Construction method of lower tower column of large-inclination variable cross-section super-high cable tower

Abstract

The application provides a construction method of a large-inclination variable cross-section super-high cable tower lower tower column, comprising the following steps: S1, a climbing formwork process is used to construct a transition section and a vertical section of the lower tower column of the cable tower; wherein the cable tower comprises the lower tower column, the lower tower column comprises the transition section, the vertical section, a small-inclination section and a large-inclination section from bottom to top; S2, a steel turnover formwork + climbing formwork combined process is used to construct the small-inclination section of the lower tower column; and S3, a steel turnover formwork + hanging frame + climbing formwork combined process is used to construct the large-inclination section of the lower tower column. Different construction processes are used for different positions of the lower tower column, the turnover use of the formwork can be increased as much as possible while the linear type of the tower column is ensured, the construction cost is reduced, and the construction efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of bridge pylon construction technology, specifically to a construction method for the lower tower column of a high-inclination, variable-section pylon. Background Technology

[0002] In bridge engineering, the construction of cable-stayed bridges across the Yellow River is a very important component. As a cable system, cable-stayed bridges have a greater span capacity and lighter structural weight, which saves materials and has good economic benefits. They have been widely used in the Yellow River Basin, and the construction of cable-stayed bridge towers is of paramount importance in the bridge construction process.

[0003] To meet urban landscape requirements, the main tower structure needs a unique aesthetic compared to previous linear designs, most commonly requiring a "diamond-shaped" main tower structure. Specifically, the lower tower column of a "diamond-shaped" main tower is a V-shaped structure with a large inclination angle and a variable cross-section, while the middle and upper tower columns are inverted Y-shaped. During construction, due to the large inclination angle, irregular cross-section, and large distribution of the concrete's self-weight, the formwork is subjected to a large load, making it difficult to fix. Controlling the alignment of the lower tower column with a large inclination angle and variable cross-section is also quite challenging.

[0004] For shorter tower columns, the scaffolding method is commonly used for construction. A scaffolding system is employed on steeply inclined surfaces to transfer the concrete load to the ground foundation. This method is characterized by its simple construction process and clear mechanical model. However, the scaffolding method is not suitable for construction near riverbanks or for middle and upper tower columns, as it involves high construction costs, long construction periods, and a large workload. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing a construction method for the lower tower column of a high-inclination, variable-section cable-stayed tower.

[0006] To solve the above-mentioned technical problems, the present invention provides a construction method for the lower tower column of a high-inclination variable cross-section cable-stayed tower, comprising:

[0007] S1. The transition section and vertical section of the lower tower column of the cable tower are constructed using the climbing formwork process;

[0008] The tower includes a lower tower column, which from bottom to top includes a transition section, a vertical section, a small-angle section, and a large-angle section.

[0009] S2. The small-angle section of the lower tower column is constructed using a combination of steel formwork and climbing formwork.

[0010] S3. The large-angle section of the lower tower column is constructed using a combination of steel formwork, hanging frame, and climbing formwork.

[0011] Furthermore, the width of the transition section decreases linearly from bottom to top. In step S1, after the last transition section is completed, a wall-mounting device is installed on the front facade of the last transition section, and pads and wall-mounting devices are installed on the side facade and chamfer of the last transition section. The climbing formwork system climbs upward, and the angle of the upper truss of the climbing formwork system is adjusted to adapt to the vertical section.

[0012] Further, step S2 includes:

[0013] S21. After the last vertical section is completed, add reinforcing diagonal braces to the upper truss to support the formwork. Install wall-attachment devices on the front facade of the last vertical section. Install pads and wall-attachment devices on the side facade and chamfer of the last vertical section. The climbing formwork system climbs upward and the construction of the first small-angle section is carried out.

[0014] S22. The climbing formwork system includes front elevation climbing formwork, side elevation climbing formwork, and chamfered climbing formwork.

[0015] After the first section with a small inclination angle is completed, wall-mounted devices are installed on the front facade of the first section with a small inclination angle, and pads and wall-mounted devices are installed on the side facade of the first section with a small inclination angle. The climbing formwork on the front facade and the climbing formwork on the side facade are raised upwards. The chamfering climbing formwork at the chamfer of the first section with a small inclination angle is replaced with a steel flip-form system. The other parts of the small inclination angle section are constructed using a combination of steel flip-form and climbing formwork.

[0016] Furthermore, during the construction of the small-angle section, when the straight guide rail using pad blocks cannot be moved smoothly upwards, a tower crane is used to replace the straight guide rail with an arc-shaped guide rail.

[0017] Furthermore, the steel formwork of the steel formwork system is a hyperboloid steel formwork.

[0018] Further, step S3 includes: after the small-angle section is completed, the climbing formwork of the front facade and the climbing formwork of the side facade are raised upwards, and the steel formwork system is lifted by a tower crane. The hanging frame system is installed on the front facade of the last small-angle section. The hanging frame system is set between the climbing formwork of the front facade and the steel formwork system. The large-angle section is constructed using a combination of steel formwork + hanging frame + climbing formwork.

