Steel box-core concrete combined cable tower construction method

Abstract

The application discloses a kind of steel box-core concrete combined cable tower construction methods, comprising the following steps: S1, the steel structure shell of steel-concrete combined section is divided into multiple steel tower blocks along vertical direction;Standard section is divided into core block and the side block of two sides;S2, hoist first section steel tower block, after installing formwork and reinforcement in steel tower block, fill concrete;S3, repeat the step S2 until the construction of steel-concrete combined section is completed;S4, hoist the core block of first section standard section on steel-concrete combined section, then hoist the side block of two sides in turn;After hoisting is completed, horizontal weld between core block, vertical weld between core block and the side block of two sides, horizontal weld between section are welded in turn;S5, after installing reinforcement in core block, pour concrete;S6, repeat the step S4-S5 until the construction of all remaining standard sections is completed.The application gives a complete and efficient steel box-core concrete combined cable tower construction method, which effectively guarantees the construction quality of cable tower.

Description

Technical Field

[0001] This invention relates to the field of cable tower construction technology. More specifically, this invention relates to a construction method for a steel box girder-concrete core composite cable tower. Background Technology

[0002] Based on the type of structural materials used in cable-stayed bridges, cable towers can be classified into concrete cable towers, steel cable towers, and steel-concrete composite cable towers. Concrete cable towers are the main type of tower used in existing large-span cable-stayed bridges in my country, such as the Sutong Yangtze River Bridge, the Shanghai-Suzhou-Tongzhou Yangtze River Bridge, and the Qingshan Bridge. These are generally constructed using hydraulic climbing formwork, which results in long construction periods, high safety risks, and difficulties in ensuring construction quality. Steel towers offer fast construction speed and high quality, but have high overall costs, large cross-sectional dimensions, and heavy segments, requiring advanced equipment hoisting capabilities. Steel-concrete composite cable tower structures can fully utilize the mechanical properties of both steel and concrete, offering better economic benefits. However, existing technologies lack suitable construction methods for steel-concrete composite cable towers, involving key and challenging aspects such as steel structure hoisting, concrete construction sequence, and structural positioning and installation. Therefore, there is an urgent need to propose a construction method for steel-concrete composite cable towers to address these issues. Summary of the Invention

[0003] One object of the present invention is to solve at least the above-mentioned problems and to provide at least the advantages that will be described later.

[0004] To achieve these objectives and other advantages according to the present invention, a construction method for a steel box-core concrete composite cable tower is provided. The steel box-core concrete composite cable tower is installed on a completed tower column and includes a steel-concrete composite section and multiple standard segments arranged sequentially from bottom to top along the height direction. The construction method for the steel box-core concrete composite cable tower includes the following steps:

[0005] S1. Pre-construction preparation: Divide the steel structure shell of the steel-concrete composite section into multiple steel tower blocks along the height direction; divide the standard segment into core blocks and side blocks set on both sides of the core blocks, wherein the core blocks are steel structure shells and the side blocks are steel box structures.

[0006] S2. Tie the bottom reinforcement of the first section of the steel tower block to the completed tower column, then hoist the first section of the steel tower block, install the required formwork and remaining reinforcement in the steel tower block, and then fill it with concrete.

[0007] S3. After the concrete strength in the steel tower block meets the requirements, repeat step S2 until the construction of the steel-concrete composite section is completed.

[0008] S4. Hoist the core block of the first standard segment onto the steel-concrete composite section, and then hoist the side blocks on both sides in sequence; after hoisting, first weld the vertical weld between the core block and the side blocks on both sides, and then weld the horizontal weld between the standard segment and the lower segment.

[0009] S5. After installing the reinforcing bars inside the core block, pour concrete.

[0010] S6. After the concrete strength in the core block meets the requirements, repeat steps S4 to S5 until the construction of all remaining standard segments is completed.

[0011] Preferably, before step S2, multiple supports are symmetrically installed on the completed tower column, and each support is provided with a three-way jack at its top.

[0012] Preferably, in step S2, an internal support truss is fixedly installed inside the first section of the steel tower block. During hoisting, the first section of the steel tower block and the internal support truss are hoisted together onto the support. The posture of the first section of the steel tower block is precisely adjusted by each of the three-way jacks. After the adjustment is in place, the internal support truss is fixedly connected to each of the supports, and each of the three-way jacks is removed.

