A mortise and tenon connected land wind power fabricated foundation structure and construction method

Abstract

The application discloses a mortise and tenon joint type land wind power assembly type foundation structure and method, and relates to the field of wind power foundation structures. The assembly type foundation structure comprises a plurality of prefabricated components which are assembled in a circumferential direction to form an annular structure. The assembly type foundation structure is characterized in that the joint sides of the prefabricated components are respectively provided with mutually matched tenons and mortises. When the adjacent prefabricated components are jointed, the tenon of one is inserted into the mortise of the other to form a grouting gap, and the gap is filled with a high-strength grouting layer. The tenon is a T-shaped solid structure, and the mortise is a T-shaped recessed structure. The surfaces of the tenon and the mortise are both reserved with shear key grooves. The prefabricated component integrally comprises a bottom plate, a column and a rib beam. The application can significantly improve the joint strength and the structural integrity without additional complex steel connecting pieces, realize efficient annular joint of the prefabricated components, improve the overall foundation integrity and stress performance, and simplify the construction process.

Description

Technical Field

[0001] This invention relates to the field of prefabricated foundation technology for onshore wind power, specifically to a mortise and tenon joint prefabricated foundation structure for onshore wind power and its construction method. Background Technology

[0002] Wind energy is one of the most promising new energy sources. In recent years, the wind power industry has achieved large-scale and leapfrog development, and onshore wind power has become a core support for energy structure transformation and the realization of green and low-carbon development. The structure of onshore wind power includes the foundation, upper tower, nacelle, hub, and blades. Among them, the wind power foundation is an important component of the wind power structure, determining whether the wind turbine can operate safely and stably.

[0003] Currently, in the construction of onshore wind power structures, foundations are typically constructed using cast-in-place methods. This method suffers from problems such as long construction cycles, extended curing times, difficulty in controlling the quality of large-volume concrete, and limitations on winter construction, hindering the large-scale, commercial, and high-quality development of wind power. Using precast assembled foundations is one way to solve these problems. Compared to traditional cast-in-place concrete foundations, precast foundations offer advantages such as reliable quality, superior efficiency, and wide applicability.

[0004] Existing prefabricated wind turbine foundations mostly use methods such as steel bar lap splicing, stirrup binding, and grouting to splice precast components. However, these connection methods have problems such as weak shear resistance of the splices, easy slippage and misalignment leading to poor overall structural integrity. At the same time, in order to enhance the connection, a large number of circumferential stirrups, U-shaped bars, dowel bars and other structural measures are often required, making the on-site procedures cumbersome. In addition, the splicing positioning is difficult, which makes it difficult to meet the actual needs of rapid assembly of wind turbine foundations. Furthermore, traditional splice connections are prone to cracking under the overturning load and horizontal shear force of the wind turbine, which further affects the safety and durability of the structure. Summary of the Invention

[0005] The purpose of this invention is to overcome the problems in existing technologies such as insufficient shear resistance at the splicing interface of prefabricated components in onshore wind power prefabricated foundations, weak connections in prefabricated wind power foundations, and complex circumferential connection measures. It provides a mortise and tenon joint structure and construction method for onshore wind power prefabricated foundations. By setting multiple matching tenons and mortises on the splicing surface of prefabricated components, the circumferential positioning and reliable connection of the prefabricated components are achieved through the cooperation of the tenons and mortises. This significantly improves the joint strength and structural integrity without the need for additional complex steel reinforcement connectors, enabling efficient circumferential splicing of prefabricated components, improving the overall integrity and load-bearing performance of the foundation, and simplifying construction procedures. It has advantages such as easy assembly, precise positioning, and direct force transmission.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] A prefabricated onshore wind power foundation structure with mortise and tenon joints includes several prefabricated components assembled in a circular direction to form a ring structure; the splicing sides of the prefabricated components are respectively provided with matching tenons and mortises; when adjacent prefabricated components are spliced, the tenon of one component extends into the mortis of the other component to form a grouting gap, which is filled with a high-strength grouting layer.

[0008] Furthermore, the tenon is a solid T-shaped structure, and the mortise is a recessed T-shaped structure.

[0009] Furthermore, both the tenon and the mortise have pre-drilled shear keyways on their surfaces.

[0010] Furthermore, the prefabricated component integrally includes a base plate, a lower column, and ribs.

