Multi-column prestressed space tower structure and construction assembly system

Abstract

The invention discloses a multi-column prestressed space tower structure and a construction assembly system.The structure comprises a foundation, inner-layer columns, outer-layer columns, prestressed cables, reinforced concrete ring beams, a steel tower drum and a flexible film, the foundation is an expanded concrete foundation, supporting columns are arranged to be of an inner-layer and outer-layer tubular structure, and the lower ends of the supporting columns are in grouting or bolted connection with the foundation; the upper-end embedded steel bars and the ring beam are poured into a whole, the prestressed cable penetrates through the inner-layer column and is anchored to the foundation and the ring beam, the ring beam is connected with the steel tower drum through a flange, and the periphery of the outer-layer column is wrapped with a flexible film to form a fence. According to the structure, through multi-column splitting, differentiated inclined arrangement and prestress pulling, the defects that a traditional tower is difficult to transport and construct, insufficient in lateral stiffness, prone to fatigue of joints, high in steel consumption and the like are overcome, welding-free assembly is achieved, the steel consumption of the tower is reduced, the maximum horizontal displacement is reduced, and high stability, fatigue resistance and economical efficiency are achieved.

Description

Technical Field

[0001] This invention belongs to the field of spatial concrete structure technology, specifically relating to a multi-column prestressed spatial tower structure and its construction assembly system. Background Technology

[0002] As the single-unit capacity of wind turbine generators increases, tower height has exceeded 150m. Traditional single-tube steel towers, lattice-type angle steel towers, and steel pipe inclined truss towers have revealed many defects under the coupled action of ultimate load and fatigue load. Specifically, the excessively large bottom diameter leads to high difficulty in manufacturing, transportation, and on-site circumferential welding construction; the overall slenderness ratio is large, the second-order effect is significant, and the lateral stiffness is insufficient; fatigue problems are prone to occur at the joints, the amount of high-altitude welding work on-site is large, and the quality control is difficult; the amount of steel used increases exponentially with the height, resulting in poor economic efficiency, and the truss structure has complex connection nodes, weak fatigue resistance, and high construction costs. Summary of the Invention

[0003] The purpose of this invention is to provide a multi-column prestressed spatial tower structure and construction assembly system to solve the technical defects of traditional towers, such as large bottom diameter, difficult transportation and construction, high slenderness ratio, insufficient lateral stiffness, easy fatigue of nodes, many high-altitude welding and difficult quality control, high steel consumption and poor economy, and complex truss nodes and weak fatigue resistance.

[0004] To achieve the above objectives, this application provides the following technical solution: A first aspect of this application provides a multi-column prestressed space tower structure, comprising: The foundation is an extended concrete foundation with prestressed ducts inside. Multiple circular tubular support columns are arranged at equal angles along the circumference of the upper part of the foundation. The supporting columns are arranged in two layers, an inner layer and an outer layer. The inclination angle of the outer layer columns is greater than that of the inner layer columns, and the cross-sectional dimensions of the inner layer columns are greater than those of the outer layer columns. The lower ends of the inner and outer columns are connected to the foundation grouting or bolted, and the upper ends are pre-embedded with steel bars, which extend into the reinforced concrete ring beam and are cast together with the reinforced concrete ring beam to form a whole. The prestressed cable is inserted into the interior of the inner column, with its lower end anchored in the prestressed duct of the foundation and its upper end passing through and anchored to the reinforced concrete ring beam. Anchor bolt holes are provided on the reinforced concrete ring beam, which is fixedly connected to the steel tower cylinder through flanges. All outer columns are wrapped with a flexible film to form an enclosure structure.

[0005] In one alternative embodiment, the support column is made of reinforced concrete or steel-concrete composite.

[0006] In one optional embodiment, grooves are provided at the connection positions of the inner and outer columns on the basis; The lower ends of the inner and outer columns are respectively embedded in the corresponding grooves and connected to the foundation grouting or bolted connection.

[0007] In one optional embodiment, prestressing ducts are provided on the reinforced concrete ring beam at the positions where the prestressing cables are inserted. The prestressed cable is inserted through the prestressed duct, and its upper end extends upward through the prestressed duct to the upper surface of the reinforced concrete ring beam.

[0008] In one alternative embodiment, the enclosure structure formed by the flexible film encloses both the inner and outer columns within its enclosed space.

[0009] In one optional embodiment, the inner and outer columns are evenly distributed along the circumferential direction of the foundation at equal included angles. Furthermore, the number of inner and outer columns is matched.