[0013] Preferably, in step S4, the core block of each standard segment is divided into two segments along the height direction. After the two segments of the core block are hoisted in sequence, the horizontal weld between the two segments is first welded to form a complete core block, and then the side blocks on both sides are hoisted.

[0014] Preferably, in step S4, multiple matching and alignment devices are provided on the outer periphery of the upper and lower mating surfaces of the core block and the side block, and the core block and the side block are positioned and temporarily connected by the corresponding upper and lower matching and alignment devices during hoisting.

[0015] Preferably, the matching and alignment device includes an L-shaped plate, the vertical section of which is fixedly connected to the side wall of the core block or the side block, the horizontal section of which is flush with the upper and lower mating surfaces of the core block or the side block, and the horizontal section of which has a through-hole bolt hole; when the upper and lower core blocks or the side blocks are hoisted and mated, the horizontal sections of the two corresponding L-shaped plates are connected by bolts.

[0016] Preferably, in step S4, after the core block is hoisted into place, it is also welded and fixed to the installed segment below by a temporary splicing plate; in step S6, after the concrete strength in the core block meets the requirements, the temporary splicing plate and each of the matching and alignment devices are removed.

[0017] Preferably, in step S4, the vertical and horizontal welds of the side blocks on both sides are welded symmetrically.

[0018] Preferably, the vertical and circumferential reinforcing bars in the core block are installed before hoisting, and in step S5, the intermediate reinforcing bars and the reinforcing bars at the cable guide positions are installed in the core block.

[0019] Preferably, step S5 further includes setting a support frame between the core block and the side block before pouring concrete into the core block.

[0020] The present invention has at least the following beneficial effects:

[0021] 1. The construction method for steel box-core concrete composite cable towers provided by this invention divides the steel box-core concrete composite cable tower structure into a steel-concrete composite section and multiple standard segments. Based on the cable tower structure and hoisting capacity requirements, the steel-concrete composite section and standard segments are further subdivided. Then, the steel-concrete composite section and each standard segment are hoisted, reinforced with steel bars, and poured with concrete in sequence until the entire steel box-core concrete composite cable tower construction is completed. This provides a complete and efficient construction method for steel box-core concrete composite cable towers, effectively ensuring the construction quality of the steel box-core concrete composite cable tower.

[0022] 2. The construction method of steel box-core concrete composite cable tower provided by the present invention provides a method for positioning and installation control of each steel tower block in the steel-concrete composite section and the core block and edge block in the standard segment during the hoisting process, which improves the construction efficiency and construction quality of steel box-core concrete composite cable tower.

[0023] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0024] Figure 1 This is a side view of the steel box-core concrete composite cable tower of the present invention;

[0025] Figure 2 This is a schematic diagram of the steel-concrete composite section described in this invention;

[0026] Figure 3 This is a schematic diagram of the internal support truss described in this invention;

[0027] Figure 4 This is a schematic diagram of the structure of the standard segment described in this invention;

[0028] Figure 5 This is a schematic diagram showing the location of each weld in the standard segment described in this invention;

[0029] Figure 6 This is a top view of the core block described in this invention;

[0030] Figure 7 This is a side view of the matching and alignment device described in this invention.

[0031] Figure 8 This is a schematic diagram of the support frame described in this invention; Detailed Implementation

[0032] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0033] It should be noted that, unless otherwise specified, the experimental methods described in the following embodiments are all conventional methods, and the reagents and materials described are all commercially available unless otherwise specified. In the description of this invention, the terms "lateral", "longitudinal", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0034] like Figures 1 to 8 As shown, a construction method for a steel box-core concrete composite cable tower is provided. The steel box-core concrete composite cable tower 1 is installed on a completed tower column 2, and includes a steel-concrete composite section T1 and multiple standard segments (T2~Tn) arranged sequentially from bottom to top along the height direction. The construction method for the steel box-core concrete composite cable tower includes the following steps:

[0035] S1. Pre-construction preparation: Divide the steel structure shell of the steel-concrete composite section T1 into multiple steel tower blocks along the height direction; divide the standard segment into core block TnH and side blocks TnB set on both sides of the core block. The core block TnH is a steel structure shell, and the side block TnB is a steel box structure.