[0011] Furthermore, the base plate is located at the bottom of the precast component and has a horizontal fan-shaped plate structure; the lower column is located on the side of the base plate with a smaller fan-shaped arc and has a vertical fan-shaped column structure, with its arc decreasing from the outside to the inside; the rib beam is located at the top of the precast component and is connected to the base plate and the lower column.

[0012] Furthermore, the top of the lower column is also provided with an upper column, and both the upper and lower columns are provided with corresponding through prestressed holes for anchoring with the tower to be installed to form a prestressed system.

[0013] The present invention also provides a construction method based on the aforementioned prefabricated foundation structure, comprising:

[0014] S1. Based on the design load, geometric dimensions, and segmentation scheme of the onshore wind power prefabricated foundation, complete the overall design and preparation of the prefabricated components;

[0015] S2. Level the site, compact the foundation, and pour the subbase in the foundation construction area to ensure that the bearing capacity and flatness of the foundation meet the design and specification requirements.

[0016] S3. Using hoisting equipment, the prefabricated components are hoisted one by one in a predetermined sequence and placed stably in the design position of the foundation layer. When hoisting into place, the tenon of a single prefabricated component is accurately inserted into the tenon groove of the adjacent prefabricated component to complete the initial positioning. All prefabricated components are assembled in a circumferential manner to form a closed and complete prefabricated foundation.

[0017] S4. Hoist the upper column to the design position, ensuring that the bottom surface of the upper column fits tightly with the top surface of the lower column, and that the prestressing holes are completely coaxial and connected. Complete the circumferential assembly of all upper columns in sequence to form a complete closed vertical column structure. Adjust the verticality and splicing gap of the upper column to ensure smooth connection between the upper and lower sections and continuous stress.

[0018] S5. After the assembly is accepted, a grouting port and an air vent are set at the top of the joint to ensure that the grouting channel is unobstructed, so that the grouting material can smoothly enter the gap between the precast components and ensure that the shear key groove area is filled densely to form a shear key.

[0019] S6. Mix the grouting material according to the design mix ratio, and inject the grouting material into the joint of the precast components through the grouting port so that the grouting material evenly fills all the gaps between the tenon and the mortise. After the grouting is completed, a grouting layer is formed, which connects the precast components into an integral load-bearing structure.

[0020] S7. Cover and cure the grouting layer, and control the curing time and ambient temperature;

[0021] S8. After curing, the prestressed tendons for tower anchoring are inserted into the prestressing holes as a whole, forming an integral part with the anchoring structure at the bottom of the tower. Symmetrical tensioning is completed according to the design stress, so that the prefabricated foundation and the tower form an integral load-bearing structure through prestressing. After tensioning, the prestressing holes are sealed by pressure grouting to protect the prestressed tendons from corrosion.

[0022] Compared with the prior art, the beneficial effects of the technical solution of the present invention are:

[0023] 1. By setting matching tenons and mortises on the sides of prefabricated components for splicing, rapid positioning and mechanical engagement of the prefabricated components are achieved. During hoisting and assembly, the tenons and mortises can limit the movement of adjacent components, reduce repeated adjustments to component positions, and improve circumferential assembly accuracy and construction efficiency; at the same time, mechanical engagement can limit relative slippage and misalignment between components, improving the reliability of splice connections.

[0024] 2. Setting a grouting gap between the tenon and mortise and filling it with high-strength grout can improve the density and integrity of the splicing interface. The high-strength grout can fill the connection gap and compensate for assembly errors. After hardening, it forms an integral connection structure with the tenon and mortise, improving the force transmission capacity at the joint and reducing the possibility of component misalignment and local cracking.

[0025] 3. Setting shear keys on the surfaces of the tenon and mortise can further enhance the shear force transmission capacity at the joint. After the grout fills the shear keys and hardens, it can form a solid structure that interlocks with the precast components, increasing the mechanical interlocking and force transmission path at the joint, further restricting slippage between components, and improving the shear and slip resistance of the joint.

[0026] 4. Through the combined action of tenons, mortises, shear keys, and high-strength grouting layers, a multi-interlocking and composite connection structure is formed. Different connection structures jointly undertake the positioning, limiting, and force transmission functions at the joints, avoiding the concentration of connection functions in a single connection form, which is conducive to improving the integrity and load-bearing performance of prefabricated foundations under horizontal shear forces and overturning actions.

