A method for replacing broken anchor bolts in wind turbine foundations

Abstract

This invention relates to the field of broken anchor bolt replacement technology, specifically to a method for replacing broken anchor bolts in wind turbine foundations. The method includes the following steps: Step 1, disassembling the upper section of the broken anchor bolt; Step 2, inserting a disassembly rod into the anchor bolt hole, with the pressure surface of the lower end of the disassembly rod pressing against the cross-section of the lower section of the broken anchor bolt, and rotating the disassembly rod to unscrew the lower section of the broken anchor bolt from the lower anchor plate; Step 3, removing the lower section of the broken anchor bolt from the anchor bolt hole; Step 4, installing a new anchor bolt. The disassembly rod in this invention can adapt to the narrow and elongated space of the anchor bolt hole. By inserting the disassembly rod into the anchor bolt hole and utilizing the friction generated by the pressure of the disassembly rod, the lower section of the broken anchor bolt rotates when the disassembly rod rotates, thus unscrewing the lower section of the broken anchor bolt from the lower anchor plate. This disassembly method is relatively simple, quick, and low-cost, making it advantageous for workers to replace broken anchor bolts outdoors.

Description

Technical Field

[0001] This invention relates to the field of broken anchor bolt replacement technology, and specifically to a method for replacing broken anchor bolts in wind turbine foundations. Background Technology

[0002] Wind turbine foundations are a crucial component of wind power equipment. They consist of an anchor cage (comprising anchor bolts, anchor plates, and other accessories) cast in concrete and are primarily used to secure the wind turbine generator set. Anchor bolts are the main load-bearing components of the wind turbine foundation. Because the wind turbine tower and wind turbine components are erected at heights of 80–150 meters, operating under harsh conditions, the anchor bolts are subjected to alternating loads in a 360° direction. Combined with issues such as poor anchor bolt manufacturing quality, rough construction, or excessively high anchor bolt tension, anchor bolts may break during normal use. To ensure the normal operation of the wind turbine foundation, broken anchor bolts need to be replaced.

[0003] Since the length of anchor bolts is usually 4 to 12 meters, the location of anchor bolt breakage is not fixed, and the anchor bolt holes in the wind turbine foundation are narrow and long, it is difficult to remove the broken anchor bolt from the anchor bolt hole.

[0004] Chinese invention patent CN105155571B discloses a method for replacing a prestressed anchor bolt assembly, which includes the following steps: First, pull out the upper section of the broken anchor bolt, then use a self-tapping drill bit to drill into the fracture section of the broken anchor bolt. While the self-tapping drill bit is drilling in, it drives the lower section of the broken anchor bolt to rotate, so that the lower section of the broken anchor bolt automatically exits the lower nut. Then, the self-tapping drill bit and the lower section of the broken anchor bolt are taken out of the anchor bolt hole together.

[0005] The above technical solution requires a high degree of flatness in the fracture section of the anchor bolt, ensuring that the borehole axis is approximately coincident with the axis of the lower section of the broken anchor bolt. If the anchor bolt undergoes necking fracture or the fracture section is beveled, it is difficult to drill a hole in the fracture section. If the borehole is located at the edge of the fracture section, and there is a large eccentricity between the borehole axis and the axis of the lower section of the broken anchor bolt, it is difficult to disassemble the lower section of the broken anchor bolt by applying torque to the borehole, making the replacement of the broken anchor bolt quite difficult. Summary of the Invention

[0006] The purpose of this invention is to provide a method for replacing broken anchor bolts in wind turbine foundations, thereby solving the technical problem that existing anchor bolt replacement methods require high flatness of the broken section of the anchor bolt, making the replacement of broken anchor bolts difficult.

[0007] To achieve the above objectives, the technical solution of the method for replacing broken anchor bolts in wind turbine foundations according to the present invention is as follows:

[0008] The method for replacing a broken anchor bolt in a wind turbine foundation includes the following steps: Step 1, disassemble the upper section of the broken anchor bolt; Step 2, insert the disassembly rod into the anchor bolt hole, and press the lower end of the disassembly rod against the cross-section of the lower section of the broken anchor bolt, then rotate the disassembly rod to unscrew the lower section of the broken anchor bolt from the lower anchor plate; Step 3, remove the lower section of the broken anchor bolt from the anchor bolt hole; Step 4, install a new anchor bolt.

