Construction linear and anti-overturning control construction method of a type cable tower

Abstract

This invention discloses a construction method for controlling the construction alignment and overturning resistance of a type A cable tower, comprising the following steps: preliminary preparation; design, verification, and evaluation of the cable tower's anti-overturning combined control system, which includes a cable tower hollow column construction alignment combined control system formed by connecting the tower column stiffening frame system and the anti-overturning system, a multi-level horizontal active cross bracing system, and a prestressed concrete upper crossbeam system. This system resists the overturning force generated by the upward suspended construction of the hollow tower column through the cable tower hollow column construction alignment combined control system. Combined with the synergistic effect of the horizontal active cross bracing system and the prestressed concrete upper crossbeam system, it jointly offsets the inward tilting force generated by the self-weight and construction load of the two limb tower columns during construction, thereby balancing the tower column overturning moment and ensuring that the cable tower alignment, inward tilting force, and tilt angle meet design requirements. The method also includes the following steps: dynamic control analysis of the spatial position of the cable tower column construction segments; construction and dismantling of the cable tower anti-overturning combined control system.

Description

Technical Field

[0001] This invention relates to the field of bridge construction technology, and in particular, to a construction method for controlling the construction alignment and anti-overturning properties of A-type cable towers. Background Technology

[0002] An A-shaped pylon is a tower-shaped structure used in cable-stayed or suspension bridges. Its structure resembles the letter "A" and is primarily used to support the main cables and transfer loads. An A-shaped pylon typically consists of two inclined columns connected by a crossbeam, forming a stable triangular structure. Taking the construction of the No. 7 pier pylon of an A-shaped single-tower cable-stayed bridge in the Guangdong Delta Plain as an example, its pylon is an A-shaped reinforced concrete structure with a total height of 124.7m. The pylon columns include solid and hollow columns. The hollow columns consist of a cavity and walls; the cavity is hollow, and the walls are the shell enclosing the cavity. Among them: the elevation +2.5m (top of the foundation) to +5.5m is a truncated cone-shaped tower base; the elevation +5.5m to +14.526m is a solid tower column with corbels and transverse bridges arranged inwards; the elevation +14.526m to +72.184m is a hollow tower column with a single-box, single-cell cross-section in the shape of a D-shaped box with three circular arc protrusions arranged inwards, with the standard section tower cavity dimensions of the central tower column being 4.81m in the longitudinal direction and 3m in the transverse direction. The tower is 70m long and 41.50m high, with an inclination angle of 81.3° on both the inner and outer sides of the tower cavity. The elevation range of +72.184m to +92.184m consists of the closure section of the two-legged tower columns arranged inwards in the transverse direction, the central diaphragm, and the prestressed concrete upper crossbeam. The standard section of the tower cavity of the middle and upper tower columns has the following dimensions: 4.81m in the longitudinal direction, 3.70m in the transverse direction, and 13.20m in height, with an inclination angle of 81.3° on both the inner and outer sides of the tower cavity. The elevations from +92.184m to +120.200m consist of hollow tower columns with a single-cell, single-box cross-section in a D-shape, with three circular arc protrusions, arranged inwards towards the transverse bridge. The standard section dimensions of the upper tower column's cavity are: 4.81m longitudinally, 3.70m transversely, and 19.50m in height. The inclination angles of both the inner and outer sides of the cavity are 81.3°. The elevations from +120.200m to +127.200m constitute the tower crown. The axes of both pylon columns in the transverse direction of the bridge are inclined inwards, with the inclination angle of both pylon columns to the horizontal plane being 81.3°.

[0003] Due to the inward tilt and high height of the pylon, under the combined effects of the pylon's self-weight, temperature, wind load, cable tension, vehicle load, and shrinkage and creep, the pylon will experience significant inward displacement (lateral bridge deviation) and inward force. This causes the bare pylon to fail to meet the requirements of the "Highway Engineering Quality Inspection and Evaluation Standard, Volume 1, Civil Engineering" (JTGF80 / 1-2017): pylon axis deviation ≤15mm and relative to the previous segment ≤8mm, pylon verticality ≤H / 3000 and ≤30mm (H is the pylon height in mm), pylon outer contour dimensions ≤±20mm, and pylon crossbeam top elevation ≤±20mm.

[0004] The existing methods for controlling the alignment of cable tower construction mainly employ the internal control method and the active cross bracing system method. (1) Internal control method: After the foundation is completed, plane and elevation control points are established on the foundation through the onshore construction control network. As the tower column rises, the control benchmark is transferred upwards step by step, and corresponding construction control points are established at different construction locations to meet the needs of measurement and layout at different construction stages. This method is easy to ensure measurement accuracy, but the measurement work is cumbersome, the benchmark transfer workload is large, and the measurement work area is small and subject to construction interference. (2) Active cross bracing system: For cable tower columns that are inclined inwards, during construction, a multi-layer active cross bracing system is set up between the two limb tower columns along the height direction. During construction, the alignment of the tower column and the strain of the cable tower are monitored in real time, and the principle of dual control of cable tower strain and alignment is adopted. The cross bracing force is adjusted in real time according to the monitoring data to ensure that the alignment and strain are within the set requirements. This control method has the following technical defects: complex construction, high cost, large interference from construction, and high technical requirements for personnel.

[0005] The existing methods for controlling the overturning resistance of cable tower construction mostly adopt the prestress control method and the temporary support method. (1) Prestress control method: During the construction of the tower column, pre-tightening components and pre-support components are arranged on the upper and lower sides of the tower column section, and these components are prestressed. By applying prestress, the inconsistency of the inner and outer compressive stress generated by the tower column under its own weight, climbing formwork and other temporary loads is offset, thereby effectively controlling the stress distribution. (2) Temporary support method: For cable tower columns that are tilted inward, in order to reduce their horizontal component, in the construction of hollow tower columns, it is necessary to erect a fixed inner formwork support to temporarily support the formwork inside the hollow tower column cavity, and increase the height of the fixed inner formwork support section by section. This not only consumes a large amount of steel pipes, fasteners or cup-lock connectors, but also has technical defects such as high construction technology requirements, high construction cost, high risk of high-altitude operation in hollow tower column construction, low resistance to the overturning of tilted hollow tower columns, and affecting the construction progress.

[0006] Therefore, in the construction of the cable-stayed bridge towers, the tower alignment and overturning resistance control are crucial aspects to ensure the safety of the bridge structure and achieve the designed alignment. Addressing the technical shortcomings of existing methods for controlling tower alignment and overturning resistance, the urgent problem to be solved in the construction of this bridge's cable towers is how to develop a hollow tower cavity anti-overturning support system that features simple support structure design, minimal stress deformation, high support safety and reliability, convenient and efficient high-altitude construction, short construction period, low cost, low risk of high-altitude operations, and strong anti-overturning capacity. Summary of the Invention

[0007] This invention provides a construction method for controlling the construction alignment and anti-overturning properties of Type A cable towers, in order to solve the technical problems of existing technologies, such as the large overturning force generated by the upward-tilting and segmented construction of hollow tower columns, resulting in the inability of the suspended construction alignment and inclination to meet design requirements; and the large inward displacement and inward force of the two limb tower columns due to their own weight and construction loads during construction, which do not meet the design and standard requirements.

[0008] The technical solution adopted in this invention is as follows: A construction method for controlling the construction alignment and overturning resistance of a type A cable tower includes the following steps: preliminary preparation; design, verification, and evaluation of the cable tower's anti-overturning combined control system; the cable tower's anti-overturning combined control system includes a cable tower hollow column construction alignment combined control system formed by connecting the tower column stiffening frame system and the anti-overturning system, a multi-level active horizontal bracing system constructed between the two limb tower columns, and a prestressed concrete upper beam system constructed at the top of the closure section of the two limb tower columns. This system, through the synergistic effect of the anti-overturning system and the tower column stiffening frame system, resists the overturning force generated by the upward tilting and suspended construction of the hollow tower column. Combined with the synergistic effect of the horizontal active horizontal bracing system and the prestressed concrete upper beam system, it jointly offsets the inward tilting force generated by the self-weight and construction load of the two limb tower columns during construction, thereby balancing the tower column overturning moment and ensuring that the cable tower alignment, inward tilting force, and tilt angle meet design requirements; dynamic control analysis of the spatial position of the cable tower column construction segments; construction and dismantling of the cable tower's anti-overturning combined control system.

[0009] Furthermore, the step "Design, Verification and Evaluation of the Cable Tower Anti-Overturning Combined Control System" specifically includes the following steps: design of the cable tower anti-overturning combined control system; design, verification and evaluation of the cable tower hollow column construction alignment combined control system; design, verification and evaluation of the horizontal active cross bracing system; design of the prestressed concrete upper beam system; and evaluation of the cable tower anti-overturning combined control system.

[0010] Furthermore, the step "Design, Verification and Evaluation of the Construction Alignment Combination Control System for Hollow Tower Columns" is used to construct the tower column stiffening frame system and the anti-overturning system, and to verify and evaluate them. The tower column stiffening frame system is a hollow cylindrical structure, including a tower column stiffening frame for pre-embedding within the wall of the next hollow tower column segment to form a steel skeleton, and several tower column reinforcing bars. The anti-overturning system is spaced within the tower column stiffening frame system, including an anti-overturning support body that acts as a central support. The bottom ends of the anti-overturning system, the tower column stiffening frame, and the tower column reinforcing bars are respectively pre-embedded and connected to the tower column concrete of the previous hollow tower column segment. The anti-overturning support body is also connected to the tower column stiffening frame system as a whole through several external fixing rods to jointly resist the overturning force generated by the upward suspended construction of the hollow tower column.

[0011] Furthermore, the step "Design, verification and evaluation of the construction alignment combination control system for the hollow tower column" specifically includes the following steps: design of the anti-overturning system; verification and evaluation of the anti-overturning system; design of the tower column stiffening frame system; and evaluation of the construction alignment combination control system for the hollow tower column.

[0012] Furthermore, the anti-overturning system includes: four load-bearing pins pre-embedded in the concrete of the previous tower segment at the inner end; two detachable load-bearing beams connected between each pair of adjacent load-bearing pins; an anti-overturning support body fixedly supported on the two load-bearing beams; and a multi-layered operating platform fixedly installed within the anti-overturning support body and spaced apart vertically. The step "Anti-overturning System Design" specifically includes the following steps: selection and fabrication of the anti-overturning support body material and structure; design and fabrication of the operating platform; design and fabrication of the load-bearing beams; selection and fabrication of the load-bearing pin material and structure. The step "Anti-overturning System Verification and Evaluation" specifically includes the following steps: calculation of the stress on the tower column concrete in both upward and downward planes; verification of the load-bearing capacity of the anti-overturning support body; verification of the load-bearing capacity of the load-bearing pins; and evaluation of the anti-overturning system.

[0013] Furthermore, each horizontal active cross bracing system includes two sets of active cross bracing systems spaced parallel to each other along the bridge direction, and multiple transverse horizontal connecting rods connecting the two sets of active cross bracing systems. Each set of active cross bracing systems includes: two sets of embedded parts pre-embedded in the concrete of the tower columns of the two limbs, two sets of supports respectively connecting the corresponding side embedded parts, two sets of corbels respectively connecting the corresponding side embedded parts, multiple pad beams, and struts, with the two sets of corbels correspondingly located below the two sets of supports; The pole is set along the transverse direction of the bridge, with its fixed end fixed to the support on the corresponding side and its movable end spaced apart from the support on the corresponding side. Multiple pad beams are vertically supported on the corbels below, and the upper ends of the multiple pad beams extend between the movable end of the strut and the support on the corresponding side. After adding pad blocks, the upper ends of the pad beams are clamped between the movable end of the strut and the support on the corresponding side. Multiple transverse horizontal connecting rods are set at intervals along the transverse direction of the bridge, and two struts are fixedly connected to the two ends of each transverse horizontal connecting rod.

[0014] Furthermore, the embedded parts include anchoring steel plates tightly attached to the outer wall of the tower column, and multiple sets of anchoring bars dispersedly arranged to anchor the anchoring steel plates to the outer wall of the tower column. Each set of anchoring bars includes: anchoring steel bars embedded in the tower column concrete after passing through the anchoring steel plates, tapered nuts and bolts threaded onto the exposed ends of the anchoring steel bars; the corbel includes a trapezoidal corbel with a trapezoidal cross-section, and a support fixed to the top of the trapezoidal corbel; the support located at the movable end of the strut includes a hollow top support, an end capping steel plate, and longitudinal and transverse stiffeners. The top support plate is fixed at one end to the corresponding side anchoring steel plate, and the other end of the top support plate protrudes outward toward the center side of the tower column and is closed by the end sealing steel plate. The longitudinal and transverse stiffening plates are fixed inside the top support plate and are fixedly connected to the end sealing steel plate and the anchoring steel plate at both ends respectively. The support located at the fixed end of the strut includes a hollow support support, one end of which is fixed to the corresponding side anchoring steel plate, and the other end of which protrudes outward toward the center side of the tower column. The cable tower anti-overturning combined control system also includes a cross strut operating platform and a construction operating platform and passage.

[0015] Furthermore, the step "Design, verification and evaluation of the horizontal active cross bracing system" specifically includes the following steps: design of the horizontal active cross bracing system; selection and fabrication of materials and structures for the horizontal active cross bracing system; verification and evaluation of the horizontal active cross bracing system; the step "Design of the prestressed concrete upper beam system" specifically includes the following steps: design of the prestressed concrete upper beam system; materials and structures.

[0016] Furthermore, the step "Dynamic Control Analysis of Spatial Position of Tower Construction Segments" specifically includes the following steps: establishing a three-dimensional model of the A-shaped tower construction stage; dynamic control analysis of the spatial position of tower construction segments.

[0017] Furthermore, the step "Construction of the Cable Tower Anti-Overturning Combined Control System" specifically includes the following steps: segmented construction of the cable tower column; including: tower column construction measurement and control methods, segmented installation of the tower column stiffening frame, segmented installation of the tower column reinforcement, segmented installation of the tower column formwork, and segmented pouring of the tower column concrete; installation and dismantling of the anti-overturning system; including: installation and dismantling of the anti-overturning system; construction of the horizontal active cross bracing system; and construction of the prestressed concrete upper beam system.

[0018] The present invention has the following beneficial effects: The construction method of this invention includes: (1) setting up an anti-overturning system inside the hollow tower column cavity of the cable tower, with the support body of the anti-overturning system as the central support body, forming a radial reaction force under the constraint of the anti-overturning system, acting on the climbing form support body, tower column stiffening frame, tower column reinforcement, tower column concrete and tower column formwork to generate support force, resisting the overturning force generated by the upward suspended construction of the hollow tower column, and also enhancing the radial stiffness and stability of the tower column stiffening frame, tower column reinforcement and tower column formwork through the anti-overturning system, preventing the transverse deviation of the hollow tower column in segmented construction, reducing the space occupied by the fixed inner formwork support, shortening the time for the support to be erected in the tower column cavity, improving the ability to resist the overturning of the hollow tower column, reducing the risk of high-altitude operation in segmented construction of the hollow tower column, thereby solving the problem of overturning force control in segmented construction of the hollow tower column, ensuring the construction safety of the hollow tower column and the long-term performance of the cable tower structure; (2) through the anti-overturning system and the tower column stiffening frame... The construction line combination control system of the hollow tower column of the cable tower constructed by the skeleton system resists the overturning force generated by the upward suspended construction of the hollow tower column, and ensures that the construction line and inclination of the hollow tower column meet the design requirements; (3) On the basis of the construction line combination control system of the hollow tower column of the cable tower, under the synergistic effect of the horizontal active cross bracing system and the prestressed concrete upper cross beam system, the inclination force generated by the self-weight and construction load of the two limb tower columns of the cable tower during the construction process is jointly offset, the overturning moment of the tower column is balanced, and the line, inclination force and inclination of the cable tower meet the design requirements; (4) By using the dynamic control and analysis system of the spatial position of the construction segment of the cable tower column, millimeter-level precision control is achieved, ensuring that the line of the cable tower column is smooth and the shape is beautiful, while shortening the construction cycle of the cable tower column, improving the efficiency, reducing on-site operation risks and environmental interference, and reducing the later maintenance cost and extending the service life of the bridge through precise control.

[0019] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0020] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a flowchart of the construction method for controlling the construction alignment and overturning resistance of a type A cable tower, a preferred embodiment of the present invention. Figure 2 This is a schematic diagram of the A-shaped cable tower column structure; Figure 3 yes Figure 2 Section I-I; Figure 4 It is an elevation view of the installation of the anti-overturning support body inside the tower column cavity and its connection with the tower column rigid frame and tower column steel bars; Figure 5 yes Figure 4 Section I-I; Figure 6 This is a schematic diagram of the tower column's stiffening frame; Figure 7 This is a schematic diagram of the anti-overturning support structure; Figure 8 This is a schematic diagram of the construction operation platform and passageway structure; Figure 9 This is a diagram of the cross-bracing operating platform; Figure 10 This is a schematic diagram of the horizontal active cross bracing system. Figure 11 This is a schematic diagram of the embedded parts, supports, steel brackets and pedestals; Figure 12 It is an analysis and calculation model for the construction stage of the cable tower column; Figure 13 It is a 3D model of the A-shaped cable tower column during the construction phase.

