Existing land wind power flat underpinning transformation foundation and construction method thereof

Abstract

The invention discloses an existing land wind power flat underpinning reconstruction foundation and a construction method thereof, and belongs to the field of land wind power foundation reconstruction, and the construction method comprises the following steps: chiseling a gap at the edge of a bottom plate of an original old foundation to expose bottom plate reinforcing steel bars; old foundation slab steel bars and new foundation slab steel bars are connected together; uHPC is used for pouring, and a UHPC cast-in-place belt is formed; l-shaped steel bars I are implanted into the side surface of a bottom plate of the original old foundation; vertically implanting L-shaped reinforcing steel bars II into the upper side slope of the bottom plate of the original old foundation; third L-shaped steel bars are implanted into the side face of the stand of the original old foundation; and after the steel bars are processed, a formwork is erected outside the original old foundation, and a new foundation is poured. On the basis that the edge of a bottom plate of an original old foundation is transformed in a small range, old foundation bottom plate reinforcing steel bars are connected with new foundation bottom plate reinforcing steel bars, meanwhile, new and old foundation connecting reinforcing steel bars are arranged on key connecting parts of the side face of the bottom plate, a side slope and a stand, and the bearing performance is improved.

Description

Technical Field

[0001] This invention relates to the field of onshore wind power foundation retrofitting technology, and in particular to an existing onshore wind power base retrofitting foundation and its construction method. Background Technology

[0002] Onshore wind farms refer to a complete set of facilities that utilize wind on land to generate electricity, with the onshore wind turbine foundation being the stable foundation within the entire system. While existing onshore wind turbine foundation retrofitting schemes do not demolish the old foundations, their utilization rate is limited; they merely use the old foundations as counterweights or fail to fully utilize their load-bearing capacity. Furthermore, the modifications to the old foundations are substantial, increasing the workload significantly and causing considerable damage to the existing foundations themselves. Summary of the Invention

[0003] The purpose of this invention is to provide a method for retrofitting existing onshore wind power foundations. By making minor modifications to the edge of the original foundation slab, the reinforcing bars of the old foundation slab are connected to the reinforcing bars of the new foundation slab. At the same time, connecting reinforcing bars of the old and new foundations are set at the sides of the slab, slopes, and key connection points of the columns to improve the load-bearing capacity.

[0004] To achieve the above objectives, the present invention provides a method for constructing an existing onshore wind power grid base retrofit foundation, comprising the following steps: Step 1, Excavation of the existing foundation: Chisel out a gap at a 45-degree angle from the edge of the existing foundation slab to expose the reinforcing steel bars of the existing foundation slab. Step 2, Connecting the old and new foundation slab reinforcement: Connect the old foundation slab reinforcement and the new foundation slab reinforcement together to form an integral reinforcement mesh; Step 3, UHPC cast-in-place strip casting: The old foundation slab reinforcement and the new foundation slab reinforcement are connected by UHPC casting to form a UHPC cast-in-place strip; Step 4, Insertion of reinforcement bars on the side of the foundation slab: Insert one L-shaped steel bar on the side of the existing foundation slab, with the hook at the end of the L-shaped steel bar facing upwards. Step 5, Slope reinforcement insertion: Vertically insert L-shaped steel bar 2 into the slope of the existing old foundation slab, with the exposed tail of the inserted L-shaped steel bar 2 bent parallel to the slope surface. Step 6, Inserting reinforcement bars on the side of the pier: Insert L-shaped steel bars into the side of the pier of the original foundation, and bend the exposed tail of the inserted L-shaped steel bars upward at 90 degrees. Step 7: New Foundation Pouring: After the steel reinforcement is processed, formwork is erected on the outside of the original old foundation and new concrete is poured to form a complete new foundation, completing the construction of the new foundation for the onshore wind power support.

[0005] Preferably, in step one, the original foundation includes a base plate and columns. Both the base plate and the columns are octagonal. The columns are located at the center of the top of the base plate, and the center of the columns and the center of the top of the base plate are on the same vertical line.

[0006] Preferably, in step one, a notch is chiseled out at a 45-degree angle towards the center of the original foundation slab along the edge of the slab.

[0007] Preferably, the top surface of the existing foundation slab is a slope.

[0008] Preferably, the L-shaped steel bar is inserted into the side concrete of the original foundation slab.

[0009] Preferably, two L-shaped steel bars are embedded in the concrete of the original foundation slab slope.

[0010] Preferably, three L-shaped steel bars are embedded in the concrete on the side of the column of the original foundation.