[0009] The beneficial effects are: the disassembly rod in this invention can adapt to the narrow and elongated space of the anchor bolt hole. By inserting the disassembly rod into the anchor bolt hole and utilizing the frictional force generated by the top pressure of the disassembly rod, the lower section of the broken anchor bolt rotates when the disassembly rod rotates, thereby unscrewing the lower section of the broken anchor bolt from the lower anchor plate. The disassembly method of this invention has lower requirements for the flatness of the anchor bolt fracture section and is relatively simple and quick, which is beneficial for workers to replace broken anchor bolts outdoors.

[0010] As a further improvement, an elastic pressure structure fixed to the side anchor bolt is used to pressurize the disassembly rod so that the top pressure surface at the lower end of the disassembly rod presses against the cross-section of the lower section of the broken anchor bolt.

[0011] The beneficial effect is that by applying pressure to the disassembly rod through the elastic pressure structure, and ensuring that there is a sufficiently large friction between the top pressure surface of the disassembly head and the cross section of the fracture, the disassembly rod can easily drive the lower section of the broken anchor bolt to rotate.

[0012] As a further improvement, the elastic pressure structure includes a sleeve for fixing to the side anchor bolt, a compression spring inside the sleeve, and a pressure rod threaded into the sleeve. The upper end of the disassembly rod is slidably fitted inside the sleeve, the upper end of the compression spring presses against the pressure rod, and the lower end of the compression spring presses against the disassembly rod.

[0013] The advantages are: this design ensures the sleeve is fixed without pressing it by hand, saving manpower; and the pressure applied to the disassembly rod can be adjusted by turning the pressure rod, which can hold itself in place after adjustment.

[0014] As a further improvement, the disassembly head at the lower end of the disassembly rod is provided with a disassembly rod insertion hole that matches the breakage of the lower section of the broken anchor bolt. The disassembly rod insertion hole has a tapered surface or an inclined surface, which constitutes the top pressure surface.

[0015] The beneficial effect is that this design allows the disassembly rod to adapt to the necked or tilted fracture surface.

[0016] As a further improvement, a top-pressing blade is provided on the top-pressing surface.

[0017] The beneficial effect is that by setting a top pressure blade on the top pressure surface, sufficient friction can be provided during the disassembly of the lower section of the broken anchor bolt to drive the lower section of the broken anchor bolt to rotate, thereby realizing the disassembly of the lower section of the broken anchor bolt.

[0018] As a further improvement, the disassembly head at the lower end of the disassembly rod is a magnetic head, or a magnet is provided on the top pressing surface of the disassembly head at the lower end of the disassembly rod. The disassembly rod uses the disassembly head to magnetically attract the lower section of the broken anchor bolt so as to remove the broken lower section of the anchor bolt from the anchor bolt hole.

[0019] The beneficial effect is that with this design, the disassembly rod can be removed from the anchor bolt hole by magnetically attracting the broken lower section of the anchor bolt through the disassembly head, making the operation more convenient.

[0020] As a further improvement, before inserting the broken section of the lower segment of the broken anchor bolt into the extraction rod hole, the tension rope between the paired rope holes is pulled to slack off and positioned above the notch on the extraction rod; after inserting the broken section of the lower segment of the broken anchor bolt into the extraction rod hole, the tension rope is pulled to slack off, and the tension rope between the paired rope holes enters through the notch between two adjacent threads of the lower segment of the broken anchor bolt, thereby fixing the lower segment of the broken anchor bolt to the lower end of the extraction rod; the lower segment of the broken anchor bolt is then removed from the anchor bolt hole by using the upper extraction rod.