[0010] In one optional embodiment, the prestressed cable is a post-tensioned longitudinal prestressed cable, and the prestressed cable, together with the foundation, inner column and reinforced concrete ring beam, forms an integral prestressed structure.

[0011] In one alternative embodiment, the prestressed duct is located at the center of the reinforced concrete ring beam.

[0012] In one optional embodiment, the embedded steel bars of the inner column are evenly distributed along the circumference of the inner column body, and the embedded steel bars of the outer column are evenly distributed along the circumference of the outer column body, and the extension direction of each embedded steel bar is adapted to the casting direction of the reinforced concrete ring beam. The inner and outer columns, together with the reinforced concrete ring beam, form a shell-like space truss structure.

[0013] A second aspect of this application provides a construction assembly system for a multi-column prestressed space tower, comprising: The multi-column prestressed spatial tower structure, prefabricated modules, prestressing tensioning devices, grouting connection components, flange positioning components, and flexible film covering mechanisms as described above; The prefabricated module is adapted to process circular tubular inner columns, outer columns, and extended concrete foundations. The prestressing tensioning device is adapted to the prestressing cables of the tower structure and completes the tensioning and anchoring; The grouting connection assembly is adapted to the groove of the foundation and the lower ends of the inner and outer columns to complete the grouting connection; The flange positioning component is adapted to the anchor bolt holes of the reinforced concrete ring beam and the flange of the steel tower to achieve coaxial positioning. The flexible film coating mechanism is arranged circumferentially around the outer column and completes the sealing and coating of the flexible film.

[0014] Compared with the prior art, the present invention has the following beneficial effects: By splitting the single large-diameter structure into inner and outer columns, the shortcomings of traditional towers with large bottom diameters and difficult transportation and construction are solved, while small-diameter tubular support columns meet the requirements for road transportation. By arranging the inner and outer columns with different inclinations and enclosing them with reinforced concrete ring beams to form a shell-like spatial structure, and cooperating with the prestressed cable-stayed foundations and reinforced concrete ring beams installed in the inner columns, the defects of high slenderness ratio, significant second-order effect and insufficient lateral stiffness are solved, reducing the maximum horizontal displacement of the tower by 30-40% and greatly improving the overall stability. By replacing welding with grouting / bolt connections, pre-embedded steel bars at the column tops and integrally casting reinforced concrete ring beams, combined with post-tensioned prestressed cables, more than 80% of fatigue-sensitive welds are eliminated, solving the defects of easy fatigue at joints, numerous high-altitude welds with difficult quality control, and complex truss joints with weak fatigue resistance, achieving on-site welding-free assembly; by constructing steel-concrete hybrid structures with reinforced concrete / steel-concrete composite support columns, the defects of high steel consumption and poor economy are solved, reducing steel consumption by 18-25% compared to traditional towers; by forming a closed enclosure structure with a flexible membrane around the outer columns, the columns and connection joints are protected, improving structural durability and further optimizing the overall mechanical performance of the tower. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This invention provides a schematic diagram of the outer column cross-section of a multi-column prestressed spatial tower structure. Figure 2 A cross-sectional view of the inner column in a multi-column prestressed spatial tower structure provided by the present invention; Figure 3 A top view of a multi-column prestressed spatial tower structure provided by the present invention; In the diagram: 1. Foundation; 2. Outer column; 3. Inner column; 4. Prestressed cable; 5. Transfer section; 6. Steel tower; 7. Anchor bolt. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0018] 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.

[0019] It should be noted that 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.

[0020] The present invention will now be described in further detail with reference to the accompanying drawings: like Figures 1-3 As shown, in a first aspect of the present invention, a multi-column prestressed spatial tower structure is provided, including a foundation 1, which is an extended concrete foundation with prestressing ducts inside. Multiple circular tubular support columns are arranged at equal angles along the circumferential direction on the upper part of the foundation 1. The support columns are arranged in two layers: an inner layer column 3 and an outer layer column 2. The inclination angle of the outer layer column 2 is greater than that of the inner layer column 3, and the cross-sectional dimensions of the inner layer column 3 are greater than those of the outer layer column 2. The lower ends of both the inner layer column 3 and the outer layer column 2 are grouted or bolted to the foundation 1, and the upper ends are pre-embedded with reinforcing bars that extend into a reinforced concrete ring beam and are cast integrally with the reinforced concrete ring beam. Prestressing cables 4 are inserted into the interior of the inner layer column 3, with their lower ends anchored in the prestressing ducts of the foundation 1 and their upper ends extending out of the reinforced concrete ring beam and anchored thereto. Anchor bolt holes are provided on the reinforced concrete ring beam, which are fixedly connected to the steel tower cylinder 6 via flanges. All outer layer columns 2 are wrapped with a flexible membrane to form an enclosure structure.

