Tower-like structure for a wind power installation, method for manufacturing such a structure and wind power installation - Patents.com

Abstract

The invention relates to a tower-like construction, in particular for a wind power installation formed as an offshore construction, having at least one lower structural part, in particular formed as a monopile, and an upper structural part, in particular formed as a transition piece, the upper structural part partially overlapping the lower structural part in order to form a slip joint, the upper structural part and the lower structural part each having a conical structural section, the upper and lower structural parts each having at least one further structural section forming a slip joint together, the further structural section being arranged above and / or below the conical structural section, viewed transversely to a central longitudinal axis of the construction, the surface normal of the further structural section intersecting the longitudinal axis at a greater angle (α) than the surface normal of the conical structural section. Furthermore, the invention relates to a method for manufacturing a tower-like construction, in which at least some of the connection elements are injection- or cast-molded onto a lower and / or upper structural part, as well as to a wind power installation, in particular an offshore wind power installation.

Description

[Technical field]

[0001] The present invention relates to a structure of the type according to the preamble of claim 1 as well as to a method for producing such a structure. The present invention also relates to a wind power installation.

[0002] The subject matter mentioned at the outset is known from EP 3443224. A tower-like construction or support structure for a wind power installation connects a nacelle, which supports a rotor, to a base, in particular to the seabed. In constructions of the type mentioned at the outset, the connection or overlap area of ​​the slip joint is limited to a conical area of ​​the lower and upper structural parts, respectively. The load transfer therefore takes place via the conical connection area. This area must be made large in accordance with the bending and supporting loads that are applied, which increases the cost of the construction.

[0003] The object of the invention is to improve the support structures provided for the loads which occur, in such a way that the production of the building structure as a whole is improved.

[0004] This problem is solved by the object of claim 1, characterized in that the upper and lower structural parts each have at least one further structural section, which together form a slip joint, and which are arranged above or below the conical structural section, viewed transversely to the central longitudinal axis of the building, and the surface perpendicular of the further structural section intersects the longitudinal axis at a greater angle than the surface perpendicular of the conical structural section. If two further structural sections of the upper and lower structural parts which together form a slip joint are provided, preferably one of these two further structural sections is arranged above each conical structural section and the other below each conical structural section, and the surface perpendiculars of the one and the other further structural section intersect the central longitudinal axis of the building at a greater angle than the surface perpendicular of the conical structural section. In this case, the surface normals are observed in a vertical longitudinal section of the building, i.e. at the same circumferential angle with respect to the central longitudinal axis of the building, which extends vertically above the foundation when the building is oriented vertically. The surface normals of each structural section run perpendicularly from the surface to the central longitudinal axis of the respective structural part, i.e. for example, the surface normals to the outer surface of the lower structural part run perpendicularly from the surface of the lower structural part through the wall of this structural part towards the central longitudinal axis. The surface of the conical structural section corresponds at least substantially, in particular completely, to the surface of a truncated cone, without taking into account manufacturing tolerances or necessarily existing protrusions, for example due to weld seams.

[0005] At least one further structural section of the lower structural part is located at a predetermined height with respect to the longitudinal central axis in order to form a slip joint with at least one further structural section of the upper structural part. If there are two further structural sections per structural part, both (second) further structural sections are also located adjacent to each other at the predetermined height. Preferably, the surface normals of these pairs of structural sections intersect the longitudinal axis at the same angle, ignoring manufacturing errors, so that these structural sections run parallel.

[0006] In the prior art, the resulting load transfer was calculated only for the conical structural section, which must be dimensioned accordingly. The larger the overlap area, the smaller the load or the larger the bending moment that can be absorbed. The larger the installation, the larger the conical section of the building or support structure, and therefore the more expensive it becomes. The invention now makes use of the recognition that the resulting load transfer can also be at least partially decoupled or divided. For purely axial loads, a significantly shorter overlap length would be sufficient for the same cone angle. Thus, according to the invention, the axial forces, which are determined in particular by the self-weight of the upper structural part and the wind power installation part attached thereto, and the bending loads, for example due to wind and waves, are at least partially decoupled. The axial forces are still absorbed by the cone, whereas the bending loads are now at least partially absorbed at least together by the additional structural section. The loads on the slip joint connection resulting from the axial and bending loads occur in this case at different points, and stress superposition is at least partially avoided. A slip joint connection is thus formed by regions of structural parts which are in contact with one another and serve for load transmission, including connecting elements which are possibly arranged between the structural parts.

