FOUNDATION FOR A WIND TURBINE

Abstract

The invention relates to a foundation for a wind power plant, wherein the foundation (10) comprises substantially prefabricated elements, preferably of reinforced concrete, with a first, vertically extending base-like section (11), on which a tower of the wind power plant can be arranged, and a second, substantially horizontally extending section (12) as foundation body, which is in contact with the ground (100), wherein the first section (11) is arranged above the second section (12). Thereby, according to the invention, it is provided that the first vertically extending base-like section (11) is formed of at least three layers (13, 16, 17) arranged one above the other, of which the upper and the lower layer (13, 17) comprise at least two ring-like layers (13a, 13b, 17a, 17b) and the middle layer (16) is formed from at least one ring-like layer (16a), in that the height (H+I, 2I) of the upper and/or lower layer (13, 17) is less than the height (J) of the middle layer (16), and in that the layers (13, 16, 17) are vertically braced to the second section (12) by means of at least two vertical tendons (19).

Claims

1-21. (canceled)

22. A foundation for a wind turbine, comprising; prefabricated elements of reinforced concrete, including; a first vertically extending base-like section on which a tower of the wind turbine can be arranged, and a second substantially horizontally extending section as a foundation body which is in contact with the ground, wherein; the first section is above the second section, wherein the first vertically extending base-like section is formed of at least three layers one above the other, the upper and lower layers are formed of at least two ring-like layers. the middle layer is formed of at least one ring-like layer, the height of at least one of the upper and lower layer is smaller than the height of the middle layer, the layers are vertically braced to the second section by means of at least two vertical tendons.

23. The foundation according to claim 22, wherein the height of the upper and lower layers is smaller in total than the height of the middle layer.

24. The foundation according to claim 22, wherein at least one of the layers comprises at least one precast element.

25. The foundation according to claim 22, wherein at least one of the layers comprises at least two precast elements.

26. The foundation according to claim 22, wherein at least two adjacent layers comprise at least two precast elements.

27. The foundation according to claim 25, wherein the at least two elements are butted together and form the ring-like layer free of horizontal fastening means in vertical joints between the at least two elements.

28. The foundation according to claim 27, wherein the at least two elements are arranged in the vertical joints in at least one of a stress-free and contact-free manner.

29. The foundation according to claim 28, wherein the vertical joints of two layers lying directly one above the other are not aligned.

30. The foundation according to claim 22, wherein the prefabricated elements of at least one of the first and second section are arranged in the vertical joints in at least one of a stress-free and contact-free manner.

31. The foundation according to claim 22, wherein the prefabricated elements of at least one of the lower and upper layers have an increased reinforcement in the normal direction

32. The foundation according to the claim 22, wherein the prefabricated elements of the middle layer have at least one increased reinforcement for dissipating shear loads in the radial direction.

33. The foundation according to claim 22, wherein the at least two tendons prestress the layers whereby all horizontal joints between the layers are under pressure in operating and loaded condition of the wind turbine.

34. The foundation according to claim 22, further comprising at least two abutment rings, against which the tendons act, at least one abutment ring is on the upper side of the first section and at least one abutment ring is on the lower side of the second section.

35. The foundation according to claim 34, wherein at least one of the at least one abutment rings comprises at least two prefabricated elements butted together.

36. The foundation according to claim 34, wherein at least one of the at least one abutment ring comprises at least two layers arranged one above the other.

37. The foundation according to claim 36, wherein the layers each comprise at least two elements butted together, the butts of two layers lying directly one above the other are not aligned.

38. The foundation according to claim 22, wherein the second section is formed of at least three horizontal elements.

39. The foundation according to claim 38, wherein the horizontal elements are laterally spaced apart from one another.

40. The foundation according to claim 39, wherein the horizontal elements are laterally parallel spaced apart from one another.

41. The foundation according to claim 22, wherein the elements of the at least three layers of the first section comprise at least two substantially vertical apertures, in each of which a tension member, including at least one of a threaded rod or an anchor bolt with counter elements is disposed.