[0027] 5. By setting prestressing holes at the top of the columns and using prestressing tendons to anchor the prefabricated foundation and tower as a whole, the integrity between the various components of the foundation can be enhanced. The prestressing tendons are arranged circumferentially and tensioned symmetrically, forming a pre-compressed and closed overall force system between the foundation assembled from prefabricated components and the upper tower. Prestressing maintains good compression between prefabricated components, reducing the possibility of joint opening and relative displacement of components under operating loads and overturning actions, and improving the crack resistance of the foundation connection area. Simultaneously, the prestressing ducts are sealed by pressure grouting after tensioning, protecting the prestressing tendons and improving the durability of the prestressed system.

[0028] 6. The construction method of prefabricated components being manufactured in the factory, hoisted and assembled on-site, grouting the joints, and prestressed integral anchoring simplifies the on-site construction process. The base slab, columns, and ribs are integrally formed, reducing complex on-site connection work; tenons and mortises facilitate component positioning; high-strength grouting material is used to form reliable joint connections; and prestressed tendons further enhance the integrity between the foundation and the tower, thereby improving construction efficiency and the overall load-bearing performance of the prefabricated foundation. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the overall structure of the prefabricated onshore wind power foundation of the present invention.

[0030] Figure 2 This is a top view of the prefabricated foundation structure.

[0031] Figure 3 This is a structural schematic diagram of a prefabricated component.

[0032] Figure 4 This is a side view of the tenon side of the precast component.

[0033] Figure 5 This is a side view of the tenon and groove side of the precast component. Detailed Implementation

[0034] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention.

[0035] Example 1, see Figures 1 to 5This embodiment provides a mortise and tenon joint prefabricated foundation structure for onshore wind power, including several prefabricated components 2 assembled along the circumference to form a ring-shaped prefabricated foundation 1. The prefabricated components 2 are generally in the shape of a convex ring structure, with a ring-shaped base plate at the bottom and a ring-shaped column at the top, which is the core lower support structure of the wind turbine. It is mainly used to bear and transmit the vertical pressure, horizontal shear force and overturning moment generated by the wind turbine's own weight, wind load, seismic action and operating vibration, providing stable, reliable and safe support and anchoring conditions for the upper tower and the unit, and ensuring the structural stability and operational safety of the wind turbine throughout its entire life cycle.

[0036] The splicing sides of the precast component 2 are respectively provided with matching tenons 6 and mortises 7; the outer dimensions of the tenon 6 are smaller than the inner cavity dimensions of the mortises 7 in the corresponding direction, so that when adjacent precast components 2 are spliced, the tenon 6 of one side can extend into the mortises 7 of the other side, and a grouting gap is formed between the tenon 6 and the mortises 7; wherein, the grouting gap on one side between the corresponding sides of the tenon 6 and the mortises 7 is 10 to 20 mm, so as to ensure that the high-strength grout can fill the gap between the tenon 6 and the mortises 7, and a connection structure is formed after the grouting hardens.

[0037] Preferably, the tenon 6 is a T-shaped solid protrusion structure located on the splicing side of the prefabricated component 2. Its outer dimensions are smaller than the inner cavity dimensions of the tenon groove 7. After assembly, it extends into the interior of the tenon groove 7 to achieve positioning and mechanical engagement.

[0038] The tenon groove 7 is a T-shaped recessed structure located on the splicing side of adjacent precast components 2. It is used to accommodate the tenon 6 and form a uniform grouting gap between it and the tenon 6. This gap is specially reserved for high-strength grouting material and is used to fill, bond, and lock the tenon and the tenon groove, so that the splicing surface changes from a separated state to a whole stress state, while compensating for assembly errors and ensuring a tight connection without voids.

[0039] The high-strength grouting layer 9 is the gap between the tenon 6 and the mortise 7, used for injecting high-strength grout. The strength of the grout is generally between C80 and C120. Referring to GB / T 50448 2015, its initial truncated cone flowability is not less than 340 mm, the flowability retained after 30 minutes is not less than 310 mm, and the vertical expansion rate after 3 hours is 0.1% to 0.35%. It has high flowability and micro-expansion characteristics, and can fully flow into and densely fill the narrow cavity of the shear keyway. The grout has high bonding strength with concrete and good durability. After hardening, it connects the components into an integral load-bearing structure.

[0040] Preferably, the precast component 2 is a factory-integrated precast concrete component, integrally cast from the base slab 3, lower column 4, and rib beam 5, forming the basic assembly unit. Its specific dimensions and quantity are determined comprehensively based on the wind turbine capacity, foundation design internal forces, annular foundation diameter, transportation width and height restrictions, and hoisting capacity; the number of circumferential segments is usually 12-20 pieces, with each component controlled within a height of 3.65m. Under the premise of meeting transportation and hoisting safety, the number of segments is minimized to improve on-site assembly efficiency.