[0021] In this embodiment, foundation 1 is an extended concrete foundation, which is cast on-site using high-strength commercial concrete with a concrete strength grade of not less than C40, to meet the overall vertical bearing capacity, overturning resistance and sliding resistance requirements of the tower.

[0022] Prestressed ducts are vertically opened inside foundation 1. The position and number of prestressed ducts correspond one-to-one with the inner column 3. The ducts are pre-embedded using corrugated metal pipes. During the pre-embedding process, the ducts are kept straight without bending or blockage. The inner diameter of the duct is larger than the nominal diameter of the prestressed cable 4 to facilitate the installation and anchoring of the prestressed cable 4.

[0023] The upper part of the foundation 1 is the column connection area. The grooves are opened at equal angles along the circumference of this area. The number of grooves is the same as the total number of inner column 3 and outer column 2, and the position of the grooves corresponds precisely to the column layout position.

[0024] The groove has a stepped structure, with the groove opening size matching the cross-sectional size of the lower end of the column. The groove depth is not less than half of the pre-embedded length at the lower end of the column. The inner wall of the groove is roughened to increase the adhesion with the grouting material and ensure the connection strength between the column and the foundation 1.

[0025] After the foundation 1 is poured, it is cured. After curing, the prestressed ducts and grooves are cleaned to remove slag and debris, so as to ensure the smooth progress of subsequent connection construction.

[0026] Furthermore, the support columns are circular tubular structures, arranged in the column connection area above foundation 1, and uniformly distributed along the circumference of foundation 1 at equal angles. They are the main vertical load-bearing components of the tower structure. The support columns are provided in at least two layers, namely inner column 3 and outer column 2, both of which are manufactured using factory prefabrication technology. The materials used are reinforced concrete or steel pipe concrete structures, which meet the limits of highway transportation. The diameter of a single column is ≤4.5m, effectively solving the manufacturing, transportation and construction problems caused by the excessively large bottom diameter of traditional towers.

[0027] The outer column 2 is arranged in the outer circumferential position of the support column. The number is determined according to the diameter, height and load requirements of the tower, and is generally 12 to 24. The inclination angle of the outer column 2 is greater than that of the inner column 3. Together with the foundation 1 and the reinforced concrete ring beam, it forms a spatial bracing structure to provide lateral stiffness for the tower and effectively reduce the second-order effect of the structure.

[0028] Furthermore, the cross-sectional dimensions of the outer column 2 are smaller than those of the inner column 3. It adopts a circular tubular cross-section. If it is a reinforced concrete structure, it is equipped with longitudinal reinforcing bars and spiral stirrups inside, and the reinforcement ratio of the longitudinal reinforcing bars is not less than 0.8%. If it is a steel-concrete composite structure, the steel pipe is made of Q355B low-alloy high-strength structural steel, and the pipe diameter to wall thickness ratio is controlled at 20~40. The inside is filled with C40 micro-expansion concrete to ensure the coordinated work of the steel pipe and the concrete.

[0029] The lower end of the outer column 2 is a pre-embedded connection end with a pre-embedded length of not less than 500mm. It is adapted to be embedded in the corresponding groove of the foundation 1 and fixedly connected to the foundation 1 by grouting or bolts. The upper end is pre-embedded with longitudinal steel bars. The length of the pre-embedded steel bars is not less than the height of the reinforced concrete ring beam. The pre-embedded steel bars are evenly distributed along the circumference of the column, with not less than 8 bars and a diameter of not less than 16mm, so as to facilitate connection with the steel bars of the reinforced concrete ring beam and be cast into a whole.

[0030] The inner layer columns 3 are arranged in the inner circumferential position of the support columns, and their number is matched with that of the outer layer columns 2, generally 6 to 12. They are arranged in an alternating manner with the outer layer columns 2 to improve the uniformity of spatial stress of the structure. The inclination angle of the inner layer columns 3 is smaller than that of the outer layer columns 2, and the cross-sectional size is larger than that of the outer layer columns 2. They are the core components for transmitting the vertical bearing capacity of the tower, and at the same time provide space for the prestressed cables 4 to pass through and be laid.