[0021] Legend: 1. Foundation; 2. Tower base; 3. Tower column; 301. Solid tower column; 302. Hollow tower column; 303. Tower column reinforcement; 304. Tower column concrete; 4. Anti-overturning system; 401. Load-bearing pin; 402. Load-bearing crossbeam; 403. Operating platform; 4031. Bottom operating platform; 4032. Top operating platform; 404. Anti-overturning support body; 4041. Steel pipe column; 4042. Height adjustment plate; 4043. Pad; 4044. Horizontal connecting rod; 4045. Diagonal support rod; 4046. Bolts and nuts; 40461. Bolt hole; 4047. Lifting hole; 5. Tower column rigid frame; 501. Vertical uprights; 502. Circumferential connecting rods; 503. Inner connecting fixing rods; 504. Outer connecting fixing rods; 6. Horizontal active bracing system; 601. Embedded parts; 6011. Anchoring steel bars; 6012. Tapered nuts; 6013. Bolts; 6014. Anchoring steel plates; 602, Support; 6021, Top support; 6022, Supporting support; 6023, End plate; 6024, Longitudinal and transverse stiffening plates; 603. Bracket; 6031. Trapezoidal Bracket; 6032. Support; 604. Pad beam; 605. Support rod; 606. Transverse tie rod; 607. Horizontal strut operating platform; 6071. Rectangular column guardrail frame; 60711. Upright; 60712. Horizontal connecting rod; 60713. Horizontal support rod; 6072. Cantilever support frame; 60721. Cantilever member; 608. Construction operation platform and access; 6081. Load-bearing tripod; 6082. Climbing cone; 6083. Distribution beam; 6084. Anti-slip steel plate; 6085. Guardrail; 7. Upper crossbeam. Detailed Implementation

[0022] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below. 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. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0023] Those skilled in the art will understand that, unless specifically stated otherwise, the term "comprising" as used in this specification means the presence of the stated features, integers, steps, operations, components, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, components, and / or combinations thereof. It should be understood that when we say a component is "connected" to another component, it can be directly connected to the other component or connected via an intermediate component. The term "and / or" as used herein includes all or any unit and all combinations of one or more associated listed items. The terms "first" and "second," etc., in this specification and claims are used to distinguish different objects, not to describe a particular order.

[0024] This application takes the construction of the No. 7 pier tower column of an A-shaped single-tower cable-stayed bridge in the Guangdong Delta Plain as an example to explain in detail the construction alignment and anti-overturning control construction methods of the A-shaped tower.

[0025] Reference Figure 1 A preferred embodiment of the present invention provides a construction method for controlling the construction alignment and overturning resistance of a type A cable tower, comprising the following steps: S1: Preliminary preparations; S2: Design, verification and evaluation of the anti-overturning combined control system for the cable tower; The anti-overturning combined control system for the cable tower includes a construction alignment control system for the hollow tower column formed by connecting the tower column stiffening frame system and the anti-overturning system 4, a multi-level active horizontal bracing system 6 for constructing between the two limb tower columns 3, and a prestressed concrete upper beam system for constructing at the top of the closure section of the two limb tower columns 3. The anti-overturning system 4 and the tower column stiffening frame system work together to resist the overturning force generated by the upward tilting and suspended construction of the hollow tower column 302. Combined with the synergistic effect of the active horizontal bracing system 6 and the prestressed concrete upper beam system, the system can jointly offset the inward tilting force generated by the self-weight and construction load of the two limb tower columns 3 during construction, so as to balance the overturning moment of the tower column 3 and ensure that the cable tower alignment, inward tilting force and tilt angle meet the design requirements. S3: Dynamic control analysis of spatial position of the three construction segments of the pylon column; S4: Construction and dismantling of the cable tower anti-overturning combined control system.

[0026] The construction method of this invention includes: (1) setting an anti-overturning system 4 inside the hollow tower column cavity of the cable tower, with the support body of the anti-overturning system 4 as the central support body, forming a radial reaction force under the constraint of the anti-overturning system 4, which acts on the climbing form support body, tower column stiffening frame, tower column reinforcement, tower column concrete and tower column formwork to generate support force, resisting the overturning force generated by the upward suspended construction of the hollow tower column 302, and through the anti-overturning system 4, the radial stiffness and stability of the tower column stiffening frame, tower column reinforcement and tower column formwork can also be enhanced, preventing the lateral deviation of the hollow tower column in the segmented construction, reducing the space occupied by the fixed inner formwork support, shortening the time of the support erection in the tower column cavity, improving the ability to resist the overturning of the hollow tower column, reducing the risk of high-altitude operation in the segmented construction of the hollow tower column, thereby solving the problem of overturning force control in the segmented construction of the hollow tower column, ensuring the construction safety of the hollow tower column and the long-term performance of the cable tower structure; (2) through the anti-overturning system 4 and the tower column stiffening frame, the radial stiffness and stability of the tower column stiffening frame, tower column reinforcement and tower column formwork can be enhanced, preventing the lateral deviation of the hollow tower column in the segmented construction, reducing the space occupied by the fixed inner formwork support, shortening the time of the support erection in the tower column cavity, improving the ability to resist the overturning of the hollow tower column, reducing the risk of high-altitude operation in the segmented construction of the hollow tower column, thereby solving the problem of overturning force control in the segmented construction of the hollow tower column, ensuring the construction safety of the hollow tower column of the cable tower and the long-term performance of the cable tower structure; The construction line combination control system of the hollow tower column of the cable tower is constructed by the skeleton system to resist the overturning force generated by the upward suspended construction of the hollow tower column 302, and ensure that the construction line and inclination of the hollow tower column meet the design requirements; (3) On the basis of the construction line combination control system of the hollow tower column of the cable tower, under the synergistic effect of the horizontal active cross bracing system 6 and the prestressed concrete upper cross beam system, the internal inclination force generated by the self-weight and construction load of the two limb tower columns 3 of the cable tower during the construction process is offset, the overturning moment of the tower column is balanced, and the line, internal inclination force and inclination of the cable tower meet the design requirements; (4) By using the dynamic control and analysis system of the spatial position of the construction segment of the cable tower column, millimeter-level precision control is achieved, ensuring that the line of the cable tower column is smooth and the shape is beautiful, while shortening the construction cycle of the cable tower column, improving the efficiency, reducing the risk of on-site operation and environmental interference, and reducing the later maintenance cost and extending the service life of the bridge through precise control.

[0027] Optionally, step "S1: Preliminary Preparation" specifically includes: 1. Preliminary construction preparation: According to the construction drawings of the No. 7 pier abutment and tower column of the cable-stayed bridge, tower column steel bars 303 and tower column stiffening frame 5 were pre-embedded in the abutment 1 to ensure that the installation position deviation of the tower column axis, tower column steel bars 303 and tower column stiffening frame 5 at the abutment 1 is less than 10mm, and the abutment concrete and tower base concrete were poured.

[0028] 2. Based on the overturning moment of each segment of tower column 3 and the internal dimensions of the tower cavity of tower column 3, determine the specifications and dimensions of the anti-overturning support body 404 component.

[0029] 3. Construction Site Preparation: At the construction site of the No. 7 pier tower column 3 of the cable-stayed bridge, prepare the following: Ф1000×12mm steel pipe, Ф426×6mm steel pipe, φ219×10mm steel pipe, 12mm, 14mm, and 20mm thick steel plates, Φ25mm anchoring steel bars, 40Cr tapered nuts, M30 bolts, M30×D15 climbing cones, Φ60mm conical steel bars, [14a, [45a] I-beams, [10b, [16b, [25b] channel steel, M24 bolts and nuts 4046, 3mm thick patterned anti-slip steel plates 6084, C50 high-performance concrete, YM15-19 anchorages, 19Φs15.20 steel strands, 100mm inner diameter high-density polyethylene (HDPE) corrugated pipes, and grout for prestressed pipe grouting.

[0030] Optionally, step "S2: Design, Verification and Evaluation of the Overturning Resistance Combined Control System" specifically includes the following steps: S201: Design of the anti-overturning combined control system for the cable tower; specifically including: the anti-overturning combined control system for the cable tower, comprising the construction alignment control system for the hollow tower column, the horizontal active cross bracing system 6 between the two limb tower columns 3, and the prestressed concrete upper crossbeam system at the top of the closure section of the two limb tower columns 3. Based on the construction alignment control system for the hollow tower column, which resists the overturning force generated by the upward suspended construction of the hollow tower column 302, the combined system, along with the horizontal active cross bracing system 6 and the prestressed concrete upper crossbeam system, jointly offsets the inward tilting force generated by the self-weight and construction load of the two limb tower columns 3 during construction, balances the overturning moment of the tower column, and ensures that the cable tower alignment, inward tilting force, and tilt angle meet the design requirements.

[0031] Design principles of Sota's anti-overturning combined control system: (1) An anti-overturning system 4 is installed inside the hollow tower column 302 of the cable tower. With the anti-overturning support body 404 as the central support, a radial reaction force is formed under the constraint of the anti-overturning system 4. This reaction force acts on the climbing formwork support body, the tower column stiffening frame 5, the tower column steel reinforcement 303, the tower column concrete 304, and the tower column formwork to generate a supporting force, resisting the overturning force generated by the upward suspended construction of the hollow tower column 302. The anti-overturning system 4 can enhance the radial stiffness and stability of the tower column stiffening frame 5, the tower column steel reinforcement 303, and the tower column formwork, prevent the lateral deviation of the hollow tower column 302 during segmented construction, reduce the space occupied by the fixed internal formwork support, shorten the time for erecting the support inside the tower column 302, improve the ability to resist the overturning of the hollow tower column 302, reduce the risk of high-altitude operations during segmented construction of the hollow tower column 302, thereby solving the problem of overturning force control during segmented construction of the hollow tower column 302, and ensuring the construction safety of the hollow tower column 302 and the long-term performance of the cable tower structure.

[0032] (2) A three-layer horizontal active cross bracing system 6 is set up between the two limb tower columns 3 along the height direction. The active cross bracing applies prestress to the inward tilting two limb tower columns 3, actively offsetting the tensile stress generated by the self-weight and construction load during the construction of the tilting two limb tower columns 3, balancing the overturning moment, preventing the concrete at the root of the tilting two limb tower columns 3 from cracking, and ensuring the structural stability of the cable tower during the construction stage. The active cross bracing provides temporary support for the construction of the tilting two limb tower columns 3, changing the passive support to the active support, reducing the additional stress in the cantilever state of the two limb tower columns 3, and ensuring the safety of the cable tower construction.

[0033] (3) A prestressed concrete upper crossbeam system is set at the top of the closure section of the two-limb tower column 3. The upper crossbeam 7 connects the two-limb inner inclined tower columns 3 to form a stable spatial structure system, preventing the bridge deck from shifting, tilting or collapsing under load. By applying compressive stress to the upper crossbeam 7 in advance, the crack resistance and stiffness of the component are improved, while the cross-sectional size and self-weight are reduced. After the upper crossbeam 7 is combined with the two-limb inner inclined tower columns 3, the torsional deformation of the inner inclined tower columns 3 during the construction and use stages can be suppressed.

[0034] S202: Design, verification and evaluation of the construction alignment combination control system for hollow tower columns; S203: Design, verification and evaluation of horizontal active cross bracing system; S204: Design of prestressed concrete upper beam system; S205: Evaluation of Sota's anti-overturning combined control system.

[0035] In this optional scheme, step "S202: Design, Verification and Evaluation of the Construction Alignment Combination Control System for Hollow Tower Columns" is used to construct the tower column stiffening frame system and the anti-overturning system 4, and to verify and evaluate them. The tower column stiffening frame system is a hollow cylindrical structure, including a tower column stiffening frame 5 for pre-embedding within the wall of the next segment of the hollow tower column 302 to form a steel frame, and several tower column reinforcing bars 303. The anti-overturning system 4 is spaced within the tower column stiffening frame system, and includes an anti-overturning support body 404 that acts as a central support. The bottom ends of the anti-overturning system 4, the tower column stiffening frame 5, and the tower column reinforcing bars 303 are respectively pre-embedded and connected to the tower column concrete 304 of the previous segment of the hollow tower column 302. The anti-overturning support body 404 is also connected to the tower column stiffening frame system as a whole through several external fixing rods 504, working together to resist the overturning force generated by the upward suspended construction of the hollow tower column 302.

[0036] In the design, the tower column 3 includes: a solid tower column 301 and a hollow tower column 302. The hollow tower column 302 is composed of a tower cavity and a tower wall. The tower cavity is a hollow structure and the tower wall is a shell that surrounds the tower cavity. The construction alignment control system for the hollow tower column of the cable tower uses internal fixing rods 503 to connect the tower column stiffening frame 5 and the tower column reinforcing bars 303 to form a steel frame. External fixing rods 504 connect and fix the tower column stiffening frame 5, the tower column reinforcing bars 303 and the anti-overturning support body 404. Then, with the anti-overturning support body 404, which has small stress deformation and high safety and reliability, as the central support, a radial reaction force is generated under the constraint of the anti-overturning system 4. This reaction force acts on the climbing formwork support body, the tower column stiffening frame 5, the tower column reinforcing bars 303, the tower column concrete 304 and the tower column formwork to generate support force, resisting the overturning force generated by the upward tilting and suspended construction of the hollow tower column 302. This constitutes the construction alignment control system for the hollow tower column of the cable tower, ensuring that the suspended construction alignment and tilt of the hollow tower column 302 meet the design requirements. At the same time, it reduces the amount of tower column stiffening frame 5 used and reduces the construction cost of the tower column 3.

[0037] Design principles of the construction alignment control system for hollow tower columns: (1) An anti-overturning system 4 is installed inside the hollow tower column 302 of the cable tower. With the anti-overturning support body 404 as the central support, a radial reaction force is formed under the constraint of the anti-overturning system 4. This reaction force acts on the climbing formwork support body, the tower column stiffening frame 5, the tower column steel reinforcement 303, the tower column concrete 304, and the tower column formwork to generate a supporting force, resisting the overturning force generated by the upward suspended construction of the hollow tower column 302. The anti-overturning system 4 can enhance the radial stiffness and stability of the tower column stiffening frame 5, the tower column steel reinforcement 303, and the tower column formwork, prevent the lateral deviation of the hollow tower column 302 during segmented construction, reduce the space occupied by the fixed internal formwork support, shorten the time for erecting the support inside the tower column 302, improve the ability to resist the overturning of the hollow tower column 302, reduce the risk of high-altitude operations during segmented construction of the hollow tower column 302, thereby solving the problem of overturning force control during segmented construction of the hollow tower column 302, and ensuring the construction safety of the hollow tower column 302 and the long-term performance of the cable tower structure.

[0038] (2) By utilizing the positioning benchmark of the tower column stiffening frame 5, the construction accuracy of surveying and setting out, formwork erection, rebar binding and cable guide pipes of the cable stay is improved; during the closure construction of the tower column 3, the tower column stiffening frame 5 can temporarily constrain the elevation change and displacement of the cantilever ends of the two limb tower columns 3 in the closure section, ensuring the closure accuracy of the two limb tower columns 3; an internal connecting rod 503 is set between the tower column stiffening frame 5 and the tower column rebar 303 to reduce the stress and deformation of the tower column 3, enhance the overall structural stability of the tower column 3, and prevent the tower column 3 from tilting or collapsing; the internal connecting rod 503 is used to connect the tower column stiffening frame 5 and the tower column rebar 303 to form a steel frame that provides high load-bearing capacity, and the concrete shell enhances stability, making the seismic performance of the tower column 3 better than that of ordinary reinforced concrete; after the tower column stiffening frame 5 is installed, it can be used as a safety fixing belt for construction personnel to improve the construction safety of the tower column 3.

[0039] (3) Through the synergistic effect of the above-mentioned anti-overturning system 4 and the tower column stiffening frame system, they jointly resist the overturning force generated by the upward suspended construction of the hollow tower column 302, ensuring that the suspended construction line and inclination of the hollow tower column 302 meet the design requirements.