[0036] S2. Tie the bottom reinforcement of the first section of the steel tower block to the completed tower column 2, then hoist the first section of the steel tower block, install the bottom formwork and reinforcement inside the steel tower block, and then fill it with concrete.

[0037] S3. After the concrete strength in the steel tower block meets the requirements, repeat step S2 until the construction of the steel-concrete composite section T1 is completed.

[0038] S4. Hoist the core block T2H of the first standard segment T2 on the steel-concrete composite section T1, and then hoist the side blocks T2B on both sides in sequence; after hoisting, first weld the vertical weld 7 between the core block and the side blocks on both sides, and then weld the horizontal weld 8 between the standard segment and the lower segment.

[0039] S5. After installing the reinforcing bars in the core block T2H, pour concrete.

[0040] S6. After the concrete strength in the core block T2H meets the requirements, repeat steps S4 to S5 until the construction of all the remaining standard segments (T3 to Tn) is completed.

[0041] In the above technical solution, conventional cable-stayed bridge towers are generally divided into lower tower columns, middle tower columns, and upper tower columns from bottom to top. In this embodiment, the completed tower columns, including the lower and middle tower columns, are traditional reinforced concrete structures, while the upper tower column is the steel box-core concrete composite tower 1. The steel-concrete composite section T1 is located at the junction of the middle and upper tower columns, serving as a transition section between the lower reinforced concrete tower column and the upper steel box-core concrete composite tower. Each standard segment (T2~Tn) is a steel box-core concrete composite structure segment, and their number is determined by the tower height.

[0042] In step S1, the steel-concrete composite section T1 and the standard segments (T2~Tn) are first divided according to the bridge tower structure and the tower crane's lifting capacity. The steel structure shell of the steel-concrete composite section T1 is divided into multiple steel tower blocks along the height direction, referring to... Figure 2 In this embodiment, the structure is divided into steel tower blocks T1GH and T1CY; the steel-concrete composite section T1 is not divided into blocks in the plane to improve the integrity and installation accuracy of the steel-concrete composite section T1. (Refer to...) Figure 4The standard segments (T2~Tn) are divided into core blocks TnH and side blocks TnB in the plane. Furthermore, considering the presence of stay cable anchor blocks, the core block TnH of each standard segment is divided into two segments along the height direction. After the two segments of the core block TnH are hoisted sequentially, the horizontal weld between the two segments is first welded to form a complete core block TnH, and then the side blocks TnB on both sides are hoisted. Depending on the segment length and hoisting weight limitations, the corresponding side blocks TnB can also be divided into two segments along the height direction. In this embodiment, the side block T2B in the standard segment T2 is divided into two segments along the height direction. For the standard segment T2, the lower segment of the core block T2H is hoisted first, and then the lower segments of the two side blocks T2B are hoisted. After the vertical welds of the lower segment of the core block T2H and the lower segments of the two side blocks T2B are completed, the upper segment of the core block T2H and the upper segments of the two side blocks T2B are hoisted in sequence. Then the vertical welds between the upper segment of the core block T2H, the upper segments of the two side blocks T2B and the upper segments of the two side blocks T2B are welded. Finally, the horizontal welds between the upper and lower segments are welded.

[0043] Considering the precise positioning of the steel tower block, such as Figure 3As shown, before step S2, multiple supports 3 and the bottom reinforcement of the first steel tower block T1GH are symmetrically installed on the completed tower column 2. Each support 3 is equipped with a three-way jack 4 at its top. Then, in step S2, the first steel tower block T1GH is hoisted. Specifically, before hoisting, the top profile of the completed tower column 2 needs to be continuously observed to determine the theoretical position of the steel tower block relative to the top surface of the completed tower column 2, eliminating the influence of the environment on the profile error of the steel-concrete composite section. Furthermore, due to the relatively low structural rigidity of the first steel tower block T1GH, an internal support truss 5 is fixedly installed inside the first steel tower block T1GH to ensure that the deformation of the first steel tower block T1GH during hoisting meets the design and specification requirements. During hoisting, the first steel tower block T1GH and the internal support truss 5 are hoisted together onto the support 3. The posture of the first steel tower block T1GH is precisely adjusted using each of the three-way jacks 4 to place the steel tower block T1GH in the predetermined position. After adjustment, the internal support truss 5 is fixedly connected to each of the supports 3, and each of the three-way jacks 4 is removed. Then, the formwork and remaining reinforcing bars are installed inside the first steel tower block T1GH, and then concrete is poured. After the concrete strength meets the requirements, the construction of the steel-concrete composite section T1 is completed according to step S3. In actual construction, to avoid the internal support truss 5 affecting the reinforcement binding, after the concrete construction of the first section of the steel tower block T1GH is completed and reaches a certain strength, part of the internal support truss 5 can be removed. After the reinforcement binding of the second section of the steel tower block T1CY is completed, the steel tower block T1CY is hoisted, and the steel tower block T1CY is welded and fixed to the steel tower block T1GH before concrete pouring is carried out to complete the construction of the entire steel-concrete composite section T1.