[0031] The inner column 3 is also a circular tubular structure. If it is a reinforced concrete structure, the concrete strength grade shall not be lower than C40, and the interior shall be equipped with double-layer longitudinal reinforcing bars and spiral stirrups, with a longitudinal reinforcing bar reinforcement ratio of not less than 1.0%. If it is a steel-concrete composite structure, the steel pipe shall be made of Q355B or Q420B low alloy high-strength structural steel, with the pipe diameter to wall thickness ratio controlled at 15~35, and the interior shall be filled with C40~C45 micro-expansion concrete to ensure its load-bearing capacity and deformation performance.

[0032] The lower end of the inner column 3 is a pre-embedded connection end with a pre-embedded length of not less than 600mm. It is embedded in the corresponding groove of the foundation 1 and fixed to the foundation 1 by grouting or bolts. A through hole is opened at the lower end corresponding to the prestressing duct position of the foundation 1 to facilitate the insertion and anchoring of the prestressing cable 4 inside the foundation 1. The interior of the inner column 3 is a hollow structure with a hollow diameter that meets the requirements for the insertion, tensioning and anchoring of the prestressing cable 4. The inner wall of the column is smooth to avoid scratching during the insertion of the prestressing cable 4. The upper end is pre-embedded with longitudinal steel bars. The specifications, quantity and layout of the pre-embedded steel bars are higher than those of the outer column 2. They are evenly distributed along the circumference of the column, with no less than 12 bars, a diameter of not less than 20mm, and a pre-embedded length of not less than 1.2 times the height of the reinforced concrete ring beam to ensure a reliable connection with the reinforced concrete ring beam.

[0033] The spacing between the inner column 3 and the outer column 2 is uniform along the circumference, and the net distance between the columns is not less than 500mm, which facilitates construction operations and subsequent flexible membrane covering. The inclination angle of the inner and outer columns is determined by mechanical calculation based on the tower height, load and lateral resistance requirements. The inclination angle of the outer column 2 is generally 10°~30°, and the inclination angle of the inner column 3 is generally 5°~15°. The two work together to form a stable spatial support system, which, together with the reinforced concrete ring beam, forms a shell-like spatial truss structure, significantly improving the overall stability of the tower and reducing the maximum horizontal displacement of the tower by 30~40% compared with traditional single-tube towers.

[0034] In this embodiment, the prestressed cable 4 is a post-tensioned longitudinal prestressed cable, and can also be used in conjunction with post-tensioned circumferential prestressed cables to form an integral prestressed structure together with the foundation 1, inner column 3 and reinforced concrete ring beam.

[0035] The prestressed cable 4 uses high-strength, low-relaxation steel strands with a nominal diameter of 15.2 mm and a standard tensile strength of not less than 1860 MPa. A single prestressed cable 4 is composed of multiple steel strands, and the specific number of strands is determined by calculation based on the stress requirements of the tower, generally 4 to 8 strands.

[0036] The prestressed cable 4 is inserted into the hollow structure inside the inner column 3. The lower end passes through the prestressing duct of the foundation 1 and is anchored inside the foundation 1. Anchors are used for fixation. The anchors are wedge-type anchors that are compatible with the specifications of the steel strands. During the anchoring process, it is ensured that the anchors are tightly fitted to the concrete of the foundation 1 without loosening or slippage. The upper end of the prestressed cable 4 passes through the prestressing duct on the reinforced concrete ring beam and extends upward through the upper surface of the reinforced concrete ring beam before being tensioned and anchored. The tensioning control stress is determined according to 0.6 to 0.7 times the standard value of the tensile strength of the steel strand. The tensioning process adopts staged tensioning and staged load holding to ensure uniform transmission of prestress, effectively eliminate deformation gaps in the tower structure, and improve the overall stiffness and fatigue resistance of the structure.

[0037] If circumferential prestressed cables are installed inside the reinforced concrete ring beam, they are arranged at equal intervals along the circumference of the ring beam, forming a spatial prestressing system with the longitudinal prestressed cables. This further eliminates fatigue-sensitive welds, making the high-cycle fatigue life of the tower ≥2×10^7 cycles, and significantly improving the fatigue resistance of the nodes and the overall structure.