[0019] Furthermore, in step S3, before the front and side facade climbing formwork rises, the upper truss diagonal bracing, the triangular frame diagonal bracing, and the lower hanger diagonal bracing are replaced with diagonal bracing with stronger support capacity.

[0020] Furthermore, in step S3, the method of replacing the tripod brace includes: fixing the lifting point of the tower crane to the end of the crossbeam of the load-bearing tripod and lifting it up so that the tripod brace is not under stress, and replacing the tripod brace.

[0021] Furthermore, during the construction of the small-angle and large-angle sections, after each ascent of the climbing formwork system, the main load-bearing platform of the load-bearing triangular frame is horizontally arranged by adjusting the tripod bracing of the climbing formwork system.

[0022] Furthermore, during the construction of the small-angle and large-angle sections, the height of the embedded parts installed on the side facade climbing formwork is adjusted according to the height of the top platform of the load-bearing triangular frame of the front facade climbing formwork, so that the main load-bearing platform of the load-bearing triangular frame of the side facade climbing formwork is at the same height as the main load-bearing platform of the load-bearing triangular frame of the front facade climbing formwork.

[0023] During the construction of the small-angle and large-angle sections, the steel formwork system includes a lower steel formwork and an upper steel formwork. After the lower steel formwork is lifted to the top of the upper steel formwork using a tower crane, the platform height of the lower steel formwork is adjusted so that it is the same as the main load-bearing platform of the load-bearing triangular frame of the side facade climbing formwork. The platform height of the upper steel formwork is then adjusted so that it is the same as the first floor height of the upper truss of the front facade climbing formwork. A ramp is then constructed using cantilevered slabs to connect the platform of the upper steel formwork with the first floor of the upper truss of the side facade climbing formwork.

[0024] During the construction of the steeply inclined section, the height of each platform of the hanging frame system is the same as the height of each platform of the climbing formwork on the front facade.

[0025] The beneficial effects of this invention are as follows:

[0026] 1. This invention proposes a construction method for the lower tower column of a high-inclination, variable-section cable-stayed tower. Different construction techniques are used for different positions of the lower tower column. While ensuring the tower column's alignment, this method can maximize the reuse of formwork, reduce construction costs, and improve construction efficiency.

[0027] 2. In this invention, a hanging frame system is used to support the changes in the front facade dimensions at the large inclination section of the lower tower column. The hanging frame system is less expensive than climbing formwork, which not only saves construction costs but also provides a safe construction platform. Furthermore, the wooden formwork from the previous chamfering can be used at the changes in the front facade dimensions, thus improving the utilization rate of the wooden formwork.

[0028] 3. This invention improves the support capacity of the upper truss for the formwork by setting reinforced diagonal braces on the upper truss of the side facade climbing formwork and replacing the upper truss diagonal braces, triangular frame diagonal braces, and lower hanging frame diagonal braces with stronger support capabilities. Furthermore, the replacement of the upper truss diagonal braces, triangular frame diagonal braces, and lower hanging frame diagonal braces does not require disassembling the climbing formwork system, thus improving construction efficiency. Connecting the top of the steel formwork of the side facade climbing formwork to the main reinforcement in the tied steel bars allows some of the concrete pressure on the steel formwork to be transferred to the main reinforcement, reducing the stress on the side facade climbing formwork and helping to ensure the alignment of the steep angle section.

[0029] 4. For sections with smaller inclination angles, this invention uses pad blocks to assist in the raising of the straight guide rail, which helps improve construction efficiency.

[0030] 5. This invention addresses the issue of height differences between platforms in steeply inclined sections by adjusting the height of each platform in the hanging frame system to be the same as the height of each platform in the front facade climbing formwork. The height of the lower steel formwork platform is adjusted to be the same as the height of the main load-bearing layer of the front facade climbing formwork, and the height of the upper steel formwork platform is adjusted to be the same as the height of the first layer of the upper truss of the front facade climbing formwork. This ensures that the hanging frame system, the front facade climbing formwork, and the lower steel formwork are all at the same height at +1 and +2 floors, facilitating the work of construction personnel. For the height differences in the side facade climbing formwork, a ramp is constructed between the steel formwork system and the side facade climbing formwork for a smooth transition, ensuring construction safety. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the structure of the ultra-high cable tower with large inclination angle and variable cross-section according to the present invention;

[0032] Figure 2 This is a construction schematic diagram of the first section of the cable tower of the present invention;

[0033] Figure 3 This is a construction schematic diagram of section 2 of the cable tower of the present invention;

[0034] Figure 4 This is a construction schematic diagram of section 4 of the cable tower of the present invention;

[0035] Figure 5 This is a schematic diagram of the side elevation climbing formwork structure of the present invention;