[0007] This applies in particular to embodiments of the invention in which, besides the conical structural section, there are upper and lower additional structural sections, with the connection regions continuing both above and below the central conical section, in which case the bending loads are transferred at least substantially, preferably at least 80%, even better at least 90%, in the additional structural sections.

[0008] Preferably, the surface normals of the further structural sections of the upper and lower structural parts are formed so as to intersect the longitudinal axis at the same angle. The extension of the structural parts, in particular of the three-part connection region, is therefore parallel, at least in the region outside the transition between the structural sections. The lower and upper structural parts form three structural sections each forming a slip joint, with one of the two further structural sections being formed above the conical structural section and the other of the two further structural sections being formed below the conical structural section.

[0009] Preferably, the angle at which the surface normal of the further structure section intersects the central longitudinal axis differs from the angle at which the conical structure section intersects the central longitudinal axis by at least 2°.

[0010] Preferably, at least one further structural section of the lower and / or upper structural part is hollow cylindrically shaped, in particular formed by a straight tube segment. The surface normal of the further structural section in this case extends in particular perpendicularly to the central longitudinal axis. The part, in particular the middle conical part (if two further structural sections are provided), which is adjacent to the at least one hollow cylindrical structural section, can be significantly smaller and therefore constructed more cheaply. In particular with regard to the manufacture of the building according to the invention and the corresponding wind power installations in the case of increasingly larger dimensions and loads, the smaller dimensioning of the middle conical structural section leads to greater cost advantages.

[0011] A particularly advantageous embodiment of the invention for load transfer during operation is obtained by a lower and an upper structural part each having a conical structural section and further structural sections formed as hollow cylinders, of which preferably one is connected upwards and one downwards (in the operating position of the structural parts with respect to the central longitudinal axis) to the conical structural section.

[0012] Preferably, a connection device is arranged between the lower and upper structural parts, which comprises a plurality of connection elements, in particular in the form of rings, plates and / or layers, and preferably elastic, in particular viscoelastic and / or compressible, for load transmission between the upper and lower structural parts. This connection device may be arranged in at least one of the two or three sections of the connection area of ​​the slip joint over the entire circumference in the circumferential direction about the central longitudinal axis and thus forming a sealing plane. However, the connection elements may also be spaced apart from one another, which are spaced apart from one another over the height of the building along the central longitudinal axis and / or in the circumferential direction. In particular, no connection elements are arranged in the transition area between, for example, a hollow cylindrical tube section or structural section and a conical structural section, whereby the positioning and fitting accuracy of the respective connection elements is improved. Preferably, at least in the longitudinal direction, a plurality of connection elements per structural section are distributed uniformly in the circumferential direction around the longitudinal axis.

[0013] In particular, the connecting device forms a circumferential seal in the conical middle structural section of the building, a sealing arrangement in this area being particularly advantageous since any relative movements between the lower and upper structural parts resulting from the occurrence of bending loads only act to a small extent in this structural section, if substantial bending loads are absorbed by the lower and upper structural sections.

[0014] In particular, the connecting element is at least primarily made of polyurethane, for example a polyurethane plate on whose surface a layer of slide lacquer or other anti-friction coating is provided, which makes the installation of the lower and upper structural parts easier.

[0015] Depending on the orientation of the structural sections to be connected of the lower and upper structural parts, the connecting elements arranged between the structural sections located above one another with respect to the longitudinal axis are provided with surface normals that are angled with respect to one another. This also applies to the observation of a vertical longitudinal section through the central longitudinal axis. Advantageously, at least one connecting element arranged between the conical structural sections is provided with a different thickness than the connecting element located next to it, seen transversely to the longitudinal axis, so that the loads that usually occur there are taken into account. The connecting element may also be provided with a thickness that varies, in particular in the direction of its surface extension.

[0016] According to a further embodiment of the construction according to the invention, at least one of the connecting elements arranged adjacent to one another in the circumferential direction about the longitudinal axis may also be provided with a greater thickness than the connecting element arranged next to it or arranged above it in relation to the longitudinal axis, thereby making it possible to compensate for errors occurring in the construction parts. For example, the connecting elements may have beveled edges in order to allow a reliable upward and downward sliding movement relative to one another during the installation of the construction by putting the upper construction part over the lower construction part. This applies in particular to the connecting elements arranged between the upper and lower hollow cylindrically shaped construction sections.

