 2, said opening 4 provided with a peripheral wall 7 defining a truncated conical shape, it is known in the prior art to use a slip joint connection between the platform 3 and the foundation pile 2, wherein the platform 3 is lowered onto the upper end 5 of the pile 2, such that the conical surfaces 6, 7 meet and gravity forces the platform 3 onto the pile 2.

[0100] It is known that the manufacturing processes that are used for manufacturing the foundation pile and the platform, and the materials used, will lead to deviations from ideal shapes and dimensions of said surfaces. Manufacturing tolerances will necessarily lead to such deviations, as can for example deformations of portions of such surfaces. For example if a pile is rolled from steel plate and the seam thereof is then welded, this may lead to local un-roundness at the location of the seam, for example due to the welding process. These problems with production tolerances and deviations increases with an increase of the diameters DPiieof the foundation piles that are used, which diameters are expected to increase further in the future, for example due to an increase of the size and power of wind turbine generators, especially off-shore. The foundation piles can have an outer diameter DPiieof seven to ten meters or more, measured directly below the truncated portion 5. Such deviations have been found to be detrimental to slip joint connections, because at least this reduces the contact between the said surfaces of the opening and the pile, which can reduce stability and can increase wear. Moreover this may lead to misalignment of the foundation pile and the structure supported thereby, such as for example a wind turbine generator. Improving manufacturing processes or machining the surfaces of the platform and / or the pile will lead to high costs, if even possible without impairing the structural integrity of the parts and the structure formed therewith. Using filling elements 9 according to the disclosure can overcome these problems in a practical and economical way.

[0101] In a method and assembly according to the disclosure the platform 3, especially the opening 4 thereof, and the foundation pile 2, especially the upper end 5 thereof, are designed such that, with the platform 3 in said predetermined position, between the truncated conical outer surface 6 of the pile 2 and the peripheral wall 7 of the opening 4 of the platform 3 said peripheral interspace 8 is formed. The opening 4 in the platform 3 is deliberately designed larger than necessary for forming a direct slip joint between the surfaces 6 and 7. Filling elements 9 are provided in said interspace 8, substantially filling the width Ws of said interspace 8, the width Ws being measured as the shortest distance between said two surfaces 6, 7 at any given position. The width Ws can therefore differ for different positions in said interspace 8.

[0102] Preferably the filling elements are adhered to the inner surface 7 of the opening 4. This significantly reduces the risk of the filling elements 9 being damaged or knocked or scraped off when fitting the platform 3. When fitting the platform 3 with the filling elements 9 over the upper end of the pile 2, a slip joint is formed between inner surfaces 33 of the filling elements 9 and the outer surface 6 of the pile 2. If the filling elements 9 are mounted to the outer surface 6 of the pile prior to placing the platform 3, such slip joint will be formed between outer surfaces 34 of the filling elements 9 and the peripheral inner surface 7 of the opening 4 of the platform 3. Also the filling element or elements can be positioned between pile 2 and platform 5 without being adhered or otherwise attached to either one. These are all considered as forming a slip joint connection between the pile 2 and the platform 5. The width Ws of the designed interspace 8, measured between the opposing surfaces 6, 7, can for example be, but is not limited to about 35 mm on average.

[0103] In embodiments as will be discussed filling elements 9 are used having a thickness T. In embodiments the thickness T may be larger than the said width W, such that they can be shaped by removing material of the standard filling elements in order to make them fit for filling part of the interspace 8. In other embodiments the thickness T may be about the same as said width Ws. In advantageous embodiments different filling elements 9 are used, which preferably all have the same length L9 and width W9, but different thicknesses T, as will be explained, in order to fit different widths of the interspace 8 in different positions.

[0104] In a method according to the disclosure the filling element or elements 9, such as pads or tiles, can be chosen or made or adapted such that they fit in said space 8 against opposite surface portions of said surfaces 6, 7. In embodiments prior to fitting the platform 3 over the pile 2 a first scan SCi is made of at least a portion 6 of the truncated outer surface 6 of the pile 2 and a second scan SC2 is made of at least a portion 7 of the peripheral wall 7 of the platform. In such embodiments the shape of at least one of the filling elements 9 can be formed and / or amended based on said first scan SCi and second scan SC2. Preferably a series of filling elements 9 is provided between the pile 2 and the platform 3, wherein the shape of the individual filling elements 9 is formed and / or amended based on said first scan SCi and said second scan SC2. Each filling element 9 can be made specifically for a specific position between the platform and the pile. In an alternative method the different filling elements 9 are chosen from a variety of filling elements having different thicknesses T, such that for each position a filling element 9 is provided having a thickness T matching the average distance between the opposite surface portions 6, 7 at a given position. In embodiments the pads 9, as indicated also referred to as tiles 9 or filling elements 9, can be of similar or the same dimensions, including thickness. Pads according to the disclosure can have substantially continuous opposite closed surfaces and a substantially constant thickness over its entire surface area. According to the disclosure the pads 9 or tiles 9 preferably have a primary surface 33 facing one of the first surface area 6 and the second surface area 7 and an opposite secondary surface 34 facing the other of the first surface area 6 and the second surface area 7, wherein at least the primary surface 33 has a surface profiling 100 allowing compression of part of said profiling 100. The primary surface 33 and secondary surface 34 are also referred to a opposite side surfaces.

[0105] Fig. 5 - 14 schematically show, by way of example, different embodiments of pads 9, also referred to as tiles 9 or filling elements 9. The pads 9 are made of a compressible material, preferably a plastic material, such as but not limited to PU. In fig. 5, 6, 7, 8, 9, 10, 11 and 14 pads 9 are shown, seen from the primary surface 33, shown the profiling 100. It shall be clear that similarly profiling 100A could be provided at the secondary surface 34, as is for example shown in fig. 5A, 6A and C and fig. 14B. Also combinations of the different profilings 100 as shown in the different embodiments can be combined in further embodiments.

[0106] As can be seen in fig. 5 - 14, 19 and 20, the profiling 100 can comprise a series of openings 101 formed in the primary surface 33 and / or a series of protrusions 102 extending from or forming part of the primary surface 33, wherein voids 103 are provided between adjacent protrusions 102. As shown and indicated also combination of openings 101 and protrusions 102 could be provided. The purpose of these openings 101 and protrusions 102 with voids 103 shall be explained hereafter.

[0107] Fig. 5 shows schematically a pad 9 with a series of openings 101. In this embodiment the openings 101 are arranged in a regular pattern, here shown as a matrix of rows and columns of openings 101. In this embodiment the matrix is shown by way of example only as a 5x5 matrix, but any number of openings 101 could be provided, for example but not limited to in an NxM matrix, wherein N and M are integers, which may be the same or different from each other. An adjacent pad 9 is shown in phantom lines, spaced apart from the pad 9 over a distance We2, as for example shown in fig. 4A. In fig. 5A a cross section of such pad 9 is shown, showing openings 101 which are substantially cylindrical, open to both the primary surface 33 and the secondary surface 34. Fig. 5B shows a cross section of a pad 9, such as shown in fig. 5, but with openings 101 which have a closed end 104 at or near the secondary surface 34.

[0108] Fig. 6 shows a pad 9, similar to fig. 5, but in this embodiment the openings 101 have a truncated conical shape, with a relatively large cross section at the primary surface 33, said cross section reducing in the direction of the secondary surface 34. As shown in fig. 6A the openings 101 can be open to both the primary surface 33 and secondary surface 34. In fig. 6B a cross section is shown of an alternative embodiment of the pad 9, wherein the openings 101 have a closed end 104, similar to fig. 5B. In fig. 6C a cross section is shown of a further alternative embodiment, in which truncated conical openings 101 have been provided in both the primary surface 33 and in the secondary surface 34, having adjacent closed ends 104. Alternatively the openings 101 at opposite sides 33, 34 of the pad 9 can be staggered relative to each other.

[0109] Fig. 7 shows a pad 9, for example similar to any one of fig. 5 - 6 or fig. 8 or fig. 11 or fig. 14, wherein the openings 101 and / or protrusions 102 are provided in staggered rows and / or columns.