[0041] The base plate 3 is located below the precast component 2 and is in the shape of a horizontal fan. Multiple base plates 3 are spliced ​​together in a ring to form a complete ring base plate, which is used to bear the vertical load and overturning moment of the wind turbine and to evenly distribute the upper load to the foundation, thereby improving the foundation's resistance to slippage and overturning.

[0042] The lower column 4 is also located below the precast component 2 and on the side of the base plate 3 with the smaller fan-shaped curvature. It is a vertical fan-shaped column with its curvature decreasing from the outside to the inside. Multiple lower columns 4 are spliced ​​together in a ring to form a complete annular column. In order to efficiently and stably transfer the load of the upper tower, the column should have sufficient vertical stiffness and bearing surface. The top surface should be kept horizontal and pre-stressed ducts should be reserved so that the tower load can be evenly and vertically transferred downward to the base plate and foundation, avoiding stress concentration and local pressure failure.

[0043] Rib 5 is located on top of precast component 2 and is connected to the base slab 3 and the lower column 4. The inner height of the rib is slightly lower than the height of the column, and the width is 350mm~400mm. It adopts a cross-sectional shape that is narrower at the top and wider at the bottom. It is cast integrally with the base slab and the column, which significantly improves the overall stiffness and load-bearing performance of the component.

[0044] Preferably, shear keyways 8 are reserved on the surfaces of both the tenon 6 and the mortise 7, and the depth of the shear keyways 8 is not less than 100mm. The shear keyways 8 are arranged at intervals along the vertical sides of the T-shaped tenon and the T-shaped mortise, and are used to harden into a solid shear-resistant structure after the grout is filled, so as to realize reliable connection and shear force transmission between prefabricated components.

[0045] Preferably, the top of the pedestal 4 is provided with multiple prestressing holes 10, which are evenly arranged circumferentially with the central axis of the lower pedestal 4 as the center, and vertically penetrate the lower pedestal 4 and the prefabricated foundation 1, for the prestressing tendons to pass through, so as to anchor the upper tower and the prefabricated foundation 1 to form an integral prestressing system. The inner diameter of the prestressing hole 10 is larger than the outer diameter of the prestressing tendon bundle. Preferably, the inner diameter of the prestressing hole 10 is 6 to 15 mm larger than the outer diameter of the prestressing tendon bundle. The prestressing holes 10 are formed by pre-embedded pipes. During the prefabrication of the lower pedestal 4 and the prefabricated foundation 1, the pre-embedded pipes are positioned according to the design position of the prestressing holes 10, and fixed inside the prefabricated components by positioning components to form a continuous and through prestressing channel. After the grouting layer reaches the design strength, the prestressing tendons are inserted into the prestressing ducts and installed synchronously with the anchoring structure at the bottom of the tower and tensioned as a whole. After tensioning to the correct position, the anchorages are locked, and finally the prestressing ducts are sealed by grouting, so that the prefabricated foundation 1 and the upper tower form a pre-stressed closed whole, thereby improving the overall structural integrity, crack resistance and fatigue resistance.

[0046] The upper column 11 is a vertical fan-shaped column. To reduce the number of joints, simplify the connection structure, and improve the overall stress continuity, the number of circumferential assembly blocks can be adjusted according to actual needs. This structure is used to extend the vertical height of the foundation to meet the connection requirements of high-concrete composite towers and ultra-high tower tubes; the upper and lower segmented design can control the height and weight of individual components, meeting transportation safety and road traffic requirements.

[0047] The tower 12 is installed on the top of the upper column 11. Through the prestressing system in the prestressing hole 10, it forms an integrated load-bearing structure with the foundation, directly bearing the wind turbine's operating load and transmitting it downwards to the prefabricated foundation, thus realizing the coordinated load-bearing and synchronous deformation of the tower and the foundation.