[0038] In this embodiment, the reinforced concrete ring beam is a cast-in-place reinforced concrete structure, located at the upper end of the inner column 3 and the outer column 2. It is the core conversion component connecting the multi-layer columns and the steel tower 6, and at the same time provides a support platform for the tensioning and anchoring of the prestressed cable 4 and the connection of the steel tower 6.

[0039] The diameter of the reinforced concrete ring beam is determined based on the upper positions of the inner column 3 and the outer column 2. The beam height is 800~1500mm and the beam width is 600~1000mm. It is cast on-site using C40~C45 high-strength commercial concrete. The beam is internally reinforced with circumferential reinforcing bars, longitudinal reinforcing bars, and shear stirrups. The reinforcement ratio of the circumferential reinforcing bars is not less than 1.0%. The longitudinal reinforcing bars are reliably connected to the embedded reinforcing bars of the inner column 3 and the outer column 2 by lap splicing or welding. The lap length is not less than 35d (d is the diameter of the reinforcing bar). Welding is double-sided welding with a weld length of not less than 5d to ensure effective force transmission.

[0040] On the reinforced concrete ring beam, prestressed ducts are opened at the positions corresponding to the inner column 3. The prestressed ducts are opened at the center of the ring beam and are coaxial with the internal hollow structure of the inner column 3 and the prestressed ducts of the foundation 1. The ducts are pre-embedded with metal corrugated pipes, and the inner diameter is 20-30mm larger than the nominal diameter of the prestressed cable 4 to ensure the straight installation of the prestressed cable 4. Anchor bolt holes are also opened at equal angles along the circumference on the ring beam. The number and position of the anchor bolt holes are adapted to the flange at the lower end of the steel tower 6. The hole diameter is 5-10mm larger than the anchor bolt diameter to facilitate the positioning and connection of the flange. The depth of the anchor bolt hole is not less than 1.2 times the pre-embedded length of the anchor bolt to ensure the anchoring strength of the anchor bolt.

[0041] The pre-embedded steel bars at the upper ends of the inner column 3 and the outer column 2 all extend into the interior of the reinforced concrete ring beam and are tied or welded with the internal steel bars of the ring beam to form an integral steel skeleton. The extension direction of the pre-embedded steel bars is adapted to the casting direction of the reinforced concrete ring beam to ensure the integrity and stress rationality of the steel skeleton. After the casting is completed, the column and the ring beam form an integrated structure without welding joints, effectively avoiding the problem of fatigue of traditional tower joints.

[0042] The steel tower tube 6 is the upper vertical component of the tower. It adopts a segmented steel pipe structure prefabricated in the factory. The steel pipe material is Q355B or Q420B low alloy high strength structural steel. The pipe diameter is determined according to the upper load of the tower and the usage requirements. The wall thickness is determined according to the stress calculation, and is generally 10~30mm.

[0043] A flange is welded to the lower end of the steel tower 6. The flange is a ring-shaped steel plate with the same material as the steel tower 6 and a thickness of not less than 40mm. Connection holes are opened at equal angles along the circumference of the flange. The number and position of the connection holes correspond one-to-one with the anchor bolt holes on the reinforced concrete ring beam, and the hole diameter is matched with the anchor bolt diameter.

[0044] The steel tower section 6 is fixedly connected to the reinforced concrete ring beam via flanges. The flanges fit snugly against the upper surface of the ring beam, and are secured using anchor bolts inserted through anchor bolt holes and connection holes. High-strength large hexagonal head bolts with a performance grade of 10.9 are used for anchor bolt tightening. The bolts are tightened using a torque wrench to the specified torque value to ensure a tight and reliable connection between the flange and the ring beam, preventing loosening and effectively transferring the load from the upper part of the tower to the reinforced concrete ring beam and the lower columns. The sections of the steel tower section 6 are connected by flanges, also secured with high-strength bolts, avoiding on-site high-altitude welding and improving construction efficiency and connection reliability.

[0045] In this embodiment, the flexible membrane enclosure structure is deployed around all outer columns 2, consisting of a flexible membrane and fasteners. It serves as the protective structure for the tower and further enhances the overall spatial integrity of the tower. The flexible membrane is made of high-strength, aging-resistant, and UV-resistant synthetic fiber film, such as polyvinyl chloride (PVC) film or polyester fiber film. The film thickness is not less than 0.5 mm, and the tensile strength is not less than 10 MPa. It possesses good toughness and durability, adapting to complex outdoor environmental conditions.