[0017] At least a part of the connection element is advantageously at least partially elastically, in particular viscoelastically deformable. This can serve to purposefully adapt the connection element to imprecision and non-flatness of the lower and upper structural parts, for example in the form of the weld seam, so that such weld seam is better surrounded by a sealing plane, for example, or gaps resulting from an imprecision in the positioning of the connection element are closed. Furthermore, the damping can be increased, and thus the long-term stability of the installation can also be increased. If a part of the connection element, i.e. at least one connection element, has a thickness that varies per se, so that, for example, deviations of the structural part or bulges of the weld seam are compensated for, this can also serve for adaptation to the structural part. That is, the individual connection elements themselves can have a thickness that varies so that deviations from the target dimensions, which may possibly exist on the structural part side, for example in the form of the weld seam, can be taken into account. The connection element can also have an inclined surface or at least partially be wedge-shaped in cross section, for example for the purpose of improving the installation.

[0018] The connection element of the connection device is preferably made, at least to a large extent, preferably completely, except for any coating or outer adhesive layer, from high-density polyurethane, which is optionally recessed. In the context of the present invention, high-density polyurethane or solid polyurethane is understood to mean a solid body that is substantially free of gas inclusions. In this case, "substantially free of gas inclusions" means that the polyurethane preferably has a gas inclusion of less than 20% by volume, particularly preferably less than 10% by volume, in particular less than 5% by volume, very particularly less than 2% by volume.

[0019] In addition to and in addition to the use of at least partially elastic load-transmitting connecting elements, the thickness of which, transverse to the respective areal extension, can in particular be between 2 and 10 cm, at least some of the connecting elements can also be made at least partially compressible, the compressibility of each connecting element being formed in particular by a structuring of the surface, by a recess in the material and / or by the material of at least one layer, in particular of a multi-layer connecting element, which can for example be a foamed polyurethane compound forming a plate-shaped connecting element.

[0020] The formation of compressible and / or at least partially elastic connection elements provides for load transmission between the lower and upper structural parts of the tower-like structure as well as damping of the forces that occur, so that the integrity of the structure is improved compared to previously known connections based on mortar or pins.

[0021] The problem stated at the beginning is also solved by a method for manufacturing a tower-like construction formed as described above or as described below, in which at least a part of the connection element is injection- or cast-molded onto the lower and / or upper structural part. Advantageously, the connection element is arranged on the transition piece, regardless of the type of manufacture. The application of the casting material, for example in the form of polyurethane, can be improved by adhesion promoters or primers, and the mounting of the plate-like connection element is improved by adhesives.

[0022] In particular, one or more magnetic holding devices can be used which hold the connection elements in place until they are securely fixed, for example by curing of the adhesive.

[0023] Advantageously, at least some of the connection elements are prefabricated and then attached onto the lower and / or upper structural parts. Preferably, all connection elements are precast, for example in the form of a plate, and then attached, in particular, onto the upper structural part. An option for fixing the connection elements that is advantageous for ease of handling consists in the use of magnetic holding devices, which hold the connection elements in the desired position on the upper and lower structural parts, at least until the connection elements are sufficiently fixed.

[0024] For deviations of the structural parts from the given shape, possibly due to manufacturing tolerances or, for example, due to weld seams, the upper and / or lower structural parts are measured after manufacture, which results in deviation dimensions resulting from possibly existing deviations from the target shape, which can be taken into account by different thicknesses and / or areal extents of the connection elements. Such deviations can already be taken into account during the manufacture of the connection elements. However, preferably, the deviation dimensions are taken into account by post-processing of at least one connection element, which can be carried out further later, for example, by removing material by milling.

[0025] The problem stated at the outset is also solved by a wind power installation, in particular an offshore wind power installation, which has a structure as described above or below.