[0048] Example 2

[0049] Based on the same inventive concept, this application also provides a construction method for the above-mentioned prefabricated foundation structure, specifically including the following:

[0050] Step 1: Based on the design load, geometric dimensions, and segmentation scheme of the onshore wind turbine prefabricated foundation, complete the overall design of prefabricated foundation 1. Determine the external dimensions, splicing angle, and height parameters of prefabricated component 2. Complete the rebar binding and formwork erection in the factory, and integrally cast the base plate 3, lower column 4, and rib beam 5. Simultaneously form the tenon 6 and mortise 7 on the splicing side of prefabricated component 2, ensuring that the external dimensions of the tenon 6 are smaller than the internal dimensions of the mortise 7 to form a uniform grouting gap. Set prestressed holes 10 at corresponding positions on the top of the lower column 4, ensuring that the anchor bolt hole positions meet the design requirements, with a hole diameter of 150mm-200mm. Set shear keyways 8 with a depth of not less than 100mm between the tenon and mortise structures. Simultaneously complete the segmented prefabrication of the upper column 11, and open coaxial prestressed holes 10 to ensure precise connection with the lower column 4. After the components are cast, cure them according to the specifications until the concrete strength reaches the design strength before use.

[0051] Step 2: Level the site, compact the foundation, and pour the subbase in the foundation construction area to ensure that the bearing capacity and flatness of the foundation meet the design and specification requirements. Determine the center point, outer contour line, splice joint position line, and installation positioning line of each prefabricated component 2 of the prefabricated foundation 1, clarify the assembly sequence and alignment benchmark, and ensure that the subsequent assembly accuracy is controllable.

[0052] Step 3: Using hoisting equipment, prefabricated components 2 are hoisted one by one in a predetermined sequence and placed stably in the designed positions on the foundation. During hoisting, the tenon 6 of each prefabricated component 2 is accurately inserted into the mortise 7 of the adjacent prefabricated component 2 to complete the initial positioning. All prefabricated components 2 are assembled circumferentially in sequence to form a closed and complete prefabricated foundation 1. During the assembly process, the planar position and splicing gap of the components are adjusted to ensure that the tenon 6 and the mortise 7 are aligned and the joint width is uniform.

[0053] Step 4: After assembling the lower column 4, hoist the upper column 11 to the designed position, ensuring a tight fit between the bottom surface of the upper column and the top surface of the lower column, and that the prestressed holes 10 are completely coaxially connected. Complete the circumferential assembly of all upper columns 11 in sequence to form a complete closed vertical column structure. Adjust the verticality and splicing gaps of the upper columns to ensure smooth connection between the upper and lower sections and continuous stress distribution.

[0054] Step 5: After the assembly is accepted, a grouting port and an air vent are set at the top of the joint to ensure that the grouting channel is unobstructed and that the grouting material can smoothly enter the gap between the precast components and fill the shear key groove 8 densely to form a shear key.

[0055] Step 6: Mix the high-strength grout according to the design mix ratio, controlling the mixing time and flowability to meet construction requirements; before grouting, seal the outer gaps of the vertical joints by using sealing material to seal the exposed gaps at the joint of the tenon 6 and the mortise 7 to prevent grout leakage during the grouting process; after sealing and waiting for the sealing material to reach its initial curing strength, grout is injected into the joint gaps of the components through the grouting port, allowing the grout to slowly and evenly fill all the gaps between the tenon 6 and the mortise 7. After grouting, a high-strength grout layer 9 is formed, connecting the precast components 2 into an integral load-bearing structure.

[0056] Step 7: Cover and cure the high-strength grouting layer 9, controlling the curing time and ambient temperature to ensure the grout fully hardens and its strength steadily increases. After the high-strength grouting layer 9 reaches its design strength, the shear keys obtained by grouting the tenon 6, mortise 7, and shear key 8, together with the high-strength grouting layer 9, form an integral structure, realizing reliable shear-resistant connection and overall force transmission between precast components, and limiting slippage and misalignment between components.

[0057] Step 8: After curing, the prestressed tendons for tower anchoring are inserted into the prestressing holes 10 as a whole, forming an integral structure with the bottom anchoring structure of the tower. Symmetrical tensioning is then performed according to the design stress, allowing the prefabricated foundation 1 and the tower 12 to form an integrated load-bearing structure through prestressing. After tensioning, the prestressing holes 10 are sealed with pressure grouting to protect the prestressed tendons from corrosion. Under the load of the upper wind turbine tower, the vertical prestressed tendons apply continuous pre-compression to the prefabricated foundation 1, keeping the splicing interface of adjacent prefabricated components 2 in a compressed state. When the wind turbine is subjected to horizontal wind load and generates an overturning moment, the overturning action is transmitted through the prestressed inter-component compression force and the mechanical interlocking action between the tenon 6 and the mortise 7. The tenon 6 and the mortise 7 interlock, restricting the relative misalignment between adjacent prefabricated components 2, and the high-strength grouting layer 9 enhances the overall connection and shear force transmission capacity of the splicing interface, thereby improving the prefabricated foundation 1's resistance to wind turbine overturning together with the vertical prestressing.