[0011] Preferably, the UHPC cast-in-place strip is cast around the edge of the original foundation slab in the area where it has been removed, thus wrapping the connection joint between the old foundation slab reinforcement and the new foundation slab reinforcement.

[0012] Preferably, the new foundation includes column one and column two, with column one located at the center of the top of column two, and the center of column one and the center of the top of column two located on the same vertical line.

[0013] The present invention also provides a foundation for the retrofitting of existing onshore wind power, which is constructed using the above-mentioned construction method for the retrofitting of existing onshore wind power.

[0014] Therefore, the present invention, by adopting the above-mentioned existing onshore wind power grid underpinning and its construction method, has the following beneficial effects: 1. This invention optimizes the arrangement of rebar to ensure that the interface between the new and old concrete can effectively transmit force. The new and old rebars are welded together to form an integral load-bearing frame. UHPC is then used to strengthen the integrity of the new and old rebars, fundamentally ensuring that the modified foundation can function as a complete single structure and effectively resist the huge overturning moment, horizontal thrust and cyclic load generated by the fresh air unit. 2. In terms of economy: The advantage of this invention is that it significantly reduces the total investment in the renovation, reduces the high costs of crushing and clearing the old foundation and the earthwork and support costs of fully excavating the new foundation in the traditional demolition scheme, makes full use of the remaining value of the original foundation, and saves the main building materials such as concrete and steel. 3. In terms of efficiency: Traditional renovation and reconstruction methods involve long construction periods, while the construction process of this invention is simplified, eliminating the need to deal with construction waste and carry out large-scale earthwork operations. The process is closely linked, greatly reducing on-site operation time. 4. Environmental protection: This invention reduces the generation and transportation of massive amounts of construction waste from the source, avoiding secondary damage to the site environment and dust pollution caused by excavation; 5. In terms of load-bearing performance: This invention effectively enhances the connection performance of new and old steel bars by welding them together with UHPC in the base plate, thereby improving the load-bearing capacity and fatigue resistance of the connection nodes.

[0015] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0016] Figure 1 This is a structural schematic diagram of an embodiment of the construction method for the existing onshore wind power grid underpinning and upgrading foundation of the present invention; Figure 2 This is a schematic diagram of the original old foundation structure of an embodiment of the existing onshore wind power grid underpinning and modification foundation of the present invention; Figure 3 This is a front view of the original old foundation of the existing onshore wind power grid base modification embodiment of the present invention; Figure 4 This is a top view of the original old foundation of the existing onshore wind power grid base modification embodiment of the present invention; Figure 5 This is a bottom view of the original old foundation of the existing onshore wind power grid base modification embodiment of the present invention; Figure 6 This is a cross-sectional view of the original old foundation of the existing onshore wind power grid underpinning and modification foundation embodiment of the present invention; Figure 7 This is a structural diagram of the new foundation of an embodiment of the existing onshore wind power grid underpinning and modification foundation of the present invention; Figure 8 This is a new foundation front view of an embodiment of the existing onshore wind power grid underpinning and modification foundation of the present invention; Figure 9 This is a top view of the new foundation of an embodiment of the existing onshore wind power grid underpinning and modification foundation of the present invention; Figure 10 This is a bottom view of the new foundation of an embodiment of the existing onshore wind power grid underpinning and modification foundation of the present invention; Figure 11 This is a cross-sectional view of the new foundation of an embodiment of the existing onshore wind power grid underpinning and modification of the present invention.

[0017] In the diagram: 1. Existing foundation; 2. Column; 3. L-shaped steel bar 1; 4. L-shaped steel bar 2; 5. L-shaped steel bar 3; 6. New foundation slab reinforcement; 7. Old foundation slab reinforcement; 8. UHPC cast-in-place strip; 9. Slab; 10. Column 1; 11. Column 2. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages disclosed in the embodiments of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the embodiments of the present invention and are not intended to limit the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments in this application without creative effort are within the scope of protection of this application. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout.

[0019] It should be noted that the terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion, such as a process, method, system, product, or server that includes a series of steps or units, not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such processes, methods, products, or devices.

[0020] Similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0021] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed when in use. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0022] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," and "connect" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0023] Example 1: The traditional demolition and reconstruction method essentially involves building a completely new, independent foundation structure on the original site, with a design no different from that of a brand new wind farm foundation.

[0024] 1. Components: Mainly includes a larger new foundation pit, a brand new steel cage, a brand new concrete foundation, and a brand new anchor bolt cage.

[0025] 2. Structure and Connection: The traditional demolition and reconstruction method involves demolishing the original old foundation 1 and rebuilding a new foundation. This new foundation has no relation to the original old foundation 1; it is essentially a completely new foundation structure.