[0036] Figure 6 This is a construction schematic diagram of section 5 of the cable tower of the present invention;

[0037] Figure 7 for Figure 6 Enlarged view of point A in the middle;

[0038] Figure 8 This is a diagram showing the layout of the climbing formwork and platform during the construction of the transition and vertical sections of the cable tower of this invention;

[0039] Figure 9 This is a diagram showing the layout of the formwork during the construction of the transition section and vertical section of the cable tower of the present invention;

[0040] Figure 10 This is a layout diagram of the climbing formwork and platform during the construction of section 19 of the cable tower of this invention;

[0041] Figure 11 This is a construction schematic diagram of section 9 of the cable tower of the present invention;

[0042] Figure 12 for Figure 11Enlarged view at point B in the middle;

[0043] Figure 13 This is a construction schematic diagram of section 10 of the cable tower of the present invention;

[0044] Figure 14 for Figure 13 Enlarged view at point C;

[0045] Figure 15 This is a construction diagram of section 14 of the cable tower of the present invention;

[0046] Figure 16 This is a schematic diagram of the hanging bracket system of the present invention;

[0047] Figure 17 This is a construction schematic diagram of section 19 of the cable tower of the present invention;

[0048] Figure 18 This is a diagram showing the layout of the formwork during the construction of Section 19 of the cable tower of this invention.

[0049] Attached reference numerals: 1. Lower tower column; 2. Middle tower column; 3. Upper tower column; 4. Lower crossbeam; 5. Tower base; 6. Transition section; 7. Vertical section; 8. Small angle section; 9. Large angle section; 10. Wooden formwork; 11. Load-bearing triangular frame; 12. Main load-bearing platform; 13. Upper truss; 14. Lower hanger; 15. Upper truss diagonal brace; 16. Lower hanger diagonal brace; 17. Triangular frame diagonal brace; 18. Embedded part; 19. Reinforcing diagonal brace; 20. Pad block; 21. Wall attachment device; 22. Steel formwork system; 23. Lower steel formwork; 24. Upper steel formwork; 25. Straight guide rail; 26. Hanging frame system; 27. Front elevation climbing formwork; 28. Side elevation climbing formwork; 29. ​​Chamfered climbing formwork; 30. Steel formwork. Detailed Implementation

[0050] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0051] like Figure 1As shown, the high-angle variable cross-section super-high cable tower of this embodiment includes, from bottom to top, a tower base 5, a lower tower column 1, a lower crossbeam 4, a middle tower column 2, and an upper tower column 3. The cable tower is divided into 38 sections except for the tower base 5. Sections 1-19 are the lower tower column 1, and the lower crossbeam 4 is located in sections 17-19. The front elevation of the lower tower column 1 is a plane, while the side elevation and chamfer of the lower tower column 1 are a combination of plane and curved surfaces. Therefore, the closer to the 19th section, the larger the inclination angle of the side elevation and chamfer of the lower tower column 1, the larger the distribution of the concrete self-weight, and the greater the load on the formwork. In this embodiment, based on the variation pattern of the side elevation and chamfer of the lower tower column 1, the lower tower column 1 is divided into transition section 6, vertical section 7, small-angle section 8, and large-angle section 9 from bottom to top. Among them, transition section 6 consists of sections 1-4, and the width of transition section 6 changes linearly, gradually decreasing from bottom to top; vertical section 7 consists of sections 5-8, and the width of vertical section 7 remains unchanged, equal to the width of the upper end of transition section 6; small-angle section 8 consists of sections 9-13, and the width of small-angle section 8 changes non-linearly, forming an arc shape; large-angle section 9 consists of sections 14-19, including a first large-angle section 9 and a second large-angle section 9. The first large-angle section 9 consists of sections 14-16, and the width of the first large-angle section 9 changes non-linearly, forming an arc shape; the second large-angle section 9 consists of sections 16-17, and the width of the second large-angle section 9 changes linearly, gradually increasing from bottom to top.

[0052] The construction method for the lower tower column of this high-angle variable cross-section cable tower is as follows:

[0053] S1. The transition section 6 and vertical section 7 of the lower tower column 1 of the cable tower are constructed using climbing formwork technology; specifically including:

[0054] S11, such as Figure 2 As shown, Figure 2 (a) in the diagram indicates the front elevation of Section 1. Figure 2 (b) illustrates the side elevation of the first section. The first section (i.e., the first transition section 6) is poured on the tower base 5 using wooden formwork 10. Embedded parts 18 are installed on the wooden formwork 10. After the concrete reaches its strength, the wooden formwork 10 and temporary supports are removed. Figure 3 As shown, the load-bearing triangular frame 11, the main load-bearing platform 12, and the upper truss 13 of the climbing formwork system are installed on the outside of the first transition section 6 using a tower crane. The load-bearing triangular frame 11 is fixed to the first section by embedded parts 18. The steel bars are tied, the wooden formwork 10 and the embedded parts 18 are installed, the formwork is closed, and the second section (i.e. the second transition section 6) is poured.