[0040] In this optional scheme, step "S202: Design, Verification and Evaluation of Construction Alignment Combination Control System for Hollow Tower Columns" specifically includes the following steps: S2021: Design of Anti-Overturning System 4; Specifically, the anti-overturning system 4 consists of load-bearing pins 401, load-bearing beams 402, anti-overturning support bodies 404, and operating platforms 403. To resist the overturning moment of the hollow tower column 302, an anti-overturning system 4 is installed inside the tower cavity of the hollow tower column 302. The load-bearing pins 401 are pre-embedded in the concrete 304 of the tower column; the two ends of the load-bearing beams 402 are suspended from the load-bearing pins 401; the anti-overturning support bodies 404 are bolted to the top surface of the load-bearing beams 402; and the operating platforms 403 are welded to the bottom and top of the anti-overturning support bodies 404, forming an anti-overturning system 4 with a simply supported structure, consisting of a pre-embedded system and a truss system. This system provides a strong supporting foundation for various loads during the construction of the hollow tower column 302 and a convenient platform foundation for construction operations. The force transmission path of the anti-overturning system 4: The vertical and horizontal loads borne by the anti-overturning support 404 are transferred to the tower column concrete 304 through the anti-overturning support 404 → load-bearing beam 402 → simply supported point between load-bearing beam 402 and load-bearing pin 401 → load-bearing pin 401. By utilizing the simply supported structure between load-bearing beam 402 and load-bearing pin 401, the various construction loads borne by the anti-overturning support 404 are distributed and transferred.

[0041] In the anti-overturning support body 404, the steel pipe column 4041, height adjustment plate 4042, and pad plate 4043 are fixed by double-sided full welding; the transverse connecting rod 4044, the diagonal support rod 4045, and the height adjustment plate 4042 are connected by M24 bolts and nuts 4046. The load-bearing crossbeam 402 and the bottom operating platform 403 are fixed by spot welding to form a whole. The anti-overturning support body 404 and the top operating platform 403 are also fixed by spot welding to form a whole, which facilitates overall hoisting and dismantling. This not only reduces the assembly workload when the anti-overturning system 4 is reused, but also saves the assembly and installation time of the anti-overturning support body 404, thereby shortening the overall construction period of the tower column 3.

[0042] S2022: Overturning Resistance System 4: Verification and Evaluation; S2023: Design of the tower column stiffening frame system; S2024: Evaluation of the construction alignment combination control system for hollow tower columns.

[0043] In this optional scheme, step "S2021: Design of Anti-Overturning System 4" specifically includes the following steps: S20211: Selection of 404 stainless steel material, structure, and fabrication for anti-overturning support structures; details are as follows: 1. Component materials and construction (1) Steel pipe column 4041: Four steel pipes of Q235 material, 4000mm in length, and φ219×10mm are used. One end of the steel pipe is cut and processed into a "wedge" beveled end face with an angle of 8.7° with its flat end face, and the other end is a flat end face.

[0044] (2) Height Adjustment Plate 4042: It consists of 8 steel plates made of Q235 material, 4000mm in length, 200mm in width, and 14mm in thickness. φ25mm bolt holes 40461 are drilled through the plate at 60mm intervals along its length, at the midpoint of the width side of any one of the steel plates. Bolt holes 40461 are drilled through the other 7 steel plates in the same manner. By utilizing the 60mm interval between adjacent bolt holes 40461, the lifting or lowering of heavy objects hoisted inside and outside the tower cavity can be adjusted in 60mm increments within a 4000mm height range on the height adjustment plate 4042, solving the problem of precise positioning and attitude adjustment of heavy objects hoisted inside and outside the inclined tower cavity.

[0045] (3) Pad plate 4043. Four square steel plates with a length of 520mm, a width of 520mm and a thickness of 14mm are used.

[0046] (4) Transverse connecting rod 4044: 12 Q235 and [16b channel steels are used. Among them, the transverse connecting rod 4044 on the length side uses 6 [16b channel steels with a length of 2580mm. Both ends of the channel steel are flat end faces. A φ25mm bolt hole 40461 is drilled at the middle of the width side of the waist plate at both ends of any channel steel, 100mm away from the end face. The transverse connecting rod 4044 on the width side uses 6 [16b channel steels with a length of 2280mm. Both ends of the channel steel are cut and processed into "wedge-shaped" beveled end faces with an angle of 8.7° with the flat end face. A φ25mm bolt hole 40461 is drilled at the middle of the width side of the waist plate at both ends of any channel steel, 100mm away from the end face, to facilitate the bolt connection between the transverse connecting rod 4044 and the height adjustment plate 4042.

[0047] (5) Diagonal support rod 4045: 8 Q235, [16b channel steels are used, of which: the length side diagonal support rod 4045 uses 4 [16b channel steels with a length of 3170mm, both ends of which are cut and processed into "wedge-shaped" beveled ends with an angle of 35.0° with their flat end faces. At the midpoint of the width side of the waist plate of any channel steel, 100mm away from the end face, a φ25mm bolt hole 40461 is drilled. The width side diagonal support rod 4045 uses 4 [16b channel steels with a length of 2720mm, both ends of which are cut and processed into "wedge-shaped" beveled ends with an angle of 34.1° with their flat end faces. At the midpoint of the width side of the waist plate of any channel steel, 100mm away from the end face, a φ25mm bolt hole 40461 is drilled to facilitate the bolt connection between the diagonal support rod 4045 and the height adjustment plate 4042.

[0048] (6) Bolts and nuts 4046: M24 high-strength bolts, nuts and washers are used.

[0049] 2. Fabrication of anti-overturning support structure like Figure 4 , Figure 7 As shown, the anti-overturning support 404 consists of 4 steel pipe columns 4041, 8 height adjustment plates 4042, 12 transverse connecting rods 4044, 8 diagonal support rods 4045, and 4 pads 4043, forming an inclined rectangular column frame with a length of 2800mm, a width of 2500mm, and a height of 4000mm, thus forming a truss system. Both length sides of the anti-overturning support 404 (inward and outward sides of the transverse bridge) are inclined towards the same side (inward side of the transverse bridge), forming an angle of 81.3° with the horizontal plane. This allows the anti-overturning support 404 to function as a modular, tool-type support device within the standard tower cavity height of 41.50m of the central tower column, enabling multiple reuses. Its specific manufacturing process is as follows: (1) Connection of height adjustment plate 4042 to steel pipe column 4041: Based on the perpendicular radial lines of the two end faces of the steel pipe column 4041, mark the welding positions of the two height adjustment plates 4042 along the axial direction of the steel pipe on the outer wall of the steel pipe column 4041. Weld the length side of any one height adjustment plate 4042 to the welding position line marked on the outer wall of the steel pipe column 4041 and weld it tightly against the outer wall of the steel pipe column 4041. Following this method, weld the length side of the other height adjustment plate 4042 to the other welding position line marked on the outer wall of the same steel pipe column 4041. After welding, make the two height adjustment plates 4042 perpendicular to each other on the outer wall of the same steel pipe column 4041, and make the two end faces of the two height adjustment plates 4042 flush with the two end faces of the steel pipe column 4041. Using the same method, complete the welding connection between the remaining 3 steel pipe columns 4041 and the remaining 6 height adjustment plates 4042.

[0050] (2) Processing of the "wedge-shaped" inclined surface: On one end face of the steel pipe column 4041, which has been welded with two height adjustment plates 4042, a "wedge-shaped" inclined end face is cut and processed to form an angle of 8.7° with the flat end face of the steel pipe column 4041. The "wedge-shaped" inclined end face processing of the remaining 3 steel pipe columns 4041 is completed in the same way.

[0051] (3) Connection between steel pipe column 4041 and pad 4043: Weld any plane of pad 4043 to the inclined end face of steel pipe column 4041 with two height adjustment plates 4042. After welding, ensure that pad 4043 completely covers the two height adjustment plates 4042 and steel pipe column 4041, and that the two height adjustment plates 4042 and steel pipe column 4041 are located in the middle of pad 4043, 50mm away from the outer edge of pad 4043. Drill four φ25mm bolt holes 40461 at the four corners of pad 4043 to facilitate quick installation between anti-overturning support body 404 and load-bearing crossbeam 402.

[0052] (4) The horizontal connecting rod 4044 is connected to the steel pipe column 4041: 1) Horizontal connection of the transverse connecting rod 4044 to the steel pipe column 4041 on the length side. Place a 2580mm long transverse connecting rod 4044 horizontally inside the height adjustment plates 4042 on two adjacent steel pipe columns 4041 on the length side, aligning the bolt holes 40461 at both ends of the transverse connecting rod 4044 with the bolt holes 40461 on the height adjustment plates 4042 of the two adjacent steel pipe columns 4041. Use M24 bolts and nuts 4046 to securely connect the transverse connecting rod 4044 to the height adjustment plates 4042. Repeat the same method to complete the transverse connection of the transverse connecting rod 4044 to the bottom, middle, and top of one steel pipe column 4041 on the length side. Repeat the same method to complete the transverse connection of the transverse connecting rod 4044 to the bottom, middle, and top of another steel pipe column 4041 on the length side.

[0053] 2) The transverse connecting rod 4044 on the width side is transversely connected to the steel pipe column 4041. A transverse connecting rod 4044 with a length of 2280mm is placed horizontally inside the height adjustment plate 4042 on the two adjacent steel pipe columns 4041 on the width side, so that the bolt holes 40461 at both ends of the transverse connecting rod 4044 are aligned with the bolt holes 40461 on the height adjustment plate 4042 of the two adjacent steel pipe columns 4041. M24 bolts and nuts 4046 are used to firmly connect the transverse connecting rod 4044 to the height adjustment plate 4042.

[0054] Following the same method, complete the lateral connection of the transverse connecting rods 4044 at the bottom, middle, and top of the steel pipe column 4041 on one side of the anti-overturning support body width to the steel pipe column 4041. Following the same method, complete the lateral connection of the transverse connecting rods 4044 at the bottom, middle, and top of the steel pipe column 4041 on the other side of the anti-overturning support body width to the steel pipe column 4041.

[0055] (5) Connection between the diagonal support rod 4045 and the steel pipe column 4041: 1) The inclined support rod 4045 on the length side is laterally connected to the steel pipe column 4041. Within the range of two adjacent transverse connecting rods 4044 on the length side of the anti-overturning support body 404, one inclined support rod 4045 with a length of 3170mm is installed. It is placed at an angle inside the height adjustment plate 4042 on the two adjacent steel pipe columns 4041 on the length side, so that the bolt holes 40461 at both ends of the inclined support rod 4045 are aligned with the bolt holes 40461 on the height adjustment plate 4042 on the two adjacent steel pipe columns 4041. M24 bolts and nuts 4046 are used to firmly connect the inclined support rod 4045 to the height adjustment plate 4042.

[0056] 2) The diagonal support rod 4045 on the width side is laterally connected to the steel pipe column 4041. Within the range of two adjacent transverse connecting rods 4044 on the width side of the anti-overturning support body 404, one diagonal support rod 4045 with a length of 2720mm is installed. It is placed at an angle inside the height adjustment plate 4042 on the two adjacent steel pipe columns 4041 on the width side, so that the bolt holes 40461 at both ends of the diagonal support rod 4045 are aligned with the bolt holes 40461 on the height adjustment plate 4042 on the two adjacent steel pipe columns 4041. M24 bolts and nuts 4046 are used to firmly connect the diagonal support rod 4045 to the height adjustment plate 4042.

[0057] (6) Lifting holes for anti-overturning support body: Drill a φ40mm lifting hole 4047 at the top of the four steel pipe columns 4041 inside the anti-overturning support body 404, at a position 60mm away from the top surface of the steel pipe column 4041, for lifting the anti-overturning support body 404.

[0058] 3. Quality requirements for 404 stainless steel anti-overturning support body Tighten all nuts on the anti-overturning support body 404. Use a truck crane or tower crane to lift the anti-overturning support body 404, placing the four pads 4043 at the bottom of the anti-overturning support body 404 on the ground, completing the fabrication of the anti-overturning support body 404. After fabrication, ensure that both length sides (outer and inner sides of the transverse bridge) of the anti-overturning support body 404 are inclined to the same side (inner side of the transverse bridge), forming an angle of 81.3° (θ=81.3°) with the horizontal plane. This allows the anti-overturning support body 404 to function as a modular tool-type support device within the standard tower cavity height of 41.50m of the central tower column, enabling it to be reused multiple times.

[0059] S20212: Design and fabrication of operating platform 403; Design of operating platform 403, including: design of bottom operating platform 4031 and top operating platform 4032.

[0060] (1) Underlying operating platform 4031. For example... Figure 4 , Figure 5 As shown, on the top surface of the two installed load-bearing beams 402, except for the installation position of the anti-overturning support body 404, multiple [8 channel steels] are arranged perpendicularly to the load-bearing beams 402 at intervals of 50cm. The channel steels are spot-welded to the load-bearing beams 402 to ensure that the channel steels do not shift forward or backward or left or right. Steel scaffolding boards are fully laid on the top surface of the channel steels to facilitate the installation of the tower column reinforcement 303, the installation and removal of the formwork inside the tower column 3, and the operation of the finishing personnel inside the tower column 3, while preventing the falling of personnel and falling objects inside the tower column 3 cavity. After installation, the outline of the bottom operating platform 4031 is the same as the outline of the tower column 3 cavity, and a 20cm distance is left between the bottom operating platform 4031 and the inner wall of the tower column concrete 304 to facilitate the installation and removal of the formwork inside the tower column 3. The load-bearing beams 402 and the bottom operating platform 4031 are welded and fixed to form a whole to facilitate overall hoisting and dismantling.

[0061] (2) Top-level operating platform 4032. For example... Figure 4 As shown, five [8 channel steels] spaced 50cm apart are installed on the top of the anti-overturning support body 404, perpendicular to the length side (inward and outward sides of the transverse bridge). The [8 channel steels are spot-welded to the transverse connecting rods 4044 to ensure the channel steels do not shift forward, backward, or left, right. A 15mm thick bamboo plywood is laid on the top surface of the channel steels to facilitate the installation of the tower column reinforcement 303 and the installation and removal of the inner formwork of the tower column 3, preventing personnel and falling objects from inside the tower column 3 cavity. The outline of the top-level operating platform 4032 is the same as the inner outline of the tower column 3 cavity, and a 50cm distance is left between the top-level operating platform 4032 and the inner wall of the tower column concrete 304 to facilitate the installation and removal of the inner formwork of the tower column 3. The anti-overturning support body 404 and the top-level operating platform 4032 are welded and fixed to form a whole to facilitate overall hoisting and dismantling.

[0062] S20213: Design and fabrication of load-bearing crossbeam 402; details are as follows: like Figure 4 , Figure 5 As shown, the anti-overturning system 4 of this application consists of two load-bearing crossbeams 402. The length of the load-bearing crossbeam 402 is slightly less than 120mm, depending on its actual length at each installation point in the transverse direction within the tower cavity of the tower column 3; its height is 250mm; and its width is 260mm. The load-bearing crossbeam 402 is made of Q235 material with a spacing of 100mm between double-section [25b channel steels. The double-section channel steels are made of continuous [25b channel steels without weld seams to improve the overall strength of the load-bearing crossbeam 402.

[0063] 1) Weld 260×278mm, 14mm thick end steel plates to both ends of the load-bearing beam 402. Weld 260×250mm, 14mm thick reinforcing steel plates to the top and bottom surfaces of both ends of the load-bearing beam 402, ensuring the outer surfaces of the reinforcing steel plates on the top and bottom surfaces are flush with and perpendicular to the sides of the end steel plates, thus improving the strength of both ends of the load-bearing beam 402. At the middle position of the load-bearing beam 402, weld a reinforcing steel plate every 500mm along the length of the beam to improve the strength of the middle section of the load-bearing beam 402.

[0064] 2) On the top surface of the load-bearing beam 402 at the installation position of the anti-overturning support 404, weld a support connecting steel plate with a length, width, and thickness of 520mm and 14mm respectively, so that the support connecting steel plate extends outward by 50mm and 209mm respectively along the transverse direction of the load-bearing beam 402. The 209mm extension forms a cantilever structure. The four support connecting steel plates cantilever structures are all located between two load-bearing beams 402 to facilitate the installation of the anti-overturning support 404 on the load-bearing beam 402. On each support connecting steel plate, drill four φ25mm bolt holes 40461 according to the positions of the pre-drilled bolt holes 40461 on the bottom pad of the anti-overturning support 404 to facilitate quick installation between the anti-overturning support 404 and the load-bearing beam 402. On the cantilevered side of the load-bearing crossbeam 402 on the bottom surface of the supporting frame connecting steel plate, two triangular support steel plates are welded perpendicularly to the load-bearing crossbeam 402 to enhance the lateral connection between the cantilevered supporting frame connecting steel plate and the load-bearing crossbeam 402, thereby enhancing the overall stability after the anti-overturning support 404 is bolted to the load-bearing crossbeam 402. The two triangular support steel plates on the same side are arranged parallel to each other between two adjacent bolt holes 40461 on the supporting frame connecting steel plate. The anti-overturning support 404 and the load-bearing crossbeam 402 are connected using M24 bolts and nuts 4046.