[0110] The openings 101 can be relatively small compared to the total surface area of the pad 9, defined by the length L9 times the width W9, for example having a diameter, when circular, in the order of centimeters, whereas the pads can have a length and width in the order of for example decimeters or more. The series of openings 101 can for example have a combined surface area at the primary surface 33 which is between 20 and 80% of the total surface area of the primary surface. For example the combined surface area can be between 40 and 75% of said total surface area. Additionally or alternatively at least a number of said openings 101, preferably each of said openings 101, can have a surface area at the primary surface 33 of nR2, wherein R is between 0,25 and 2 times a thickness T of the pad 9 at the relevant opening 101, or a similar surface area when having a different, non-circular shape.

[0111] Fig. 8 - 11 show embodiments of pads 9 which are provided with a profiling 100 at least at the primary surface 33 formed by or comprising protrusions 102.

[0112] In fig. 8 an embodiment is shown, by way of example comprising protrusions formed by truncated conical studs 105, as can be seen also in the side view of fig. 8A. Similar to fig. 5 - 6 the studs 105 are provided, in this embodiment and by way of example only, in a NxM matrix, but can also be provided in a different arrangement, such as for example but not limited to in staggered rows and / or columns, or in a random pattern. The studs 105 are spaced apart from each other, such that voids 106 are provided between adjacent studs 105, as will be discussed.

[0113] Fig. 9 the protrusions 102 are shown as ribs 107, which can have a curved or tapering cross section, for example having a rectangular shape in cross section or a trapezoid shape in cross section, as shown in fig. 9A or a wavy or curved cross section, such that the profiling 100 in a side view can have a substantially sinusoid profile. The ribs in this example have longitudinal axis L107 extending parallel to each other. In use the longitudinal axis L107 preferably will extend in a plane comprising a longitudinal axis A - A of the pile 2, as for example show in fig. 2. In alternative embodiments during use the longitudinal axis L107 can extend in other directions, for example substantially horizontally or angled relative to said axis A - A. voids 106 are provided between the ribs 107. The ribs 107 can also have different orientations and configurations, for example in the view of fig. 9 curved or wavy, such as sinusoid. Fig. 10 shows an embodiment of a pad 9 wherein the protrusions 102 comprise intersecting ribs 107. In fig. 10 the intersecting ribs 107 have longitudinal axis L107 which extend at an angle relative to each other, for example an angle of 90 degrees. Between the ribs 107 voids 106 are again formed, which in this embodiment are square truncated pyramid shaped.

[0114] Fig. 11 shows a further alternative embodiment of a pad 9 according to the disclosure, seen at the primary surface 33, wherein studs 105 and openings 101 are provided, for forming the profiling 100. In this embodiment, by way of example only, rows of studs 105, in fig. 11 shown horizontally, are alternated with parallel rows of opening 101. The studs 105 and openings 101 are in this embodiment by way of example shown as having a similar, truncated pyramid shape. These can however obviously also be formed differently in shape and / or dimensions and / or ordered differently relative to each other.

[0115] Fig. 14 shows a further alternative embodiment, wherein the profiling 100 comprises ribs 107 and / or studs 105 and / or openings 101. In fig. 14A a cross section along the line XIVA - XIVA is shown, of an embodiment in which ribs 107 are shown, alternating with rows of truncated openings 101. Fig. 14B shows a similar cross section of an alternative embodiment according to fig. 14, wherein ribs 107 are alternating with rows of studs 105.

[0116] As can for example be seen in fig. 14B, the protrusions 102, such as ribs 107 or studs 105 can be hollow. For example openings 105 can be provided from the secondary surface 34, opening towards or into the ribs 107 or studs 105. In alternative embodiments the ribs 107 and / or studs 105 can be hollow, comprising a void enclosed within the ribs or studs.

[0117] Fig. 12 and 13 show deformation of parts of pads 9 when compressed between a pile 2 and platform 3, especially between surfaces 6 and 7 thereof, due mainly to gravity forces G acting on the platform 3. In fig. 12A a part of a pad 9 is shown, schematically and partly in cross section, in undeformed state, having its original thickness T and an opening 101. In this embodiment the opening 101 is shown according to fig.

[0118] 5 and 5A, by way of example only. Other openings 101 can be used in the same or a similar way. In fig. 12A the minimal distance Ds between the surfaces 6 and 7 is larger than the thickness T, for example because the platform 3 is being positioned over the upper end 5 of the pile 2, but has to be lowered further to reach its final position.

[0119] When the platform 3 is lowered further onto the pile 2, the surfaces

[0120] 6 and 7 will be forced closer together, reducing the distance Ds. At some position of the platform relative to the pile the distance Ds will be reduced to less than the thickness T of the pad 9 at least at a given position, such that further lowering of the platform will compress part of the pad 9.

[0121] In fig. 12B the same part of the pad 9 is shown, between the surfaces 6 and 7 when the platform 3 is for example in its final, desired position, as for example shown in fig. 2. The force or pressure F, which is the result or the force-component of gravity G, perpendicular to the surfaces 6, 7, compresses the pad 9 in order to accommodate the resulting space 8 between said surfaces. As can be seen in fig. 12B the side 101 A of the opening 101 will bulge inward into the opening 101, allowing for a reduction in thickness of the pad 9 to less than the original thickness T, without excessive forces. In fig. 12B the bulging is indicated by reference sign 9C. The bulging 9C reduces the volume of the opening 101.

[0122] Fig. 13A and B show compression of a pad 9, similar to fig. 12A and B, wherein the pad 9 has protrusions 102, such as studs 105 and / or ribs 107. Again by lowering the platform 3 onto the pile 2, the interspace 8 between the surface 7 of the opening in the platform 3 and the surface 6 of the pile 2 will be reduced, at least in its width Ws, to less than the height or thickness T of the pad measured at the protrusions, thus compressing at least part of the protrusions 102, said protrusions bulging into the voids 106 between the protrusions 102. Again in fig. 13B the bulging is indicated by reference sign 9C. The original shape of the protrusion 102 is indicated by dotted lines.

[0123] The pads 9 can be inserted between the platform 3 and pile 2, and are preferably adhered to one of said surfaces 6, 7. In advantageous embodiments the pads are adhered to one of the surfaces 6, 7 by the secondary surface, the profiling 100 facing in the opposite direction. The pads can for example be adhered to the second surface area, by the secondary surface, the surface profiling facing the first surface area.

[0124] Fig. 2A and 2B show in part an alternative embodiment of a pile 2 and platform 3, with pads 9 enclosed there between. In these embodiments the pile 2 is provided with a first flange 110, extending outward from the pile 2 at a lower end of the first surface area 6, extending over a lower edge of at least one pad 9. The platform 3 is provided with a second flange 111, extending inward from the platform 3 at an upper end of the second surface area 7, extending over an upper edge of at least one pad 9. In embodiments only one of said flanges 110, 111 can be provided. These flange or flanges 110, 111 prevent the pads 9 for leaving the space 8 between the surface areas 6, 7 and can also prevent the pads 9 from bulging out of said space 8. Moreover they can provide for an easy positioning of the pads 9.

[0125] Fig. 15 shows schematically a system 20 for use in an embodiment of a method of the disclosure, wherein pads 9 are individually or by group chosen or machined or manufactured for specific positions. With such system 20 one or more first scan SCi and one or more second scan SC2 is made using at least one scanner 21. In embodiments the or each scanner 21 is a laser scanner. In the embodiment shown in fig. 15 the system 20 comprises a computer system 22, to which the or each scanner 21 is connected, by wire 23 or wireless. Scanning data of the at least one scanner 21 is fed into the computer system 22. A computer program CP is provided in said computer system 22 for processing said scanning data. It should be noted that the computer system 22 can comprise a single computer or multiple computers or similar data processing units, but can also be provided differently, for example entirely or in part cloud based.