[0046] The flexible membrane is arranged circumferentially around the outer column 2, completely enclosing the space between the inner column 3, the outer column 2, and the columns. The upper and lower ends of the flexible membrane are fixed to the outer side of the reinforced concrete ring beam and the upper outer side of the foundation 1, respectively, using stainless steel clips or expansion bolts to ensure the membrane is firmly fixed and free from detachment or tearing. The flexible membrane enclosure structure can effectively block the erosion of the columns and connection nodes by external environmental factors such as wind, sand, rain, and snow, improving the durability of the structure. At the same time, it can reduce the local effect of wind load on the columns and optimize the wind load stress characteristics of the tower.

[0047] In a second aspect, this invention provides a construction and assembly system for a multi-column prestressed spatial tower, which is adapted to the factory prefabrication and on-site assembly of the aforementioned multi-column prestressed spatial tower structure. This system enables standardized, modular, and prefabricated construction of the tower structure, significantly improving construction efficiency, reducing on-site high-altitude operations, and lowering the difficulty of construction quality control.

[0048] The construction assembly system includes the aforementioned multi-column prestressed spatial tower structure, prefabricated modules, prestressing tensioning devices, grouting connection components, flange positioning components, and flexible film covering mechanisms. Each device / component works together to complete the factory processing, on-site connection, prestressing tensioning, flange positioning, and flexible film covering of the tower components.

[0049] Specifically, the prefabrication module is a dedicated module for factory processing, including steel pipe processing equipment, rebar processing equipment, concrete pouring equipment, molds and testing equipment. It is adapted to process the prefabricated parts of the inner layer column 3, outer layer column 2 and extended concrete foundation 1 of the circular tubular structure, so as to realize the standardized prefabrication of the core load-bearing components of the tower in the factory and ensure the processing accuracy and quality consistency of the components.

[0050] The steel pipe processing equipment includes plate rolling machines, welding machines, straightening machines, etc., used to process the steel pipe parts of the inner layer column 3 and outer layer column 2 of the steel pipe concrete structure. The plate rolling accuracy is controlled within ±1mm. Welding adopts submerged arc automatic welding. The weld quality reaches the first-class weld standard. After straightening, the straightness error of the steel pipe is ≤L / 1000 (L is the length of the steel pipe).

[0051] Steel bar processing equipment includes steel bar cutting machines, bending machines, thread rolling machines, etc., used to process the steel bar skeleton of reinforced concrete columns and reinforced concrete ring beams. The processing dimensional error of the steel bars is ≤ ±5mm.

[0052] Concrete pouring equipment includes a mixing plant, a delivery pump, a vibrator, etc., used for pouring reinforced concrete columns, precast foundations, and on-site poured reinforced concrete ring beams. The concrete mix proportion is determined by testing. Layered vibration is used during the pouring process to ensure that the concrete is dense and free from defects such as honeycomb and pitting.

[0053] The mold is made of steel, which has sufficient strength, rigidity and stability. The dimensional error of the mold is ≤±2mm, ensuring the accuracy of the cross-sectional dimensions of the prefabricated components.

[0054] The testing equipment includes ultrasonic flaw detectors, concrete rebound hammers, and dimensional measuring instruments, used to inspect the weld quality, concrete strength, and dimensional accuracy of precast components. Only components that pass inspection can be shipped from the factory. The inner column 3 and outer column 2, fabricated from precast modules, are either entirely precast or precast in sections. The precast columns in sections are connected by flanges for easy transportation and on-site assembly. All precast components are marked and numbered at the factory, indicating their location and orientation to ensure accurate on-site assembly.

[0055] The prestressing tensioning device is compatible with the prestressed cable 4 of the tower structure and is used to complete the on-site installation, tensioning and anchoring of the prestressed cable 4. It includes jacks, oil pumps, tensioning frames, anchorages, limiting devices and testing instruments. The jacks are through-type hydraulic jacks, and the rated tension force is determined according to the tensioning control stress of the prestressed cable 4, which is generally 2000~5000kN. The oil pump is a high-pressure electric oil pump, which is used in conjunction with the jacks and has a stable oil supply pressure. The tensioning frame is used to fix the jacks and ensure the straightness and stability of the tensioning process.

