Pipe barrel type wind tower foundation in soft soil area and construction method of pipe barrel type wind tower foundation

Abstract

The invention relates to the technical field of wind tower foundations, in particular to a soft soil area pipe barrel type wind tower foundation and a construction method thereof.The wind tower foundation comprises an original circular-truncated-cone-shaped foundation, a new foundation and secant piles, a new top platform is poured at the top of the original circular-truncated-cone-shaped foundation, and the new foundation is arranged on the side surface of the original circular-truncated-cone-shaped foundation; first hidden beams are arranged on the periphery of the new top platform in the circumferential direction, reinforcing steel bars in the first hidden beams are connected with anchor bolt cage reinforcing steel bars in the original circular-truncated-cone-shaped foundation, new unit pre-stressed anchor bolts are arranged in the first hidden beams, and the new unit pre-stressed anchor bolts are anchored into the original circular-truncated-cone-shaped foundation. Second hidden beams are arranged outside the new foundation in the annular direction, and secant piles are arranged below the second hidden beams. Under the condition that the occupied area of an original foundation is not enlarged basically, the overall strength is improved, the bearing capacity of the original foundation is improved, and the engineering cost and the construction period are saved.

Description

Technical Field

[0001] The invention relates to the technical field of wind tower foundations, and in particular to a tubular wind tower foundation in a soft soil area and a construction method thereof. Background Art

[0002] In June 2023, the National Energy Administration issued the "Management Measures for the Renovation, Upgrading and Decommissioning of Wind Farms", which encourages wind farms with a capacity of less than 1.5MW and connected to the grid for more than 15 years to carry out renovation, upgrading and decommissioning. According to this measure, many old wind farms across the country are planning to renovate or expand their capacity. In the future, wind power upgrading and renovation will be an important direction for the development of wind power new energy.

[0003] At present, in the wind farm wind turbine renovation project, the existing technology for the existing wind turbine foundation is basically to dismantle the original foundation and build a new foundation. However, this method has the following disadvantages:

[0004] The existing technology demolishes the original foundation and builds a new one. The capacity of a single machine in the upgrading and renovation project is large, and the existing foundation red line does not meet the requirements; the existing technology demolishes the original foundation and builds a new one. The original foundation, roads and other facilities are largely abandoned, which is weak in economic efficiency and unfavorable in engineering cost and construction period;

[0005] In view of the above drawbacks, a technical solution for in-situ transformation based on the original foundation is urgently needed, and therefore, the present invention is proposed. Summary of the invention

[0006] The object of the present invention is to provide a tubular wind tower foundation in a soft soil area and a construction method thereof, which can solve the above-mentioned technical problems.

[0007] The present invention provides a tubular wind tower foundation for a soft soil area, comprising an original truncated cone-shaped foundation, a new top platform cast on the top of the original truncated cone-shaped foundation, a new foundation provided on the side surface of the original truncated cone-shaped foundation, a first hidden beam provided in a circumferential direction around the new top platform, the steel bars in the first hidden beam being connected to the anchor cage steel bars in the original truncated cone-shaped foundation, a new prestressed anchor bolt of the unit provided in the first hidden beam, the new prestressed anchor bolt of the unit being anchored in the original truncated cone-shaped foundation, one end of the above-mentioned prestressed anchor bolt of the new unit protruding from the surface of the new top platform and connected to the newly-installed tower barrel on the upper part.

[0008] Furthermore, the top of the first hidden beam is more than 1 meter higher than the outdoor floor.

[0009] Furthermore, the projected area of ​​the new foundation is the same as the projected area of ​​the original truncated cone foundation.

[0010] Furthermore, a second hidden beam is provided in an outer ring direction of the new foundation, and the second hidden beam is connected to the new foundation through steel bars.

[0011] Furthermore, the second hidden beam is lower than the outdoor floor and is flush with the new foundation.

[0012] Furthermore, a hard interlocking pile connected to the second hidden beam is provided under the second hidden beam.

[0013] Furthermore, a plurality of circumferential steel bars and a plurality of radial steel bars are provided at the top of the new foundation, and the radial steel bars are anchored in the first hidden beam.

[0014] Furthermore, the annular steel bars are evenly arranged from top to bottom within the embedding depth range to prevent concrete splitting.