[0026] 3. Operation: Step 1 - Existing Foundation Treatment: Use heavy machinery such as large hydraulic breakers and excavators to completely break and demolish the existing wind turbine foundation. Step 2 - Waste Removal: Remove all construction waste, including broken concrete blocks and reinforcing bars, from the site and dispose of it properly. Step 3 - Earthwork Excavation: Excavate a new foundation pit that is larger and deeper than the original foundation and provide necessary support. Step 4 - New Construction: Similar to building a new wind farm, perform a series of procedures including foundation pouring, reinforcing bar binding, formwork erection, pre-embedded anchor bolt positioning, concrete pouring and curing, etc. Step 5 - Backfilling and Restoration: Backfill the earthwork, restore the site, and install the new wind turbine. Rebar connection involves drilling holes in the old structure, inserting the new connecting reinforcing bars into the holes, and then injecting anchoring adhesive.

[0027] Traditional demolition and reconstruction methods involve completely abandoning the existing old foundation and rebuilding a new foundation with larger dimensions and reinforcement on the original or new site. This method has significant drawbacks: First, it requires heavy machinery for demolition, cleaning, and removal of the old foundation, generating a large amount of construction waste, which is both environmentally unfriendly and costly. Second, the process of building a new foundation, from excavation and rebar tying to pouring and curing, is lengthy, leading to prolonged downtime for wind farms and significant power generation losses. Finally, the value of the original foundation's concrete materials is completely wasted, resulting in resource waste. Rebar anchoring simply involves inserting new rebar into the old structure; there is no connection between the old and new rebars, preventing them from transferring force and sharing loads, resulting in poor overall structural performance and fatigue resistance.

[0028] like Figure 1 As shown, the construction method for upgrading existing onshore wind power to a foundation according to the present invention includes the following steps: Step 1, as follows Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 As shown, the original old foundation 1 is excavated: a notch is chiseled at a 45-degree angle towards the center of the old foundation 1 base slab 9 along the edge of the concrete to expose the reinforcing steel 7 of the old foundation base slab. The edge of the old foundation 1 base slab 9 is chiseled in a small area at a 45-degree angle (or other angle) to expose the reinforcing steel 7 of the old foundation base slab while minimizing damage to the original old foundation 1.

[0029] The existing foundation 1 consists of a base slab 9 and columns 2. Both the base slab 9 and columns 2 are octagonal. Column 2 is located at the center of the top of the base slab 9, and the center of column 2 and the center of the top of the base slab 9 are on the same vertical line. The top surface of the base slab 9 of the existing foundation 1 is a slope.

[0030] Step 2, Connecting the old and new foundation slab reinforcement bars 9: Connect the old foundation slab reinforcement bars 7 and the new foundation slab reinforcement bars 6 together to form an integral reinforcement mesh. The connection method for the old and new reinforcement bars is welding.

[0031] Step 3, UHPC cast-in-place strip 8: The old foundation slab reinforcement 7 and the new foundation slab reinforcement 6 are connected by UHPC casting to form UHPC cast-in-place strip 8, which enhances the strength and fatigue resistance of the connection point of the old and new foundation slab reinforcement 9.

[0032] The UHPC cast-in-place strip 8 is located at the bottom of the base slab 9 of the original old foundation 1. The UHPC cast-in-place strip 8 is cast around the edge of the base slab 9 of the original old foundation 1, covering the connection joint between the old foundation base slab reinforcement 7 and the new foundation base slab reinforcement 6.

[0033] Step 4, Insertion of reinforcement bars on the side of the base slab 9: Insert L-shaped reinforcement bars 3 into the side of the base slab 9 of the original old foundation 1. The L-shaped reinforcement bars 3 are inserted into the concrete on the side of the base slab 9 of the original foundation. The hooks at the ends of the L-shaped reinforcement bars 3 face upwards (the exposed ends of the reinforcement bars need to be bent upwards to increase pull-out resistance), which is used to enhance the connection strength between the old and new foundation base slabs 9.

[0034] Step 5, Slope Reinforcement Insertion: Vertically insert L-shaped steel bars 2 and 4 into the slope of the existing foundation 1's base slab 9. The exposed tails of the inserted L-shaped steel bars 2 and 4 bend parallel to the slope surface, thereby enhancing the overall slope performance of the new and old foundations.

[0035] Step Six: Reinforcing Steel Insertion on the Side of Column 2: L-shaped reinforcing steel bar 3.5 is inserted into the side of Column 2 of the existing old foundation 1, embedded within the concrete. The exposed tail of the inserted L-shaped reinforcing steel bar 3.5 is bent upwards at a 90-degree angle to enhance the overturning resistance of the new and old foundations.