[0055] S12, such as Figure 3 As shown, Figure 3 (a) in the diagram illustrates the front elevation of Sections 1-2. Figure 3(b) shows the side elevation of sections 1-2. After the concrete of section 2 (i.e., transition section 6) reaches its strength, the wooden formwork 10 is removed and the upper truss 13 is moved back. The wall attachment device 21 is installed on transition section 6. The straight guide rail 25 and hydraulic system are installed on the load-bearing triangular frame 11 of the climbing formwork system. The climbing formwork system is lifted using the straight guide rail 25 and hydraulic system. The lower hanger 14 is installed under the load-bearing triangular frame 11 of the climbing formwork system. The reinforcing steel is tied, the wooden formwork 10 and the embedded parts 18 are installed, the formwork is closed, and the pouring of section 3 (i.e., transition section 6) is carried out.

[0056] S13, such as Figure 4 As shown, after the concrete of the third section (i.e., the third transition section 6) reaches its strength, the wooden formwork 10 is removed and moved to the upper truss 13. The wall-mounted device 21 is installed on the third section, the climbing formwork system rises upwards, the reinforcing steel is tied, the wooden formwork 10 and embedded parts 18 are installed, the formwork is closed, and the fourth section (i.e., the last transition section 6) is poured. Figure 4 As shown.

[0057] like Figure 5 As shown, the climbing formwork system includes a load-bearing triangular frame 11, a main load-bearing platform 12, an upper truss 13, and a lower hanger 14. The load-bearing triangular frame 11 is threadedly connected to the tower column via embedded parts 18. The main load-bearing platform 12 is installed on the upper part of the load-bearing triangular frame 11, the upper truss 13 is installed above the main load-bearing platform 12, and the lower hanger 14 is installed below the load-bearing triangular frame 11. The load-bearing triangular frame 11 includes triangular frame diagonal braces 17, and the tilt angle of the load-bearing triangular frame 11 can be adjusted by the triangular frame diagonal braces 17. The lower hanger 14 includes lower hanger diagonal braces 16. The lower hanger 14 has an adjustable tilt angle, and the upper truss 13 includes an upper truss diagonal brace 15. The upper truss diagonal brace 15 can adjust the tilt angle of the upper truss 13. The climbing formwork system in this embodiment has a total of six layers. The lower hanger 14 includes two layers, the main load-bearing platform 12 is one layer, and the upper truss 13 includes three layers. Each layer is equipped with a double channel steel beam. The beam is parallel to the outer facade of the lower pressure column. Anti-slip steel textured plate is laid on the beam to form a platform. The platform is enclosed as a whole by steel pipes and safety nets. Each platform is equipped with a manhole and a staircase connecting the two adjacent platforms.

[0058] It should be noted that the climbing formwork system includes the front climbing formwork 27, the side climbing formwork 28, and the chamfered climbing formwork 29. Before installing the wooden formwork 10, the upper truss 13 located on the side facade and chamfer of the lower tower column 1 needs to be adjusted to an inclined state by using the upper truss diagonal brace 15, so that the inclination angle of the wooden formwork 10 installed on the upper truss 13 is the same as the inclination angle of the transition section 6. The lower end of the wooden formwork 10 should be tightly pressed against the surface of the previously poured concrete structure to ensure no grout leakage and no misalignment.

[0059] S14, such as Figure 6 As shown, Figure 6 (a) in the diagram illustrates the front elevation of sections 1-5. Figure 6 (b) illustrates the side elevations of sections 1-5. After the concrete of section 4 (i.e., the final transition section 6) reaches its strength, the wooden formwork 10 is removed and moved to the upper truss 13. A wall-mounted device 21 is installed on the front elevation of section 4. Pads 20 and wall-mounted devices 21 are installed on the side elevations and chamfered corners of section 4. The climbing formwork 27 on the front elevation rises normally. The climbing formwork 28 on the side elevations and the chamfered climbing formwork 29 are lifted and fixed to the wall-mounted devices 21 with pads 20. The pads 20 allow for the smooth lifting of the straight guide rail 25 after the fifth section is poured. Figure 7 As shown, the pad 20 is placed between the embedded part 18 and the wall-mounted device 21, which can change the inclination angle of the straight guide rail 25 so that the straight guide rail 25 will not interfere with the fifth section when it is lifted; adjust the angle of the upper truss 13 of the climbing formwork system to adapt to the vertical section 7, tie the reinforcing bars, install the wooden formwork 10 and the embedded part 18, close the formwork and pour the fifth section (i.e. the first vertical section 7);

[0060] After the concrete of Section 5 (i.e., the first vertical section 7) reaches its strength, the wooden formwork 10 is removed and moved to the upper truss 13. The wall-mounted device 21 is installed on Section 5. The front climbing formwork 27 climbs upward normally. The straight guide rails 25 of the side climbing formwork 28 and the chamfered climbing formwork 29 are supported by pads 20, so that the straight guide rails 25 will not interfere with Section 5 when they are lifted, so that the side climbing formwork 28 and the chamfered climbing formwork 29 can climb upward smoothly. Then the steel bars are tied, the wooden formwork 10 and the embedded parts 18 are installed, the formwork is closed and the second vertical section 7 is poured.