[0021] The beneficial effect is that by using the combination of the extraction rod and the tension rope, the lower section of the broken anchor bolt can be stably fixed on the extraction rod, ensuring that the lower section of the broken anchor bolt can be removed from the anchor bolt hole.

[0022] As a further improvement, before inserting the broken section of the lower segment of the broken anchor bolt into the extraction rod hole, one end of the tension rope is fixed to the upper end of the extraction rod, while the other end of the tension rope is a free end.

[0023] The beneficial effect is that with this design, after inserting the take-out rod into the hole at the break of the lower section of the broken anchor bolt, the tensioning rope can be tightened simply by pulling the free end, making the operation more convenient.

[0024] As a further improvement, the upper section of the broken anchor bolt was removed by using a tensioner to break the nylon nut below the upper anchor plate.

[0025] The beneficial effect is that it is applicable to the removal of broken positioning anchors.

[0026] As a further improvement, before installing new anchor bolts, clean the oil stains off the new anchor bolts, then put the heat shrink tubing with adhesive onto the smooth rod of the new anchor bolt, heat the heat shrink tubing to gradually shrink and wrap the new anchor bolt.

[0027] The beneficial effect is that the adhesive inside the heat shrink tubing melts and adheres to the bare rod, forming a water- and oxygen-proof anti-corrosion layer to protect the new anchor bolts. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of the broken anchor bolt before its upper section is removed in this invention;

[0029] Figure 2 This is a schematic diagram of the structure after the upper section of the broken anchor bolt of the present invention has been removed;

[0030] Figure 3 This is a schematic diagram of the structure of the broken anchor bolt disassembly device of the present invention;

[0031] Figure 4 for Figure 3 A schematic diagram of the structure of the disassembly rod;

[0032] Figure 5 for Figure 3 A schematic diagram of the structure before the middle fracture anchor bolt removal device is used to remove the lower section of the fractured anchor bolt.

[0033] Figure 6 for Figure 5 The left view;

[0034] Figure 7 This is a schematic diagram of the structure of the first disassembly head of the present invention;

[0035] Figure 8 This is a schematic diagram of the structure of the second type of disassembly head of the present invention;

[0036] Figure 9 This is a schematic diagram of the structure of the third type of disassembly head of the present invention;

[0037] Figure 10 for Figure 3 A schematic diagram of the structure after the middle fracture anchor bolt removal device has removed the lower section of the fractured anchor bolt;

[0038] Figure 11 This is a schematic diagram of the structure of the broken anchor bolt removal device of the present invention;

[0039] Figure 12 for Figure 11 A schematic diagram of the structure before the lower section of the broken anchor bolt is removed using the intermediate fracture anchor bolt dismantling device;

[0040] Figure 13 for Figure 12 A magnified view of a portion of the image;

[0041] Figure 14 This is a schematic diagram of the structure of the new anchor rod of the present invention.

[0042] In the diagram: 11. Force transmission rod segment; 12. Tightening rod segment; 13. Disassembly head; 14. Tightening part; 15. Fixing elongated hole; 16. Sleeve; 17. Compression spring; 18. Pressure rod; 19. Fixing plate; 20. Lower section of broken anchor bolt; 21. Disassembly rod insertion hole; 22. Top pressure blade; 23. Tightening tool; 24. Upper section of broken anchor bolt; 25. Anchor bolt hole; 26. Tensioner; 27. Lower anchor plate; 28. New anchor bolt; 29. ​​Heat shrink tubing; 30. Removal rod; 31. Tensioning rope; 32. Notch; 33. Fixing column; 34. Rope threading hole; 35. Upper anchor plate; 36. Nylon nut; 37. Tower flange; 38. Removal rod insertion hole. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention; that is, the described embodiments are merely some embodiments of the invention, not all embodiments. The components of the embodiments of the invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0044] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0045] It should be noted that relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any actual relationship or order between these entities or operations. Furthermore, terms such as "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. Additionally, the terms "front," "rear," "upper," "lower," "left," and "right" are based on the orientation and positional relationships shown in the accompanying drawings and are used only for the convenience of describing the invention, not to indicate that the referred device or component must have a specific orientation, and therefore should not be construed as limiting the invention.