[0126] In the embodiment of fig. 15 the system 20 is designed for scanning the inner surface 7 of the opening 4, or at least relevant parts thereof, as well as the outer surface 6 of the upper end 5 of the foundation pile 2, or at least a relevant part thereof. In the embodiment shown the foundation pile 2 is to this end laid in a horizontal position, for example rotatable around its longitudinal axis A - A extending horizontally, as shown in fig. 15. A first scanner 21A is placed next to the relevant surface 6 or part thereof, such that a first scan SCi, schematically represented by striped lines 24, can be made of said surface 6 or part thereof. Scanning data is fed into the computer system 20. The platform 3 is placed with its bottom surface 10 on a surface area 25. A second scanner 2 IB is placed inside the opening 4, such that a second scan SC2, schematically represented by striped lines 26, can be made of said surface 7 or part thereof. Scanning data is fed into the computer system 20. Based on the scanning data the computer system can model the surfaces 6, 7 or portions 6A, 7A thereof, including any deviation from a desired surface or surface portion. These models of the surfaces or surface portions shall be referred to also as surfaces 6iSt and 7iSt-

[0127] The scanners 21A, 2 IB can be hand held scanners or can be (semi)automated scanners, for example tripod or robot or otherwise mounted scanners. Such scanners and scanner systems as such as well- known in the art. It shall be clear that scanning data as discussed can also be obtained differently, for example with the platform and / or pile in different orientations. In the embodiments shown the scanning data is obtained at a production location, for example on-shore, with the pile not yet installed or even shipped out to a mounting location, which may be on- or off-shore. It will however be clear that the scanning data can also be obtained at different locations, wherein for example the scanning can be performed after having mounted the foundation pile at a destined location. Then filling elements 9 can also be used for adjusting for any for example non- vertical position of the foundation pile.

[0128] In embodiments of the system 20 and method as disclosed the computer program CP comprises a computer model of a desired truncated conical surface 6S0n of the foundation pile 2 and a computer model of a desired peripheral wall surface 7sou of the opening 4 of the platform 3. The computer program CP is designed for comparing the scanning data, i.e. the surface models 6iSt and 7iSt based on said scanning data with the computer models of the desired surfaces 6son and 7sou as provided in the computer system 22. Comparing these models will show where deviations exist and what these deviations are, and can result in a model of the interspace 8 as for example shown in fig. 3. The computer program CP may in embodiments further be designed for defining a computer defined shape of at least one filling element 9sou based on such comparison, as for example shown in fig. 17 and 18. Thus each filling element 9 can be specifically manufactured for a specific position between the platform 3 and the pile 2. Additionally or alternatively the computer program CP can be designed to choose a filling element 9 for each position based on its thickness T matching best the average distance between said surface portions 6, 7 at said position.

[0129] As shown in fig. 15 the system 20 can comprise or be connected to a machining system 27, here schematically shown, for forming and / or machining filling elements 9 to make them fit the intended position as filling element 9sou. The machining system 27 can for example comprise a CNC machining system. By way of example the machining system 27 such as a CNC based machining tool can shape a filling element 9 based on the computer defined shape as discussed here before, for example from a block of polyurethane or other suitable material, especially plastic, or from an already formed standard filling element 9, as will be discussed hereafter.

[0130] In the same or alternative embodiments the computer system 22 can comprise a computer model of a standard filling element 9, wherein the computer program CP is further designed to define a computer machining program for machining said standard filling element 9 based on a comparison between the computer model of the standard filling element 9 and the computer defined shape of said at least one filling element 9S0n. The said computer machining program can then be used for operating the machining system 27.

[0131] In the same or alternative embodiments the computer program CP can comprise a computer model of a preferred interspace 8 between said peripheral surface 7 of the opening 4 and said truncated conical surface 6 of the pile 2, wherein based on the scanning data from the scanners 21 deviations between the actual interspace 8 and the preferred interspace 8 are calculated, and wherein at least one and preferably each filling element 9 is machined and / or chosen based on said calculated deviations.

[0132] Thus methods of forming and / or amending and / or choosing filling elements 9 for use in fitting a platform 3 with an opening 4 over an upper end 5 of a foundation pile 2 can comprise the steps of making a first scan SCi of at least a first portion of the surface 6 of the pile 2 at a predetermined position and a second scan SC2 of at least a first portion of a peripheral surface 7 of the opening 4 of the platform 3, opposite the first portion of the pile surface 6 and machining and / or choosing based on at least thickness T of the filling elements 9 for each position the at least one filling element 9 to be fitted between said first portion of the surface 6 of the foundation pile 2 and said first portion of the peripheral surface 7 of the opening 4. The filling element 9 is thus formed and / or amended and / or chosen such that it can be positioned in close contact with the first surface portions 6A, 7A. Said at least one filling element 9S0n is preferably formed and / or machined and / or chosen such that during use it bridges the actual interspace 8 between said first surface portions 6, 7, for which the filling element can be partly compressed by the forces exerted thereon by the platform, especially the force of gravity. As discussed, in a method according to the disclosure preferably a series of filling elements 9 is provided for positioning in the interspace 8 between the surface 6 of the foundation pile 2 at said predefined positions and the peripheral surface 7 of the opening 4, in a matrix arrangement of the filling elements 9, comprising rows 60 and columns 61 of filling elements 9, with channels 62, 63 there between, as for example shown in fig. 4. As discussed a large number of filling elements 9 can be used, for example but not limited to between 100 en 3000 or more such filling elements for a pile 2 with an upper diameter of the truncated conical upper end 5 of between for example but not limited to between 3 and 15 meters, for example between 7 and 10 meters and a height H of the opening 4 of for example between 0,5 and 3 meters. The number of filling elements can for example be chosen such that they each fill between 1 and 5 degrees, for example between 2 and 4 degrees of the circumference of the peripheral surface, leaving enough space for forming the channels, and between for example between 2 and 10 percent, such as for example between 2 and 6 percent of the height H of the platform opening. In such embodiments standard filling elements 9 can be used which are at least substantially flat. In embodiments such standard filling elements 9 can then be machined for fitting the curved surfaces. Alternatively a standard filling element 9 can be formed having a predefined curved shape, especially when a relatively small number of such segments is used for filling the interspace 8. In other embodiments standard flat filling elements and / or elements or pads 9 having openings 101 and / or protrusions 105, 107 with voids 106 can be used and can then be bent to fit, or can be compressed to fit.

[0133] In an assembly of a foundation pile 2 and a platform 3 mounted with an opening 4 over an upper end 5 of said foundation pile 2 according to the disclosure each of said filling elements 9 can have been machined and / or chosen for fitting at a specific position between said platform 3 and said pile 2, wherein the filling elements may have been machined on at least a surface 33 facing the surface 6 of the foundation pile 2 and / or a surface 34 facing the peripheral surface 7 of the opening 4, more preferably both of said side surfaces 33, 34, based on scanning data obtained of the relevant surface portion 6 of the pile 2 and / or scanning data obtained of the relevant surface portion 7 of the opening 4.

[0134] In embodiments the filling elements 9 can be mounted to one of the surfaces 6, 7 before mounting the platform 3 onto the foundation pile 2. This can be done with the pile and / or platform in a position as for example shown in fig. 15. Mounting the filling elements 9 can in embodiments be performed onshore. The filling elements 9 can for example be glued to one of the surfaces 6, 7. In a preferred, advantageous embodiment the filling elements 9 are mounted to the inner surface 7 of the opening 4 in the platform 3.

[0135] By using the model and the scanning data as disclosed, a model can be formed of the actual interspace 8 between the foundation pile 2 and the platform 3 to be used together. Then filling elements 9, 9S0n can be formed, and / or chosen from a variety of filling elements, for positioning in said actual interspace 8, for example using a system as discussed with reference to fig. 15. The filling elements 9 can be individually shaped, in order to properly fill the actual interspace 8 at a given position. In embodiments a standard filling element 9 can be used as starting point, for example a rectangular or square, flat or curved filling element, or a profiled filling element, which can be machined on an inner surface 33 and / or an opposite outer surface 34, based on the scanning data and models as discussed. An example of a shaped filling element 9S0n is shown in fig. 17, with the original inner surface 33 schematically shown partly in broken lines, and the shaped inner surface 33’ in solid lines. The standard filling element 9 can be curved according to the diameters of the inner and outer surfaces 6, 7 of the model, such that a series of such elements can fill the interspace 8 in a side-by-side position, having side surfaces 37 fitting against each other or at least in close adjacent position. As indicated, in a similar way openings and / or protrusions can be provided on one or either of said surfaces 33, 34.

[0136] Fig. 3 shows schematically a model of an interspace 8 formed between surfaces 6 of the pile and 7 of the opening 4, as discussed. In fig. 3 for part of said interspace 8 a series of filling elements 9 is shown, forming rows 60 and columns 61 of filling elements, with intermediate channels 62, 63 as will be discussed. It will be understood that for the full circumference of the pile and opening such an arrangement of filling elements 9 with intermediate channels 62, 63 will be provided. For the sake of clarity only said limited number of filling elements is shown. Fig. 4 shows part of the series of filling elements 9, in frontal isometric view, adhered to an inner surface 7 of opening 4. In this embodiment the filling elements 9 are shown as square tiles. They are positioned forming a matrix for filling elements 9, which a network of intersecting first channels 62 and second channels 63 extending there between. In fig. 4A schematically, by way of example only, four filling elements are shown of such matrix, in which each filling element 9 is a square tile with sides of 200 mm, the channels 62, 63 there between having a width of 20 mm. Obviously other dimensions can be chosen.