[0061] S16, repeat step S15 until the construction of the vertical section 7 (sections 5-8) of the lower tower column 1 is completed.

[0062] like Figure 8 As shown, during the construction of transition section 6 and vertical section 7, four sets of hydraulic climbing formwork were used for each front facade of the lower tower column 1, two sets of hydraulic climbing formwork were used for each side facade, and two sets of hydraulic climbing formwork were used for each chamfer. Figure 9 As shown, during the construction of transition section 6 and vertical section 7, each side of the lower tower column 1 is constructed using wooden formwork 10.

[0063] S2. The small-angle section 8 of the lower tower column 1 is constructed using a combination of steel formwork and climbing formwork; specifically including:

[0064] S21, such as Figure 11 As shown, Figure 11 (a) in the diagram illustrates the front elevation of Sections 7-19. Figure 11(b) shows the side elevation of sections 7-19. After the concrete of section 8 (the last vertical section 7) reaches its strength, the wooden formwork 10 is removed and the upper truss 13 is moved back. Reinforcing diagonal braces 19 are added to the upper truss 13 to support the formwork. The wall attachment device 21 is installed on the front elevation of section 8. The pads 20 and the wall attachment device 21 are installed on the side elevation and chamfer of section 8. The pads 20 enable the straight guide rail 25 to be lifted smoothly after the pouring of section 9, avoiding interference between the straight guide rail 25 and section 9. The climbing formwork system climbs upward, the angle of the upper truss 13 of the climbing formwork system is adjusted to adapt to the small angle section 8, the reinforcing bars are tied, the wooden formwork 10 and the embedded parts 18 are installed, the formwork is closed and the pouring of section 9 (the first small angle section 8) is carried out.

[0065] S22, such as Figure 13 As shown, Figure 13 (a) in the diagram illustrates the front elevation of Sections 7-19. Figure 11 (b) illustrates the side elevations of sections 7-19. After the concrete of section 9 (the first small-angle section 8) reaches its strength, the wooden formwork 10 is removed and the upper truss 13 is moved back. A wall-mounting device 21 is installed on the front elevation of section 9, and pads 20 and wall-mounting devices 21 are installed on the side elevations of section 9. The chamfered climbing formwork 29 at the chamfer of section 9 is replaced with a steel formwork system 22. The steel formwork system 22 includes a lower steel formwork 23 and an upper steel formwork 24. The lower steel formwork 23 is installed on the first small-angle section 8 via embedded parts 18, as shown below. Figure 12 , 14 As shown, the lower steel formwork 23 is installed first and fixed on the embedded part 18 in section 9. Then the upper steel formwork 24 is installed and connected to the lower steel formwork 23 by bolts.

[0066] S23, the front facade climbing formwork 27 and the side facade climbing formwork 28 climb upwards, adjust the angle of the upper truss 13 of the climbing formwork system, tie the reinforcing bars, install the wooden formwork 10 and the embedded parts 18 on the front facade climbing formwork 27, install the steel formwork 30 and the embedded parts 18 on the side facade climbing formwork 28, install the embedded parts 18 on the inner side of the upper steel flip formwork 24, close the formwork and pour the 10th section (the second section with a small inclination angle 8);

[0067] After the concrete in Section S24, Section 10 (Section 2, Small Inclined Angle Section 8) reaches its strength, remove the wooden formwork 10 and the steel formwork 30 on the side climbing formwork 28, and move the upper truss 13 back. Install pads 20 and wall-mounting devices 21 on the front and side facades of Section 10. The front climbing formwork 27 and side climbing formwork 28 are raised upwards. Adjust the angle of the upper truss 13 of the climbing formwork system. Disassemble and separate the lower steel flip-formwork 23 from the embedded section of Section 9. Use a tower crane to lift the lower steel flip-formwork 23. The upper end of the upper steel formwork 24 is connected to the upper steel formwork 24 by bolts. At this time, the lower steel formwork 23 is located in the 10th section, and the upper steel formwork 24 is located in the 11th section to be constructed. The reinforcing bars are tied, and wooden formwork 10 and embedded parts 18 are installed on the front climbing formwork 27. Steel formwork 30 and embedded parts 18 are installed on the side climbing formwork 28. Embedded parts 18 are installed on the inside of the upper steel formwork 24. The formwork is closed and the 11th section (the third section with a small inclination angle 8) is poured.

[0068] S25, repeat step S24 until the construction of the small-angle section 8 (sections 9-13) of the lower tower column 1 is completed.