[0065] 3) On the steel plates at both ends of the load-bearing beam 402, within a range of 171mm from the bottom surface, cut a "U-shaped" groove with an arc diameter of 64mm and a rectangular width of 64mm. After cutting, make the "U-shaped" groove face the bottom surface of the load-bearing beam 402. At the center of the width side of the reinforcing steel plate on both ends of the load-bearing beam 402, within a range of 200mm from the end face of the load-bearing beam 402, cut a "rectangular" groove with a length of 200mm and a width of 64mm along the length direction of the load-bearing beam 402, so that the "rectangular" groove and the "U-shaped" groove are perpendicularly intersecting and connected and on the same vertical plane, so as to facilitate the free insertion of the load-bearing pin 401 in the "rectangular" groove and the "U-shaped" groove during the installation and removal of the load-bearing beam 402.

[0066] 4) On the double-channel steel waist plate surface at both ends of the load-bearing crossbeam 402, at a position 90mm from the end face and 83mm from the bottom face of the load-bearing crossbeam 402, vertically cut square safety pin holes with a width of 40mm and a height of 40mm respectively, along the channel steel waist plate surface upwards. The safety pin is made of a trapezoidal steel plate of Q235 material, with a small end width of 35mm, a large end width of 45mm, a height of 360mm, and a thickness of 25mm. At the center of the width of the small end of the safety pin, within a range of 100-130mm from the end face of the small end, drill four φ10mm safety lock round holes every 10mm from the small end to the large end for installing safety locks and preventing the safety pin from slipping towards the large end.

[0067] S20214: Selection of material, structure, and manufacturing process for load-bearing pins made of 401 stainless steel; details are as follows: like Figure 4 , Figure 5 As shown, by utilizing the strength and elastic modulus advantages of the tower column concrete 304 and the load-bearing pin 401, a cantilever beam support structure capable of resisting large bending moments and shear forces is formed. The gripping and adhesion force of the tower column concrete 304 to the load-bearing pin 401 ensures the stability of the load-bearing pin 401 during the construction of the tower column 3. The plastic tape wrapped around the surface of the load-bearing pin 401 weakens the connection between the tower column concrete 304 and the load-bearing pin 401, ensuring that the load-bearing pin 401 can be easily pulled out after manual knocking when it is removed, and can be reused.

[0068] 1. Material of Load-Bearing Pin 401. Load-bearing pin 401 is made of Q345 steel, 60mm diameter round steel bar, and consists of a 200mm long, 60mm Φ round steel bar and a 400mm long, 40mm Φ conical steel bar. If any damage to the load-bearing pin 401 is found before installation, it must not be used and must be replaced immediately.

[0069] 2. Construction of Load-Bearing Pin 401. A 600mm long, 60mm diameter circular steel bar is machined into a conical small end face with a top diameter of 40mm and a bottom diameter of 60mm within a 400mm range from one end of the bar. At the other end, a circular large end face with a diameter of 60mm is formed within a 200mm range from the other end face. The small end face of the load-bearing pin 401 is pre-embedded in the tower column concrete 304, while the large end face protrudes 200mm from the inner wall surface of the tower column concrete 304, forming a cantilever beam support structure to facilitate the installation of the anti-overturning support body 404 and the load-bearing crossbeam 402.

[0070] In this optional scheme, step "S2022: Anti-overturning system 4 verification and evaluation" specifically includes the following steps: 1. Calculation of stress on the 304 stainless steel concrete surface of the tower column; details are as follows: (1) Given conditions: The steel pipe column 4041 of the anti-overturning support body 404 is made of Q235 steel pipe with a diameter of φ219×10mm. The transverse connecting rod 4044 and the diagonal support rod 4045 are both made of Q235 steel with [16b channel steel. The load-bearing beam 402 is made of Q235 steel with double [25b channel steel. The load-bearing pin 401 is made of Q345 steel with a diameter of 60mm and is composed of a 200mm long, Φ60mm long round steel bar and a 400mm long, Φ40mm long conical steel bar. The anti-overturning support body 404 has a length of 2800mm, a width of 2500mm, and a height of 4000mm. The two length sides (inward and outward sides of the transverse bridge) of the anti-overturning support body 404 and the vertical contour surface of the concrete inside the tower cavity of tower column 3 (inward and outward sides of the transverse bridge) are all inclined to the same side (inward side of the transverse bridge) and form an angle of 81.3° with the horizontal plane (θ=81.3°). On the inner wall concrete of the transverse bridge side of the tower cavity of tower column 3, four sets of load-bearing pins 401 are pre-embedded on the same horizontal section.

[0071] (2) Calculation of stress on the 304 concrete surface of the tower column: The stress on the 304 concrete surface of the tower column is calculated according to the following formulas based on the standards of "Plywood for Concrete Formwork" (GB / T17656-2018), "Code for Design of Building Structures" (GB50009-2012), "Standard for Design of Steel Structures" (GB50017-2017), and "Standard for Acceptance of Construction Quality of Steel Structures" (GB50205-2020): ; In the formula: -The self-weight of the concrete acting on the overhead formwork (kN); - The component of the concrete's self-weight parallel to the formwork direction, (kN); - The component of the concrete's self-weight perpendicular to the formwork (kN); - Concrete volume (m³) 3 ); 304 g of concrete per tower segment =82.8m 3 ; - The density of concrete (kN / m³) 3 Take 25kN / m 3 ; - The angle between the vertical profile of the concrete inside the tower cavity of tower column 3 and the horizontal plane is taken as θ=81.3°.

[0072] Calculated using the above formula, we can obtain: As described above, the anti-overturning support structure 404 has two steel pipe columns 4041 on both its upward and downward sides subjected to stress, and the height of the steel pipe columns 4041 is 4.0m. Therefore, using structural calculation software, the following can be obtained: ① Forces acting on the supine side: =255.98kN / m; Force on the downward plane: =39.08kN / m; in: - Linear loads parallel to the template direction; - Linear loads perpendicular to the template direction.

[0073] ② Taking a safety factor of 1.2 for both the concrete self-weight load and the support self-weight, then, =307.18kN / m, =46.89kN / m.

[0074] 2. Overturning support structure 404 bearing capacity verification; details are as follows: In this embodiment, since the strength of the steel pipe column 4041 is much greater than the horizontal load it may bear, no calculation is required; only the horizontal bracing channel steel needs to be calculated. For the anti-overturning support body 404, only whether the horizontal bracing can guarantee the collapse of the anti-overturning support body 404 itself is considered; for the load-bearing pin 401, only the maximum stress of the load-bearing pin 401 and the maximum compressive stress of the concrete are considered. From the above, it can be seen that: =307.18kN / m, =46.89kN / m, the load was applied to the finite element analysis model, and the self-weight of the support was added automatically by the software.

[0075] (1) Applying load The load effect combination is: 1.20 × (structural self-weight + concrete self-weight).

[0076] (2) Results Analysis 1) Construction conditions: combined stress, shear stress and bending moment, and reaction force of the load-bearing pin 4.

[0077] Load-bearing pin 4: The maximum vertical reaction force is 80.3kN and the maximum horizontal reaction force is 71.8kN. This data will be used for subsequent calculations of the embedded parts system.

[0078] 2) Construction conditions: bending strength, shear strength, and stability are detailed in Table 1.

[0079] Table 1 Summary of Calculation Results for Bending Strength, Shear Strength, and Stability From the table above, we can see that: a. The maximum bending strength of the member is 110.10 N / mm². 2 <[f]=215N / mm 2 (Bending strength of Q235 steel) meets the requirements.

[0080] b. The maximum shear strength of the member is 38.50 N / mm². 2 <[t]=125N / mm 2 (Q235 steel shear strength) meets the requirements.

[0081] c. The maximum stability coefficient of the compression member is 0.571 < 1, which meets the requirements.

[0082] d. The maximum slenderness ratio is 70.145 < 200, which meets the requirements.

[0083] The bending strength, shear strength, and stability are all less than the specified values. Therefore, all members meet the stress requirements during the construction phase.

[0084] 3) Construction conditions: Deformation Under construction conditions, the finite element analysis results show that the maximum deformation of 3.89 mm is within the range of elastic deformation.

[0085] During the construction phase, all members met the specifications in terms of bending strength, shear strength, stability, and deformation, ensuring the structure's safety and reliability, and making it ready for use.

[0086] 3. Load-bearing capacity verification of 401 bearing pin; details are as follows: (1) Maximum compressive stress in concrete: In the formula: - Maximum compressive stress in concrete (N / mm²) 2); - The vertical load borne by the load-bearing pin 401 (kN); In this embodiment of the application, the maximum vertical reaction force of the load-bearing pin 401 is 80.3kN; - Elastic modulus of concrete, (N / mm²) 2 In this embodiment of the application, the elastic modulus of the C50 tower column concrete 304 is taken as 3.45 × 10⁻⁶. 4 N / mm 2 ; - Elastic modulus of 401 load-bearing pin (N / mm) 2 The elastic modulus of the steel in this embodiment is 2.06 × 10⁻⁶. 5 N / mm 2 ; - The value is 3.14; - Diameter of load-bearing pin 401 (mm); In this embodiment, the diameter of load-bearing pin 401 is 60mm.

[0087] Calculations show that the maximum compressive stress in the C50 tower column concrete is 304. =21.1 N / mm 2 <23.1N / mm 2 (Design value of axial compressive strength of C50 concrete) meets the requirements.

[0088] (2) Maximum stress of load-bearing pin 401: In the formula: - Maximum stress of the 401 load-bearing pin (N / mm) 2 ); - The vertical load borne by the load-bearing pin 401 (kN); In this embodiment of the application, the maximum vertical reaction force of the load-bearing pin 401 is 80.3kN; - Elastic modulus of concrete, (N / mm) 2 In this embodiment of the application, the elastic modulus of the C50 tower column concrete 304 is taken as 3.45 × 10⁻⁶. 4 N / mm 2 ; - Elastic modulus of 401 load-bearing pin (N / mm) 2 The elastic modulus of the steel in this embodiment is 2.06 × 10⁻⁶. 5 N / mm 2 ; - The value is 3.14; - The diameter of the load-bearing pin 401 is (mm); in this embodiment, the diameter of the load-bearing pin 401 is 60mm.

[0089] Calculations show that the maximum stress of the load-bearing pin 401 is... =236.5 N / mm 2 <290N / mm 2 (Q345 steel with a diameter of 60mm) meets the bending strength requirements.

[0090] (3) The length of the load-bearing pin 401 embedded in the 304 concrete of the tower column: In the formula: - The length of the load-bearing pin 401 embedded in the concrete 304 of the tower column (mm); in this embodiment of the application, the embedment length of the load-bearing pin 401 is 400mm.

[0091] - Elastic modulus of concrete, (N / mm) 2 In this embodiment of the application, the elastic modulus of the C50 tower column concrete 304 is taken as 3.45 × 10⁻⁶. 4 N / mm 2 ; - Elastic modulus of 401 load-bearing pin (N / mm) 2 The elastic modulus of the steel in this embodiment is 2.06 × 10⁻⁶. 5 N / mm 2 ; - The value is 3.14; - Diameter of load-bearing pin 401 (mm); In this embodiment, the diameter of load-bearing pin 401 is 60mm.

[0092] Calculations show that the required embedment length of the load-bearing pin 401 is no less than 126.9 mm. In the actual structure of this application embodiment, the embedment length of the load-bearing pin 401 is 400 mm; therefore, the local bearing capacity meets the specification requirements.

[0093] 4. Evaluation of the anti-overturning system 4: By using structural calculation software and finite element analysis software to establish models, analyze and verify the stress on the 304 concrete surface of the tower column, the bearing capacity of the anti-overturning support body 404, and the bearing capacity of the load-bearing pin 401, it can be concluded that the anti-overturning system 4 meets the requirements of the specifications.

[0094] Optionally, step "S2023: Design of the Tower Column Stiffening Frame System" specifically includes: like Figure 4, Figure 5 , Figure 6 As shown, the tower column stiffening frame 5 serves as the positioning and support framework for the tower column reinforcement 303 and the tower column formwork, and its positioning accuracy is crucial. Within the tower wall area of ​​the tower column 3, a double-layer tower column stiffening frame 5 is installed radially around the tower column 3. The outer layer tower column stiffening frame 5 and the inner layer tower column stiffening frame 5 are connected and fixed by internal connecting rods 503, and they form an angle of 81.3° with the horizontal plane in both the height direction and the horizontal plane, thus forming a tower column stiffening frame system with a "three-circular arc protrusion D-shaped" cross-section. The positioning benchmark function of the tower column stiffening frame 5 improves the construction accuracy of surveying and setting out, formwork erection, rebar tying, and cable guide pipe installation. During the closure construction of tower column 3, the tower column stiffening frame 5 can temporarily constrain the elevation changes and displacements of the cantilever ends of the two limbs of tower column 3 in the closure section, ensuring the closure accuracy of the two limbs of tower column 3. The tower column stiffening frame 5 and the tower column rebar 303 are connected by an internal fixing rod 503 to form a steel frame, reducing the stress and deformation of tower column 3, enhancing the overall structural stability of tower column 3, and preventing tower column 3 from tilting or collapsing. The steel frame formed by the tower column stiffening frame 5 and the tower column rebar 303 provides high load-bearing capacity, and the concrete shell enhances stability, making the seismic performance of tower column 3 superior to that of ordinary reinforced concrete. After installation, the tower column stiffening frame 5 can also serve as a safety harness for construction personnel, improving the construction safety of tower column 3.

[0095] 1. Materials and Structure (1) Material: such as Figure 6 As shown, the tower column stiffening frame 5 is welded together from vertical uprights 501, circumferential connecting rods 502, and internal fixing rods 503. The vertical uprights 501 are made of Q235B angle steel with a diameter of ∠100×100×10mm, the circumferential connecting rods 502 are made of Q235B angle steel with a diameter of ∠75×75×8mm, and the internal fixing rods 503 are made of Q235B angle steel with a diameter of ∠75×75×8mm. The upper and lower sections of the tower column stiffening frame 5 are joined together using ∠125×125×10mm as connecting feet for welding connection.

[0096] (2) Construction: such as Figure 4 , Figure 5 As shown, within the tower wall area of ​​tower column 3, three layers of tower column steel bars 303 are arranged radially around the tower column 3, from 100mm away from the outer edge of the outer contour of tower column 3 towards the center of the tower cavity, forming a "three-circular arc protrusion D-shaped" cross-section. Specifically, the outer and middle layers of tower column steel bars 303 are arranged 100mm away from the outer edge of tower column 3, with a spacing of 160mm between them; the middle layer of tower column steel bars 303 is arranged 100mm away from the side edge of the tower cavity of tower column 3, with a distance of 420mm from the middle layer of tower column steel bars 303.

[0097] like Figure 5 , Figure 6As shown, at a position 260mm away from the outer edge of the tower column 3, between the outer layer tower column reinforcement 303 and the middle layer tower column reinforcement 303, a "three-circular arc protruding D-shaped" outer layer tower column stiffening frame 5 with the same cross-sectional shape as the tower column 3 is set radially around the tower column 3. The outer layer tower column stiffening frame 5 is extended straight along the bridge to both sides of the tower column 3 until it intersects with the outer layer tower column stiffening frame 5 on the transverse bridge of the tower column 3. Located 300mm from the side edge of the tower cavity, between the central tower column reinforcement 303 and the intermediate tower column reinforcement 303, a "D-shaped" inner tower column stiffening frame 5 with the same cross-sectional shape as the tower cavity is installed radially around the "D-shaped" octagonal tower column 3. The inner tower column stiffening frame 5 extends linearly to both ends of the longitudinal bridge direction of the tower column 3, intersecting with the outer tower column stiffening frame 5 on both sides of the transverse bridge direction. Similarly, the inner tower column stiffening frame 5 extending linearly inwards from the transverse bridge direction of the tower column 3 extends linearly to the inner tower column stiffening frame 5 on both sides of the longitudinal bridge direction. Multiple 420mm long internal connecting fixing rods 503 are used to weld and fix the outer tower column stiffening frame 5 to the inner tower column stiffening frame 5, thus forming a "three-arc protruding D-shaped" tower column stiffening frame 5.