[0137] Fig. 4A - 4E show schematically filling elements or pads 9 in cross sectional side views and / or top or bottom view, as rectangles. This is only shown as such by way of example. The elements or pads 9 can have different cross sections, and can for example be as disclosed in fig. 5 - 11 or 14, and they can have for example a trapezoid or curved cross section.

[0138] In fig. 4B - 4D the first surface area 6 is indicated by striped line 6, the surface area 7 by full line 7.

[0139] In fig. 4B a cross sectional view is shown along the line IV - IV in fig. 3, of a first possible embodiment of (part of) an interspace 8, wherein the width Ws , i.e. the shortest distance between opposite surfaces 6, 7, is substantially constant over the shown portion of the surfaces 6, 7. A series of filling elements 9 is shown, each having the same thickness T, consistent with said width Ws, measured between opposing surfaces 33, 34 of the filling elements 9. In this embodiment therefore all filling elements 9 can be the same. They can have a profiled surface or surfaces 33, 34, such as having openings 101 and / or protrusions 105, 107, even better allowing compression of the pads 9 or parts thereof, which also applies to the embodiments of fig. 4C - 4E.

[0140] In fig. 4C a similar cross sectional view is shown, of a second embodiment, in which the width Ws of the interspace 8 gradually increases in downward direction, i.e. in a direction away from the top 13 of the pile 2, from a width Ws(i) to a width Ws<2). In this embodiment the thickness T1-5 of the series of filling elements 9 also gradually increases in said downward direction, from a thickness Ti at the upper end to a thickness T5 at the lower end of said portion of the interspace 8, wherein each of said filling elements 9 can have, but not necessarily is, a constant thickness T. Each filling element 91-5 is specifically chosen and / or machined or otherwise formed based on its thickness T1-5 best fitting the intended position. During use the filling elements 9 can be compressed slightly, in order to adjust to the relevant somewhat trapezium or wedge shaped section of the interspace 8 in which the filling element is positioned. Such compression can be very limited when filling elements are used have a length L which is small compared to the height H of the opening 4. As discussed, by providing profiling 100 as for example shown in fig. 5 - 11 or 14, this can even better be accommodated for, which can also have the advantage that only a limited number of different pads 9 need to be used or less amendments are necessary for such pads.

[0141] In fig. 4D again a cross sectional view is shown along the line IV - IV in fig. 3, similar to fig. 4B and 4C, but in this embodiment the part of the interspace 8 shown has a varying width Ws, due to a dent 64 in the surface 6 of the pile 2. At said dent 64 the width Ws(dent) is larger than the width Ws(i), (2) at the upper end and lower end of the part of the interspace 8 shown. In this embodiment the five filling elements 91-5 are again chosen from a series of filling elements depending on their thickness T1-5, best fitting the desired position. In this embodiment for example the first filling element 9i has a thickness Ti, which is the same thickness T5 of the fifth filling element 9s. The second filling element 92 has a slightly larger thickness T2, whereas the third and fourth filling elements 9s and 94 have an even larger thickness T3 and T4. As is schematically shown in fig. 4D the fourth filling element 94 is to be compressed at an edge portion 9A in order to at least partly assume a wedge shaped form, indicated by the striped line 9B.

[0142] In fig. 4B - D vertical cross sections are shown. It shall however be clear that similarly filling elements 9 can be provided in horizontal direction, i.e. in a direction perpendicular to that shown in fig. 4B - D, in which again individual filling elements 9 can be chosen or made based on their thickness T for specific positions at said surfaces 6, 7, for example based on the discussed scans SC made. An embodiment is shown in fig. 4E, in cross sectional view along the line IVE - IVE in fig. 3, by way of example. In this embodiment part of the interspace 8 is shown, in top view, curved with substantially a radius of the relevant cross section of the pile 2. Ten filling elements 9 are shown, of which the left hand first two filling elements 9i and 92 and the and the right hand last five filling elements 9e- 10 in fig. 4E have the same thickness T. The fourth filling element 94 has a larger thickness T4, in order to fill a larger distance between the surfaces 6, 7. The third and fifth filling elements 9s, 9s are again wedge shaped, having an inclining cq declining thickness, for example having been machined as such or being compressed, in order to accommodate the changing distance between said surfaces 6, 7. As discussed, such compression can even better be accommodated when using pads or filling elements 9 having profiling 100 as discussed, on either or both surfaces 33, 34. As is shown schematically in fig. 4, a camera or similar inspection tool 65 can be entered into at least some of the channels 62, 63, for inspection of for example the filling elements 9 and / or the surfaces 6, 7, and especially any coating provided on such surfaces 6, 7. The inspection tool 65 for example has a vision angle facing sideways, as schematically shown in fig. 4 by the dotted lines 66. The inspection tool 65 can be connected to a display unit and / or a computer system 72 or the like, in a known manner. The inspection tool 65 can for example be an endoscope or periscope like instrument, or any other suitable such tool known in the art. Additionally or alternatively the inspection tool can comprise means for emitting and / or receiving other inspection radiation, for example for non-optical inspection.

[0143] In the embodiments shown in the drawings between each pair of adjacent filling elements 9 a channel 62, 63 is formed, such that a network of intersecting channels 62, 63 is formed. A first series of channels 62 is formed extending in a direction between an upper side 12 of the platform 3 and a lower side 10 of the platform 3. The channels of the first series of channels 62 have at least an upper open end 67 or a lower open end 68, for introducing the inspection tool 65 into the channel 62. In preferred embodiments both the upper end 67 and the lower end 68 of each channel 62 of said first series is open, such that the tool 65 can be introduced from either end. Moreover, by providing at least some and preferably all of the channels 62 of said first series of channels is open on opposite ends 67, 68, such that water and air can pass therethrough freely, contrary to the prior art in which gaskets are provided in an interspace between for example a pile and a transition piece, filling and thus closing off such interspace. Thus the platform 3 can drain more easily.

[0144] The filling elements 9 can have a non-square or non-rectangular shape, seen in the direction perpendicular to the thickness direction, for example having rounded or chamfered corners, which will make it easier to maneuver an inspection tool 65 such as an endoscope or remote controlled camera to move from a first channel 62 into a second channel 63, the second channels extending in peripheral direction through the interspace 8. A filling element or pad 9 can for example be a tile having a circular or oval shape, or a polygonal shape, for example having six or eight corners.

[0145] A tile should be understood in the present disclosure at least as a substantially flat object, preformed prior to providing it into an interspace 8, having a length dimension and a width dimension, also referred to as length L9 and width W9, which are substantially larger than a thickness T or at least than an average thickness T of said element 9. Each filling element or tile 9 can for example have but is not limited to having a shape with a length L9 and width W9, such that it fits within an rectangle or square having sides between 10 and 60 cm, preferably between 15 and 30 cm, and an average, preferably a constant thickness T of between l / 40thand l / 4thof the largest of the length and the width, preferably between l / 20thand l / 6th, such as for example but not limited to between l / 15thand l / 8th. As indicated, the elements or tiles 9, also referred to as pads 9, can have at least one profiled surface 33, 34 as discussed, for improving compressibility, which profiling may also improve bending.

[0146] The channels 62, 63 preferably have a width We2, We3, measured as the smallest distance between adjacent filling elements 9, which is substantially smaller that the smallest of the length L9 and width W9 of the filling elements 9, for example a width We2, Wus between l / 40thand l / 4thof the largest of the length L9 and width W9, preferably between l / 20thand l / 6th, such as for example but not limited to between 1 / 15thand l / 8th.’

[0147] By way of example, the elements 9 can be made of plastic material, such as PU, for example a PU with a density of about 1.1 g / cm3or more, for example 1.2 g / cm3or more, such as for example between 1.20 and 1.25 g / cm3(ASTM D 792-91). The filling elements can for example have an average thickness T, for example a constant thickness T, of between about 10 and about 70 mm, preferably between 20 and 50 mm. The filling elements 9 have overall dimensions which are relatively small compared to said diameter DPiieof the pile 2, for example a length and a width dimension, when considering a rectangular or square element 9, in the order of centimeters or decimeters, and a thickness as indicated. In fig. 4A an example is shown of a filling element 9 embodied by a tile, which has a length L9 measured in the direction of the column 61, parallel to the longitudinal axis A - A, of 20 cm, and a width W9 measured parallel to the row 60, of again 20 cm, the filling element 9 being square. Preferably the plastic material is free of open or closed cells comprising gas.