Description

[0030] In the following, the invention is explained in more detail by means of embodiment examples in connection with a drawing. Thereby show:

[0031] FIG. 1 a sectional view of a preferred embodiment of a foundation according to the invention

[0032] FIG. 2 a spatial view of FIG. 1,

[0033] FIG. 3 a top view of FIG. 1,

[0034] FIGS. 4a to 4e Views of a horizontal element according to the invention,

[0035] FIG. 5a a plan view of arranged surface elements of the foundation according to the invention,

[0036] FIG. 5b a detailed view of FIG. 5a,

[0037] FIGS. 6a to 8b Views of base segments according to the invention in plan view and as a spatial view,

[0038] FIG. 9a a spatial view of an anchor cage according to the invention,

[0039] FIG. 9b a detailed view of FIG. 9a,

[0040] FIG. 10 a top view of an upper abutment ring of the anchor cage shown in FIG. 9a,

[0041] FIG. 11 a top view of a lower abutment ring of the anchor cage shown in FIG. 9a,

[0042] FIG. 12a, a sectional view through the anchor cage according to the invention as shown in FIG. 9a,

[0043] FIG. 12b a detailed view of FIG. 12a,

[0044] FIG. 13a, 13b atop view and a side view of a cover plate according to the invention, and

[0045] FIGS. 14a to 14d different arrangement options to FIG. 5a.

[0046] In FIG. 1, a foundation 10 according to the invention is arranged in a sectional view in a pit 101 in the ground 100, on a possibly compacted cleanliness layer 102. The foundation 10 has a first section 11 and a second section 12. Furthermore, a third section (not shown) can also optionally be provided under the second section 12, which is then preferably provided in a recess (not shown) if it should be necessary for structural reasons to extend the base further into the ground.

[0047] The first section 11 is designed as a base 20, which is built up of several layers 13, 16, 17, wherein the layers 13, 16, 17 are built up of, for example, 5 layers 13a, 13b, 16a, 17a, 17b. If necessary, further layers can be provided.

[0048] The layers 13a, 13b, 16a, 17a, 17b are constructed from closed base sections 14, which in turn are constructed from individual base segments 33, 34, 35 (see FIGS. 6a to 8b). The base sections 14 are preferably designed here as circular rings, so that the base section 11 has an interior space 15. An alternative structure, e.g. a polygonal structure, is possible.

[0049] The layers 13, 16, 17 are preferably composed here of the individual layers 13a, 13b, 16a, 17a, 17b, the layers themselves being composed of base segments 33, 34, 35 matching the layers. The uppermost layer 13 has two layers 13a, 13b. The top layer 13a is composed of base segments 33, for example as shown in FIG. 6a, 6b, with a height H. On their upper side 36, for example, three recesses 37 are provided here, into which an upper connecting flange 51 of an anchor cage 50, see FIGS. 9a to 12a, can be inserted. In the recesses 37, the openings 18 for the tendons 19 are provided.

[0050] Below this, a layer 13b is provided, which is composed of base segments 35 (FIGS. 7a, 7b) with a height I, which are also provided with openings 18 for the tendons 19. The height I can be identical to the height H of the base segments 34 and is preferably the same.

[0051] Below this is the layer 16a as the middle layer 16, which is composed of base segments 34 with a height J. The base segments 34 are also provided with openings 18 for the tendons 19.

[0052] Provided below this is the lower layer 17 with layers 17a, 17b, which in turn are formed from base segments 34.

[0053] The base segments 33, 34, 35 are preferably designed very precisely with regard to the height H, I, J, i.e. with the smallest possible height deviations, in order to effect the largest possible contact surface of the base segments 33, 34, 35 on one another when these are mounted on top of one another to form the base 20 and are prestressed.

[0054] The height H, I of the base segments 33, 35 is designed in such a way that, when installed, it is essentially only loaded in tension/compression, i.e. it is subjected to a load in the normal direction. The reinforcement is also designed for this purpose (not shown), consisting essentially of reinforcement in the normal direction. Preferably, the heights H and I are the same.