[0046] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0047] Example 1 of the method for replacing broken anchor bolts in wind turbine foundations according to the present invention:

[0048] In this embodiment, the method for replacing the broken anchor bolts in the wind turbine foundation will utilize a broken anchor bolt disassembly device and a broken anchor bolt removal device.

[0049] like Figures 3 to 9 As shown, the broken anchor bolt removal device includes a removal rod and an elastic pressure structure. The maximum outer diameter of the removal rod is smaller than the diameter of the anchor bolt hole 25, so that the removal rod can be inserted into the anchor bolt hole 25. The removal rod includes a force transmission rod section 11, a screwing rod section 12, and a removal head 13. The removal head 13 is located at the lower end of the force transmission rod section 11 and has a pressing surface for pressing against the cross-section of the lower section 20 of the broken anchor bolt. The screwing rod section 12 is located at the upper end of the force transmission rod section 11 and has a screwing part 14. The screwing part 14 is screwed by a screwing tool 23 to drive the removal rod to rotate, thereby removing the lower section 20 of the broken anchor bolt. The screwing tool 23 is a wrench.

[0050] It should be noted that if the diameter of the holes on the upper anchor plate 35 and the tower flange 37 is greater than or equal to the maximum outer diameter of the disassembly rod, then it is not necessary to enlarge the holes on the upper anchor plate 35 and the tower flange 37; if the diameter of the holes on the upper anchor plate 35 and the tower flange 37 is less than the maximum outer diameter of the disassembly rod, then it is necessary to enlarge the holes on the upper anchor plate 35 and the tower flange 37 to ensure that the disassembly rod can be inserted into the anchor bolt hole 25.

[0051] like Figure 4 As shown, the disassembly head 13 is detachably connected to the lower end of the force transmission rod section 11, and the tightening rod section 12 is detachably connected to the upper end of the force transmission rod section 11. Preferably, the disassembly head 13 and the tightening rod section 12 are threadedly connected to the lower and upper ends of the force transmission rod section 11, respectively, wherein the tightening direction of the disassembly head 13 and the tightening rod section 12 is the same as the loosening direction of the lower section 20 of the broken anchor bolt.

[0052] In this embodiment, the force transmission rod segment 11 is a telescopic rod segment so that the length of the force transmission rod segment 11 can be adjusted, ensuring that after the disassembly rod is inserted into the anchor bolt hole, the screwing rod segment 12 can still protrude outside the anchor bolt hole.

[0053] In this embodiment, the screwing part 14 is a square prism structure. In other embodiments, the screwing part can be a hexagonal prism structure.

[0054] In this embodiment, the disassembly head 13 has three forms to adapt to different fracture planes. The first form is as follows: Figure 7 As shown, the disassembly head 13 is provided with a disassembly rod insertion hole 21, which has a tapered surface adapted to the necked fracture of the lower section 20 of the broken anchor bolt. The tapered surface constitutes the aforementioned top pressure surface. The second form is as follows... Figure 8As shown, the disassembly head 13 is provided with a disassembly rod insertion hole 21, which has an inclined surface adapted to the necked fracture of the lower section 20 of the broken anchor bolt, and the inclined surface constitutes the aforementioned top pressure surface. The third form is as follows... Figure 9 As shown, the disassembly head 13 does not have a disassembly rod insertion hole, and the lower end plane of the disassembly head 13 forms a top pressure surface. At this time, the cross-section of the lower section 20 of the broken anchor bolt is a flat fracture surface.

[0055] In this embodiment, each of the disassembly heads 13 has a pressing blade 22 on its pressing surface, which can provide sufficient friction during the disassembly of the lower section 20 of the broken anchor bolt to drive the lower section 20 of the broken anchor bolt to rotate, thereby realizing the disassembly of the lower section 20 of the broken anchor bolt. In other embodiments, the pressing blade can be replaced by a pressing protrusion.