[0044] In step S4, the core block T2H of the first standard segment T2 is first hoisted onto the steel-concrete composite section T1, and then the side blocks T2B on both sides are hoisted in sequence.

[0045] To control the installation accuracy of the core block TnH and the side block TnB, such as Figure 6 As shown, multiple matching and alignment devices 9 are provided on the outer periphery of the upper and lower mating surfaces of the core block TnH and the side block TnB. During hoisting, the core block TnH and the side block TnB are positioned and temporarily connected through the corresponding matching and alignment devices 9. Specifically, refer to... Figure 7The matching and alignment device 9 includes an L-shaped plate 10. The vertical section 103 of the L-shaped plate 10 is fixedly connected to the sidewalls of the core block TnH and the side block TnB. The horizontal section 101 of the L-shaped plate 10 is flush with the upper and lower mating surfaces of the core block TnH and the side block TnB, and the horizontal section 101 of the L-shaped plate 10 has a through bolt hole 102. When the upper and lower core blocks TnH or the side blocks TnB are hoisted and connected, the horizontal sections 101 of the two corresponding L-shaped plates 10 are connected by bolts to temporarily connect the upper and lower core blocks TnH or the side blocks TnB. Further, after the core block TnH is hoisted into place, it is also welded and fixed to the installed segment below by a temporary splicing plate. In step S6, when the concrete strength in the core block TnH meets the requirements, the temporary splicing plate and each of the matching and alignment devices 9 are removed. Preferably, in steps S2 and S3, during the construction of the steel-concrete composite section T1, multiple matching and alignment devices 9 are also provided on the outer periphery of the upper and lower mating surfaces of each steel tower block.

[0046] After hoisting and temporary connection are completed, the vertical weld 7 between the core block T2H and the side blocks T2B on both sides is welded first. Then, the horizontal weld 8 between the standard segment and the lower steel-concrete composite section T1 is welded. For standard segments T3 to Tn, the horizontal weld 8 is between them and the lower standard segments. To avoid the welding of the side blocks TnB affecting the shape of the core block TnH, the vertical and horizontal welds of the side blocks TnB on both sides are welded symmetrically.

[0047] Then, in step S5, reinforcing bars are installed and concrete is poured inside the core block T2H. Specifically, the vertical and circumferential reinforcing bars inside the core block TnH are installed before hoisting. In step S5, intermediate reinforcing bars and reinforcing bars at the cable guide positions are installed inside the core block TnH. That is, the vertical and circumferential reinforcing bars inside the core block TnH should be constructed on the platform below the tower and hoisted to the tower together with the core block TnH, reducing the construction time of the reinforcing bars on the tower and improving the construction efficiency of the cable tower. The concrete poured in the core block TnH is micro-expansion concrete. Before construction, the concrete mix ratio should be determined through experimental research and hydration heat simulation analysis, under the conditions of pumping, temperature control, and anti-voiding of the ultra-high cable tower. Preferably, the pouring height of the concrete in the core block TnH is 0.5m below its top surface to avoid concrete loss during welding of the core block above.

[0048] Furthermore, to prevent the outer wall of the core block TnH from deforming during concrete pouring, step S5 further includes setting a support frame between the core block TnH and the side block TnB before pouring concrete into the core block TnH. For example... Figure 8As shown, in this embodiment, the support frame includes a crossbeam 11 disposed between the core block TnH and the side block TnB. Both ends of the crossbeam 11 abut against the side wall of the side block TnB. Then, the lead screw 12 and the pad beam 13 are respectively disposed on both sides of the crossbeam 11. The other ends of the lead screw 12 and the pad beam 13 abut against the side wall of the side block TnB and the side wall of the core block TnH, respectively, thereby providing support for the two side walls of the core block TnH.