[0015] Furthermore, the top of the new foundation is lower than the outdoor floor by more than or equal to 500 mm, so that the surface can be covered with green plants after the in-situ transformation of the entire foundation is completed.

[0016] The present invention also provides a method for constructing a tubular wind tower foundation in a soft soil area, comprising the following steps:

[0017] Step 1: Roughen the outer surface of the original truncated cone foundation.

[0018] Step 2: Cast a new top platform on the top of the original truncated cone foundation, set a first hidden beam in the circumferential direction around the new top platform, and the first hidden beam steel bar is reliably connected to the anchor cage steel bar in the original truncated cone foundation; set the new unit prestressed anchor bolt in the first hidden beam, and anchor the new unit prestressed anchor bolt into the original truncated cone foundation; the first hidden beam 6 is more than 1 meter higher than the outdoor floor;

[0019] Step 3: Cast a new foundation on the side surface of the original truncated cone foundation. Multiple circumferential steel bars and multiple radial steel bars are set on the top of the new foundation to bear force. Multiple radial steel bars are anchored in the first hidden beam of the new top platform. The new foundation is not less than 500mm lower than the outdoor floor, so that the surface can be covered with green plants after the overall foundation in-situ transformation is completed. The new foundation is connected to the original truncated cone foundation and the first hidden beam through steel bars. Specifically, the new steel bars are welded to the steel bars in the original truncated cone foundation and extended into the new foundation, so that the new and old foundations bear force together to ensure the overall rigidity of the new and old foundations.

[0020] Step 4: A second hidden beam is set in the outer ring of the new foundation. The second hidden beam is connected to the new foundation through steel bars to ensure the overall rigidity. The second hidden beam is lower than the outdoor floor and is flush with the new foundation. Hard bite piles are set under the hidden beam.

[0021] Beneficial effects:

[0022] The present invention casts a new top platform on the original truncated cone foundation of the wind tower, a new foundation is arranged on the side surface of the original truncated cone foundation, a first hidden beam is arranged in the circumferential direction around the new top platform, the steel bars in the first hidden beam are connected to the anchor cage steel bars in the original truncated cone foundation, a new unit prestressed anchor bolt is arranged in the first hidden beam, the new unit prestressed anchor bolt is anchored in the original truncated cone foundation, one end of the new unit prestressed anchor bolt protrudes from the surface of the new top platform and is connected to the newly-installed tower tube on the upper part, a second hidden beam is arranged in the circumferential direction outside the new foundation, and a snap pile is arranged under the second hidden beam. Without substantially expanding the area occupied by the original foundation, the overall strength is increased, the bearing capacity of the original foundation is improved, and the engineering cost and construction period are saved. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 A top view of a tubular wind tower foundation in a soft soil area according to an embodiment of the present invention;

[0025] Figure 2 A side cross-sectional view of a tubular wind tower foundation in a soft soil region according to an embodiment of the present invention;

[0026] Explanation of the accompanying drawings: 1-original truncated cone foundation, 2-second hidden beam, 3-hard interlocking piles, 4-new foundation, 5-new top platform, 6-first hidden beam, 7-prestressed anchor bolts of new unit, 8-new tower, 9-original pile foundation, 10-outdoor floor. DETAILED DESCRIPTION

[0027] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0029] In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined. In addition, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] Example 1

[0031] A tube-type wind tower foundation in soft soil areas, such as Figure 1-2 As shown, it includes an original truncated cone foundation 1, a new top platform 5 is cast on the top of the original truncated cone foundation 1, a new foundation 4 is arranged on the side surface of the original truncated cone foundation 1, a first hidden beam 6 is arranged in a circumferential direction around the new top platform 5, the top of the first hidden beam 6 is more than one meter higher than the outdoor floor 10, the steel bars in the first hidden beam 6 are connected with the anchor cage steel bars in the original truncated cone foundation 1, a new unit prestressed anchor 7 is arranged in the first hidden beam 6, the new unit prestressed anchor 7 is anchored in the original truncated cone foundation 1, one end of the above-mentioned new unit prestressed anchor 7 protrudes from the surface of the new top platform 5 and is connected to the newly arranged tower 8 on the upper part.