[0026] Further advantages and details of the invention will become apparent from the following description of the drawings, in which: FIG. [Brief description of the drawings]

[0027] [Figure 1] FIG. 1 shows an object according to the invention. [Diagram 2] 1 is a cross-sectional view of an object according to the invention; [Diagram 3] FIG. 3 is a detailed view of the object according to the invention shown in FIG. 2; [Figure 4] FIG. 2 shows a further object according to the invention. [Diagram 5] 5 is a partial view of the object according to the invention shown in FIG. 4; [Figure 6] FIG. 5 is a (partial) vertical cross-section of the object shown in FIG. [Figure 7] FIG. 2 shows a vertical longitudinal section of a further object according to the invention; [Figure 8] FIG. 2 shows a vertical longitudinal section of a further object according to the invention; [Figure 9] FIG. 2 shows a vertical longitudinal section of a further object according to the invention; [Figure 10] FIG. 2 shows a vertical longitudinal section of a further object according to the invention; [Figure 11] FIG. 2 shows a vertical longitudinal section of a further object according to the invention;

[0028] The individual technical features of the embodiments described below can also be combined with the features of the respective claims and with the features of at least one of the independent claims to form further configurations according to the invention. Wherever possible, identical reference numbers are used to refer to elements having the same functional effect.

[0029] The wind power installation according to the invention is preferably designed as an offshore wind power installation and has a lower structural part 2 on which an upper structural part 4 is placed, which in this case (FIG. 1) is designed as a monopile. The upper structural part 4 forms the transition to a nacelle 8 with rotor blades 6 as a transition piece.

[0030] The wind power installation thus also comprises a construction according to the invention, which comprises a lower and an upper structural part 2, 4 and possibly a connection device arranged between them. The lower structural part 4 is arranged vertically on the seabed or foundation 10 and protrudes above the water level 12. The loads acting on the connection between the lower structural part and the upper structural part are caused on the one hand by the weight load of the transition piece and the nacelle 8 arranged thereon, which are directed vertically to the foundation 10. Additional loads running horizontally to the foundation are caused by wind and waves, which also act on the transition piece and thus have to be transferred from the monopile via the connection. Vibrations or shocks possibly acting on the monopile are also possibly additionally transmitted in the direction of the transition piece.

[0031] The construction and connection according to the invention in the form of a slip joint for a building or wind power installation shown in FIG. 1 is disclosed in FIG. 2. The connection area 14 extends from the lower end 16 of one connection element 18 to the upper end 20 of another connection element 18. Overall, there are three structural sections for the lower structural part 2 and the upper structural part 4, respectively, which form the slip joint connection. The first structural section 22 is defined by a lower hollow cylindrical part of the upper structural part 2, which is located in the connection area. This section is located below a conical structural section 24, which is also referred to below as the middle structural section of the transition piece. On the upper side, it is followed by a structural section 26, which is also formed as a hollow cylinder and has a smaller outer diameter than the lower structural section 22. Lower, middle and upper are understood as relative positions with respect to a central longitudinal axis 28, which runs perpendicular to the foundation 10 and through the middle of the building. The surface normal 29 to the outer surface of the lower structural part 2 and to the inner surface of the upper structural part 4 intersects the central longitudinal axis extending in the centre of the building as seen from above at different angles α depending on the assignment to the structural sections, i.e. the upper and lower structural sections 22 and 32 or 26 and 36, which both follow the central conical structural section 24 and 34, extend at an angle to the central conical structural section. In the conical structural sections 24 and 34 the surface normal 29 intersects the longitudinal axis 28 at an angle of approximately 85°, whereas in the subsequent upper and lower structural sections the surface normal extends perpendicular to the longitudinal axis, i.e. at an angle of 90°.

[0032] On the side of the lower part or monopile, the sections can be defined in the same way as the sections 22, 24 and 26 of the transition piece. The lower hollow cylindrical section 32 of the lower part 2 is the lower section. This lower section merges upwards into a central conical section 34 formed by the conical region of the lower part 2, which is again upwardly followed by a hollow cylindrical section 36, the outer and inner diameters of which are smaller than those of the lower section 32, which is also hollow cylindrical. All sections 22, 24, 26, 32, 34, 36 are formed around the central longitudinal axis 28. In the drawings, the sections 22, 24, 26, 32, 34, 36 are partially indicated by brackets rather than by arrows for the sake of simplicity.

[0033] In the embodiment according to Fig. 2, the connecting element 18 is arranged only between the hollow-cylindrical structural sections 26 and 36 or between 22 and 32 and serves for the transmission of the bending moments occurring. Since the vertical loads due to weight are essentially constant and therefore little damping is required, the conical structural sections 24 and 34 overlap one another, so that there is a direct load transmission between the conical elements. The bending loads occurring with relatively significant differences are transmitted essentially in the structural sections 22, 32 and 26, 36 and partly by the inclined surfaces of the conical connecting sections. This is due in particular to the length of the upper and lower structural sections and their distance from one another.