[0049] In step S6, after the concrete strength in the core block T2H meets the requirements, steps S4 to S5 are repeated until the construction of all the remaining standard segments (T3 to Tn) is completed.

[0050] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A construction method for a steel-box-core concrete composite cable tower, wherein the steel-box-core concrete composite cable tower is installed on a completed tower column, comprising a steel-concrete composite section and multiple standard segments arranged sequentially from bottom to top along the height direction; characterized in that, The construction method for the steel box-core concrete composite cable tower includes the following steps: S1. Pre-construction preparation: Divide the steel structure shell of the steel-concrete composite section into multiple steel tower blocks along the height direction; divide the standard segment into core blocks and side blocks set on both sides of the core blocks, wherein the core blocks are steel structure shells and the side blocks are steel box structures. S2. Tie the bottom reinforcement of the first section of the steel tower block to the completed tower column, then hoist the first section of the steel tower block, install the required formwork and remaining reinforcement in the steel tower block, and then fill it with concrete. S3. After the concrete strength in the steel tower block meets the requirements, repeat step S2 until the construction of the steel-concrete composite section is completed. S4. Hoist the core block of the first standard segment onto the steel-concrete composite section, and then hoist the side blocks on both sides in sequence; after hoisting, first weld the vertical weld between the core block and the side blocks on both sides, and then weld the horizontal weld between the standard segment and the lower segment. Each of the standard segments is divided into two segments along the height direction. After the two segments of the core block are hoisted in sequence, the horizontal weld between the two segments is first welded to form a complete core block, and then the side blocks on both sides are hoisted. S5. After installing the reinforcing bars inside the core block, pour concrete. S6. After the concrete strength in the core block meets the requirements, repeat steps S4 to S5 until the construction of all the remaining standard segments is completed. Before step S2, multiple supports are symmetrically installed on the completed tower column, and a three-way jack is provided on the top of each support. In step S2, an internal support truss is fixedly installed inside the first section of the steel tower block. During hoisting, the first section of the steel tower block and the internal support truss are hoisted together onto the support. The posture of the first section of the steel tower block is precisely adjusted by each of the three-way jacks. After the adjustment is in place, the internal support truss is fixedly connected to each of the supports, and each of the three-way jacks is removed.

2. The construction method for a steel box-core concrete composite cable tower as described in claim 1, characterized in that, In step S4, multiple matching and alignment devices are provided on the outer periphery of the upper and lower mating surfaces of the core block and the edge block. During hoisting, the core block and the edge block are positioned and temporarily connected by the corresponding matching and alignment devices.

3. The construction method for a steel box-core concrete composite cable tower as described in claim 2, characterized in that, The matching and alignment device includes an L-shaped plate. The vertical section of the L-shaped plate is fixedly connected to the side wall of the core block or the side block. The horizontal section of the L-shaped plate is flush with the upper and lower mating surfaces of the core block or the side block. The horizontal section of the L-shaped plate has a through screw hole. When the upper and lower core blocks or the side blocks are hoisted and mated, the horizontal sections of the two corresponding L-shaped plates are connected by bolts.

4. The construction method for a steel box-core concrete composite cable tower as described in claim 2, characterized in that, In step S4, after the core block is hoisted into place, it is also welded and fixed to the installed segment below by a temporary splicing plate; in step S6, when the concrete strength inside the core block meets the requirements, the temporary splicing plate and each of the matching and alignment devices are removed.

5. The construction method for a steel box-core concrete composite cable tower as described in claim 1, characterized in that, In step S4, the vertical and horizontal welds of the side blocks on both sides are welded symmetrically.

6. The construction method for a steel box-core concrete composite cable tower as described in claim 1, characterized in that, The vertical and circumferential reinforcing bars in the core block are installed before hoisting. In step S5, the intermediate reinforcing bars and the reinforcing bars at the cable guide positions are installed in the core block.

7. The construction method for a steel box-core concrete composite cable tower as described in claim 1, characterized in that, Step S5 also includes setting up a support frame between the core block and the side block before pouring concrete into the core block.

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