[0032] A plurality of circumferential steel bars and a plurality of radial steel bars are arranged on the top of the new foundation 4. The radial steel bars are anchored in the first hidden beam 2. The circumferential steel bars are evenly arranged from top to bottom within the buried depth range to prevent concrete splitting. The top of the new foundation 4 is lower than the outdoor floor by more than or equal to 500mm, so that the surface can be covered with green plants after the overall foundation in-situ transformation is completed.

[0033] A second hidden beam 2 is provided in the outer ring direction of the new foundation 4. The second hidden beam 2 is connected to the original truncated cone-shaped foundation 1 through steel bars. The second hidden beam 2 is lower than the outdoor floor 10, and its top is flush with the new foundation 4. A hard bite pile 3 connected to the second hidden beam 2 is provided. The use of hard bite piles 3 can greatly reduce the bottom area of ​​the foundation. In the upgrading and reconstruction project, it can meet the requirement that the foundation of a single machine does not exceed the original red line, and effectively reduce the project cost and construction period.

[0034] Method Example:

[0035] Step 1: roughening the outer surface of the original truncated cone foundation 1;

[0036] Step 2: Cast a new top platform 5 on the top of the original truncated cone foundation 1, and set a first hidden beam 6 in the circumferential direction around the new top platform 5. The steel bars of the first hidden beam 6 are reliably connected to the steel bars of the anchor cage in the original truncated cone foundation 1; the prestressed anchor bolts 7 of the new unit are set in the first hidden beam 6, and the prestressed anchor bolts 7 of the new unit are anchored in the original truncated cone foundation 1; the height of the first hidden beam 6 is determined according to the length of the prestressed anchor bolts 7 of the new unit, and the first hidden beam 6 is generally more than 1 meter higher than the outdoor floor;

[0037] Step 3: pour a new foundation 4 on the side surface of the original truncated cone foundation 1, set multiple circumferential steel bars and multiple radial steel bars on the top of the new foundation 4 to bear force, and anchor multiple radial steel bars into the first hidden beam 6 of the new top platform; the new foundation 4 is not less than 500mm lower than the outdoor floor, so that the surface can be covered with green plants after the overall foundation in-situ transformation is completed; the new foundation 4 is connected to the original truncated cone foundation 1 and the first hidden beam 6 through steel bars; specifically, the new steel bars are welded to the steel bars in the original truncated cone foundation and extend into the new foundation, so that the new and old foundations bear force together, ensuring the overall rigidity of the new and old foundations;

[0038] Step 4: A second hidden beam 2 is set in the outer ring of the new foundation 4. The second hidden beam 2 is connected to the new foundation 4 through steel bars to ensure the overall rigidity; the second hidden beam 2 is lower than the outdoor floor and is flush with the new foundation 4; a hard bite pile 3 is set under the hidden beam 2.

[0039] Application examples:

[0040] A 1.5MW wind turbine was upgraded to a 6.25MW unit. The original foundation was a 15-meter-diameter truncated cone gravity foundation in a soft soil area with a red line width of 17 meters. The original foundation steel reinforced concrete consumption was about 400m 3 .

[0041] If the traditional technology of dismantling the original foundation and building a new one is adopted, the wind load bending moment of the 1.5MW unit after upgrading to a 6.25MW unit will be more than three times the original bending moment of 46,000 kNm, the diameter of the new foundation will be about 22 meters, and the amount of concrete used will be about 800m 3, and the new foundation far exceeds the original foundation red line, conventional technology will not be able to solve the problem of restricted land acquisition.

[0042] With the technical solution of this application, the width of the second hidden beam of the new foundation is only 0.8m, and the diameter of the entire device is about 16.6m. Within the red line range, the problem of restricted land acquisition is solved, and the amount of reinforced concrete used for the new foundation is about 300m 3 , saving 500m3 of reinforced concrete compared with conventional technology 3 , saving about 62.5% of the engineering workload, with obvious results.

[0043] Considering that the wind tower foundation is subjected to the dynamic effect of wind load for a long time, the foundation is mainly controlled by the bending moment of wind load. The bending moment of the new unit is generally more than twice the original bending moment. The present invention mainly aims at the foundation conditions in soft soil areas, innovates the reinforcement structure form and studies the relevant key nodes and material properties to form a universal in-situ transformation technology for wind tower foundations, which can extend the life and resource utilization of existing foundations and facilities to the greatest extent, comprehensively solve a series of problems existing in the existing technology such as environmental protection, land acquisition, construction period, investment, etc., and provide technical guarantee for the acquisition and implementation of future wind power upgrading and transformation projects.