[0056] like Figure 5 and Figure 6 As shown, an elastic pressure structure is connected to the upper end of the screwing rod section 12 to apply pressure to the disassembly rod. The elastic pressure structure includes a sleeve 16, a compression spring 17 inside the sleeve 16, and a pressure rod 18 connected to the sleeve 16. The lower end of the pressure rod 18 is provided with an upper spring seat. The upper end of the screwing rod section 12 is slidably fitted into the sleeve 16 through the lower spring seat. The upper end of the compression spring 17 presses against the upper spring seat, and the lower end of the compression spring 17 presses against the lower spring seat. That is, the pressure rod 18 and the screwing rod section 12 are located on the upper and lower sides of the compression spring 17, respectively.

[0057] like Figure 3 and Figure 5 As shown, the sleeve 16 is provided with a fixing plate 19 for fixing to the side anchor bolt. This design ensures that the sleeve 16 is fixed without pressing it by hand, saving manpower. The fixing plate 19 is provided with a fixing elongated hole 15 to accommodate anchor bolts with different spacing.

[0058] In this embodiment, the pressure rod 18 is threaded onto the sleeve 16. This design allows the pressure applied to the disassembly rod to be adjusted by turning the pressure rod 18, and the pressure rod 18 can remain in that position after adjustment.

[0059] like Figures 10 to 13 As shown, the broken anchor bolt removal device includes a removal rod 30 and a tension rope 31. The lower end of the removal rod 30 is provided with a removal rod insertion hole 38 for inserting the broken end of the lower section 20 of the broken anchor bolt. The hole wall of the removal rod insertion hole 38 is provided with a notch 32 and a pair of rope holes 34. The pair of rope holes 34 are located on both sides of the notch 32 in the circumferential direction of the removal rod 30.

[0060] In this embodiment, the tension rope 31 passes through the pair of rope holes 34. Both ends of the tension rope 31 are located at the upper end of the take-out rod 30. The upper end of the take-out rod 30 is provided with a fixing post 33 for fixing the end of the tension rope 31. The fixing post 33 constitutes a fixing structure.

[0061] like Figure 10 and Figure 12 As shown, pairs of rope holes 34 are symmetrically arranged on both sides of the extraction rod 30; two fixing posts 33 are provided and symmetrically arranged on the outer circumference of the extraction rod 30, that is, the rope holes 34 and the fixing posts 33 are arranged correspondingly. Among them, before the broken end of the lower section 20 of the broken anchor bolt is inserted into the extraction rod insertion hole 38, one end of the tension rope 31 is fixed to one of the fixing posts 33, and the other end of the tension rope 31 is a free end.

[0062] In this embodiment, the notch 32 is an inwardly sloping notch that slopes from top to bottom. In this embodiment, both ends of the tension rope 31 pass through the outside of the rope hole 34. In other embodiments, the notch can be a rectangular notch.

[0063] In this embodiment, the tension rope 31 is a high-strength nylon rope. Because nylon ropes are prone to deformation, they need to be glued in place when the nylon ropes between the paired rope holes are in a slack state. In other embodiments, an auxiliary nylon rope can be used to hold the nylon ropes between the paired rope holes. After inserting the extraction rod into the extraction hole 38 at the break in the lower section of the broken anchor bolt, one end of the auxiliary nylon rope is released and the other end is pulled to remove the auxiliary nylon rope.

[0064] In this embodiment, the extraction rod 30 is a hollow rod, and its inner diameter is larger than the diameter of the lower section 20 of the broken anchor bolt. The lower end of the extraction rod 30 has a thinner wall to facilitate its entry into the annular space formed by the lower section 20 of the broken anchor bolt and the wall of the anchor bolt hole 25. In other embodiments, the extraction rod can be a solid rod, in which case the extraction rod insertion hole 38 is a blind hole.

[0065] The specific method for replacing the broken anchor bolts in the wind turbine foundation of this invention is as follows:

[0066] 1) Remove the upper section of the broken anchor bolt.

