Method for assembling and disassembling construction platform for maintaining and reinforcing tower top steel structure of multi-tower cable-stayed bridge

Abstract

The invention relates to a method for assembling and disassembling a construction platform for maintaining and reinforcing a tower top steel structure of a multi-tower cable-stayed bridge, which adopts a cantilever hanger to assist in hoisting the tower top of a cable tower to assemble, displace and install, effectively improves the assembly efficiency and the installation precision of a steel truss construction platform, and utilizes uninstalled rod pieces transported to the tower top as counter weight pieces, so that the construction platform is convenient to assemble and disassemble. The construction safety of the symmetric cantilever steel truss construction platform is ensured; the safety and the stability of the cantilever steel truss construction platform during operation are effectively ensured by adopting a bag water pressure weight and balance weight technology in the cantilever steel truss construction platform; by adopting the technology of closing the canopy at the upper part of the safety protection fence, the safety of the construction site at the top of the main tower of the cable bent tower in rainy days is effectively improved.

Description

Technical Field

[0001] The invention belongs to the technical field of bridge engineering, and in particular relates to a method for assembling and disassembling a construction platform for repairing and reinforcing tower tops of a multi-tower cable-stayed bridge. Background Art

[0002] With the progress of bridge engineering construction, there are more and more bridge projects in operation, and the structural construction is more complex and diverse. Many bridges have encountered some problems that need to be repaired and reinforced after years of operation. Especially when repairing and reinforcing multi-tower cable-stayed bridges, the top priority is the safety of existing line construction and driving safety. The installation and removal of the tower top construction platform is a key step in the repair and reinforcement of cable-stayed bridges. It is necessary to ensure the safety of construction workers and construction quality. The existing technology needs to be improved, so there is an urgent need for a more effective measure to solve this problem. Summary of the invention

[0003] The purpose of the present invention is to overcome the deficiencies in the prior art and to provide a method for assembling and disassembling a construction platform for repairing and reinforcing a tower top steel structure of a multi-tower cable-stayed bridge.

[0004] The method for assembling and disassembling a construction platform for repairing and reinforcing a tower top steel structure of a multi-tower cable-stayed bridge comprises the following steps:

[0005] Step 1: Install the bottom hoop structure at the side end of the top of the main tower, install the bottom platform of the safety protection enclosure, install the enclosure frame around the bottom platform of the safety protection enclosure, and install a closed canopy on the top of the enclosure frame;

[0006] Step 2: Install a temporary hoisting structure on the top of the main tower of the cable tower to hoist the components of the cantilever steel truss construction platform;

[0007] Step 3: Set the cantilever steel truss construction platform embedded parts on both sides of the top of the cable tower main tower, lay a cushion beam in the center of the top of the cable tower main tower, and assemble the middle part of the cantilever steel truss construction platform;

[0008] Step 4: Push the middle part of the assembled cantilever steel truss construction platform to the left to assemble the right cantilever part; push the assembled cantilever steel truss construction platform part to the right to assemble the left cantilever part;

[0009] Step 5: Move the cantilever steel truss construction platform to both sides of the middle part of the top of the main tower to form a symmetrical structure;

[0010] Step 6. Install the pulley block and lifting system on the left cantilever and the right cantilever.

[0011] Preferably, the cantilever steel truss construction platform includes a middle part, a left cantilever part and a right cantilever part, which are assembled in three times; in step three, a cushion beam is laid in the center of the top of the main tower of the cable tower, and the rods and parallel connection structure of the middle part of the cantilever steel truss construction platform are assembled above the cushion beam, and the rods are bolted together by pins; in steps four to five, the assembled cantilever steel truss construction platform part is translated so that the left cantilever part or the right cantilever part to be assembled is located above the main tower of the cable tower.

[0012] Preferably, in step four, when assembling the right cantilever part of the tower top cantilever steel truss construction platform, the completed cantilever steel truss construction platform part is pushed to the left, so that the right end of the middle part of the cantilever steel truss construction platform is moved above the pad beam, and a first counterweight is set above the right end of the middle part of the cantilever steel truss construction platform, and the middle part of the cantilever steel truss construction platform is temporarily welded and fixed to the embedded parts of the cantilever steel truss construction platform on the left side, and then the right cantilever part is assembled at the right end of the middle part of the cantilever steel truss construction platform; the left cantilever part is assembled by the same method, but in the opposite direction.