[0098] 2. Processing and manufacturing; such as Figure 4 , Figure 5 , Figure 6 As shown, the tower column stiffening frame 5 is a permanent prefabricated stiffening frame, which is welded together from vertical uprights 501, circumferential connecting rods 502, and internal fixing rods 503. Each segment of the tower column stiffening frame 5 is 4000mm long. By connecting the tower column stiffening frame 5 to the tower column reinforcing bars 303 with internal fixing rods 503 to form a steel frame, high load-bearing capacity is provided, reducing the stress and deformation of the tower column 3, enhancing the overall structural stability of the tower column 3, and preventing the tower column 3 from tilting or collapsing. After installation, the tower column stiffening frame 5 can also serve as a safety harness for construction workers, improving construction safety. Specific processing and fabrication: (1) According to the design position of the tower column reinforcement 303 in the construction drawing of the tower column 3, the outer tower column stiffening frame 5 is set at a position 260mm away from the outer edge of the tower column 3, between the outer tower column reinforcement 303 and the middle tower column reinforcement 303. The inner tower column stiffening frame 5 is set at a position 300mm away from the side edge of the tower cavity of the tower column 3, between the middle tower column reinforcement 303 and the middle tower column reinforcement 303.

[0099] (2) On the hardened concrete pavement at the construction site of the No. 7 pier tower column 3, the installation positions of the outer tower column stiffening frame 5 and the inner tower column stiffening frame 5 are laid out, and the planar position outlines of the outer tower column stiffening frame 5 and the inner tower column stiffening frame 5 are drawn with red paint.

[0100] (3) On the outline of the tower column stiffening frame 5 plane position, the tower column stiffening frame is processed and manufactured in 4 sections using vertical uprights 501 angle steel, circumferential connecting rods 502 angle steel and internal connecting fixing rods 503 angle steel.

[0101] (4) The tower column stiffening frame of section 4 is lifted by tower crane to the top of the tower column stiffening frame 5 that is exposed outside the completed tower column 3 for extension connection. The upper and lower tower column stiffening frames 5 are connected by welding with connecting foot plates.

[0102] 3. Processing and manufacturing quality requirements; Allowable deviations in the processing and manufacturing of the tower column stiffening frame 5: length and width ≤ ±5mm, diagonal ≤ ±6mm, axis ≤ 2mm, and the tower column stiffening frame 5 shall form an angle of 81.3° with the horizontal plane in the height direction, and the same as the tilt angle of the tower column 3.

[0103] Optionally, step "S2024: Evaluation of the Construction Alignment Combination Control System for Hollow Tower Columns" specifically includes: The anti-overturning system 4 was modeled, analyzed, and verified using structural calculation software and finite element analysis software to study the stress on the 304 concrete surface of the tower column, the bearing capacity of the anti-overturning support body 404, and the bearing capacity of the load-bearing pin 401. It can be concluded that the anti-overturning system 4 meets the requirements of the specifications. The tower column rigid frame 5 and tower column reinforcing bars 303 are connected by internal fixing rods 503 to form a steel frame. External fixing rods 504 connect and fix the tower column rigid frame 5, tower column reinforcing bars 303, and anti-overturning support body 404. The anti-overturning support body 404, with its low stress deformation and high reliability, serves as the central support. Under the constraint of the anti-overturning system 4, radial reaction force is generated, acting on the climbing formwork support body, tower column rigid frame 5, tower column reinforcing bars 303, tower column concrete 304, and tower column formwork to generate supporting force. This resists the overturning force generated by the upward suspended construction of the hollow tower column 302, forming a combined control system for the construction alignment of the hollow tower column, ensuring that the suspended construction alignment and inclination of the hollow tower column 302 meet design requirements. This system provides high load-bearing capacity, reduces the stress and deformation of the tower column 3, enhances the overall structural stability of the tower column 3, and prevents the tower column 3 from tilting or collapsing.

[0104] Optionally, each horizontal active cross bracing system 6 includes two sets of active cross bracing systems arranged parallel to each other along the bridge direction, and multiple transverse horizontal connecting rods 606 connecting the two sets of active cross bracing systems. Each set of active cross bracing systems includes: two sets of embedded parts 601 respectively embedded in the concrete 304 of the tower columns 3 of the two limb tower columns; two sets of supports 602 respectively connected to the corresponding side embedded parts 601; two sets of corbels 603 respectively connected to the corresponding side embedded parts 601; multiple pad beams 604; and struts 605, with the two sets of corbels 603 respectively located below the two sets of supports 602; struts 605 Along the transverse direction of the bridge, the fixed end of the support rod 605 is fixed to the corresponding side support 602, and the movable end of the support rod 605 is spaced apart from the corresponding side support 602. Multiple pad beams 604 are vertically supported on the lower corbel 603, and the upper ends of the multiple pad beams 604 extend between the movable end of the support rod 605 and the corresponding side support 602. After adding pad blocks, the upper ends of the pad beams 604 are clamped between the movable end of the support rod 605 and the corresponding side support 602. Multiple transverse horizontal connecting rods 606 are arranged sequentially at intervals along the transverse direction of the bridge, and the two ends of each transverse horizontal connecting rod 606 are fixedly connected to two support rods 605.

[0105] Furthermore, the embedded part 601 includes an anchoring steel plate 6014 tightly attached to the outer wall of the tower column 3, and multiple sets of anchoring bars dispersedly arranged to anchor the anchoring steel plate 6014 to the outer wall of the tower column 3. Each set of anchoring bars includes: an anchoring steel bar 6011 embedded in the tower column concrete 304 after passing through the anchoring steel plate 6014, a tapered nut 6012 threaded onto the exposed end of the anchoring steel bar 6011, and a bolt 6013; the bracket 603 includes a trapezoidal bracket 6031 with a trapezoidal cross section, and a support 6032 fixed to the top of the trapezoidal bracket 6031; the support 602 located at the movable end of the strut 605 includes a hollow top support 6021, a sealing steel plate 6023, and longitudinal and transverse reinforcements. The stiffening plate 6024 and the top support 6021 are fixed at one end to the corresponding side anchoring steel plate 6014. The other end of the top support 6021 protrudes outward toward the center side of the tower column 3 and is closed by the end sealing steel plate 6023. The longitudinal and transverse stiffening plates 6024 are fixed inside the top support 6021 and are fixedly connected at both ends to the end sealing steel plate 6023 and the anchoring steel plate 6014 respectively. The support 602 located at the fixed end of the strut 605 includes a hollow support 6022. One end of the support 6022 is fixed to the corresponding side anchoring steel plate 6014, and its opposite end protrudes outward toward the center side of the tower column 3. The cable tower anti-overturning combined control system also includes a cross strut operating platform 607 and a construction operating platform and passage 608.

[0106] In this optional scheme, step "S203: Design, Verification and Evaluation of Horizontal Active Cross-bracing System 6" specifically includes the following steps: S2031: Horizontal Active Cross-Brace System Design; specifically including: Because the pylon is an inwardly inclined structure, during construction, the pylon experiences significant inward displacement and inward force due to the self-weight of the constructed tower segment 3 and the construction load. This causes the bending moment at the base of the inwardly inclined tower segment 3 to increase continuously as the tower segment 3 rises. To ensure the transverse stability of the bridge during pylon construction, it is necessary to overcome the inward displacement and inward force of the pylon structure. Therefore, a three-stage horizontal active cross bracing system 6 is installed during pylon construction. Each horizontal active cross bracing uses two Ф1000×12mm steel pipes and is prestressed. Two Ф1000×12mm steel pipes are connected laterally using Ф426×6mm steel pipes.

[0107] A calculation model of the tower column 3 was established using finite element analysis software. Each component was simulated using beam elements, and the construction stages were analyzed according to the actual construction process. The simulation analyzed the application location and magnitude of the active cross bracing to ensure the safety and controllable deformation of the cable tower construction. Details are as follows: Figure 2 As shown, when tower column 3 is constructed to the 8th segment, the first horizontal active cross bracing system 6 is installed at an elevation of 24.3m. Each strut 605 applies an active jacking force of 1500kN, with two struts totaling 3000kN, and these forces must be applied symmetrically simultaneously. When tower column 3 is constructed to the 13th segment, the second horizontal active cross bracing system 6 is installed at an elevation of 45.5m. Each strut 605 applies an active jacking force of 1200kN, with two struts totaling 2400kN, and these forces must be applied symmetrically simultaneously. When tower column 3 is constructed to the 19th segment, the third horizontal active cross bracing system 6 is installed at an elevation of 67.3m. Each strut 605 applies an active jacking force of 1000kN, with two struts totaling 2000kN, and these forces must be applied symmetrically simultaneously.

[0108] S2032: Horizontal Active Cross-Brace System: Material Selection, Construction, and Manufacturing; specifically including: like Figure 2 , Figure 3 , Figure 8 , Figure 9 , Figure 10 , Figure 11 As shown, the horizontal active cross bracing system 6 includes: embedded parts 601, supports 602, corbels 603, pad beams 604, struts 605, transverse horizontal connecting rods 606, cross-bracing operating platform 607, and construction operating platform and passageway 608. Among them: embedded parts 601 include: anchoring steel bars 6011, tapered nuts 6012, bolts 6013, and anchoring steel plates 6014; supports 602 include: top support 6021, supporting support 6022, end-sealing steel plates 6023, and longitudinal and transverse stiffening plates 6024; corbels 603 include: trapezoidal corbels 6031 and brackets 6032.

[0109] 1. Component materials and construction (1) Embedded part 601: such as Figure 10 , Figure 11 As shown, the embedded part 601 includes: anchoring steel bars 6011, tapered nuts 6012, bolts 6013, and anchoring steel plates 6014. There are a total of 12 sets of embedded part 601 structures, with 4 sets used in each of the first, second, and third horizontal active cross bracing systems 6. Each set of embedded part 601 structures includes: 25 800mm long, HRB400, Φ25mm anchoring steel bars 6011, 25 40Cr tapered nuts 6012, 25 sets of M30 bolts 6013 (bolts, nuts, and washers), and one Q235B material, 1800×1200×20mm anchoring steel plate 6014.

[0110] (2) Construction operation platform and passageway 608: such as Figure 8 As shown, the construction operation platform and passageway 608 consists of a load-bearing tripod 6081, a climbing cone 6082, a distribution beam 6083, and a guardrail 6084. The load-bearing tripod 6081 is constructed by welding double-ply [10b channel steel, and the climbing cone 6082 is used to fix the load-bearing tripod 6081 to the concrete 304 wall of the tower column. A distribution beam 6083 is installed on top of the load-bearing tripod 6081, and a 3mm patterned anti-slip steel plate 6084 is laid on top of the distribution beam 6083, with a guardrail 6085 1.2m high installed.

[0111] (3) Cross-bracing operating platform 607: such as Figure 9 As shown, the cross-bracing operating platform 607 is constructed by welding a rectangular column guardrail frame 6071 with a length of 2200mm and a width of 1300mm and cantilever support frames 6072 located at both ends of the rectangular column guardrail frame 6071.

[0112] (4) Top support 6021: such as Figure 10 , Figure 11As shown, the top support 6021 is constructed of Q235B steel pipe with a longitudinal side upper bottom edge of 273mm, a lower bottom edge of 336mm, and a height of 1000mm. The cross-section is Φ1000×12mm steel pipe, welded to a Q235B steel plate with a Φ1000×20mm circular end cap. This forms an inclined surface end with the same inclination angle (θ=81.3°) as the tower column 3, and an open flat end. Inside the steel pipe of the top support 6021, longitudinal and transverse stiffening plates 6024 with a thickness of 20mm and a weld depth of 273~336mm are connected to the inner wall of the steel pipe. After welding, the outer surface of one end of the longitudinal and transverse stiffening plate 6024 is made flush with the open flat end face of the top support 6021 steel pipe, and the outer surface of the other end of the longitudinal and transverse stiffening plate 6024 is made flush with the inclined end face of the top support 6021 steel pipe, forming a grid-like end face, so as to increase the section modulus and moment of inertia of the top support 6021 steel pipe, and improve the bending resistance, torsion resistance and overall stiffness of the top support 6021 steel pipe.

[0113] (5) Support 6022: such as Figure 10 , Figure 11 As shown, the support 6022 is made of Q235B material, with a longitudinal side upper bottom edge of 273mm, a lower bottom edge of 336mm, a height of 1000mm, and a trapezoidal shape. The cross-section is made of Φ1000×12mm steel pipe, forming an inclined surface end with the same inclination angle (θ=81.3°) as the tower column 3, and an open flat end at the other end.

[0114] (6) Beef leg 603: such as Figure 2 , Figure 3 , Figure 10 , Figure 11 As shown, the bracket 603 includes an inverted trapezoidal bracket 6031 and a support 6032. The components and their construction are as follows: each horizontal active cross bracing system 6 includes a movable end and a fixed end. There are two sets of bracket structures for each movable and fixed end.

[0115] (7) 604 bearing pad: such as Figure 10 , Figure 11As shown, the support beam 604 uses two double-section [45a] I-beams made of Q235 steel and 1340mm in length. Two double-section [45a] I-beams are vertically installed on the top surface of the top steel plate of the trapezoidal bracket 6031, between the top support 6021 and the strut 605. The two double-section [45a] I-beams are located between the axial centerline and the outer edge of the top support 6021, respectively, ensuring that the lateral spacing between the two double-section [45a] I-beams is not less than the radial width of the jack. The end faces of the two legs of the I-beams are tightly attached to the top support 6021 and the strut 605, respectively, and strain monitoring points are embedded therein. After the active jacking force is applied, use a steel plate with a thickness of 5mm, 10mm or 20mm to fill the gap between the pad beam 604 and the support rod 605 or between the pad beam 604 and the top support 6021. Then weld the two legs of the pad beam 604 I-beam to the top support 6021 and the support rod 605 respectively.

[0116] (8) Support rod 605: such as Figure 2 , Figure 3 , Figure 10 , Figure 11 As shown, a Q235 steel pipe with a diameter of 1000×12mm is used. Inside one end of the strut 605, a 20mm thick steel plate is welded to a 300mm deep longitudinal and transverse stiffening plate 6024, connecting it to the inner wall of the pipe. The outer surfaces of the stiffening plates 6024 are flush with the end face of the strut 605, forming a grid-like end face. This increases the section modulus and moment of inertia of the strut 605, improving its bending, torsional, and overall stiffness. A 1000×20mm circular end-sealing steel plate 6023 is welded to the outside of the grid-like end face to form a closed flat end, which connects to the movable end support beam 604 and the top support 6021. The other end of the strut 605 is an open flat end, welded to the open flat end of the fixed end support 6022.

[0117] The first horizontal active cross bracing system has a strut length of 29.35m and a weight of 18.41T; the second horizontal active cross bracing system has a strut length of 22.90m and a weight of 14.43T; and the third horizontal active cross bracing system has a strut length of 16.51m and a weight of 10.499T. After the first, second, and third horizontal active cross bracing systems have their struts 605 welded together on the ground, they are then hoisted using a tower crane. Each horizontal active cross bracing system has two parallel struts 605, with the center lines of the two struts 605 4200mm apart. All welds on the struts 605 must undergo non-destructive testing to ensure their quality meets the specifications before construction and use.

[0118] (9) Horizontal horizontal connecting rod 606: such as Figure 3As shown, the transverse horizontal connecting rod 606 is made of Q235 steel pipe, 3200mm in length, and Ф426×6mm in diameter. Four transverse horizontal connecting rods 606 are evenly spaced along the axial direction of the first horizontal active cross bracing system 6 between the two support rods 605. Three transverse horizontal connecting rods 606 are evenly spaced along the axial direction of the second horizontal active cross bracing system 6 between the two support rods 605. Two transverse horizontal connecting rods 606 are evenly spaced along the axial direction of the third horizontal active cross bracing system 6 between the two support rods 605. The transverse horizontal connecting rods 606 form a 90° angle with the support rods 605.

[0119] S2033: Verification and Evaluation of Horizontal Active Bracing System; specifically including: 1. Computational model. For example... Figure 12 As shown, the horizontal active cross bracing system 6 of the cable tower was established using finite element analysis software. The calculation model of the cable tower column 3 was established, and each component was simulated using beam elements. The construction stage analysis was carried out according to the actual construction process.

[0120] 2. Constraints. In the model, the bottom of the tower is fixed, the tower base 2 is rigidly connected to the tower column 3, the upper crossbeam 7 is rigidly connected to the tower column 3, and the active cross brace is rigidly connected to the tower column 3.

[0121] 3. Design Principles. The horizontal active bracing design is determined based on the construction process and the principle of controlling the tensile stress of the tower under the most unfavorable working conditions to not exceed 1.4 MPa. After repeated trial calculations, it was initially determined that the tower should be equipped with three jacking supports, with the following jacking forces: the first jacking force is 1500 kN, the second jacking force is 1200 kN, and the third jacking force is 1000 kN.

[0122] 4. Results of cable tower structural analysis and calculation (1) Application of the first top support: Before the first top support was applied, the maximum compressive stress on the inner side of the tower was -1.77 MPa, and the maximum tensile stress on the outer side of the tower was 0.19 MPa. The most unfavorable position was located at the connection between the tower base 2 and the tower column 3. After the first top support was applied, the maximum compressive stress on the inner side of the tower was -1.08 MPa, and the maximum compressive stress on the outer side of the tower was -0.44 MPa. When the first top support was applied, the lateral deformation of the top support point of the single tower column 3 was 1.7 mm.