[0148] In the embodiments shown the filling elements all have substantially the same length L9 and width W9 dimensions, but may have different thicknesses and / or different profiling. However, also filling elements, especially tiles can be used having differing length and / or width dimensions. In such embodiments preferably all filling elements 9 in any single row 60 of filling elements 9 at least have the same length dimension L9, the length L9 measured in the direction perpendicular to the periphery of the pile 2.

[0149] As indicated different filling elements 9 can have different thicknesses T and / or different profiling, such that for each position in said interspace 8 a filling element or tile or pad 9 can be chosen having the appropriate thickness T, based on for example the scans as discussed. In order to easily distinguish between the tiles they can for example be coded, such as but not limited to color coded, in which each thickness tile has its own color indication. For example a series of tiles can be provided with thicknesses T increasing in steps of for example but not limited to 2 mm, each of said tiles in the series having a different color. This will make picking the appropriate tiles 9 more easy for a user. Coloring can be provided for example after producing the tiles or during production, for example by mixing the color through the material of which the tiles are made. The filling elements are preferably made of a compressible material, such that the shape and dimensions of the filling elements can be amended to adapt to the interspace portion it is enclosed in, for example due to the weight of the platform. To this end the material used for the filling elements, such as but not limited to elastomers like PUR, wherein the filling elements are preferably chosen such that for each filling element 9 during use a compression of the relevant filling element or part thereof due to the weight of the platform 3 is less than 15% of the thickness of the filling element, preferably less than 10% of said thickness. As discussed, profiling of one or both of the surfaces 33, 34 can even more easily provide for compressibility, without excessive stresses.

[0150] By using separate filling elements 9 in said interspace the further advantage is obtained that changes in the width of the interspace 8 can easily be adapted for by using filling elements with different thicknesses T and / or profiling next to each other, as for example schematically shown in fig. 4C and D and fig. 4E. Moreover, this can limit the compression necessary for the individual elements 9 and / or the force needed for such compression. Moreover, if desired this allows for using filling elements having different properties next to each other, for example filling elements made of different materials, having different densities, for example for providing different compressibility, or different shapes, in order to accommodate specific needs for support at different positions in said interspace 8.

[0151] By using seperate filling elements 9, which are relatively small compared to the surface area of the pile and opening between which they are to be used, a further advantage can be obtained in that single filling elements or even a group of a limited number of such filling elements 9 can be allowed to fail, for example due to overpressure, which could occur when for example the thickness of such tile does not match, especially is larger than the distance between the surfaces at the given position, or when for example contamination has entered between the said filling element and one of the surfaces 6, 7. Such filling element may be damaged or disintegrate without substantially influencing the stability or position of the platform relative to the pile. It would even be allowable if a filling element is not present in a given position, since neighboring filling elements will easily accommodate for the absence of support by such single filling element or small group of such filling elements.

[0152] The relevant surfaces 6, 7 of the pile 2 and opening 4 are preferably provided with, especially covered by a protective coating, such as for example but not limited to an anti-corrosion and / or anti-fouling coating, as known in the art of off shore, wherein the filling elements 9 are preferably adhered to the said coating on the surface of the opening 4 after application of the coating but prior to placing the platform 3 on the pile 2.

[0153] Fig. 16 shows an embodiment of part of a platform 3 on a pile 2, in top view. The pile 2 in this embodiment has been made of metal, rolled from metal plate wherein meeting ends of the plate are welded together, forming a closing weld 39. Due to the rolling process and / or the welding, bringing heat locally into the metal, the pile 2 can comprising a slightly bulging area 40 around the weld 39. This can mean that the pile 2 at that location deviates from a desired circular cross section, as drawn in as a circle 41 in striped line. In embodiments like shown in fig. 20 this can be accommodated for by a filling element 9sou which has been shaped such that the inner surface 33 is provided with a surface portion fitting said bulging deviation 40 of the pile 2. In fig. 20 only the one filling element is shown. The rest of the interspace 8 can be filled with further filling elements 9, 9sou, which may or may not be amended from standard filling elements 9.

[0154] WO2023 / 275153 discloses a method and system for mounting a tower of a wind generator or a transition piece for mounting a tower of a wind generator on a foundation pile, by a slip joint between at least a truncated conical part of the foundation pile and an equally truncated conical part of the tower or transition piece. In the description of this document it is indicated that connecting elements can be placed between said truncated conical portions and cylindrical portions directly above and below said truncated conical portions. In the disclosure two rings of sixteen such connecting elements each are shown, positioned between the truncated conical portions, as well as two such rings of sixteen connecting elements directly above and directly below said truncated conical portions. In WO2023 / 275153 it is described that the connecting elements can be made of an elastic material and can be at least partly compressible, wherein the compressibility can be improved by structuring of the surfaces. No such structuring is described or shown in this publication. As an alternative it is described that openings can be provided in the surfaces for improving compressibility.

[0155] It has been found that for mounting a tower or transition piece to a foundation pile this system may provide sufficient compressibility of the connecting elements for compensating for un-roundness of the pile and tower or transition piece, because the pile and, especially, the tower or transition piece will also allow for some deformation during and after forming the slip joint, due to the weight of the structure supported and the relative flexibility of the parts.

[0156] Platforms for mounting on a foundation pile will not provide for such flexibility and deformation, whereas the weight of a platform will be significantly lower than that of a wind turbine, and therefore it has been found that the relatively large connecting elements as disclosed in WO2023 / 275153 will not be suitable for providing a proper support of the platform on a foundation pile.

[0157] It has been found that by pads or tiles as disclosed hereafter, especially with reference to fig. 21 - 27 will be highly efficient and effective in mounting a platform on a foundation pile by a slip joint, especially with large diameter foundation piles, such as for example foundation piles having a diameter at the lower end of the truncated conical portion for forming the shp joint of seven meters or more, such as for example 10 meters or more, especially but not exclusively when the slip joint is only formed between the platform and the truncated conical portion of the foundation pile, and not any portion above or below said portion.

[0158] In preferred embodiments of the disclosure slip-joints 100 are formed between a pile 2 and a platform 3 by using a first type of pad and a second type of pad and / or tiles comprising such first and second types of pads or at least having a primary surface formed similar to a combination of said first and second types of pads. In this description the first type of pads will be also be referred to as first pads 9A, the second type of pads as pads 9B.

[0159] Fig. 21 shows in top view and in cross section along the line A - A a first pad 9A, made of an elastic, compressible material such as PU. The first type of pad 9A has a primary surface 100 and an opposite, secondary surface 100A, wherein the primary surface 100 comprises protrusions 102 and voids 103 between the protrusions 102. The secondary surface 100A in this embodiment is substantially flat. Fig. 22 shows in top view and in cross section along the line B - B a second pad 9B, made of an elastic, compressible material such as PU, preferably the same material as that of the first pads 9A. The second pad 9B has a primary surface 100 and an opposite, secondary surface 100A. The primary surface 100 is defined by or at least comprises a substantially flat primary surface area 100B, whereas the secondary surface 100A is also substantially flat.

[0160] The protrusions 102 in these embodiments are spherical or semi- spherical, having a convex outer surface 102A, with an apex 200. The protrusions are preferably all the same. The voids 103 between the protrusions 9 have a concave bottom 103A.

[0161] The protrusions 102 and voids 103 define, in a cross section of the pads 9A, a sinusoidal or semi-sinusoidal profile, as schematically shown in fig. 23C for a small part of said cross section. In these embodiments the protrusions preferably have a constant radius of curvature R102 over most of the surface 102A, including the apex 200, for example over about 140 degrees, 70 degrees on opposite sides of the apex 200. The bottom 103A preferably also has a spherical or semi spherical shape, having a constant radius of curvature R103 over most of the surface 103A, including the apex 300, for example over about 140 degrees, 70 degrees on opposite sides of the apex 300.