[0034] In the detailed view according to Figure 3 it can be seen that the connection elements 18 do not extend into the conical region from the respective upper structure sections 26 and 36. This makes it easier to form and position the connection elements.

[0035] The structural sections of the lower and upper structural parts form a total of three connection sections of the connection region 14. The first connection section includes the lower structural sections 22 and 32. The middle connection section is a connection section including the conical structural sections of the lower and upper structural parts 2, 4. The third connection section includes the region of the upper hollow cylindrical structural sections 26 and 36. Each of these connection sections may have one or more parts of the connection device.

[0036] In the embodiment according to Fig. 4, two rows of connecting elements 18 arranged adjacent to one another in the circumferential direction are provided per connection section, which are pre-fixed at a distance from one another on the transition piece. The connecting elements 18 located on the conical connection section have a uniform thickness, whereas the connecting elements 18 arranged in the respective lower row of the hollow-cylindrical structural section have a varying thickness in the direction of the longitudinal axis 18, which significantly facilitates the sliding of the two structural parts relative to one another during assembly (Figs. 5 and 6). In order to further improve the assembly of the building, an additional row, i.e. the second upper row of the hollow-cylindrical structural section, likewise has connecting elements whose thickness at the lower end is smaller than that at the upper end.

[0037] The thickness of the connecting element 18 preferably varies by at least 30% of the thickness, more preferably by at least 80% and up to 90% of the thickness, with the thinner end of the connecting element 18 facing downwards when the connecting element 18 is attached to the upper structural part 4. If the connecting element 18 is attached to the side of the monopile or the lower structural part 2, the thinner end of the connecting element 18 is placed upwards before the two structural parts are plugged into each other.

[0038] Instead of two rows of connection elements 18, it is also possible to provide only one connection element 18 per connection section, in which case, similar to the embodiment according to FIG. 6, these connection elements 18 arranged between the hollow cylindrical structural sections also have a varying thickness (FIG. 7).

[0039] In the embodiment according to FIG. 8, the thickness of the connection element 18 does not change. The surface normals 31 of the connection elements arranged one above the other intersect the central longitudinal axis and the central longitudinal axis 28 at different angles β and are therefore at an angle to each other. The connection elements have in this case a uniform thickness in all three connection sections of the connection area 14. The thickness is commonly observed transversely to the surface extension of the connection element. However, for the measurement of the thickness of the connection element, the connection element is not considered to be loaded by the structural part of the building. The thickness is in particular between 2 and 10 cm, preferably at least 1 / 5, even more preferably 1 / 10, of the width and / or length of the connection element 18. The thickness of the connection element lying flat on the ground is measured perpendicular to the foundation. If the connection element is arranged in a hollow cylindrical part of the building, the thickness is defined perpendicular to the longitudinal axis. If the connecting element is arranged on a conical connecting section, the thickness of the connecting element 18 is measured perpendicular to the surfaces of the lower and upper structural parts, in which case the areal extension is respectively observed perpendicular to the direction in which the thickness is measured.

[0040] As an alternative to the plate-like connecting elements, the connecting device may also have rounded connecting elements, which may extend all around the longitudinal axis and thus form a seal. The connecting elements may alternatively be provided solely for supporting purposes and may, for example, be fixed at intervals, in particular on the transition piece, and then pressed onto the monopile.

[0041] Generally speaking, the lower structure does not have to be a monopile: it is also conceivable that the tower-like structure has multiple slip joint connections and is formed, for example, as a tripod, so that the three legs of the wind power installation are each formed by a slip joint connection.

[0042] Preferably, the dimensioning of the connection elements 18 is made according to the loads occurring in each area.

[0043] In FIG. 9, the connection elements 18 arranged between the lower structural sections 22 and 32 and between the upper structural sections 26 and 36 occupy a relatively small area in the illustrated vertical cross section, whereas the connection elements 18 arranged in the conical connection section are made significantly larger.