[0069] It should be noted that as the height increases, the inclination angle of the side facade and the chamfer of the small inclination section 8 gradually increases. By replacing the wooden formwork 10 on the side facade with steel formwork 30 and the chamfer climbing formwork 29 with a steel flipping formwork system 22, the support for the concrete and the maintenance of the alignment of the lower tower column 1 can be guaranteed. In addition, the gradual increase in the width of the small inclination section 8 will affect the upward movement of the straight guide rail 25. When the straight guide rail 25 still cannot move upward smoothly even with the use of pads 20, it is necessary to use a tower crane to replace the straight guide rail 25 with an arc-shaped guide rail to ensure the smooth upward movement of the climbing formwork system. In this embodiment, after the completion of the construction of section 12, the straight guide rail 25 needs to be replaced with an arc-shaped guide rail.

[0070] As the height increases, the width of the small angle section 8 continuously increases. Since the chamfered part is replaced with steel formwork 30, the wooden formwork 10 corresponding to the chamfered climbing formwork 29 can be applied to the position where the size changes on the front facade, which can save the amount of formwork used and realize the full utilization of the wooden formwork 10.

[0071] It is understandable that the side elevation of the small-angle segment 8 is curved, while the chamfer of the small-angle segment 8 is hyperboloid. Therefore, the steel formwork 30 of the steel formwork system 22 is a hyperboloid steel formwork 30. The steel formwork 30 for both the side elevation and the chamfer is fully fitted, meaning that the side elevation and the chamfer both use steel formwork 30. The steel formwork 30 for the side elevation and the chamfer is connected by locating pins and bolts, and the locating pins prevent misalignment.

[0072] S3. The large-angle section 9 of the lower tower column 1 is constructed using a combination of steel formwork, hanging frame, and climbing formwork; specifically including:

[0073] S31, such as Figure 15As shown, Figure 15 (a) in the diagram illustrates the front elevation of Sections 7-19. Figure 15 (b) in the diagram illustrates the side elevations of sections 7-19. Figure 15 (c) in the diagram illustrates the chamfering of sections 7-19. After the concrete of section 13 (the last section with a small inclination angle 8) reaches its strength, the wooden formwork 10 and the steel formwork 30 on the side climbing formwork 28 are removed, and the upper truss 13 is moved back. The upper truss diagonal brace 15, the tripod diagonal brace 17, and the lower hanger diagonal brace 16 are replaced with diagonal braces with stronger support capacity. The method for replacing the tripod diagonal brace 17 is as follows: fix the lifting point of the tower crane to the end of the crossbeam of the load-bearing tripod 11 and lift it up so that the tripod diagonal brace is not under stress, and then replace the tripod diagonal brace. The upper truss diagonal brace 15 and the lower hanger diagonal brace 16 can be directly replaced.

[0074] Wall-mounted devices 21 are installed on the front and side facades of Section 13. The climbing formwork 27 on the front facade and 28 on the side facades are raised upwards. The angle of the upper truss 13 of the climbing formwork system is adjusted. A tower crane is used to lift the lower steel formwork 23 to the upper end of the upper steel formwork 24 and connect it to the upper steel formwork 24. A hanging bracket system 26 is installed on the front facade of Section 13, such as... Figure 10 As shown, Figure 10 The illustration shows half of the cross-section during the pouring of section 19. Figure 10 The structure of the steel formwork system 22 is not shown in the diagram. The hanging bracket system 26 is installed between the climbing formwork 27 on the front facade and the steel formwork system 22 via embedded parts 18; as shown Figure 16 The diagram shown is a structural schematic of the hanging bracket system 26.

[0075] Because the width of the steepest section 9 increases very rapidly, the location of this width increase is... Figure 9 At the location where the dimensions change, which is the front facade, the pressure is relatively small. Therefore, a hanging system 26 is used for the installation and support of the wooden formwork 10. Figure 18 As shown, the front facade uses wooden formwork 10, while the side facades and chamfers use steel formwork 30. The scaffolding system 26 is low-cost and also provides a safe construction platform. The height of each platform of the scaffolding system 26 is the same as the height of each platform of the front facade climbing formwork 27.

[0076] Next, the reinforcing bars are tied, and wooden formwork 10 and embedded parts 18 are installed on the front facade climbing formwork 27 and the hanging system 26. Steel formwork 30 and embedded parts 18 are installed on the side facade climbing formwork 28. Embedded parts 18 are installed on the inside of the upper steel formwork 24. The formwork is closed, and the top of the steel formwork 30 on the side facade climbing formwork 28 is pulled against the main reinforcement in the tied reinforcing bars, so that part of the load borne by the steel formwork 30 is transferred to the tied reinforcing bars, which can reduce the pressure on the side facade climbing formwork 28 and ensure the stability of the structure.