[0162] In the embodiment shown the first pads 9A comprise a preferred number of nine protrusions 102. However, a different number could be provided. In the embodiments shown the protrusions 102 are arranged in a preferred regular 3x3 matrix 206. However, they can also be arranged differently, for example in a staggered configuration.

[0163] In fig. 23 curvatures of the surfaces 102 A, 103A are schematically shown by larger spheres 201 and smaller spheres 202, having the respective radii R102, R103, wherein the center points C201, C202 are connected by an imaginary line 203 including an angle a of about 20 degrees with an imaginary plane 204 through the centers of the larger spheres 201.

[0164] The first pads 9 A preferably have a thickness T9A , also referred to as maximum thickness, measured between the secondary surface 100A and the apexes 200 of the protrusions 102 of between 20 and 40 mm, for example between 25 and 35 mm and preferably about 30 mm. The second type of pads 9B have a thickness T9B measured between the primary 100 and secondary surfaces 100A which is smaller than a maximum thickness T9A of the first type of pads.

[0165] The maximum thickness T9A of the first type of pads 9A is preferably between 1.1 and 6 times the thickness of the pads of the second type of pads, preferably between 1.2 and 4 times, more preferably between 1.3 and 3 times. The said maximum thickness T9A of the first type of pads 9 A is most preferably about 1.5 times the thickness T9B of the second type of pads 9B. The protrusions 102 preferably have a radius of curvature R102 of between about 22 and 25 mm, preferably about 23.5 mm. The bottom portion 103A preferably has a radius of curvature R103A of between about 9 and 11 mm, preferably about 10 mm, wherein the distance T103B between the apex 300 of the bottom portion 103A of each void 103 and the adjacent secondary surface 100A is between about 8 and 12 mm, preferably about 10 mm.

[0166] The pads 9 A, 9B are preferably square, symmetrical in rotation over 90 degrees around an axis through their center, perpendicular to the secondary surface 100A. Fig. 21A shows a perspective view of three first pads 9 A.

[0167] The first pads 9 A and second pads 9B can be individually placed, for example adhered to a surface of the pile 2 or of the platform 3. First pads 9A can form a first series of pads, the second pads 9B a second series of pads. In fig. 22A and 22B by way of example only examples of positioning of first and second pads 9A, 9B are shown, wherein eight first pads 9A are placed in a square around a single second pad 9B, with some distance relative to each other, forming channels as discussed. In fig. 22A the square is placed such that the channels extend parallel and perpendicular to the longitudinal axis A - A of the pile 2. In fig. 22B the square has been rotated over 45 degrees relative to the position of fig. 22A.

[0168] Alternative to placing individual pads 9, a series of pads can be interconnected, forming a tile 400. For example, eight pads 9A of the first series of pads and one pad 9B of the second series of pads can be interconnected, forming a tile 400. In embodiments all or some of the pads 9A, 9B are interconnected relatively rigidly to each other and / or some of the pads 9 A, 9B are hingedly connected to each other.

[0169] Fig. 23 shows an embodiment of a tile 400 having a profiled primary surface 100 and a substantially flat opposite secondary surface 100A. The profiling comprises rows of protrusions 102 and voids 103 between the protrusions 102, similar to or identical to the first pads 9A, wherein the protrusions have a convex surface 102A, and are preferably spherical or semi-spherical. The voids 103 between the protrusions 102 have a concave bottom 103, wherein central to the tile 400 a substantially flat primary surface portion 100B is provided, similar to or identical to a second pad 9B. The said substantially flat primary surface portion 100B is provided at a level Q between the secondary surface 100A and apexes 200 of the protrusions 102, preferably at a level Q between at a lower side of the protrusions or between said lower side and the said apexes 200. The lower side of the protrusions 102 should be understood as at a plane G as shown in fig. 23C, extending perpendicular to the plane of drawing and through the point where the imaginary line 203 crosses the spheres 201 and 202.

[0170] For the sake of clarity, in e.g. fig. 21, 22A and B, 23, 24 and 25 the protrusions are shown schematically, wherein the inner circle represents the level of plane G, the outer circles representing the voids 103. The voids 103 can form a circular indentation around the protrusions, like a moat.

[0171] Preferably a tile 400 comprises at least three side-by-side, substantially rectangular tile portions 401, 402, 403, wherein a middle tile portion 402 is positioned between two outer tile portions 401 and 403, as shown in fig. 23. The middle tile portion is hingidly connected to each of said outer tile portions 401, 402, through living hinges 405 at opposite longitudinal sides thereof. The outer tile portions 401, 403 each comprise three sets of nine protrusions 102 arranged in a matrix M, and said middle tile portion 402 comprises two sets of nine protrusions 102 arranged in a similar matrix M, wherein between said matrices M of the middle tile portion 402 a flat primary surface area 100B is provided. The outer portions 401, 403 are preferably configured substantially like three first pads 9A interconnected relatively rigidly. The middle portion 402 is preferably configured substantially like a second pad 9B with on either side a first pad 9A relatively rigidly connected thereto. In the embodiment shown the tile 400 is substantially square, having sides of between 500 and 700 mm, preferably about 600 mm. The protrusions 102 are preferably as described before, having a radius of curvature R102 of about 23 to 24 mm. Between adjacent protrusions 102 a void can be provided having a concave bottom 103 with a radius of curvature R103 of about 10 mm. In embodiments the voids 103 could be designed differently, or left out. The tile 400 is made of a compressible plastic material, preferably PU, wherein the tile preferably has a thickness T9A measured between the secondary surface 100A and apexes 200 of the protrusions of about 30 mm and a thickness measured between the secondary surface 100A and the flat primary surface area 100B of about 20 mm. The apexes 300 of the voids 103 preferably are about 10 mm off from the secondary surface 100A.

[0172] Apexes 200 of adjacent protrusions 102 within a matrix M can be about 61 mm apart, whereas apexes 200 of protrusions 102 closest to each other of neighboring matrices M can be about 77 mm apart.

[0173] Fig. 24 shows an isometric view of a tile 400 according to the disclosure, showing the matrices M of spherical protrusions 102 and the central elevated substantially flat primary surface area 100B.

[0174] Fig. 25 shows a view of a number of tiles 400 provided on a surface of a pile 2 or platform 3, in rows and columns, wherein the hinges 405 extend parallel to a longitudinal axis A - A of the pile 2 and / or opening of the platform 3. First and second pads 9A, 9B could be used for forming the same configuration. Using tiles 400 makes positioning easier and less time consuming. The living hinges 400 allow easy bending of the tiles 400 which easily enables adhering the tiles 400 to curved surfaces. In broken lines further tiles 400 are indicated, showing that a multitude of such tiles is provided between the surfaces 6, 7. By way of example, if tiles 400 are used according to the disclosure, having a size of 600 by 600 mm, in a slip joint having an average diameter of 10 meters, i.e. having an average circumferential length of 31,4 meters, and using an interspace forming channels 62, 63 between adjacent tiles 400 of 5 cm, will provide full circumferential coverage by about 48 tiles in circumferential direction. When using individual pads about 144 pads need to be provided in circumferential direction.

[0175] Fig. 26 and 27 show, schematically and in cross section part of a slip joint of the disclosure, wherein a tile 400 is shown between two opposite truncated conical surfaces 6, 7, similar to e.g. fig. 13A and 13B. A similar view is obtained when using individual pads 9A, 9B. In fig. 26 and 27 the cross section view is taken vertically, across the central, substantially flat primary surface portion 100B.

[0176] In fig. 26 the surface portion 7 of the platform 3 is placed at a level such that it touches the apexes 200 of the protrusions 102. When lowering the platform, for example by the weight of the platform, a force F is applied, which will lead to sliding of the surface 7 along the apexes 200 and compression of the protrusions 102. As can be seen in fig. 27 the platform 3 can be lowered to the extent that the protrusions 102 are compressed to the extent that the surface 7 hits the substantially flat primary surface 100B, substantially preventing further movement or at least requiring substantial higher forces for further movement. Obviously the same effect is achieved when using the first and second pads 9 A, 9B as described, the second pads 9B providing the substantially flat primary surface area 100B.

[0177] It has been found that by providing a stop by at least one such substantially flat primary surface area 100B too much deformation of the protrusions can be avoided, preventing damage to the protrusions, such as shear, whereas the protrusions will provide sufficient support, even if the stop, i.e. the substantially flat primary surface area of a tile 400 or second pad 9B or of a series thereof is not reached.