[0056] The workflow of the prestressing tensioning device is as follows: First, the prestressing cable 4 is threaded through the inner column 3 and the prestressing ducts of the foundation 1 and reinforced concrete ring beam using a cable threading machine. Then, jacks are installed on the ends of the prestressing cables 4 on the upper surface of the reinforced concrete ring beam. Oil is supplied to the jacks through an oil pump to achieve staged tensioning and staged load holding of the prestressing cable 4. During the tensioning process, the tension force and elongation value are controlled simultaneously to ensure the quality of prestressing tensioning. After tensioning, the prestressing cable 4 is anchored to the upper surface of the reinforced concrete ring beam using anchors. A limiting device is installed to prevent the anchors from loosening. Finally, the prestressing ducts are grouted using cement grout with a strength grade of not less than M30. The grouting is full to achieve corrosion protection for the prestressing cable 4.

[0057] The grouting connection assembly is adapted to the groove of foundation 1 and the lower ends of inner column 3 and outer column 2 to complete the grouting connection between the column and foundation 1. It includes high-strength non-shrink grout, grouting pump, grouting pipe, sealing material and testing equipment. The grout is selected as high-strength non-shrink grout of grade C60 or above, which has the characteristics of good fluidity, fast strength development, shrinkage compensation and high bonding strength. The grouting pump is an electric grouting pump with stable pressure, which can realize long-distance and high-pressure delivery of grout. The grouting pipe is a high-pressure rubber pipe with a pressure resistance of not less than 5MPa. The sealing material is water-swellable waterstop strip and sealant, which is used to seal the gap between the lower end of the column and the groove to prevent grout leakage.

[0058] The construction process of the grouting connection assembly is as follows: First, the lower end of the column is embedded into the groove of foundation 1. The verticality and position of the column are adjusted. Then, the gap between the column and the groove is sealed with sealing material. Grouting port and vent are reserved. Then, the mixed grout is pumped into the groove through the grouting pipe from the grouting port until dense grout flows out of the vent. Finally, the grouting port and vent are sealed and cured for no less than 7 days. After the curing is completed, the grouting connection strength is tested to ensure that the connection is reliable.

[0059] The flange positioning component is adapted to the anchor bolt holes of the reinforced concrete ring beam and the flange of the steel tower 6 to achieve coaxial positioning of the steel tower 6 and the reinforced concrete ring beam. It includes positioning pins, a level, a total station, an adjusting bracket, and a fixing clamp. The diameter of the positioning pin is adapted to the diameter of the anchor bolt holes and the flange connection holes, with an accuracy of h6 grade, to achieve precise alignment between the flange and the anchor bolt holes of the ring beam. The level and total station are used to detect the horizontality of the flange and the verticality of the steel tower 6. The horizontality error is controlled within ±0.1mm / m, and the verticality error is controlled within ±0.5%. The adjusting bracket is a height-adjustable steel structure bracket used to support the lower end of the steel tower 6 to achieve adjustment of the height and verticality of the steel tower 6. The fixing clamp is used to temporarily fix the adjusted steel tower 6 to prevent displacement during the positioning process.

[0060] The working process of the flange positioning component is as follows: First, the positioning pin is inserted into the anchor bolt hole of the reinforced concrete ring beam and the connection hole of the flange of the steel tower 6 to achieve the initial coaxial positioning of the flange and the ring beam. Then, the steel tower 6 is hoisted onto the adjustment bracket. The verticality of the steel tower 6 is checked by a total station, and the height of the adjustment bracket is adjusted to ensure that the verticality of the steel tower 6 meets the requirements. Next, the horizontality of the flange is checked by a level and adjusted by shimming with thin steel plates. Finally, the steel tower 6 is temporarily fixed with a fixing clamp. After the positioning is completed, high-strength bolts are inserted and tightened, and the positioning pin and adjustment bracket are removed.

[0061] The flexible film covering mechanism is arranged circumferentially around the outer perimeter of the outer column 2 to complete the closed covering of the flexible film. It includes a film unwinding device, a tensioning device, a fastener installation device, and a cutting device. The film unwinding device is used to unwind the rolled flexible film to achieve continuous film laying. The tensioning device is used to tension the flexible film to keep the film taut and free from wrinkles and slack. The tension stress is controlled at 10-20% of the tensile strength of the film.

[0062] The fastener installation equipment includes electric drills, wrenches, etc., used to install stainless steel clips, expansion bolts and other fasteners on the outside of the foundation 1 and the reinforced concrete ring beam to fix the flexible membrane; the cutting equipment is used to precisely cut the flexible membrane according to the outer dimensions of the outer column 2 to ensure that the membrane's covering size and shape are compatible.