[0067] like Figure 1 and Figure 2 As shown, the tensioner 26 is installed on the anchor head of the upper section 24 of the broken anchor bolt. The tensioner 26 lifts the upper section 24 of the broken anchor bolt to break the nylon nut 36 below the upper anchor plate 35. The tensioner 26 is then removed, the upper section 24 of the broken anchor bolt is taken out, and debris such as nylon nut fragments in the anchor bolt hole 25 is cleaned.

[0068] It should be noted that only positioning anchors in the wind turbine foundation have nylon nuts installed below the upper anchor plate. If it is a regular anchor, the upper section 24 of the broken anchor can be removed directly.

[0069] 2) Disassemble the lower section of the broken anchor bolt

[0070] like Figure 5 and Figure 6As shown, before disassembly, observe the fracture surface of the upper section 24 of the broken anchor bolt and measure its length. Select a suitable disassembly head 13 and force transmission rod section 11, and assemble them with the screwing rod section 12 to form a disassembly rod. Insert the disassembly rod into the anchor bolt hole 25 and insert the fracture surface of the lower section 20 of the broken anchor bolt into the disassembly rod insertion hole 21 of the disassembly head 13. At this time, a part of the screwing rod section 12 is exposed in the anchor bolt hole. Connect the elastic pressure structure to the screwing rod section 12 and fix the elastic pressure structure to the adjacent anchor bolt head. Adjust the downward pressure of the disassembly rod by screwing the pressure rod 18 downward to ensure that the top pressure surface of the disassembly head 13 and the cross section of the fracture surface have sufficient friction. Then, apply the disassembly torque to the disassembly rod using the screwing tool 23 to drive the lower section 20 of the broken anchor bolt to rotate, thereby disassembling the lower section 20 of the broken anchor bolt. After the lower section 20 of the broken anchor bolt is completely unscrewed from the nut of the lower anchor plate 27, remove the elastic pressure structure and take out the disassembly rod. Figure 10 As shown.

[0071] 3) Remove the lower section of the broken anchor bolt.

[0072] like Figure 12 and Figure 13 As shown, first, the tension rope 31 is passed through the paired rope holes 34 at the notch 32 of the extraction rod 30. Then, the portion of the tension rope 31 located between the paired rope holes 34 is dragged upwards to above the notch 32 and fixed with adhesive. At this time, the portion of the tension rope 31 located between the paired rope holes 34 is in a relaxed state. Next, one end of the tension rope 31 is fixed to one of the fixing posts 33, and the other end of the tension rope 31 is free. Then, the extraction rod 30 is inserted into the anchor bolt hole 25, so that the broken end of the lower section 20 of the broken anchor bolt enters the extraction rod insertion hole 38. The free end of the tension rope 31 is pulled and the extraction rod 30 is slowly rotated until the tension rope 31 located in the paired rope holes 34 is taut and enters between two adjacent threads of the lower section 20 of the broken anchor bolt. The tension rope 31 is kept taut, and the free end of the tension rope 31 is fixed to the other fixing post 33. Finally, the extraction rod 30 is taken out along the anchor bolt hole 25, and under the action of the tension rope 31, the lower section 20 of the broken anchor bolt can be taken out along with the extraction rod 30.

[0073] 4) Corrosion protection treatment of new anchor bolts

[0074] like Figure 14 As shown, clean the oil and debris from the smooth rod of the new anchor bolt 28, and then fit a heat shrink tube 29 with adhesive onto the smooth rod of the new anchor bolt 28. Heat the heat shrink tube 29 evenly, and it will gradually shrink and wrap around the new anchor bolt 28. The adhesive on the inside of the heat shrink tube 29 will melt and adhere to the smooth rod, forming a water- and oxygen-proof anti-corrosion layer, thus completing the anti-corrosion treatment.

[0075] 5) Tensioning treatment of new anchor bolts

[0076] Clean the debris in the anchor bolt hole 25 with a vacuum cleaner, insert the new anchor bolt 28 (after anti-corrosion treatment) into the anchor bolt hole 25, rotate the upper end of the new anchor bolt 28 so that the lower thread of the new bolt 28 engages with the nut below the lower anchor plate 27, install the nut and matching parts on the upper end of the new anchor bolt 28, use the tensioner 26 to tension the upper end of the new anchor bolt 28, tighten the nut, remove the tensioner 26, and complete the pre-tensioning of the new anchor bolt 28.