[0013] Preferably, in step four, when the cantilever steel truss construction platform is pushed to the left or right side, one end of the assembled cantilever steel truss construction platform part is moved to above the pad beam in the middle of the top of the main tower of the cable tower, and a counterweight is arranged above the end of the cantilever steel truss construction platform here, and the counterweight is specifically a rod that has been transported to the top of the tower and has not yet been installed.

[0014] Preferably, in step six, the pulley block includes a second pulley block, the hoisting system includes a second winch, a second winch limiting groove, a second winch hoisting wire rope and a construction hanging basket, and weight bags are symmetrically arranged on the cantilever steel truss construction platform for horizontal balancing weights, and a safety net is laid on the left and right cantilevers of the cantilever steel truss construction platform.

[0015] Preferably, in step one, a lightning rod is installed in the middle part of the main tower of the cable tower, and a bottom clamp structure is installed at the side end of the top of the main tower of the cable tower. The bottom clamp structure supports the bottom platform of the safety protection enclosure, and vertical connecting columns of the safety protection enclosure are installed at the four corners of the bottom platform of the safety protection enclosure. The vertical connecting columns of the safety protection enclosure are equipped with tower top lighting lamps. Adjacent vertical connecting columns of the safety protection enclosure are connected by three-layer horizontal connecting rods of the safety protection enclosure. Several vertical connecting rods of the safety protection enclosure are installed between adjacent vertical connecting columns of the safety protection enclosure. The safety protection enclosure is installed on the inner side of the enclosure frame composed of the vertical connecting columns of the safety protection enclosure, the horizontal connecting rods of the safety protection enclosure and the vertical connecting rods of the safety protection enclosure, and a closed canopy is installed on the upper horizontal connecting rods of the safety protection enclosure. The length, width and height dimensions of the safety protection enclosure are all larger than the steel structure construction platform on the top of the tower.

[0016] Preferably, after the tower top cantilever steel truss construction platform is installed and inspected and qualified, the operation of the tower top cantilever steel truss construction platform is started. After the operation of the tower top cantilever steel truss construction platform is completed, the cantilever steel truss construction platform is dismantled. The disassembly sequence is opposite to the assembly and shifting installation sequence of the cantilever hanger auxiliary lifting tower top.

[0017] The beneficial effects of the present invention are:

[0018] 1) The present invention adopts the technology of quickly installing the safety protection enclosure on the top of the cable tower with the bottom clamp, which effectively improves the safety protection capability of the cable tower top construction site. The easily expandable connection method greatly improves the construction efficiency and reduces the operation difficulty of the staff.

[0019] 2) The symmetrical cantilever steel truss construction platform at the top of the cable tower of the present invention adopts the cantilever hanger-assisted lifting cable tower top assembly and displacement installation technology, which effectively improves the assembly efficiency and installation accuracy of the steel truss construction platform, and utilizes the uninstalled rods transported to the top of the tower as counterweights, thereby ensuring the safety of the construction of the symmetrical cantilever steel truss construction platform.

[0020] 3) The present invention adopts the water pressure weight and balance counterweight technology in the bag of cantilever steel truss construction platform, which effectively ensures the safety and stability of the cantilever steel truss construction platform during operation.

[0021] 4) The present invention adopts the technology of enclosing the upper part of the safety protection enclosure to effectively improve the safety of the construction site on the top of the main tower of the cable tower on rainy days. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the structure of the safety protection enclosure that can be quickly installed on the top of the bottom hoop tower when the canopy is in the closed state;

[0023] Figure 2 It is a schematic diagram of the structure of the safety protection enclosure that can be quickly installed on the top of the bottom hoop tower when the canopy is in the open state;

[0024] Figure 3 This is a schematic diagram of the installation structure of the temporary steel hanger;

[0025] Figure 4 This is a schematic diagram of the embedded parts structure of the cantilever steel truss construction platform on the top of the tower;

[0026] Figure 5 This is a schematic diagram of the assembly structure of the middle part of the cantilever steel truss construction platform on the top of the tower;

[0027] Figure 6 It is a structural schematic diagram of the middle part of the assembled tower top cantilever steel truss construction platform being pushed to the left;