[0055] The height J of the base segments 34 is designed in such a way that it is essentially only loaded in shear when installed. The reinforcement is also designed for this purpose (not shown), consisting essentially of reinforcement in the radial direction, particularly preferably in the form of stirrups.

[0056] The arrangement of segments 33, 34, 35 to form ring-like layers 13a, 13b, 16a, 17a, 17b and the arrangement layers 13a, 13b, 16a, 17a, 17b one above the other to form layers 13, 16, 17, which then form the base, is shown spatially in FIG. 2. The base segments 33, 34, 35 are provided butted side by side so that vertical gaps 38 exist between them. These are preferably designed as gaps, for example, with a thickness of several millimeters, e.g. 30 mm. These vertical joints 38 are preferably not filled with mortar or in-situ concrete. Furthermore, preferably no horizontal connecting means are provided.

[0057] Furthermore, the vertical joints of the individual layers 13a, 13b, 16a, 17a, 17b are preferably provided such that the vertical joints 38 of adjacent layers 13a, 13b, 16a, 17a, 17b are not aligned, i.e. are not arranged one above the other. As shown in FIG. 2, it is advantageous if the vertical joints 38 are always arranged offset clockwise or counterclockwise by substantially the same value.

[0058] Horizontal joints 39 exist between layers 13a, 13b, 16a, 17a, 17b and are preferably not filled with mortar or cast-in-place concrete.

[0059] The base segments 33, 34, 35 have vertical apertures 18 in which tendons 19, for example anchor rods or reinforcement rods 19 with counter elements such as nuts 21, are provided to pretension the foundation 10 during assembly. These, together with abutments 51, 54 composed of flange plates 52, 55, form an anchor cage 50. Part of the upper abutment 51 may also be the connection adapter 53 for the tower, for example if the tower is a steel tower.

[0060] The second section 12 is flat. Alternatively, however, it can also be implemented in a star shape. A top view of the foundation 10 is shown in FIG. 3. FIG. 2 shows a spatial view of the foundation 10. The second section 12 is made of horizontal elements 22 in the form of rib elements. These are shown in FIGS. 4a to 4e. These extend radially outward as viewed from the interior 15.

[0061] They have a base plate 23 that is trapezoidal in shape, for example, so that all assembled base plates form a polygonal surface (see FIGS. 3, 5a) that approximates a circular shape. Alternatively, circular segments or a mixed form of circular segment and trapezoidal shape are also possible. Spaces B can preferably be provided between side walls 44 of the base plates 23, depending on the diameter of the tower to be erected.

[0062] At the inner end 24 of the base plate 23, a support section 25 is provided with a body and side walls 29 that substantially preferably corresponds to the base 20 of the first section 11. Apertures 18 may also be provided in the support section 25. Alternatively, reinforcing bars or anchor rods 19 may be installed in the support section 25 in alignment with the apertures 18 in the first section 11 and extend outwardly from the concrete of the pedestal-like section 25 of the horizontal member 22. The base 20 with its at least one base element 14 is arranged on the support section 25.

[0063] Perpendicular to the base plate is the stiffening wall 26, the height of which decreases, for example, towards the outer end 27 of the base plate 23.

[0064] The base plate 23 is parallel tapered with respect to the side surfaces 29 of the body 30 of the support section 25. The parallel taper 31 is shown by the arrow D in FIG. 4c. This preferably achieves a reduction in material. The body 30 has a transition region 32 with which the stiffening wall 26 is connected to the support section 25 in a reinforcing manner.

[0065] Between the side surfaces 29 of the support sections 25, as shown in FIG. 5b as section E to FIG. 5a, a distance C is preferably provided as a vertical joint 40 when the horizontal elements 22 are arranged, which is preferably designed as an air gap. This results in vertical joints 40, which are also preferably not filled with mortar or in-situ concrete. Furthermore, preferably no horizontal connecting means are provided.

[0066] An upwardly open cavity 28 is formed between two adjacent stiffening walls 26, into which fill soil 104 can be placed, thereby providing a surcharge load on the second section 12 of the foundation 10.