[0044] Although the following terms are used more frequently in this article: 1-original truncated cone foundation, 2-second hidden beam, 3-hard interlocking pile, 4-new foundation, 5-new top platform, 6-first hidden beam, 7-prestressed anchor bolts of new unit, 8-new tower, 9-original pile foundation, 10-outdoor floor, etc., the possibility of using other terms is not excluded. These terms are used only to more conveniently describe and explain the essence of the present invention. It is contrary to the spirit of the present invention to interpret them as any additional restrictions.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A tubular wind tower foundation in soft soil area, comprising an original truncated cone foundation, characterized in that: A new top platform is cast on the top of the original truncated cone-shaped foundation, a new foundation is provided on the side surface of the original truncated cone-shaped foundation, a first hidden beam is provided in a circumferential direction around the new top platform, the steel bars in the first hidden beam are connected to the anchor cage steel bars in the original truncated cone-shaped foundation, a new unit prestressed anchor bolt is provided in the first hidden beam, and the new unit prestressed anchor bolt is anchored in the original truncated cone-shaped foundation.

2. The soft soil area tubular wind tower foundation according to claim 1, characterized in that: The top of the first hidden beam is more than 1 meter higher than the outdoor floor.

3. The soft soil area tubular wind tower foundation according to claim 1, characterized in that: The projected area of ​​the new foundation is the same as the projected area of ​​the original truncated cone foundation.

4. The soft soil area tubular wind tower foundation according to claim 3, characterized in that: A second hidden beam is provided in the outer ring direction of the new foundation, and the second hidden beam is connected to the new foundation through steel bars.

5. The soft soil area tubular wind tower foundation according to claim 4, characterized in that: The second hidden beam is lower than the outdoor floor and is flush with the new foundation.

6. The soft soil area tubular wind tower foundation according to claim 4, characterized in that: A hard engaging pile connected to the second hidden beam is provided under the second hidden beam.

7. The soft soil area tubular wind tower foundation according to claim 4, characterized in that: A plurality of circumferential steel bars and a plurality of radial steel bars are arranged at the top of the new foundation, and the radial steel bars are anchored into the first hidden beam.

8. The soft soil area tubular wind tower foundation according to claim 7, characterized in that: The annular steel bars are evenly arranged from top to bottom within the embedding depth range.

9. The soft soil area tubular wind tower foundation according to claim 4, characterized in that: The top of the new foundation is at least 500 mm lower than the outdoor floor, so that the surface can be covered with green plants after the in-situ transformation of the overall foundation is completed.

10. A method for constructing a tubular wind tower foundation in a soft soil area, characterized in that: The following steps are involved: Step 1: Roughen the outer surface of the original truncated cone foundation. Step 2: Cast a new top platform on the top of the original truncated cone foundation, set a first hidden beam in the circumferential direction around the new top platform, and the first hidden beam steel bar is reliably connected to the anchor cage steel bar in the original truncated cone foundation; set the new unit prestressed anchor bolt in the first hidden beam, and anchor the new unit prestressed anchor bolt into the original truncated cone foundation; the first hidden beam 6 is more than 1 meter higher than the outdoor floor; Step 3: Cast a new foundation on the side surface of the original truncated cone foundation. Multiple circumferential steel bars and multiple radial steel bars are set on the top of the new foundation to bear force. Multiple radial steel bars are anchored in the first hidden beam of the new top platform. The new foundation is not less than 500mm lower than the outdoor floor, so that the surface can be covered with green plants after the overall foundation in-situ transformation is completed. The new foundation is connected to the original truncated cone foundation and the first hidden beam through steel bars. Specifically, the new steel bars are welded to the steel bars in the original truncated cone foundation and extended into the new foundation, so that the new and old foundations bear force together to ensure the overall rigidity of the new and old foundations. Step 4: A second hidden beam is set in the outer ring of the new foundation. The second hidden beam is connected to the new foundation through steel bars to ensure the overall rigidity. The second hidden beam is lower than the outdoor floor and is flush with the new foundation. Hard bite piles are set under the hidden beam.

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