[0178] Fig. 17 shows in cross sectional side view part of a platform 3 mounted over a pile 2, wherein part of the actual interspace 8 is shown, filled with filling elements 9, wherein the actual surface 6iSt of the pile 2 is shown in solid line, the originally desired surface 6 in broken line, whereas the actual surface 7iSt of the opening 4 is shown in solid line, the originally desired surface 7 on broken line. Fig. 18B shows in cross sectional side view a filling element 9, machined for filling the relevant part of the interspace 8 in fig. 17, whereas fig. 18A shows such filling element 9 for filling the same part of a desired interspace 8. In fig. 18B the inside surface 33 of the filling element 9 has been made more concave and with a different incline than the inner surface 33 of the filling element of fig. 18A whereas the outer surface 34 is made to have a different inclination as well than the outer surface of the element shown in fig. 18B.

[0179] Fig. 19 discloses a first alternative positioning of filling elements, especially tiles 19. In this embodiment again square tiles 9 are shown, placed in a grid or matrix of rows 60 and columns 61, with channels 62, 63 there between, but in this embodiment the grid or matrix has been rotated relative to the position as shown in fig. 3 and 4, for example over 45 degrees as shown in fig. 19. This means that the longitudinal axis 69 the first series of channels 62 extend at an angle a relative to the longitudinal axis A - A, wherein said angle is in the embodiment shown 45 degrees, whereas the longitudinal axis 70 of the channels 63 of the second series of channels extend at a similar angle a but mirrored relative to said axis A - A, the longitudinal axis 69, 70 enclosing right angles. In such embodiments all of the channels will be open to the environment directly at opposite upper and lower ends 67, 68. The inspection tool 65 can thus be inserted into and moved through all of these channels 62, 63 more easily.

[0180] In fig. 19 one of the pads or tiles 9’ is shown as having a profiling 100, for example as disclosed in any one of fig. 5 - 11 or 14. Such profiling 100 can be provided for some or all of the pads 9.

[0181] Fig. 20 schematically shows a further alternative positioning of filling elements, especially tiles 9, similar to that of fig. 19, but wherein the filling elements or tiles 9 are not square but rhombus shaped. In the embodiment shown the rhombus shaped filling elements or tiles 9 are placed such that their sharper angled corners face up- and downward. The channels 62, 63 therefore extend at angles a relative to the axis A - A deviating from 45 degrees, even though they can be the same but mirrored relative to the axis A - A. The angle a can for example be between 15 and 45 degrees. Alternatively the angle can be chosen between 45 and 75 degrees.

[0182] Again in fig. 20 one of the pads 9’ is shown having a profiling 100 as for example shown in any of fig. 5 - 11 or 14. One, some or all of the pads 9 can have such profiling, which may be the same or different for some or all of the pads 9.

[0183] It shall be clear that the filling elements 9 can also be integrally made to fit an interspace 8, based on at least scanning data of the actual surfaces 6, 7 of the pile 2 and platform 3, instead of being made from a standard filling element. If the filling element is to be machined for fitting a specific position, a standard filling element preferably will have a thickness to fit an interspace 8 having a maximum expected width, such that the elements 9 can be reduced in size in order to fit smaller interspaces. Alternatively or additionally material can be added to a standard filling element 9.

[0184] In each and every embodiment disclosed one or more of the pads 9 can be, and preferably is provided with a profiling 100, as for example shown in any of the figures, especially according to any one of fig. 5 - 11 or 14, including but not limited to fig. 5A, 5B, 6A, 6B, 6C, 8A, 9A, 11A, 14A, 14B or 14C.

[0185] The invention is by no means limited to the embodiments disclosed herein by way of example only. Many amendments can be made within the concept of the disclosure, including combinations of some or all of the features of the methods and structures as disclosed. For example, in the drawings filling elements 9 in embodiments are shown as individual filling elements. It will however be clear that each filling element can also be configured of parts of filling elements fitted together, in thickness direction and / or in length and / or width direction, the combined parts forming a filling element as discussed here before, applied with channels as discussed. A filling element as disclosed can be a pad or a tile. It will be clear that the number of filling elements used will depend on inter alia the relevant diameters of the pile and opening and the size of the filling element, wherein for example the compressibility of the filling elements can play a role. The number and size of filling elements used and the dimensions of the channels will also depend on the weight of the platform and the average inclination of the surfaces 6, 7. The filling elements can be shaped differently, for example as triangles or parallelepipeds. In embodiments filling elements can be used having different lengths and / or widths, for example such that filling elements in one or more rows have the same width as filling elements in one or more neighboring rows, but different lengths. Tiles and pads can be combined for forming a slip joint. Tiles and / or pads can be arranged differently, for example in different groupings, in arrangements without channels 62, 63, can have different sizes and different configurations. The number of first pads and second pads or protrusions and substantially flat primary surface areas can be chosen, dependent on the circumstances, such as for example the weight of the platform, size and configuration thereof and deviations from the desired dimensions. In the embodiments shown and discussed the channels 62 and 63 extend at right angles relative to each other. Alternatively they can include different angles, for example when using triangular filling elements.

Claims

Claims1. Slip-joint between a platform and a pile, wherein the pile has a first surface area at or near a top end of the pile and the platform has an opening defined at least partly by a second surface area, wherein in the slip joint between the first surface area and the second surface area at least one first series of pads or tiles is provided, the pads or tiles made at least partly of a flexible material, wherein the pads or tiles of the at least one first series of pads or tiles has a primary surface facing one of the first surface area and the second surface area and an opposite secondary surface facing the other of the first surface area and the second surface area, wherein at least the primary surface has a surface profiling allowing compression of part of said profiling.

2. Slip -joint according to claim 1, wherein the profiling comprises at least one of: a series of openings formed in said primary surface, formed such that at least part of material of the pad surrounding an opening can be forced inward, reducing a volume of said opening; and a series of protrusions with at least one void between said protrusions, formed such that at least part of the protrusions can be compressed by deformation into said at least one void.

3. Slip -joint according to claim 1 or 2, wherein the primary surface comprises a series of openings, wherein at least part of the openings has a closed end, preferably a closed end at or near the secondary surface or at least between the primary and secondary surface.

4. Slip-joint according to any one of claims 1 - 3, wherein the primary surface comprises a series of openings, wherein at least a number of said openings is substantially truncated conical.

5. Slip -joint according to any one of claims 1 - 4, wherein the primary surface comprises a series of openings, wherein: the series of openings have a combined surface area at the primary surface which is between 20 and 80% of the total surface area of the primary surface, preferably between 40 and 75%; and / or at least a number of said openings, preferably each of said openings, has a surface area at the primary surface of nR2, wherein R is between 0,25 and 2 times a thickness of the pad at the relevant opening.

6. Slip-joint according to the preceding claims, wherein the primary surface comprises a series of ribs forming at least part of the profiling.

7. Slip-joint according to claim 6, wherein at least a number of said ribs extend substantially parallel to each other.

8. Slip-joint according to claim 6 or 7, wherein the ribs have a general longitudinal direction, wherein of at least a series of said ribs said general longitudinal axis extends in a plane comprising a longitudinal axis of the pile.

9. Slip-joint according to claim 8, wherein at least a number of said ribs intersect.

10. Slip-joint according to any one of claims 6 - 9, wherein the ribs have a curved or tapering cross section.

11. Slip-joint according to any one of the preceding claims, wherein the primary surface comprises a plurality of studs extending in a direction away from the secondary surface, said protrusions forming part of the profiling.

12. Slip-joint according to claim 11 wherein the studs are pyramid shaped or semi-spherically or ovoid shaped.

13. Slip-joint according to claim 11 or 12, wherein the studs are provided in a matrix.

14. Slip-joint according to any one of claims 6 - 13, wherein at least some of the protrusions, such as ribs and / or studs, are hollow.

15. Slip-joint according to claim 14, wherein at least some of the hollow protrusions are open towards the secondary surface.

16. Slip-joint according to any one of the preceding claims, wherein the at least one pad is made using a polymeric material, wherein the at least one pad is preferably made using polyurethane.

17. Slip-joint according to any one of the preceding claims, wherein a series of pads is provided between the first surface area and the second surface area, wherein preferably at least a number of said pads are spaced apart from neighboring pads.

18. Slip-joint according to claim 17, wherein a matrix of pads is provided between the first surface area and the second surface area.

19. Slip-joint according to any one of the preceding claims, wherein the at least one pad has been adhered to the second surface area, by the secondary surface, the surface profiling facing the first surface area.