[0058] This invention is not limited to the embodiments described above. The above description of specific embodiments is intended to illustrate and explain the technical solutions of this invention. The specific embodiments described above are merely illustrative and not restrictive. Without departing from the spirit and scope of the claims, those skilled in the art can make many specific modifications based on the teachings of this invention, and these modifications all fall within the scope of protection of this invention.

Claims

1. A prefabricated onshore wind power foundation structure with mortise and tenon joints, characterized in that, It includes several prefabricated components (2) assembled along the circumference to form a ring structure; the splicing sides of the prefabricated components (2) are respectively provided with matching tenons (6) and mortises (7); when adjacent prefabricated components (2) are spliced, the tenon (6) of one extends into the mortises (7) of the other to form a grouting gap, which is filled with a high-strength grouting layer (9).

2. The prefabricated foundation structure according to claim 1, characterized in that, The tenon (6) is a solid T-shaped structure, and the mortise (7) is a recessed T-shaped structure.

3. The prefabricated foundation structure according to claim 1 or 2, characterized in that, Both the tenon (6) and the mortise (7) have shear keyways (8) pre-reserved on their surfaces.

4. The prefabricated foundation structure according to claim 1, characterized in that, The precast component (2) is integrally formed and includes a base plate (3), a lower column (4), and a rib beam (5).

5. The prefabricated foundation structure according to claim 4, characterized in that, The base plate (3) is located at the bottom of the precast component (2) and has a horizontal fan-shaped plate structure; the lower column (4) is located on the side of the base plate (3) with a smaller fan-shaped arc and has a vertical fan-shaped column structure, with its arc decreasing from the outside to the inside; the rib beam (5) is located at the top of the precast component (2) and is connected to the base plate (3) and the lower column (4).

6. The prefabricated foundation structure according to claim 4 or 5, characterized in that, The lower column (4) is also provided with an upper column (11) at the top. Both the upper column (11) and the lower column (4) are provided with corresponding through prestressed holes for anchoring with the tower to be installed to form a prestressed system.

7. A construction method for a prefabricated foundation structure according to any one of claims 1-6, characterized in that, include: S1. Based on the design load, geometric dimensions and segmentation scheme of the onshore wind power prefabricated foundation, complete the overall design and preparation of the prefabricated component (2); S2. Level the site, compact the foundation, and pour the subbase in the foundation construction area to ensure that the bearing capacity and flatness of the foundation meet the design and specification requirements. S3. Using hoisting equipment, hoist the prefabricated components (2) one by one in a predetermined order and place the prefabricated components (2) stably in the design position of the foundation layer; when hoisting into place, make the tenon (6) of a single prefabricated component (2) accurately extend into the tenon (7) of the adjacent prefabricated component (2) to complete the initial positioning; complete the circumferential assembly of all prefabricated components (2) in sequence to form a closed and complete prefabricated foundation; S4. Hoist the upper column (11) to the design position so that the bottom surface of the upper column and the top surface of the lower column (4) fit tightly together and the prestressed holes are completely coaxially connected. Complete the circumferential assembly of all upper columns in sequence to form a complete closed vertical column structure. Adjust the verticality and splicing gap of the upper column to ensure that the upper and lower sections are connected smoothly and the stress is continuous. S5. After the assembly is accepted, a grouting port and an air vent are set at the top of the joint to ensure that the grouting channel is unobstructed, so that the grouting material can smoothly enter the gap between the precast components (2) and ensure that the shear key groove (8) area is filled densely to form a shear key. S6. Mix the grouting material according to the design mix ratio, and inject the grouting material into the joint of the precast components through the grouting port so that the grouting material evenly fills all the gaps between the tenon and the mortise. After the grouting is completed, a grouting layer is formed, which connects the precast components into an integral load-bearing structure. S7. Cover and cure the grouting layer, and control the curing time and ambient temperature; S8. After curing, the prestressed tendons for tower anchoring are inserted into the prestressing holes as a whole, forming an integral part with the anchoring structure at the bottom of the tower. Symmetrical tensioning is completed according to the design stress, so that the prefabricated foundation and the tower form an integral load-bearing structure through prestressing. After tensioning, the prestressing holes are sealed by pressure grouting to protect the prestressed tendons from corrosion.

Images