[0077] This invention overcomes the limitations of the narrow and elongated space of the anchor bolt hole, enabling the disassembly and removal of anchor bolts at any fracture section and fracture location, and provides a simple and reliable anti-corrosion treatment method to replace broken anchor bolts in prestressed wind turbine foundations.

[0078] Example 2 of the method for replacing broken anchor bolts in wind turbine foundations according to the present invention:

[0079] The difference between this embodiment and Embodiment 1 is that in Embodiment 1, an elastic pressure structure fixed to the side anchor bolt is used to pressurize the disassembly rod so that the top pressure surface at the lower end of the disassembly rod presses against the cross-section of the lower section of the broken anchor bolt. In this embodiment, the elastic pressure structure is a rigid pressure device, such as a jack.

[0080] Example 3 of the method for replacing broken anchor bolts in wind turbine foundations according to the present invention:

[0081] The difference between this embodiment and Embodiment 1 is that in Embodiment 1, the elastic pressure structure includes a sleeve for fixing to the side anchor bolt, a compression spring inside the sleeve, and a pressure rod threaded into the sleeve. The upper end of the disassembly rod is slidably fitted inside the sleeve, the upper end of the compression spring presses against the pressure rod, and the lower end of the compression spring presses against the disassembly rod. In this embodiment, the elastic pressure structure includes a compression spring and a pressure plate. The upper end of the compression spring is positioned and presses against the pressure plate, and the lower end of the compression spring is positioned and presses against the disassembly rod. At this time, a person or a telescopic cylinder needs to continuously press the pressure plate to maintain the top pressure.

[0082] Example 4 of the method for replacing broken anchor bolts in wind turbine foundations according to the present invention:

[0083] The difference between this embodiment and Embodiment 1 is that in Embodiment 1, the lower section of the broken anchor bolt is removed from the anchor bolt hole using a removal rod and a tension rope. In this embodiment, the lower section of the broken bolt is shorter and lighter, and the disassembly head is a magnetic head. When the disassembly rod is removed from the anchor bolt hole, the magnetic attraction of the disassembly head is used to remove the lower section of the broken anchor bolt from the anchor bolt hole. In other embodiments, the disassembly head is not a magnetic head, but a magnet is placed on the top pressure surface of the disassembly head.

[0084] Example 5 of the method for replacing broken anchor bolts in wind turbine foundations according to the present invention:

[0085] The difference between this embodiment and Embodiment 1 is that in Embodiment 1, a pull-out rod and a tension rope are used to remove the lower section of the broken anchor bolt from the anchor bolt hole. In this embodiment, no tension rope is used, and the pull-out rod does not have a notch or a fixing post. Instead, an upward-sloping barb is provided on the wall of the pull-out rod insertion hole. After the lower section of the broken anchor bolt is inserted into the pull-out rod insertion hole, the end of the barb can enter between two adjacent threads to hook the lower section of the broken anchor bolt, and then the lower section of the broken anchor bolt is removed from the anchor bolt hole by the pull-out rod.

[0086] Example 6 of the method for replacing broken anchor bolts in wind turbine foundations according to the present invention:

[0087] The difference between this embodiment and Embodiment 1 is that in Embodiment 1, before the broken section of the lower segment of the broken anchor bolt is inserted into the extraction rod hole, one end of the tension rope is fixed to the fixed column, and the other end of the tension rope is a free end. In this embodiment, before the broken section of the lower segment of the broken anchor bolt is inserted into the extraction rod hole, both ends of the tension rope are free ends.

[0088] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. The scope of patent protection of the present invention shall be determined by the claims. Similarly, any equivalent structural changes made based on the description and drawings of the present invention shall also be included within the scope of protection of the present invention.