20. Slip-joint according to any one of the preceding claims, wherein: the pile is provided with a first flange, extending outward from the pile at a lower end of the first surface area, extending over a lower edge of at least one pad; and / or the platform is provided with a second flange, extending inward from the platform at an upper end of the second surface area, extending over an upper edge of at least one pad.

21. Slip-joint according to any one of the preceding claims, wherein the primary surface has protrusions, which protrusions have a convex surface, and are preferably spherical or semi-spherical.

22. Slip-joint according to claim 21, wherein the voids between the protrusions have a concave bottom.

23. Slip-joint according to claim 21 and 22, wherein the protrusions and voids define, in a cross section of the pads of the first series of pads, a sinusoidal or semi-sinusoidal profile.

24. Slip-joint according to any one of claims 21 - 23, wherein the pads of the first series of pads comprise nine protrusions at the primary surface and a substantially flat or curved secondary surface.

25. Slip-joint according to any one of claims 21 - 24, wherein the pads of the first series of pads have a thickness measured between the secondary surface and the apexes of the protrusions of between 20 and 40 mm, for example between 25 and 35 mm and preferably about 30 mm.

26. Slip-joint according to any one of the previous claims, wherein at least one second series of pads is provided, wherein the pads of the second series of pads have substantially flat or curved primary and secondary surfaces.

27. Slip -joint according to claim 26, wherein the pads of the second series of pads have a thickness measured between the primary and secondary surfaces which is smaller than a maximum thickness of the pads of the first series of pads.

28. Slip-joint according to any one of claims 21 - 25 and 27, wherein the maximum thickness of the pads of the first series of pads is measured between the secondary surface and the apexes of the protrusions, and wherein said maximum thickness is between 1.1 and 6 times the thickness of the pads of the first series of pads, preferably between 1.2 and 4 times, more preferably between 1.3 and 3 times.

29. Slip-joint according to claim 28, wherein the said maximum thickness of the pads of the first series of pads is 1.5 times the thickness of the pads of the second series of pads.

30. Slip-joint according to any one of claims 26 - 29, wherein the first and second series of pads are provided such that eight pads of the first series of pads are arranged around one pad of the second series of pads.

31. Slip-joint according to claim 30, wherein the eight pads of the first series of pads and the one pad of the second series of pads form a square, with the pad of the second series of pads placed central to said square.

32. Slip-joint according to claim 30 or 31, wherein the eight pads of the first series of pads and the pad of the second series of pads are interconnected, forming a tile, wherein preferably some of the pads are interconnected relatively rigidly to each other and some of the pads are hingedly connected to each other.

33. Slip-joint according to any one of claims 21 - 32, wherein the protrusions have a radius of curvature of between about 22 and 25 mm, preferably about 23.5 mm.

34. Slip-joint according to claim 33 and 22, wherein the bottom portion has a radius of curvature of between about 9 and 11 mm, preferably about 10 mm, wherein the distance between the apex of the bottom portion of each void and the adjacent secondary surface is between about 8 and 12 mm, preferably about 10 mm.

35. Pad for forming a slip-joint according to any one of the preceding claims, between a platform and a pile.

36. Pad according to claim 35, wherein the pad has a primary surface which is profiled and an opposite secondary surface which is substantially flat or curved.

37. Pad according to claim 35, wherein the pad has a primary surface comprising: an array of studs, preferably a matrix of spaced apart studs and / or an array of openings, preferably a matrix of spaced apart openings.

38. Pad according to any one of claims 35 - 37, wherein the pad has a length direction, which during use extends in a vertical plane comprising a longitudinal axis of a pile with which it is used, and a width direction, perpendicular to the length direction, a primary surface at a side of the pad and a secondary surface at an opposite side of the pad, wherein the pad hasa cross section seen in said longitudinal direction, said cross section comprising alternating peaks and valleys forming the primary surface.

39. Pad according to any one of claims 35 - 38, wherein the secondary surface is provided with indentations, partly allowing for compression of the profiling at the secondary surface.

40. Pad according to claim 36, wherein the pad is a first type of pad whereof said primary surface comprises protrusions and voids between the protrusions, wherein the protrusions have a convex surface, and are preferably spherical or semi-spherical.

41. Pad according to claim 40, wherein the voids between the protrusions have a concave bottom.

42. Pad according to claim 40 and 41, wherein the protrusions and voids define, in a cross section of the pads, a sinusoidal or semi-sinusoidal profile.

43. Pad according to any one of claims 40 - 42, wherein the pads comprise nine protrusions at the primary surface.

44. Pad according to any one of claims 40 - 43, having a thickness measured between the secondary surface and the apexes of the protrusions of between 20 and 40 mm, for example between 25 and 35 mm and preferably about 30 mm.

45. Set of one or more first type of pads according to any one of claims 40 - 44 and at least one second type pad, the second type pad having substantially flat or curved opposite primary and secondary surfaces.

46. Set according to claim 45, wherein the second type of pads have a thickness measured between the primary and secondary surfaces which is smaller than a maximum thickness of the first type of pads.

47. Set according to claim 46, wherein the maximum thickness of the first type of pads is measured between the secondary surface and the apexes of the protrusions, and wherein said maximum thickness is between 1.1 and6 times the thickness of the pads of the second type of pads, preferably between 1.2 and 4 times, more preferably between 1.3 and 3 times.

48. Set according to claim 47, wherein the said maximum thickness of the first type of pads is 1.5 times the thickness of the second type of pads.

49. Pad according to any one of claims 35 - 44 or set of any one of claims 45 - 48, wherein the protrusions have a radius of curvature of between about 22 and 25 mm, preferably about 23.5 mm.

50. Pad according to any one of claims 35 - 44 or set of any one of claims 45 - 49, wherein the bottom portion has a radius of curvature of between about 9 and 11 mm, preferably about 10 mm, wherein the distance between the apex of the bottom portion of each void and the adjacent secondary surface is between about 8 and 12 mm, preferably about 10 mm.

51. Tile having a profiled primary surface and a substantially flat opposite secondary surface, wherein the profiling comprises rows of protrusions and voids between the protrusions, wherein the protrusions have a convex surface, and are preferably spherical or semi-spherical and wherein the voids between the protrusions have a concave bottom, wherein central to the tile a substantially flat primary surface portion is provided.

52. Tile according to claim 51, wherein the said substantially flat primary surface portion is provided at a level between the secondary surface and apexes of the protrusions, preferably at a level between a lower side of the protrusions and the said apexes.

53. Tile according to claim 51 or 52, wherein the tile comprises at least three side-by-side, substantially rectangular tile portions, wherein a middle tile portion is positioned between two outer tile portions and is hingidly connected to each of said outer tile portions, the outer tile portions each comprising three sets of nine protrusions arranged in a matrix, and said middle tile portion comprises two sets of nine protrusions arranged in a similar matrix, wherein between said matrices of the middle tile portion a flat primary surface area is provided.

54. Tile according to claim 53, wherein the tile is substantially square, having sides of between 500 and 700 mm, preferably about 600 mm, wherein the protrusions have a radius of curvature of about 23 to 24 mm, and wherein between adjacent protrusions a void is provided having a concave bottom with a radius of curvature of about 10 mm, wherein the tile is made of a compressible plastic material, preferably PU, wherein the tile has a thickness measured between the secondary surface and apaxes of the protrusions of about 30 mm and a thickness measure between the secondary surface and the flat primary surface area of about 20 mm.

55. Method for fitting a platform on a pile by a slip joint formed between an internal surface area of the platform and an external surface area of the pile, wherein at least one of the platform and the pile is provided with at least one pad or tile having a primary surface at a first side of the pad or tile and a secondary surface at an opposite second side, wherein the primary surface has ribs and / or studs and / or openings forming at least part of said primary surface, wherein the platform is slid over an upper end of the pile, such that the said internal surface of the platform is brought adjacent the said external surface of the pile, the at least one pad or tile being positioned in between said external and said internal surface, where at least part of the ribs and / or studs is deformed by compression by the weight of the platform and / or material of the pad is deformed into said openings.

56. Method for use of a pad according to any one of claims 35 - 44 or a tile according to any one of claims 51 - 54, wherein the pad or tile is manufactured such that at least the secondary surface is substantially flat, wherein the pad or tile is bent for adhering the secondary surface to the platform or the pile.

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