[0067] To allow the cavities 28 to be filled with backfill soil 104 and to prevent it from entering the interior 15, barrier elements (not shown) can be placed against the body 30 of the support section 25 or transition area 32.

[0068] Furthermore, cover plates 48 (FIGS. 13a, 13b) are provided to be placed on two adjacent base plates 23 to cover the gap B between two side surfaces 44 to prevent the backfill soil 104 from entering or passing through the gap B. The cover plates 48 have a tapered section 49 that is adapted to the transition area 32. The cover plate 48 allows the full ballast load of the backfill soil 104 to be applied to the second section 12 by insertion into the cavity 28.

[0069] The interior space 15 may be backfilled with backfill soil 104 and covered with a cover element 103 after the foundation 10 is completed.

[0070] As shown in FIGS. 14a to 14d, it is possible to form a second section with a horizontal element 22 that has differently sized interior spaces 15 by moving the horizontal elements 22 inward or outward along a ray extending from the center point, as shown by the double arrow A in FIG. 19d. Inwardly, this is limited by the fact that the side surfaces 44 of the base plates 23 of the horizontal elements 22 are in contact. Outwardly, this depends on the radius of the tower to be erected, which is shown by a circle 46 in FIGS. 14a to 14d. The distance B is preferably the same over the entire length of the side surfaces 44 from the inner end 24 to the outer end 27, so that two side surfaces 44 are arranged parallel to each other. Through this, foundations for towers with different diameters can be erected in a simple manner preferably with a single horizontal element 22.

[0071] To provide the necessary bracing between the layers 13, 16, 17 of the first section and the horizontal elements 22 of the second section 12, an anchor cage 50 is formed, as shown in FIGS. 9a to 12b, which is formed by an upper and a lower abutment 51, 54, shown in FIGS. 10 and 11, which are connected to tendons 19, for example in the form of anchor bars or reinforcement bars, and counter elements 21, for example nuts.

[0072] The upper and lower abutment elements 51, 54 are composed, for example, of three concentric abutment rings 51a, 51b, 51c, 54a, 54b, 54c, of which the middle abutment ring 51b preferably contains the connection adapter 53 for the tower of the wind turbine. The abutment rings 51a, 51b, 51c, 54a, 54b, 54c can be provided from individual flange plates 52, 55, which are arranged butted together, as this is shown in FIG. 3, FIG. 9b as section F to FIG. 9a and FIG. 12b as section G to FIG. 12a. Furthermore, several flange plates 52, 55 can also be arranged one above the other. In this case, these are then preferably arranged in such a way that their vertical joints 56 do not overlap in adjacent layers of the flange plates 52, 55. Preferably, the flange plates 52, 55 are not welded to each other, but lie on or against each other. The flange plates 52, 55 have apertures 57 and can be provided with different widths and different numbers of rows of apertures 57 per flange plate 52, 55.

[0073] Preferably, the abutment ring 51b may be integral with the connection adapter 53 as a flange plate 52.

TABLE-US-00001 List of reference signs 10 foundation 11 first section 12 second section 13 upper layer 13a layer 13b layer 14 base section 15 Interior space 16 middle layer 16a layer 17 lower layer 17a layer 17b layer 18 opening 19 tendon/anchor rods 20 socket 21 counter element/nut 22 horizontal element/rib element 23 base plate 24 inner end 25 bearing section 26 stiffening wall 27 external end 28 cavity 29 side wall 30 body 31 parallel taper 32 transition area 33 upper base segment 34 middle base segment 35 base segment 36 top side 37 recess 38 vertical joint 39 horizontal joint 40 vertical joint 44 side wall 45 radius 46 circle 48 cover plate 49 tapered section 50 anchor cage 51 top abutment 52 flange plate 53 connection adapter 54 lower abutment 55 flange plate 56 vertical joint 100 ground 101 pit 102 cleanliness layer 103 cover element 104 backfill soil A Shift direction B distance C distance D arrow of the parallel taper E detailed view F detailed view G detailed view H height I height J height