[0123] (2) Application of the second support: Before the application of the second support, no tensile stress was observed on the inner and outer sides of the tower. The maximum compressive stress on the inner side of the tower was -2.19 MPa, and the maximum compressive stress on the outer side of the tower was -0.23 MPa. After the application of the second support, the maximum compressive stress on the inner side of the tower was -1.17 MPa, and the maximum compressive stress on the outer side of the tower was -0.98 MPa. When the second support was applied, the lateral deformation of the three support points on one side of the tower column was 16.2 mm.

[0124] (3) Application of the third support: Before the application of the third support, no tensile stress was observed on the inner and outer sides of the tower. The maximum compressive stress on the inner side of the tower was -2.83 MPa, and the maximum compressive stress on the outer side of the tower was -1.25 MPa. After the application of the third support, the maximum compressive stress on the inner side of the tower was -1.70 MPa, and the maximum compressive stress on the outer side of the tower was -2.15 MPa. When the third support was applied, the lateral deformation of the three support points on one side of the tower column was 46.4 mm.

[0125] 5. Stability calculation of the 605 horizontal active cross brace of the cable tower (1) The results of the horizontal active cross bracing of the tower and the maximum axial force during construction are shown in Table 2.

[0126] Table 2 Summary of Horizontal Active Cross Bracing Force and Maximum Axial Force of the Tower (2) The calculation results of the horizontal active cross bracing of the cable tower under pressure and bending are shown in Table 3.

[0127] Table 3 Summary of Horizontal Active Bracing Results for Cable Towers 6. Evaluation of the Horizontal Active Cross-bracing System By using finite element analysis software to establish a model, conduct analysis and verification, it can be found that the strength and bending stability of the first to third horizontal active cross braces of 605 all meet the requirements.

[0128] Optionally, step "S204: Design of Prestressed Concrete Upper Beam System" specifically includes the following steps: S2041: Design of prestressed concrete upper beam system; specifically including: The bridge begins to gradually close towards the center of the tower from an elevation of +72.184m (top of section 17), completing the closure of tower 3 at an elevation of +92.184m (top of section 23). A solid-section prestressed concrete upper crossbeam structure is then installed at the top of this closure section. This prestressed concrete upper crossbeam system connects the two inclined towers 3 via upper crossbeam 7, forming a stable spatial structural system to prevent the bridge deck from shifting, tilting, or collapsing under load. By pre-applying compressive stress to the upper crossbeam 7, the crack resistance and stiffness of the component are improved, while reducing the cross-sectional dimensions and self-weight. After the upper crossbeam 7 is combined with the inclined towers 3, it can suppress torsional deformation of the inclined towers 3 during construction and use.

[0129] S2042: Materials and Construction; Specifically, the upper crossbeam 7 is a solid prestressed concrete structure with a cross-section height of 2.5m, a longitudinal width of 6.25m, and a transverse length of 20.7m. The concrete for upper crossbeam 7 is C50 high-performance concrete. The prestressed steel strands are 19Φs15.20 steel strands, and the anchorage specifications are YM15-19 (anchor plate diameter 206mm, thickness 75mm; anchor pad diameter 285mm, thickness 280mm; spiral reinforcement diameter 16mm, spiral outer diameter 280mm). The corrugated pipes are 100mm inner diameter high-density polyethylene (HDPE) corrugated pipes. Prestressed steel strand tensioning, anchoring, and sealing can only be carried out after the concrete strength of upper crossbeam 7 reaches 90% of the design strength and 85% of the elastic modulus. All prestressed steel strands are tensioned symmetrically at both ends. Vacuum grouting is used for duct grouting immediately after tensioning. The water-cement ratio of the grout used for prestressed duct grouting is 0.26 to 0.28, its initial fluidity is greater than 10 to 17 seconds, and its fluidity after 30 minutes is not greater than 20 seconds.

[0130] Step "S205: Evaluation of Sota's Anti-Overturning Combined Control System" specifically includes: The anti-overturning combined control system of the tower includes the construction alignment combined control system of the hollow tower column, the horizontal active cross bracing system 6 between the two limb tower columns 3, and the prestressed concrete upper cross beam system at the top of the closure section of the two limb tower columns 3. (1) Anti-overturning system 4: By using structural calculation software and finite element analysis software to establish a model, analyze and verify the stress on the inverted and inclined surfaces of the tower column concrete 304, the bearing capacity of the anti-overturning support body 404, and the bearing capacity of the load-bearing pin 401, it can be found that the anti-overturning system 4 meets the requirements of the specification. (2) Horizontal active cross bracing system 6: By using finite element analysis software to establish a model, analyze and verify, it can be found that the strength and bending stability of the first to third horizontal active cross bracing rods 605 meet the requirements. (3) The upper crossbeam 7 connects the two inclined tower columns 3 to form a stable spatial structure system, preventing the bridge deck from shifting, tilting or collapsing under load; by applying compressive stress to the upper crossbeam 7 in advance, the crack resistance and stiffness of the component are improved, while the cross-sectional size and self-weight are reduced; after the upper crossbeam 7 is combined with the two inclined tower columns 3, the torsional deformation of the inclined tower columns 3 during construction and use can be suppressed.

[0131] Through the synergistic action of the aforementioned hollow tower column construction alignment control system, the horizontal active cross bracing system 6, and the prestressed concrete upper cross beam system, the system jointly resists the inward tilting force generated by the self-weight and construction loads of the two tower columns 3 during construction, balances the overturning moment of the tower columns, and ensures that the tower alignment, inward tilting force, and inclination meet the design requirements. This system provides high load-bearing capacity, reduces the stress and deformation of the tower column 3, enhances the overall structural stability of the tower column 3, and prevents the tower column 3 from tilting or collapsing.

[0132] Step S3: Dynamic Control Analysis of Spatial Position of Tower Column Construction Segments; Before the construction of tower column 3, a 3D model of the A-shaped tower column 3 construction segment is created using BIM software to visually demonstrate the tower structure, support system, and construction process; During the construction of tower column 3, the design position + pre-offset value of the axis of the tower column stiffening frame 5, tower column reinforcement 303, tower column formwork, upper crossbeam 7, and the outline point of the tower structure, as well as the design elevation value + pre-lift value, are used as control values ​​to adjust the top position of each segment of tower column 3. The system involves positioning and verification of the tower column's concrete 304 before pouring. After the construction of each segment of the tower column 3 and the upper crossbeam 7, the measured values ​​of the axis and elevation of the tower column stiffening frame 5, tower column reinforcement 303, tower column formwork, upper crossbeam 7, and tower structure outline points at the top of each segment of tower column 3 are used to create a real-time displacement measurement map of the spatial position of the tower column 3 construction segments using the same BIM software. This map is then compared with the 3D model of the A-shaped tower column 3 construction stage for dynamic control and analysis of the spatial position of the tower column 3 construction segments. This system achieves millimeter-level precision control, ensuring smooth lines and beautiful shapes of the tower column 3; shortening the construction cycle of the tower column 3 and improving efficiency; reducing on-site operation risks and environmental interference; and simultaneously reducing later maintenance costs and extending the bridge's service life through precise control. Specifically, the system includes the following steps: 1. Establish a 3D model of the A-shaped cable tower column during the construction phase; specifically including: such as Figure 13 As shown, before the construction of tower column 3, based on the construction requirements of dividing tower column 3 into 33 segments and a standard vertical pouring height of 3.9m, BIM software was used to create a 3D model of the A-shaped tower column 3 construction segments, visually displaying the tower structure, support system, and construction process, including the spatial positions of the tower stiffening frame 5, tower reinforcement 303, tower formwork, upper crossbeam 7, and the outline points of the tower structure at the top of each segment. This provided a reliable construction basis for the construction of tower column 3. The model accurately simulated the stress, deformation, and stability of tower column 3 during construction, ensuring construction safety; verified the feasibility of the construction process, reducing risks in actual construction; and predicted the bending moment and tensile stress at the base of tower column 3 during the construction stage, preventing concrete cracking or excessive deformation. The precise positioning of the tower's shape using BIM technology improved construction accuracy, and the active support technology effectively counteracted the overturning moment, controlled the displacement and stress of tower column 3, and enhanced safety.

[0133] 2. Dynamic control analysis of the spatial position of the tower column construction segments; specifically including: during the construction of tower column 3, using the design position + pre-offset value of the axis of the tower column stiffening frame 5, tower column reinforcement 303, tower column formwork, upper crossbeam 7 and the outline point of the tower structure as control values, to carry out the layout and positioning of the top of each segment of tower column 3 and the verification and positioning measurement before the pouring of tower column concrete 304. After the construction of each segment of the tower column 3 and the upper crossbeam 7, the measured values ​​of the axis and elevation of the tower column stiffening frame 5, tower column steel bar 303, tower column formwork, upper crossbeam 7 and tower structure outline points at the top of each segment of the tower column 3 are used to establish a real-time displacement measurement map of the spatial position of the tower column 3 construction segment using the same BIM software. Then, the three-dimensional model of the construction stage of the A-shaped tower column 3 is used to conduct dynamic control analysis of the spatial position of the tower column 3 construction segment: (1) The axis deviation and elevation deviation of the tower column stiffening frame 5, tower column steel bar 303, tower column formwork, upper crossbeam 7 and tower structure outline points are determined to determine whether the pre-deviation value is too large or too small, and the construction layout pre-deviation value of the next construction segment of the tower column 3 is adjusted in time; (2) The construction alignment of each segment of the tower column 3 is quickly judged to meet the design requirements, so as to realize the correction while construction and ensure that the construction alignment of the tower column 3 meets the design requirements.

[0134] Optionally, step "S4: Construction and dismantling of the cable tower anti-overturning combined control system" specifically includes the following steps: S401: The pylon towers are constructed segmentally. The pylon tower of pier #7 of the cable-stayed bridge is an A-shaped reinforced concrete structure with a total height of 124.7m. The pylon includes a base, lower tower column, middle tower column, upper middle tower column, upper tower column, and tower crown. The construction of pylon column 3 is divided into 33 segments, with each segment having a standard vertical pouring height of 3.9m. The specific steps include: 1. Measurement and control methods for tower construction; specifically including: The construction measurement control of Tower 3 is carried out according to five major steps: installation of Tower Column Stiffening Frame 5 → layout of the vertical main reinforcement edge frame line of Tower Column 3 → layout of the axis points and corner points of Tower Column 3 section → installation of embedded parts → installation of Tower Column formwork. From Tower Column Stiffening Frame 5 to Tower Column formwork installation, each step relies on the measurement results of the previous step, forming a closed-loop control; through phased review and cross-verification, error transmission is minimized to ensure the accuracy of the cable tower structure. Among them: (1) Laying out the tower column stiffening frame 5: The laying out position of the tower column stiffening frame 5 is 260mm away from the outer contour edge of the tower column 3. This not only provides space for the laying out of the vertical main reinforcement of the tower column 3, but also does not affect the binding of the tower column reinforcement 303. The design position of its axis + pre-deflection value of 10mm and the design elevation value + pre-lift value of 10mm are used as control values. The elevation and inclination of the current segment of the tower column stiffening frame 5 are mainly controlled, and the deviation is controlled within the allowable range. The stability of the tower column stiffening frame 5 is ensured through multiple checks, providing a reliable benchmark for the subsequent laying out of the vertical main reinforcement of the tower column 3.

[0135] (2) Laying out key points of the outer contour of tower column 3: According to the segmental construction requirements designed in the construction drawings of tower column 3, draw the plan view of each segment of tower column 3. After verification and comparison, it can be used for laying out. According to the design position of its axis + pre-offset value of 10mm and the design value of elevation + pre-raise value of 10mm as the control values, strictly control the elevation and plan position of the key points of the outer contour of tower column 3, and lay out the position of the key points of the outer contour of tower column 3 on the welded tower column stiffening frame 5 angle steel. After the laying out is completed, do a good job of measurement and handover, mark the position and quantity of the key points of the outer contour of tower column 3, so as to facilitate the construction of construction personnel. The key points of the outer contour of tower column 3 include: the axial center point of the transverse bridge to the outer side, the axial center point of the transverse bridge to the inner side, the outward convex arc point of the longitudinal bridge to the front side, and the outward convex arc point of the longitudinal bridge to the rear side, a total of 4 key points of the outer contour.

[0136] (3) Verification of tower column reinforcement 303: During the binding process of tower column reinforcement 303, a steel tape measure is used to verify the distance between the installation position of the vertical main reinforcement of tower column 3 and the layout point; the design position of its axis + pre-deflection value 10mm and the design elevation value + pre-lifting value 10mm are used as control values ​​to mainly control the thickness of the reinforcement protective layer.

[0137] (4) Tower column formwork positioning: According to the assembly sequence of the tower column formwork, each point of the tower column formwork is checked in turn, including: the centerline of tower column 3, the junction of the curved section and the straight section; according to the design position of its axis + pre-offset value of 10mm and the design elevation value + pre-raise value of 10mm as the control values, the main control is to lay out the centerline of the tower column formwork and check the line type of tower column 3.

[0138] 2. The tower column stiffening frame is installed in 5 segments, one segment at a time; specifically including: (1) The stiffening frame 5 of the tower column of the pier cap 1, tower base 2 and solid tower column 301 is installed in sections. Before the first 3.0m high concrete pour of the pier cap 1 of No. 7, the stiffening frame 5 of the tower column and the stiffening frame of the tower base 2 must be pre-embedded in the range of the tower base 2, so that the bottom end of both extends into the pier cap by 4.0m, and the top end protrudes 1.50m to 2.50m from the top surface of the pier cap 1. The outer stiffening frame 5 of the tower column and the inner stiffening frame 5 are welded and fixed by the inner connecting rod 503, and the stiffening frame 5 of the tower column and the stiffening frame of the tower base 2 are welded and fixed by the inner connecting rod 503. As the tower column 3 of the cable tower continues to rise, the stiffening frame 5 of the tower column is spliced ​​section by section in sequence. The upper and lower sections of the stiffening frame 5 of the tower column are joined together, and ∠125×125×10mm is used as the connecting foot plate for welding connection.

[0139] 1) Installation of the tower column stiffening frame 5 in the pier cap section. Using the corner point of pier cap 1 as the feature point, install the positioning keel. Using the positioning keel as the overall guide, and according to its axial design position + pre-offset value of 10mm and elevation design value + pre-lift value of 10mm as the control values, install the tower column stiffening frame 5.

[0140] 2) Installation of the tower column stiffening frame 5 in the tower base section. Using the tower base 2 stiffening frame as the positioning reference, the spatial position of the tower column stiffening frame 5 at the top of the tower base 2 is marked on the internal connecting rod 503 between the tower base 2 stiffening frame and the tower column stiffening frame 5, according to its axial design position + pre-offset value of 10mm and elevation design value + pre-lift value of 10mm. The tower column stiffening frame 5 is installed one by one at the marked positions, extending 300mm beyond the top concrete surface of the tower base 2. After installation, its axial offset at the top of the tower base 2 is ≤5mm, elevation ≤±5mm, and verticality ≤H / 3000 (H is the height of the tower base 2, in mm), to prevent uneven mass distribution or insufficient strength of the tower column stiffening frame 5 at the tower base 2, which could lead to uneven settlement or deformation of the tower column 3 during construction, thus affecting the linear accuracy of the tower column 3.

[0141] 3) Install the stiffening frame 5 of the solid tower column 301 segment by segment. Using the corner points of the solid tower column 301 as feature points, install the positioning keel. Using the positioning keel as the overall guide, and according to the design position of its axis + pre-offset value of 10mm and the design elevation value + pre-lift value of 10mm as control values, install the stiffening frame 5 of the tower column, ensuring that the stiffening frame 5 extends 300mm beyond the top concrete surface of each segment of the solid tower column 301. After installation, ensure that the axis offset at the top of each segment of the solid tower column 301 is ≤5mm, the elevation is ≤±5mm, and the verticality is ≤H / 3000 (H is the height of each segment of the solid tower column 301, in mm), to prevent uneven mass distribution or insufficient strength of the stiffening frame 5 at the top of each segment of the solid tower column 301, which could lead to uneven settlement or deformation of the tower column 3 during construction, thus affecting the linear accuracy of the tower column 3.