[0036] Step Seven: As Figure 7 , Figure 8 , Figure 9 , Figure 10 , Figure 11 As shown, the new foundation is poured: After the reinforcement is processed, formwork is erected on the outside of the original old foundation 1 and new concrete is poured to form a complete new foundation, completing the construction of the new foundation for the onshore wind power support. The new foundation includes column 10 and column 21. Column 10 is located at the center of the top of column 21, and the center of column 10 and the center of the top of column 21 are on the same vertical line.

[0037] Example 2: The present invention describes a foundation for retrofitting existing onshore wind power, which is constructed using the aforementioned construction method for such a foundation.

[0038] Therefore, the present invention adopts the above-mentioned existing onshore wind power support and reconstruction foundation and its construction method. On the basis of making small-scale modifications to the edge of the original old foundation slab 9, the old foundation slab reinforcement 7 is connected to the new foundation slab reinforcement 6. At the same time, the new and old foundation connection reinforcement is set at the key connection parts of the slab side, slope and column 2 to improve the bearing capacity.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for constructing an existing onshore wind power grid base retrofit foundation, characterized in that, Includes the following steps: Step 1, Excavation of the existing foundation: Chisel out a gap at a 45-degree angle from the edge of the existing foundation slab to expose the reinforcing steel bars of the existing foundation slab. Step 2, Connecting the old and new foundation slab reinforcement: Connect the old foundation slab reinforcement and the new foundation slab reinforcement together to form an integral reinforcement mesh; Step 3, UHPC cast-in-place strip casting: The old foundation slab reinforcement and the new foundation slab reinforcement are connected by UHPC casting to form a UHPC cast-in-place strip; Step 4, Insertion of reinforcement bars on the side of the foundation slab: Insert one L-shaped steel bar on the side of the existing foundation slab, with the hook at the end of the L-shaped steel bar facing upwards. Step 5, Slope reinforcement insertion: Vertically insert L-shaped steel bar 2 into the slope of the existing old foundation slab, with the exposed tail of the inserted L-shaped steel bar 2 bent parallel to the slope surface. Step 6, Inserting reinforcement bars on the side of the pier: Insert L-shaped steel bars into the side of the pier of the original foundation, and bend the exposed tail of the inserted L-shaped steel bars upward at 90 degrees. Step 7: New Foundation Pouring: After the steel reinforcement is processed, formwork is erected on the outside of the original old foundation and new concrete is poured to form a complete new foundation, completing the construction of the new foundation for the onshore wind power support.

2. The construction method for the existing onshore wind power grid underpinning and upgrading foundation according to claim 1, characterized in that: In step one, the original foundation includes a base plate and columns. Both the base plate and columns are octagonal. The columns are located at the center of the top of the base plate, and the center of the columns and the center of the top of the base plate are on the same vertical line.

3. The construction method for the existing onshore wind power grid underpinning and upgrading foundation according to claim 2, characterized in that: In step one, a notch is chiseled out at a 45-degree angle from the edge of the original foundation slab towards the center of the slab.

4. The construction method for the existing onshore wind power grid underpinning and upgrading foundation according to claim 3, characterized in that: The top surface of the existing foundation slab is a slope.

5. The construction method for the existing onshore wind power grid underpinning and upgrading foundation according to claim 1, characterized in that: L-shaped steel bars are inserted into the side concrete of the existing foundation slab.

6. The construction method for the existing onshore wind power grid underpinning and upgrading foundation according to claim 1, characterized in that: Two L-shaped steel bars were implanted into the concrete of the original foundation slab slope.

7. The construction method for the existing onshore wind power grid underpinning and upgrading foundation according to claim 1, characterized in that: Three L-shaped steel bars were inserted into the concrete side of the original foundation column.

8. The construction method for the existing onshore wind power grid underpinning and upgrading foundation according to claim 1, characterized in that: The UHPC cast-in-place strip is cast around the edge of the old foundation slab in the area where it has been removed, thus enclosing the joint where the old foundation slab reinforcement and the new foundation slab reinforcement are connected.

9. The construction method for the existing onshore wind power grid base-supporting transformation foundation according to claim 1, characterized in that: The new foundation consists of column one and column two, with column one located at the center of the top of column two, and the center of column one and the center of the top of column two lying on the same vertical line.

10. A foundation for retrofitting existing onshore wind power, characterized in that: It was constructed using the construction method for the existing onshore wind power grid underpinning and upgrading foundation as described in any one of claims 1-9.

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