[0063] The construction process of the flexible film covering mechanism is as follows: First, the flexible film is laid out circumferentially around the outer perimeter of the outer column 2 through the unwinding device. The position of the film is adjusted so that the film wraps all the inner column 3 and the outer column 2. Then, the film is tensioned by the tensioning device to make the film taut. Then, the upper and lower ends of the film are fixed to the outer side of the foundation 1 and the reinforced concrete ring beam respectively by the fixing device. Finally, the overlap of the film is sealed by hot melt welding or sealant bonding to ensure the sealing of the enclosure structure.

[0064] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A multi-column prestressed spatial tower structure, characterized in that, include: The foundation is an extended concrete foundation with prestressed ducts inside. Multiple circular tubular support columns are arranged at equal angles along the circumference of the upper part of the foundation. The supporting columns are arranged in two layers, an inner layer and an outer layer. The inclination angle of the outer layer columns is greater than that of the inner layer columns, and the cross-sectional dimensions of the inner layer columns are greater than those of the outer layer columns. The lower ends of the inner and outer columns are connected to the foundation grouting or bolted, and the upper ends are pre-embedded with steel bars, which extend into the reinforced concrete ring beam and are cast together with the reinforced concrete ring beam to form a whole. The prestressed cable is inserted into the interior of the inner column, with its lower end anchored in the prestressed duct of the foundation and its upper end passing through and anchored to the reinforced concrete ring beam. Anchor bolt holes are provided on the reinforced concrete ring beam, which is fixedly connected to the steel tower cylinder through flanges. All outer columns are wrapped with a flexible film to form an enclosure structure.

2. The multi-column prestressed spatial tower structure according to claim 1, characterized in that, The support columns are made of reinforced concrete or steel-concrete composite.

3. The multi-column prestressed spatial tower structure according to claim 1, characterized in that, Grooves are provided at the connection positions of the inner and outer columns on the above basis; The lower ends of the inner and outer columns are respectively embedded in the corresponding grooves and connected to the foundation grouting or bolted connection.

4. The multi-column prestressed spatial tower structure according to claim 1, characterized in that, Prestressing ducts are provided on the reinforced concrete ring beam at the positions where the prestressing cables are inserted. The prestressed cable is inserted through the prestressed duct, and its upper end extends upward through the prestressed duct to the upper surface of the reinforced concrete ring beam.

5. The multi-column prestressed spatial tower structure according to claim 1, characterized in that, The enclosure structure formed by the flexible film encloses both the inner and outer columns within its enclosed space.

6. The multi-column prestressed spatial tower structure according to claim 1, characterized in that, The inner and outer columns are evenly distributed along the circumferential direction of the foundation at equal included angles. Furthermore, the number of inner and outer columns is matched.

7. The multi-column prestressed spatial tower structure according to claim 1, characterized in that, The prestressed cable is a post-tensioned longitudinal prestressed cable, and the prestressed cable, together with the foundation, inner column and reinforced concrete ring beam, forms an integral prestressed structure.

8. The multi-column prestressed spatial tower structure according to claim 4, characterized in that, The prestressed ducts are located at the center of the reinforced concrete ring beam.

9. The multi-column prestressed spatial tower structure according to claim 1, characterized in that, The embedded steel bars of the inner column are evenly distributed along the circumference of the inner column body, and the embedded steel bars of the outer column are evenly distributed along the circumference of the outer column body, and the extension direction of each embedded steel bar is adapted to the casting direction of the reinforced concrete ring beam. The inner and outer columns, together with the reinforced concrete ring beam, form a shell-like space truss structure.

10. A construction and assembly system for a multi-column prestressed spatial tower, characterized in that, include: The multi-column prestressed spatial tower structure, prefabricated module, prestressing tensioning device, grouting connection assembly, flange positioning component, and flexible film covering mechanism as described in any one of claims 1-9; The prefabricated module is adapted to process circular tubular inner columns, outer columns, and extended concrete foundations. The prestressing tensioning device is adapted to the prestressing cables of the tower structure and completes the tensioning and anchoring; The grouting connection assembly is adapted to the groove of the foundation and the lower ends of the inner and outer columns to complete the grouting connection; The flange positioning component is adapted to the anchor bolt holes of the reinforced concrete ring beam and the flange of the steel tower to achieve coaxial positioning. The flexible film coating mechanism is arranged circumferentially around the outer column and completes the sealing and coating of the flexible film.

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