[0077] Finally, the 14th section (the first section with a large inclination angle, section 9) was poured;

[0078] After the concrete in Section S32 and Section 14 reaches its strength, remove the wooden formwork 10 and the steel formwork 30 on the side facade climbing formwork 28. Then move the upper truss 13 and the vertical support frame of the hanging system 26. Install the wall-mounted device 21 on the front and side facades of the first section with a large inclination angle 9. The front facade climbing formwork 27 and the side facade climbing formwork 28 are raised upwards. Adjust the angle of the upper truss 13 of the climbing formwork system. Use a tower crane to lift the lower steel formwork 23 to the upper end of the upper steel formwork 24 and connect it to the upper steel formwork 24. Using a tower crane, the hanging system 26 is lifted and installed onto the embedded part 18 of the 14th section. The reinforcing bars are tied. Wooden formwork 10 and embedded parts 18 are installed on the climbing formwork 27 and the hanging system 26 on the front facade. Steel formwork 30 and embedded parts 18 are installed on the climbing formwork 28 on the side facade. Embedded parts 18 are installed on the inner side of the upper steel formwork 24. The formwork is closed. The top of the steel formwork 30 on the climbing formwork 28 on the side facade is pulled against the main reinforcing bars in the tied reinforcing bars. The 15th section (the second section with a large inclination angle 9) is poured.

[0079] S33, repeat step S32 until the construction of the large-angle section 9 of the lower tower column 1 is completed.

[0080] During the construction of the small-angle section 8 and large-angle section 9 in steps S2 and S3, after each time the climbing formwork system climbs up, the tripod bracing should be adjusted so that the main load-bearing platform 12 of the load-bearing triangular frame 11 is arranged horizontally, which facilitates the operation of construction personnel and improves the safety of the platform.

[0081] like Figure 17 As shown, the inclination angle of the side facade climbing formwork 28 gradually increases with the inclination angle of the lower tower column 1, resulting in a height difference between the height of each platform of the side facade climbing formwork 28 and the platform height of the front facade climbing formwork 27. To reduce the impact of this height difference, the height of the embedded parts 18 installed on the side facade climbing formwork 28 is adjusted according to the height of the top platform of the load-bearing triangular frame 11 of the front facade climbing formwork 27, so that the main load-bearing platform 12 of the load-bearing triangular frame 11 of the side facade climbing formwork 28 is at the same height as the main load-bearing platform 12 of the load-bearing triangular frame 11 of the front facade climbing formwork 27; the steel formwork 30 method of the steel formwork system 22 Holes are drilled all over the top and bottom of the formwork. The platform of the steel formwork system 22 uses an adjustable screw, allowing the platform of the steel formwork system 22 to be adjusted vertically. After the lower steel formwork 23 is lifted to the top of the upper steel formwork 24 using a tower crane, the platform height of the lower steel formwork 23 needs to be adjusted so that the platform height of the lower steel formwork 23 is the same as the height of the main load-bearing platform 12 of the load-bearing triangular frame 11 of the side facade climbing formwork 28. This ensures that the height of the main load-bearing platform 12 of the front facade climbing formwork 27, the main load-bearing platform 12 of the side facade climbing formwork 28, and the platform height of the lower steel formwork 23 are the same. Figure 17 The height of the middle and upper floors is the same, which facilitates construction.

[0082] In addition, the platform height of the upper steel formwork 24 also needs to be adjusted so that the platform height of the upper steel formwork 24 is the same as the first layer height of the upper truss 13 of the front facade climbing formwork 27, that is... Figure 17 The height of the +2 layer of the upper steel formwork 24 is the same as the height of the +2 layer of the climbing formwork 27 on the front facade. However, there is a height difference between the +2 layer of the upper steel formwork 24 and the +2 layer of the climbing formwork 28 on the side facade, and the height difference increases as you climb higher. Therefore, a ramp is built using cantilevered slabs to connect the platform of the upper steel formwork 24 with the first layer (the +2 layer of the climbing formwork 28 on the side facade) of the upper truss 13.

[0083] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A construction method for the lower tower column of a high-inclination, variable-section cable-stayed tower, characterized in that: include: S1. The transition section (6) and vertical section (7) of the lower tower column (1) of the cable tower are constructed using climbing formwork technology. The tower includes a lower tower column (1), which from bottom to top includes a transition section (6), a vertical section (7), a small-angle section (8), and a large-angle section (9). S2. The small-angle section (8) of the lower tower column (1) is constructed using a combination of steel formwork and climbing formwork. S3. The large-angle section (9) of the lower tower column (1) is constructed using a combination of steel formwork, hanging frame and climbing formwork. Step S2 includes: S21. After the last vertical section (7) is completed, a reinforcing brace (19) is added to the upper truss (13) to support the formwork. A wall-mounted device (21) is installed on the front facade of the last vertical section (7). Pads (20) and wall-mounted devices (21) are installed on the side facade and chamfer of the last vertical section (7). The climbing formwork system climbs upward and the construction of the first small-angle section (8) is carried out. S22. The climbing formwork system includes the front elevation climbing formwork (27), the side elevation climbing formwork (28), and the chamfered climbing formwork (29). After the first section of the small-angle section (8) is completed, a wall-mounted device (21) is installed on the front facade of the first section of the small-angle section (8), and a pad (20) and a wall-mounted device (21) are installed on the side facade of the first section of the small-angle section (8). The climbing formwork (27) on the front facade and the climbing formwork (28) on the side facade are raised upwards. The chamfered climbing formwork (29) at the chamfer of the first section of the small-angle section (8) is replaced with a steel flip-form system (22). The other parts of the small-angle section (8) are constructed using a combination of steel flip-form and climbing formwork. Step S3 includes: After the small-angle section (8) is completed, the front facade climbing formwork (27) and the side facade climbing formwork (28) are raised upwards, and the steel formwork system (22) is lifted by a tower crane. The hanging frame system (26) is installed on the front facade of the last small-angle section (8). The hanging frame system (26) is set between the front facade climbing formwork (27) and the steel formwork system (22). The large-angle section (9) is constructed using a combination of steel formwork + hanging frame + climbing formwork.