[0142] (2) Install the stiffening frame 5 of the hollow tower column 302 segment by segment. Using the anti-overturning support body 404 as the positioning reference, mark the spatial position of the stiffening frame 5 at the top of each segment of the hollow tower column 302 according to the design position of its axis + pre-offset value of 10mm and the design elevation value + pre-lift value of 10mm. Mark the position on the external connecting rod 504 between the stiffening frame 5 and the anti-overturning support body 404. Install the stiffening frame 5 of the tower column one by one at the marked position, and make the stiffening frame 5 extend 300mm beyond the top concrete surface of each segment of the hollow tower column 302. After installation, ensure that the axial deviation at the top of each segment of the hollow tower column 302 is ≤5mm, the elevation is ≤±5mm, and the verticality is ≤H / 3000 (H is the height of each segment of the hollow tower column 302, in mm). This is to prevent uneven mass distribution or insufficient strength of the tower column stiffening frame 5 at each segment of the hollow tower column 302, which could lead to uneven settlement or deformation of the tower column 3 during construction, thereby affecting the linear accuracy of the tower column 3.

[0143] 3. The tower column reinforcement is installed in sections using 303 stainless steel; specifically including: (1) The steel bars 303 of the foundation 1, tower base 2 and solid tower column 301 are installed in sections.

[0144] 1) Installation of tower column reinforcement 303 in section 1 of the pier cap. Before the first 3.0m high concrete pour of pier cap 1 of pier #7, tower column reinforcement 303 must be pre-embedded within the range of tower base 2, so that its bottom end extends 4.0m into pier cap 1. Using the tower column stiffening frame 5 as the positioning reference, the spatial position of the tower column reinforcement 303 at the top of pier cap 1 is marked on the inner connecting rod 503 between the outer and inner tower column stiffening frames 5, according to the design position of its axis + pre-offset value of 10mm and the design elevation value + pre-lift value of 10mm. The tower column reinforcement 303 is then installed one by one at the marked position, so that the tower column reinforcement 303 extends 1.50m to 2.50m beyond the top surface of the concrete of pier cap 1. After installation, ensure that the axial deviation at the top of the pier 1 is ≤5mm, the elevation is ≤±5mm, and the verticality is ≤H / 3000 (H is the pre-embedded depth of the tower column steel bar 303, in mm), to prevent uneven mass distribution or insufficient strength of the tower column steel bar 303 at the pier 1, which could lead to uneven settlement or deformation of the tower column 3 during construction, thereby affecting the linear accuracy of the tower column 3.

[0145] 2) Installation of the tower column reinforcement 303 in section 2 of the tower base. Using the tower column stiffening frame 5 as the positioning reference, the spatial position of the tower column reinforcement 303 at the top of the tower base 2 is marked on the inner connecting rod 503 between the outer and inner tower column stiffening frames 5, according to the design position of its axis + pre-offset value of 10mm and the design elevation value + pre-raise value of 10mm. The tower column reinforcement 303 is then installed one by one at the marked positions, extending 1.50m to 2.50m beyond the concrete top surface of the tower base 2. After installation, the axial offset at the top of the tower base 2 should be ≤5mm, the elevation ≤±5mm, and the verticality ≤H / 3000 (H is the height of the tower base 2, in mm). This prevents uneven mass distribution or insufficient strength of the tower column reinforcement 303 at the tower base 2, which could lead to uneven settlement or deformation of the tower column 3 during construction, thus affecting the linear accuracy of the tower column 3.

[0146] 3) Install the steel bars 303 of the solid tower column 301 segment by segment. Using the tower column stiffening frame 5 as the positioning reference, mark the spatial position of the steel bars 303 at the top of each segment of the solid tower column 301 according to the design position of the axis + pre-offset value of 10mm and the design elevation value + pre-raise value of 10mm. Mark the position on the inner connecting rod 503 between the outer and inner tower column stiffening frames 5. Install the steel bars 303 one by one at the marked positions, so that the steel bars 303 extend 1.50m to 2.50m beyond the top concrete surface of each segment of the solid tower column 301. After installation, ensure that the axial deviation at the top of each segment of the solid tower column 301 is ≤5mm, the elevation is ≤±5mm, and the verticality is ≤H / 3000 (H is the height of each segment of the solid tower column 301, in mm). This is to prevent uneven mass distribution or insufficient strength of the tower column reinforcement 303 at the top of each segment of the solid tower column 301, which could lead to uneven settlement or deformation of the tower column 3 during construction, thereby affecting the linear accuracy of the tower column 3.

[0147] (2) Install the tower column steel bars 303 in sections of the hollow tower column 302 segment by segment. Using the anti-overturning support body 404 as the positioning reference, the spatial position of the tower column steel bars 303 at the top of each section of the hollow tower column 302 is marked with lines on the inner connecting rod 503 between the outer tower column stiffening frame 5 and the inner tower column stiffening frame 5 and the outer connecting rod 504 between the tower column stiffening frame 5 and the anti-overturning support body 404. Install the tower column steel bars 303 one by one at the marked positions, and make the tower column steel bars 303 extend 1.50m to 2.50m beyond the concrete top surface of each section of the solid tower column 301. After installation, ensure that the axial deviation at the top of each segment of the hollow tower column 302 is ≤5mm, the elevation is ≤±5mm, and the verticality is ≤H / 3000 (H is the height of each segment of the hollow tower column 302, in mm). This prevents uneven mass distribution or insufficient strength of the tower column reinforcement 303 at each segment of the hollow tower column 302, which could lead to uneven settlement or deformation of the tower column 3 during construction, thus affecting the linear accuracy of the tower column 3. Before the tower column formwork is installed, cut off the external fixing rod 504 between the tower column reinforcement 303 and the anti-overturning support body 404 that affects the installation of the tower column formwork, while retaining the external fixing rod 504 between the top of the tower column reinforcement 303 and the top steel pipe column 4041 of the anti-overturning support body 404.

[0148] 4. The tower column formwork is installed segment by segment; specifically including: (1) Install the formwork of the solid tower column 301 segment by segment. Using the tower column stiffening frame 5 as the positioning reference, the spatial position of the tower column formwork at the top of each segment of the solid tower column 301 is marked on the inner connecting rod 503 between the outer tower column stiffening frame 5 and the inner tower column stiffening frame 5, according to the design position of its axis + pre-offset value of 10mm and the design elevation value + pre-lift value of 20mm. Install the tower column formwork at the marked position one by one, and make the tower column formwork extend 50mm beyond the concrete top surface of each segment of the solid tower column 301. After installation, ensure that the axial deviation at the top of each segment of the solid tower column 301 is ≤5mm, the elevation is ≤±5mm, and the verticality is ≤H / 3000 (H is the height of each segment of the solid tower column 301, in mm). This is to prevent the axial deviation of the tower column formwork at each segment of the solid tower column 301 from being too large, which would result in the protective layer thickness of the tower column reinforcement 303 being too large or too small during the construction process, thus affecting the linear accuracy of the tower column 3. It is also to prevent the surface laitance of the tower column concrete 304 from being too thick after final setting, and to prevent the elevation of the tower column concrete 304 after roughening from being lower than the design elevation at the top of each segment of the solid tower column 301, thus affecting the linear accuracy of the tower column 3.

[0149] (2) Install the formwork of the hollow tower column 302 segment by segment. Using the tower column stiffening frame 5 as the positioning reference, mark the spatial position of the tower column formwork at the top of each segment of the hollow tower column 302 according to the design position of its axis + pre-offset value of 10mm and the design elevation value + pre-lift value of 20mm. Mark the position on the inner connecting fixing rod 503 between the outer tower column stiffening frame 5 and the inner tower column stiffening frame 5. Install the tower column formwork at the marked position one by one, and make the tower column formwork extend 50mm beyond the top concrete surface of each segment of the hollow tower column 302. After installation, ensure that the axial deviation of the hollow tower column 302 at the top of each segment is ≤5mm, the elevation is ≤±5mm, and the verticality is ≤H / 3000 (H is the height of each segment of the hollow tower column 302, in mm). This is to prevent the axial deviation of the tower column formwork at each segment of the hollow tower column 302 from being too large, which would result in the protective layer thickness of the tower column reinforcement 303 being too large or too small during the construction of the tower column 3, thus affecting the linear accuracy of the tower column 3. It is also to prevent the concrete 304 from having too thick a layer of laitance on its surface after final setting, and to prevent the elevation of the concrete 304 after roughening from being lower than the design elevation of the top of each segment of the solid tower column 301, thus affecting the linear accuracy of the tower column 3.

[0150] 5. The tower column concrete is poured in sections in stages using 304 stainless steel; specifically including: The tower column concrete 304 uses C50 high-performance concrete. The 304 concrete for the tower column is poured in horizontal layers, and the top layer of concrete must be poured before the bottom layer of concrete has initially set; the concrete pouring speed... =0.2~0.3m / h; concrete pouring layer thickness 300mm; concrete vibration using φ70mm immersion vibrator until the concrete stops sinking, air bubbles stop escaping, and slurry appears on the surface. Strictly control the pouring speed of the 304 concrete for the tower column, thereby controlling the lateral pressure of the 304 concrete on the formwork.

[0151] In this optional scheme, S402: Installation and removal of the anti-overturning system 4; since the inclination of the anti-overturning support body 404 is the same as that of the tower column 3, both forming an angle of 81.3° with the horizontal plane, the anti-overturning support body 404 can be used as a modular tool-type support device within the standard section tower cavity height of 41.50m of the middle tower column, and can be reused multiple times, specifically including: S4021: Anti-overturning system 4 installation; specifically includes: 1. Install load-bearing pin 401. (For example...) Figure 4 , Figure 5 As shown, during the construction of the fifth hollow non-standard section tower column 3, a load-bearing pin 401 must be pre-embedded horizontally at a 5° downward angle at a position 400mm away from the top surface of the concrete 304 of this section tower column. Four load-bearing pins 401 are also pre-embedded on the same horizontal section to provide support for the anti-overturning support body 404 and the load-bearing beam 402. When pre-embedding the load-bearing pins 401, a 600mm long, Φ60mm conical steel bar is pre-embedded horizontally at a 5° downward angle at a position 1400mm in front of and 1400mm behind the centerline of the transverse bridge direction on the outer and inner inner walls of the tower cavity of the fifth hollow non-standard section tower column 3.

[0152] After installation, the load-bearing pin 401 should protrude 200mm from the inner wall surface of the tower column concrete 304; the installation position of a single load-bearing pin 401 should have a horizontal deviation of no more than 5mm and a vertical deviation of no more than 10mm; the installation positions of the four load-bearing pins 401 should all be 400mm from the top surface of the tower column concrete 304 segment and on the same horizontal plane; the center lines of the axes of the two forward-facing load-bearing pins 401 inside the hollow tower column 302 should coincide one-to-one, and the center lines of the axes of the two rear-facing load-bearing pins 401 inside the hollow tower column 302 should coincide one-to-one.

[0153] 2. Installation of load-bearing crossbeam 402. (For example...) Figure 4 , Figure 5As shown, after the concrete 304 of the fifth hollow non-standard section tower column reaches a strength of 15MPa, a tower crane is used to lift the load-bearing beam 402 to the pre-embedded position of the load-bearing pin 401. The rectangular slots on the bottom surfaces of both ends of the load-bearing beam 402 are placed directly above the pre-embedded load-bearing pin 401, and the load-bearing beam 402 is slowly lowered so that both ends of the load-bearing beam 402 are suspended on the pre-embedded load-bearing pin 401. The small end of the safety pin is passed through the square safety pin hole on the load-bearing beam 402. A φ10mm round steel bar is passed through the safety lock hole on the safety pin, the round steel bar is bent and the safety pin is locked to prevent the safety pin from slipping towards its large end.

[0154] 3. Installation of the anti-overturning support 404. First, use a tower crane to lift the pre-assembled anti-overturning support 404 from the ground to directly above the two load-bearing crossbeams 402, so that the two length sides (i.e., the inward and outward sides of the crossbeams) of the anti-overturning support 404 span the two load-bearing crossbeams 402, with the length sides (outward sides of the crossbeams) facing the inner cavity of the hollow tower column 302, and the length sides (inward sides of the crossbeams) facing the inner cavity of the hollow tower column 302. Next, align the pre-drilled bolt holes 40461 of the four pads 4043 at the bottom of the anti-overturning support 404 with the pre-drilled bolt holes 40461 on the top surface of the load-bearing crossbeams 402, and slowly lower the anti-overturning support 404 again. Finally, use M24 bolts and nuts 4046 to securely connect the anti-overturning support 404 to the load-bearing crossbeams 402.

[0155] 4. Installation of the underlying operating platform 4031. (e.g., ...) Figure 4 , Figure 5 As shown, on the top surface of the two installed load-bearing beams 402, except for the installation position of the anti-overturning support body 404, multiple [8 channel steels] are arranged perpendicularly to the load-bearing beams 402 at intervals of 50cm. The channel steels are spot-welded to the load-bearing beams 402 to ensure that the channel steels do not shift forward or backward or left or right. Steel scaffolding boards are fully laid on the top surface of the channel steels to facilitate the installation of the tower column reinforcement 303, the installation and removal of the formwork inside the tower column 3, and the operation of the finishing personnel inside the tower column 3, while preventing the falling of personnel and falling objects inside the tower column 3 cavity. After installation, the outline of the bottom operating platform 4031 is the same as the outline of the tower column 3 cavity, and a 20cm distance is left between the bottom operating platform 4031 and the inner wall of the tower column concrete 304 to facilitate the installation and removal of the formwork inside the tower column 3.

[0156] 5. Installation of the top-level operating platform 4032. (e.g., ...) Figure 4As shown, five [8 channel steels] with a spacing of 50cm are arranged on the top of the anti-overturning support body 404, perpendicular to the length side (inward and outward of the transverse bridge). The [8 channel steels are spot-welded to the transverse connecting rods 4044 to ensure that the channel steels do not shift forward or backward or left or right. A 15mm thick bamboo plywood is laid on the top surface of the channel steels to facilitate the installation of the tower column reinforcement 303 and the installation and removal of the inner formwork of the tower column 3, and to prevent the fall of operators and falling objects from the tower column 3 cavity. After installation, the outline of the top operating platform 4032 is the same as the inner outline of the tower column 3 cavity, and a 50cm distance is left between the top operating platform 4032 and the inner wall of the tower column concrete 304 to facilitate the installation and removal of the inner formwork of the tower column 3.

[0157] S4022: Removal of the anti-overturning system 4; specifically, after the completion of the construction of the standard section hollow tower column 302 in section 6, the anti-overturning system 4 inside the tower cavity of the non-standard section hollow tower column 302 in section 5 shall be removed. The removal sequence is as follows: anti-overturning support body 404 and top operating platform 4032 → load-bearing beam 402 and bottom operating platform 4031 → load-bearing pin 401. During removal, the anti-overturning support body 404 and top operating platform 4032, and the load-bearing beam 402 and bottom operating platform 4031 shall be removed using a tower crane. The load-bearing pin 401 shall be removed manually using a specially designed staircase.

[0158] In this optional scheme, S403: Construction of the horizontal active cross bracing system 6; specifically including: like Figure 2 , Figure 3 , Figure 8 , Figure 9 , Figure 10 , Figure 11 As shown, the construction of the horizontal active cross bracing system 6 includes: embedded parts 601, supports 602, corbels 603, pad beams 604, struts 605, transverse horizontal connecting rods 606, cross strut operating platform 607, construction operating platform and passage 608, application of active jacking force, stress monitoring and control, etc.

[0159] 1. Construction of Embedded Part 601. During the construction of the tower column 3 to the 5th, 10th and 16th segments, embedded parts 601 for the first horizontal active cross bracing system 6 (elevation 24.3m), the second horizontal active cross bracing system 6 (elevation 45.5m) and the third horizontal active cross bracing system 6 (elevation 67.3m) are respectively pre-embedded. Each set of embedded parts 601 includes: 25 Φ25mm anchoring steel bars 6011, 25 40Cr tapered nuts 6012, 1 anchoring steel plate 6014, and 25 sets of M30 bolts 6013 (screw, nut and washer).

[0160] 2. Construct a construction operation platform and passageway 608. When the tower column is constructed to the 8th, 13th, and 19th segments, in order to facilitate the installation and removal of horizontal active bracing, elevator docking, installation and removal of tower column closure section supports, and safe passage, a construction operation platform and passageway 608 will be installed 500mm directly below the corbel 603. This platform will only be used as a standing platform for construction personnel and will not be used to place heavy objects.

[0161] 3. Install the bracket 603. (For example...) Figure 10 , Figure 11 As shown, each horizontal active cross bracing system 6 includes a movable end and a fixed end. The bracket 603 includes a movable end bracket and a fixed end bracket. There are two sets of each type of bracket structure. 4. Install the top support 6021 and the supporting support 6022. The top centerline of the top support 6021 and the supporting support 6022 is located 650mm from the top steel plate of the corbel 603 on the outer side of the pre-embedded anchor steel plate 6014 at the middle position. Weld the inclined ends of the steel pipes of the top support 6021 and the supporting support 6022 to the outer side of the anchor steel plate 6014 on the tower column 3, respectively. The flat ends of their openings are positioned away from the anchor steel plate 6014 and form a 90° angle with the centerlines of the top support 6021 and the supporting support 6022. Weld the flat end of the opening of the steel pipe of the top support 6021 to a Φ1000×20mm circular end-sealing steel plate 6023 to form a closed flat end. Weld the flat end of the opening of the steel pipe of the supporting support 6022 to the flat end of the opening of the strut 605.