Claims

1. A method for replacing broken anchor bolts in wind turbine foundations, characterized in that, Includes the following steps: Step 1: Disassemble the upper section (24) of the broken anchor bolt; Step 2: Insert the disassembly rod into the anchor bolt hole (25) and press the lower end of the disassembly rod against the cross-section of the lower section (20) of the broken anchor bolt, and rotate the disassembly rod to unscrew the lower section of the broken anchor bolt from the lower anchor plate (27); Step 3: Remove the lower section of the broken anchor bolt from the anchor bolt hole (25); Step 4: Install a new anchor bolt (28). Before inserting the broken end of the lower section of the broken anchor bolt into the extraction rod insertion hole (38), pull the tension rope (31) between the paired rope holes (34) to make it slack and above the notch (32) on the extraction rod (30); after inserting the broken end of the lower section of the broken anchor bolt (20) into the extraction rod insertion hole (38), pull the tension rope to make the tension rope between the paired rope holes taut and enter through the notch between two adjacent threads of the lower section of the broken anchor bolt (20), thereby fixing the lower section of the broken anchor bolt (20) to the lower end of the extraction rod; remove the lower section of the broken anchor bolt (20) from the anchor bolt hole by using the upper extraction rod.

2. The method for replacing broken anchor bolts in wind turbine foundations according to claim 1, characterized in that, The disassembly rod is pressurized by an elastic pressure structure fixed on the side anchor bolt so that the top pressure surface at the lower end of the disassembly rod presses against the cross-section of the lower section (20) of the broken anchor bolt.

3. The method for replacing broken anchor bolts in wind turbine foundations according to claim 2, characterized in that, The elastic pressure structure includes a sleeve (16) for fixing to the side anchor bolt, a compression spring (17) inside the sleeve (16), and a pressure rod (18) threadedly connected to the sleeve (16). The upper end of the disassembly rod is slidably fitted inside the sleeve (16), the upper end of the compression spring (17) presses against the pressure rod (18), and the lower end of the compression spring (17) presses against the disassembly rod.

4. The method for replacing broken anchor bolts in wind turbine foundations according to claim 1, 2, or 3, characterized in that, The disassembly head (13) at the lower end of the disassembly rod is provided with a disassembly rod insertion hole (21) that is adapted to the break of the lower section (20) of the broken anchor bolt. The disassembly rod insertion hole (21) has a conical surface or an inclined surface, which constitutes the top pressure surface.

5. The method for replacing broken anchor bolts in wind turbine foundations according to claim 1, 2, or 3, characterized in that, The top pressure surface is provided with a top pressure blade (22).

6. The method for replacing broken anchor bolts in wind turbine foundations according to claim 1, 2, or 3, characterized in that, The disassembly head (13) at the lower end of the disassembly rod is a magnetic head or a magnet is provided on the top pressing surface of the disassembly head (13) at the lower end of the disassembly rod. The disassembly rod magnetically attracts the lower section (20) of the broken anchor bolt through the disassembly head (13) to remove the lower section (20) of the broken anchor bolt from the anchor bolt hole (25).

7. The method for replacing broken anchor bolts in wind turbine foundations according to claim 1, characterized in that, Before the broken end of the lower section (20) of the broken anchor bolt is inserted into the extraction rod insertion hole (38), one end of the tension rope (31) is fixed to the upper end of the extraction rod (30), and the other end of the tension rope (31) is a free end.

8. The method for replacing broken anchor bolts in wind turbine foundations according to claim 1, 2, or 3, characterized in that, The upper section (24) of the broken anchor bolt is removed by breaking the nylon nut (36) below the upper anchor plate (35) using the tensioner (26).

9. The method for replacing broken anchor bolts in wind turbine foundations according to claim 1, 2, or 3, characterized in that, Before installing the new anchor bolt (28), clean the oil stains on the new anchor bolt (28), and then put the heat shrink tube (29) with adhesive on the smooth rod of the new anchor bolt (28). Heat the heat shrink tube (29) to gradually shrink it to wrap the new anchor bolt (28).

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