[0044] 10 and 11 show simplified alternative embodiments of tower-like constructions, in which the conical structural section 22 or 24 is followed upwards by only one hollow-cylindrical structural section 26 or 36 (FIG. 10) or downwards by only one hollow-cylindrical structural section 22 or 32. In this case, the connecting elements arranged in each section are formed so as to be chamfered accordingly for advantageous guidance of the lower structural section 22 (FIG. 11) or structural section 26 of the upper structural part 4 during assembly. Preferably, the chamfering of the connecting elements 18 in the conical region is generally not performed. Nevertheless, even in this region, the thickness of the connecting elements can be adapted to any deviations from the target dimensions that may occur.

Claims

1. A tower-like construction for a wind power installation, in particular configured as an offshore construction, comprising at least one lower structural part (2), in particular configured as a monopile, and an upper structural part (4), in particular configured as a transition piece, the upper structural part being partially placed on the lower structural part (2) to form a slip joint, the upper structural part and the lower structural part each comprising a conical structural part (24, 34), 1. A tower-like building, characterized in that the upper and lower structural parts (2, 4) each have at least one further structural section (22, 32, 26, 36) forming a slip joint together, the further structural section being arranged above and / or below the conical structural section (24, 34) in a transverse direction to a central longitudinal axis (28) of the building, the surface normal (29) of the further structural section intersecting the longitudinal axis (28) at a greater angle (α) than the surface normal (29) of the conical structural section.

2. 2. The building according to claim 1, wherein the surface normals (29) of the further structural sections (22, 26) of the upper structural part (4) and the surface normals (29) of the further structural sections (32, 36) of the lower structural part (2) intersect the longitudinal axis (28) at the same angle (α).

3. 3. The building construction according to claim 1 or 2, wherein the lower and upper structural parts (2, 4) respectively form three structural sections (22, 32, 26, 36) forming the slip joint, one of the two further structural sections (26, 36) being formed above the conical structural section (24, 34) and the other of the two further structural sections being formed below the conical structural section (24, 34).

4. 3. The building construction according to claim 1 or 2, characterized in that at least one of the further structural sections (22, 32, 26, 36) of the lower and / or upper structural part (2, 4) is hollow cylindrically shaped.

5. 5. The building structure according to claim 4, wherein the lower and upper structural parts (2, 4) each have two separate structural sections (22, 32, 26, 36), the separate structural sections (22, 32, 26, 36) being hollow cylindrical in shape.

6. 3. The building according to claim 1 or 2, wherein a connection device is arranged between the lower structural part (2) and the upper structural part (4) for load transmission between the upper structural part (4) and the lower structural part (2), the connection device comprising a plurality of connection elements (18), in particular ring-shaped, plate-shaped and / or layer-shaped and preferably elastic and / or compressible.

7. 7. The building construction according to claim 6, wherein the connecting elements (18) arranged between the structural sections (22, 24, 26, 32, 34, 36) of the lower and upper structural parts (2, 4) which are situated one above the other with respect to the longitudinal axis (28) have surface normals (31) which are angled with respect to each other.

8. 7. The construction of claim 6, wherein one of the connection elements (18) arranged adjacent to one another in a circumferential direction about the longitudinal axis has a greater thickness than the connection element (18) arranged next to it.

9. The construction of claim 6, wherein at least a portion of the connection element (18) is at least partially elastically deformable.

10. 7. The construction according to claim 6, wherein at least some of the connection elements (18) are at least partially compressible, in particular the compressibility of each of the connection elements being formed by a structuring of the surface and / or by the material of at least one layer of the connection element (18), in particular of a multi-layer structure.

11. 7. A method for manufacturing a tower-like structure according to claim 6, characterized in that at least a part of the connection element (18) is injection- or cast-molded onto the lower and / or upper structural part (2, 4).

12. 3. A method for manufacturing a tower-like structure according to claim 1 or 2, characterized in that at least part of the connecting element (18) is pre-manufactured and then mounted on the lower and / or upper structural part (2, 4), in particular in this case using at least one magnetic holding device for fixing the connecting element (18).

13. 13. The method according to claim 12, further comprising measuring the upper and / or lower structural parts (2, 4) after production and taking into account deviations in dimensions resulting from deviations from the target shape by different thicknesses and / or areal extents of the connecting elements (18).

14. 14. The method according to claim 13, characterized in that the deviation dimension is taken into account by post-machining at least one of the connecting elements (18).

15. 3. A wind power installation, in particular an offshore wind power installation, characterized in that it comprises a structure according to claim 1 or 2.

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