[0162] 5. Install strut 605. Figure 2 As shown, after the weld quality of strut 605 meets the specifications through non-destructive testing, a tower crane is used to lift strut 605 to directly above the horizontal brace installation position. The closed flat end of strut 605 is placed in the groove of the corbel 603 support 6032 steel plate on the side of the top support 6021, and the open flat end of strut 605 is placed in the groove of the corbel 603 support 6032 steel plate on the side of the support 6022. The strut 605 and the top support are then adjusted. The top surfaces of 6021 and support 6022 are kept at the same elevation, ensuring that the center lines of the strut 605, top support 6021, and support 6022 overlap and correspond one-to-one. The open flat end of strut 605 and the open flat end of support 6022 are fully welded together. The closed flat end of strut 605 and the closed flat end of top support 6021 are connected by a pad beam 604 after applying active jacking force.

[0163] 6. Apply active support force. Figure 2As shown, 1) Add pad beam 604. Two double-layered [45a] I-beams are vertically added to the top surface of the top steel plate of the corbel 603, between the top support 6021 and the strut 605. The lateral spacing between the two double-layered [45a] I-beams is not less than the radial width of the jack, and the two legs of the I-beams are tightly attached to the top support 6021 and the strut 605 respectively. Strain monitoring points are then installed. 2) Apply active jacking force. The active jacking force applied by a single strut 605 of the first horizontal active cross bracing system 6 is 1500kN, for a total of 3000kN from two struts. This force must be applied symmetrically and simultaneously. The active jacking force applied by a single strut 605 of the second horizontal active cross bracing system 6 is 1200kN, for a total of 2400kN from two struts. This force must also be applied symmetrically and simultaneously. The third horizontal active cross bracing system has a single strut 605 that applies an active jacking force of 1000kN, with two struts totaling 2000kN. This force must be applied symmetrically and simultaneously. 3) Positioning welding of pad beam 604. After the active jacking force is applied, use 5mm, 10mm, or 20mm thick steel plates to fill the gap between pad beam 604 and strut 605, or between pad beam 604 and jacking support 6021. Then, weld the two ends of the I-beam of pad beam 604 tightly to the jacking support 6021 and strut 605, respectively.

[0164] 7. Connection of transverse horizontal connecting rods 606. After the pad beam 604 is welded tightly to the top support 6021 and the strut 605, a φ22mm safety steel wire rope is installed 1500mm directly above the two parallel struts 605 of each horizontal active cross bracing system 6 to facilitate the operator's suspension of a safety belt and prevent the operator from falling during welding. Between the two parallel struts 605 of each horizontal active cross bracing system 6, a cross-spanning strut operating platform 607 is used, and transverse horizontal connecting rods 606 are welded perpendicular to the two parallel struts 605. Four transverse horizontal connecting rods 606 are welded between the two parallel struts 605 of the first horizontal active cross bracing system 6, three transverse horizontal connecting rods 606 are welded between the two parallel struts 605 of the second horizontal active cross bracing system 6, and two transverse horizontal connecting rods 606 are welded between the two parallel struts 605 of the third horizontal active cross bracing system 6.

[0165] 8. Stress Monitoring and Control. After the transverse horizontal bracing rods 606 are connected, initial values ​​are collected and monitoring records are made for the strain monitoring points of the first, second, and third horizontal active bracing systems 6. During the construction of the tower column 3, the stress monitoring frequency for each horizontal active bracing system 6 is once a week.

[0166] In this optional scheme, S404: Construction of the prestressed concrete upper beam system; when the construction of the two-legged tower column 3 reaches the top of the 17th segment (elevation +72.184m), it begins to gradually close towards the center of the tower, forming a rounded chamfer, until the closure of the two-legged tower column 3 is completed at the top of the 23rd segment (elevation +89.684m), and a solid section prestressed concrete upper beam system is constructed on top of it; specifically including: 1. Construction Measurement Control of Upper Crossbeam 7. To prevent concrete creep, shrinkage, and weight-related settlement of the pylon, a pre-camber of 24.6mm was set for the construction of Upper Crossbeam 7. The bottom formwork for Upper Crossbeam 7 was laid out, and characteristic points of Upper Crossbeam 7 were marked on the bottom formwork, along with the bridge axis and the pylon centerline. After the side formwork of Upper Crossbeam 7 was erected, the same method was used to mark the characteristic points, bridge axis, and pylon centerline of Upper Crossbeam 7. The formwork for Upper Crossbeam 7 was adjusted to the designed position, and its verticality or inclination was controlled. During the concrete pouring process of Upper Crossbeam 7, displacement and support deformation were monitored.

[0167] 2. Prestressed System Installation. The prestressed ducts are fixed using a grid-like positioning mesh. After the positioning mesh is installed, corrugated pipes are inserted through the mesh openings, first inserting and fixing the lower (outer) layer of corrugated pipe, then inserting and fixing the upper (inner) layer, ensuring a tight fit between the corrugated pipe and the positioning mesh. The centerline of the pipe end is perpendicular to the anchor plate. After the reinforcement binding and pipe installation are completed, scaffolding boards are immediately laid. Inspectors and construction workers must not step on the reinforcement and pipes to prevent damage, flattening, or deformation. The coordinates of the corrugated pipe's endpoints at length and height on the upper crossbeam 7, as well as at the 1 / 2 and 1 / 4 sections, are checked, and the pipe's linearity and fixing measures are inspected. Anchor plates, spiral reinforcement, prestressing tendons, and anchorages are installed, ensuring the installation quality meets the design and requirements of the "Technical Specification for Highway Bridge and Culvert Construction" (JTG / T3650).

[0168] 3. Construction of Concrete Pouring for Upper Horizontal Beam 7. The C50 high-performance concrete for Upper Horizontal Beam 7 can only be poured after the reinforcement, prestressing system, various embedded components, and formwork installation quality of Upper Horizontal Beam 7 have been inspected and accepted as qualified. The concrete for Upper Horizontal Beam 7 will be poured in horizontal layers, with the top layer poured before the bottom layer has initially set. The concrete pouring speed is 0.2–0.3 m / h; the layer thickness is 300 mm; a φ70 mm immersion vibrator will be used for compaction until the concrete stops sinking, air bubbles stop escaping, and a layer of cement paste appears on the surface. The vibrator must not touch the corrugated pipe or anchor plate to prevent cracking or bending of the corrugated pipe. Strict control of the concrete pouring speed is crucial to control the lateral pressure of the Upper Horizontal Beam 7 concrete on the formwork. During the pouring of concrete for the upper crossbeam 7, the deflection of the support should be monitored at all times, and the stress on the support and formwork should be closely observed to ensure the safe and smooth completion of the pouring of concrete for the upper crossbeam 7. After the concrete for the upper crossbeam 7 is poured, it should be covered with plastic film for moisturizing and heat preservation for no less than 14 days.

[0169] 4. Prestressing tensioning. The prestressed steel strands can only be tensioned and anchored after the concrete of the upper crossbeam 7 reaches 90% of its design compressive strength and 85% of its elastic modulus. All prestressed steel strand tensioning employs symmetrical tensioning at both ends.

[0170] 5. Grouting and Anchoring of Ducts. Grouting of the prestressed ducts can only be carried out after the prestressed steel strand bundles have been tensioned and anchored. The water-cement ratio of the grout used for grouting is 0.26–0.28, with an initial flowability of 10–17 seconds and a flowability of 10–20 seconds after 30 minutes. After the duct grouting is completed, the upper crossbeam 7 is anchored using polymer fiber reinforced concrete.

[0171] The method of the present invention further includes step S5: Scope of application.

[0172] The above describes the construction method for controlling the alignment and overturning resistance of A-shaped cable towers. In addition to being applied to the construction of cable-stayed bridge towers as described in the above embodiments, it can also be applied to the construction of inclined or vertical high piers and thin-walled hollow columns for highways, railways and urban bridges.

[0173] The above description is merely a preferred embodiment of the present invention and is not intended to limit the 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 construction method for controlling the construction line shape and overturning resistance of a cable-stayed tower of Type A, characterized by, Includes the following steps: Preliminary preparations; Design, verification and evaluation of the anti-overturning combined control system of the cable tower; The anti-overturning combined control system of the cable tower includes the construction line combination control system of the hollow tower column formed by connecting the tower column stiffening frame system and the anti-overturning system (4), the multi-level active horizontal bracing system (6) used to construct between the two limb tower columns (3), and the prestressed concrete upper beam system used to construct at the top of the closure section of the two limb tower columns (3). The anti-overturning system (4) and the tower column stiffening frame system work together to resist the overturning force generated by the upward suspended construction of the hollow tower column (302). Combined with the synergistic effect of the horizontal active horizontal bracing system (6) and the prestressed concrete upper beam system, the inward tilting force generated by the self-weight and construction load of the two limb tower columns (3) during the construction process is offset to balance the overturning moment of the tower column (3) and ensure that the cable tower line, inward tilting force and tilt meet the design requirements. Analysis of dynamic control of spatial position of tower column (3) construction segment; Construction and dismantling of the anti-overturning combined control system for cable towers.

2. The A-type cable tower construction linear shape and overturning control construction method according to claim 1, characterized in that, The step "Design, Verification and Evaluation of Sota Anti-Overturning Combined Control System" specifically includes the following steps: Design of Sota's anti-overturning combined control system; Design, verification and evaluation of the construction alignment combination control system for hollow tower columns; Design, verification and evaluation of horizontal active cross bracing system (6); Design of prestressed concrete upper beam system; Evaluation of Sota's anti-overturning combined control system.

3. The A-type cable tower construction linear shape and anti-overturning control construction method according to claim 2, characterized in that, The step "Design, verification and evaluation of the construction alignment combination control system of the hollow tower column" is used to construct the tower column stiffness skeleton system and anti-overturning system (4), and to verify and evaluate them; The tower column stiffening frame system is a hollow cylinder, including a tower column stiffening frame (5) for pre-embedded in the wall of the next segment of hollow tower column (302) to form a steel frame and several tower column steel bars (303). The anti-overturning system (4) is spaced within the tower column stiffening frame system, including an anti-overturning support body (404) that acts as a central support. The bottom ends of the anti-overturning system (4), the tower column stiffening frame (5) and the tower column steel bars (303) are respectively pre-embedded and connected to the tower column concrete (304) of the previous segment of hollow tower column (302). The anti-overturning support body (404) is also connected to the tower column stiffening frame system as a whole through several external connecting fixing rods (504) to work together to resist the overturning force generated by the upward suspended construction of the hollow tower column (302).

4. The A-type cable tower construction linear shape and anti-overturning control construction method according to claim 3, characterized in that, The step "Design, Verification and Evaluation of Construction Alignment Combination Control System for Hollow Tower Columns" specifically includes the following steps: Anti-overturning system (4) design; (4) Verification and evaluation of the anti-overturning system; Tower column rigid frame system design; Evaluation of the construction alignment combination control system for hollow tower columns.

5. The A-type cable tower construction linear shape and anti-overturning control construction method according to claim 4, characterized in that, The anti-overturning system includes: four load-bearing pins (4) embedded in the concrete (1) of the previous tower column at the inner end; two load-bearing crossbeams (5) detachably connected between each two adjacent load-bearing pins (4); an anti-overturning support body (6) fixedly supported on the two load-bearing crossbeams (5); and a multi-layer operating platform fixedly installed in the anti-overturning support body (6) and spaced apart vertically. The step "Anti-overturning system (4) design" specifically includes the following steps: material and structure selection and processing of the anti-overturning support body (404); design and processing of the operating platform (403); design and processing of the load-bearing beam (402); material and structure selection and processing of the load-bearing pin (401); The steps “Anti-overturning system (4) verification and evaluation” specifically include the following steps: calculation of the stress on the tower column concrete (304) up and down surfaces; verification of the bearing capacity of the anti-overturning support body (404); verification of the bearing capacity of the load-bearing pin (401); and evaluation of the anti-overturning system (4).

6. The construction method for controlling the construction alignment and anti-overturning properties of Type A cable towers according to claim 2, characterized in that, Each horizontal active cross bracing system (6) includes two sets of active cross bracing systems spaced parallel to each other along the bridge direction, and multiple transverse horizontal connecting rods (606) connecting the two sets of active cross bracing systems. Each set of active cross bracing systems includes: Two sets of embedded parts (601) are pre-embedded in the concrete (304) of the tower column (3) of the two limb tower columns (3), two sets of supports (602) are respectively connected to the corresponding side embedded parts (601), two sets of corbels (603) are respectively connected to the corresponding side embedded parts (601), multiple pad beams (604) and struts (605), and the two sets of corbels (603) are respectively set below the two sets of supports (602); The strut (605) is set along the transverse direction of the bridge. Its fixed end is fixed to the support (602) on the corresponding side, and its movable end is spaced apart from the support (602) on the corresponding side. Multiple pad beams (604) are vertically supported on the lower corbel (603). The upper ends of the multiple pad beams (604) extend into the space between the movable end of the strut (605) and the support (602) on the corresponding side. After adding pad blocks, the upper ends of the pad beams (604) are clamped between the movable end of the strut (605) and the support (602) on the corresponding side. Multiple transverse horizontal connecting rods (606) are arranged sequentially at intervals along the transverse direction of the bridge, and two support rods (605) are fixedly connected to both ends of each transverse horizontal connecting rod (606).

7. The construction method for controlling the construction alignment and overturning resistance of type A cable towers according to claim 6, characterized in that, The embedded part (601) includes an anchoring steel plate (6014) that is closely attached to the outer wall of the tower column (3), and multiple sets of anchoring bars that are dispersedly arranged to anchor the anchoring steel plate (6014) to the outer wall of the tower column (3). Each set of anchoring bars includes: an anchoring steel bar (6011) that is embedded in the concrete (304) of the tower column after passing through the anchoring steel plate (6014), a tapered nut (6012) and a bolt (6013) that are threaded onto the exposed end of the anchoring steel bar (6011). The bracket (603) includes a trapezoidal bracket (6031) with a trapezoidal cross section, and a support (6032) fixed to the top of the trapezoidal bracket (6031). The support (602) located at the movable end of the strut (605) includes a hollow top support (6021), a sealing steel plate (6023), and longitudinal and transverse stiffening plates (6024). One end of the top support (6021) is fixed to the corresponding side anchoring steel plate (6014), and the other end of the top support (6021) protrudes outward toward the center side of the tower column (3) and is closed by the sealing steel plate (6023). The longitudinal and transverse stiffening plates (6024) are fixed inside the top support (6021) and the sealing steel plate (6023) and anchoring steel plate (6014) are fixedly connected at both ends respectively. The support (602) located at the fixed end of the strut (605) includes a hollow support (6022). One end of the support (6022) is fixed to the corresponding side anchoring steel plate (6014), and the other end of it protrudes outward toward the center side of the tower column (3). The anti-overturning combined control system of the cable tower also includes a cross strut operating platform (607) and a construction operating platform and passage (608).

8. The construction method for controlling the construction alignment and anti-overturning properties of Type A cable towers according to claim 6, characterized in that, The steps “Design, verification and evaluation of horizontal active cross bracing system (6)” specifically include the following steps: design of horizontal active cross bracing system (6); selection and processing of materials and structure of horizontal active cross bracing system (6); verification and evaluation of horizontal active cross bracing system (6); The step "Design of Prestressed Concrete Upper Beam System" specifically includes the following steps: design of prestressed concrete upper beam system; materials and construction.

9. The A-type cable tower construction linear shape and anti-overturning control construction method according to claim 1, characterized in that, The step "Dynamic Control Analysis of Spatial Position of Tower Construction Segments" specifically includes the following steps: Establish a 3D model of the A-shaped cable tower column during the construction phase; Analysis of dynamic control of spatial position of tower column construction segments.

10. The A-type cable tower construction linear shape and overturning control construction method according to claim 1, characterized in that, The "Construction of the Cable Tower Anti-Overturning Combined Control System" specifically includes the following steps: The tower column is constructed in sections; including: tower column construction measurement and control methods, tower column stiffness frame (5) section-by-section installation, tower column reinforcement (303) section-by-section installation, tower column formwork section-by-section installation, and tower column concrete (304) section-by-section pouring construction. Installation and removal of the anti-overturning system (4); including: installation of the anti-overturning system (4) and removal of the anti-overturning system (4); Construction of the horizontal active cross bracing system (6); Construction of the prestressed concrete upper beam system.

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