2. The construction method for the lower tower column of a high-inclination, variable-section cable-stayed tower according to claim 1, characterized in that: The width of the transition section (6) decreases linearly from bottom to top. In step S1, after the last transition section (6) is completed, the wall-mounted device (21) is installed on the front facade of the last transition section (6), and the pads (20) and wall-mounted devices (21) are installed on the side facade and chamfer of the last transition section (6). The climbing formwork system climbs upward and the angle of the upper truss (13) of the climbing formwork system is adjusted to adapt to the vertical section (7).

3. The construction method for the lower tower column of a high-inclination, variable-section cable-stayed tower according to claim 1, characterized in that: During the construction of the small-angle section (8), when the straight guide rail (25) cannot be moved smoothly using the pad block (20), the straight guide rail (25) is replaced with an arc-shaped guide rail using a tower crane.

4. The construction method for the lower tower column of a high-inclination, variable-section cable-stayed tower according to claim 1, characterized in that: The steel formwork (30) of the steel formwork system (22) is a hyperboloid steel formwork (30).

5. The construction method for the lower tower column of a high-inclination, variable-section cable-stayed tower according to claim 1, characterized in that: In step S3, before the front facade climbing formwork (27) and the side facade climbing formwork (28) are raised, the upper truss diagonal brace (15), the triangular frame diagonal brace (17) and the lower hanging frame diagonal brace (16) are replaced with diagonal braces with stronger support capacity. The method of replacing the triangular frame diagonal brace (17) includes fixing the lifting point of the tower crane to the end of the crossbeam of the load-bearing triangular frame (11) and lifting it up so that the triangular frame diagonal brace (17) is not under stress, and replacing the triangular frame diagonal brace (17).

6. The construction method for the lower tower column of a high-inclination, variable-section cable-stayed tower according to claim 5, characterized in that: In step S3, before pouring concrete, the top of the steel formwork (30) on the side climbing formwork (28) is pulled against the main reinforcement in the tied steel bars.

7. The construction method for the lower tower column of a high-inclination, variable-section cable-stayed tower according to claim 1, characterized in that: During the construction of the small-angle section (8) and the large-angle section (9), after each time the climbing formwork system climbs up, the main load-bearing platform (12) of the load-bearing triangular frame (11) is arranged horizontally by adjusting the triangular frame diagonal brace (17) of the climbing formwork system.

8. The construction method for the lower tower column of a high-inclination, variable-section cable-stayed tower according to claim 1, characterized in that: During the construction of the small-angle section (8) and the large-angle section (9), the height of the embedded parts (18) installed on the side facade climbing formwork (28) is adjusted according to the height of the top platform of the load-bearing triangular frame (11) of the front facade climbing formwork (27), so that the main load-bearing platform (12) of the load-bearing triangular frame (11) of the side facade climbing formwork (28) is the same as the main load-bearing platform (12) of the load-bearing triangular frame (11) of the front facade climbing formwork (27); During the construction of the small-angle section (8) and the large-angle section (9), the steel formwork system (22) includes a lower steel formwork (23) and an upper steel formwork (24). After the lower steel formwork (23) is lifted to the upper end of the upper steel formwork (24) by using a tower crane, the platform height of the lower steel formwork (23) is adjusted so that the platform height of the lower steel formwork (23) is the same as the height of the main load-bearing platform (12) of the load-bearing triangular frame (11) of the side facade climbing formwork (28). The platform height of the upper steel formwork (24) is adjusted so that the platform height of the upper steel formwork (24) is the same as the height of the first layer of the upper truss (13) of the front facade climbing formwork (27). The platform of the upper steel formwork (24) and the first layer of the upper truss (13) of the side facade climbing formwork (28) are connected by using cantilevered plates to form a ramp. During the construction of the steep angle section (9), the height of each platform of the hanging frame system (26) is the same as the height of each platform of the climbing formwork (27) on the front facade.

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