[0028] Figure 7It is a schematic diagram of the construction platform structure for assembling the cantilever steel truss construction platform at the top of the tower for the right cantilever part;

[0029] Figure 8 It is a schematic diagram of the structure of the cantilever steel truss construction platform of the assembled tower top pushed to the right;

[0030] Fig. 9 It is a schematic diagram of the construction platform structure for assembling the cantilever steel truss of the tower top for the left cantilever part;

[0031] Fig.10 It is a schematic diagram of the structure of the construction platform of the cantilever steel truss of the assembled tower top being pushed to the left;

[0032] Fig.11 It is a structural schematic diagram of the pulley block and hoisting system of the cantilever steel truss construction platform on the top of the tower.

[0033] In the figure: 1-main tower of cable tower, 2-lightning rod, 3-bottom hoop structure, 4-bottom platform of safety protection enclosure, 5-vertical connecting column of safety protection enclosure, 6-horizontal connecting rod of safety protection enclosure, 7-vertical connecting rod of safety protection enclosure, 8-safety protection enclosure, 9-tower top lighting, 10-enclosed canopy, 11-first chemical bolt, 12-first winch, 13-limiting groove of first winch, 14-temporary hanger of steel section, 15-lifting wire rope of first winch, 16-first pulley block, 17-lifting object outside the tower, 1 8-the second chemical bolt, 19-base, 20-stiffening plate, 21-pad beam, 22-lower chord, 23-upper chord, 24-diagonal web, 25-vertical pole, 26-pin shaft, 27-the first counterweight, 28-lower crossbeam, 29-upper crossbeam, 30-right cantilever part, 31-left cantilever part, 32-the second counterweight, 33-the second winch, 34-the second winch limiting groove, 35-safety net, 36-ballast bag water, 37-the second pulley block, 38-construction hanging basket, 39-the second winch hoisting wire rope. DETAILED DESCRIPTION

[0034] The present invention is further described below in conjunction with embodiments. The description of the following embodiments is only used to help understand the present invention. It should be noted that for ordinary persons in the art, without departing from the principle of the present invention, the present invention can also be modified in some ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0035] Embodiment 1

[0036] As an example, Figure 1 To the picture Fig.11 As shown in the figure, the main construction process of the installation and disassembly of the steel structure construction platform for the repair and reinforcement of the tower top of the multi-tower cable-stayed bridge is as follows:

[0037] Step 1: Install safety protection enclosure: Figure 1 and Figure 2 As shown, a lightning rod 2 is installed in the middle of the main tower 1 of the cable tower, a bottom hoop structure 3 is installed at the side end of the top of the main tower 1 of the cable tower, and a safety protection enclosure bottom platform 4 is supported on the bottom hoop structure 3. Safety protection enclosure vertical connecting columns 5 are installed at the four corners of the safety protection enclosure bottom platform 4. The safety protection enclosure vertical connecting columns 5 are equipped with tower top lighting lamps 9. Adjacent safety protection enclosure vertical connecting columns 5 are connected by three-layer safety protection enclosure horizontal connecting rods 6. A plurality of safety protection enclosure vertical connecting rods are installed between adjacent safety protection enclosure vertical connecting columns 5. The safety fence 8 is installed inside the enclosure frame composed of the connecting rod 7, the safety fence vertical connection column 5, the safety fence transverse connection rod 6 and the safety fence vertical connection rod 7. A closed canopy 10 is installed on the upper safety fence transverse connection rod 6. The safety fence 8 is larger than the tower top steel structure construction platform in length, width and height. Closing the closed canopy 10 on rainy days can protect the tower top steel structure construction platform and the staff. The closed canopy 10 is in a closed state on non-rainy days.

[0038] Step 2. Preparation for the installation of the cantilever steel truss construction platform: After the cantilever steel truss construction platform is processed in the factory, it is pre-assembled first to ensure that each rod is processed correctly and mark the installation position of each rod.

[0039] Step 3: Install temporary steel hanger: Figure 3 As shown, the first chemical bolt 11, the first hoist 12, the first hoist limit groove 13, the steel temporary hanger 14, the first hoist hoisting wire rope 15 and the first pulley block 16 are transported from the main tower 1 of the cable tower to the top of the main tower 1 of the cable tower, and the steel temporary hanger 14, the first hoist 12, the first hoist hoisting wire rope 15 and the first pulley block 16 are installed on the top of the main tower 1 of the cable tower. The steel temporary hanger 14 is fixed to the top of the main tower 1 of the cable tower by means of the first chemical bolt 11 embedding reinforcement, and the first hoist 12 is limited by the first hoist limit groove 13. The temporary hoisting structure composed of the first chemical bolt 11, the first hoist 12, the first hoist limit groove 13, the steel temporary hanger 14, the first hoist hoisting wire rope 15 and the first pulley block 16 is used to hoist the hoisting object 17 outside the tower, and to assist in hoisting the cantilever steel truss construction platform.

[0040] Step 4: Construction of embedded parts of the cantilever steel truss construction platform on the top of the tower: Figure 4 As shown, the embedded parts of the cantilever steel truss construction platform at the top of the cable tower main tower 1 are set by the second chemical bolt 18, and the base 19 and the stiffening plate 20 are welded.

[0041] Then the middle part, right cantilever part and left cantilever part of the cantilever steel truss construction platform are assembled in sections, and then the pulley block and lifting system are installed on the left cantilever and the right cantilever to complete the installation of the cantilever steel truss construction platform and carry out the cantilever steel truss construction platform operation. After the construction of the cantilever steel truss construction platform on the top of the tower is completed, the cantilever steel truss construction platform is disassembled. The disassembly sequence is opposite to the assembly, shifting and installation sequence of the cantilever hanger auxiliary lifting tower top.

[0042] Embodiment 2

[0043] As another embodiment, this embodiment 2 proposes, based on the embodiment 1, a more specific method for assembling and disassembling a construction platform for repairing and reinforcing a tower top steel structure of a multi-tower cable-stayed bridge, such as Figures 5 to 11 As shown:

[0044] In step 4, the middle part of the cantilever steel truss construction platform on the top of the tower is assembled: the cushion beam 21 is laid, and the lower chord 22, upper chord 23, diagonal web members 24, vertical rods 25 and flat joint structure of the middle part of the cantilever steel truss construction platform are assembled, and all rods are bolted together by pins 26.

[0045] Push the middle part of the assembled tower top cantilever steel truss construction platform to the left: Use the uninstalled rod transported to the tower top as the first counterweight 27, push the middle part of the assembled cantilever steel truss construction platform to the left, and temporarily weld it to the base 19 to fix it.

[0046] Assembling the right cantilever part of the tower top cantilever steel truss construction platform: assembling the lower chord 22, upper chord 23, diagonal web 24, vertical rod 25, lower cross beam 28 and upper cross beam 29 of the right cantilever part 30 of the cantilever steel truss construction platform, the lower chord 22 and the upper chord 23 are welded and connected, and the other rods are bolted by the pin 26.

[0047] Push the assembled tower top cantilever steel truss construction platform to the right: Use the uninstalled rod transported to the tower top as the second counterweight 32, push the assembled cantilever steel truss construction platform part to the right, and temporarily weld it to the base 19 to fix it.

[0048] Assembling the left cantilever part of the tower top cantilever steel truss construction platform: assembling the lower chord 22, upper chord 23, diagonal web 24, vertical rod 25, lower cross beam 28 and upper cross beam 29 of the left cantilever part 31 of the cantilever steel truss construction platform, the lower chord 22 and the upper chord 23 are welded and connected, and the other rods are bolted by the pin 26.

[0049] Push the assembled tower top cantilever steel truss construction platform to the left: push the hoisted cantilever steel truss construction platform to the left to form a symmetrical structure on both sides of the middle part of the top of the cable tower main tower 1, position the cantilever steel truss construction platform, and weld the lower chord 22 of the cantilever steel truss construction platform to the base 19.

[0050] Installation of the pulley block and hoisting system of the cantilever steel truss construction platform on the top of the tower: install the second winch 33, the second winch limit slot 34, the second winch hoisting wire rope 39, the second pulley block 37, and the construction hanging basket 38 of the cantilever steel truss construction platform, and hoist the internal pressure bag water 36 balancing weight of the cantilever steel truss construction platform, and lay the safety protection net 35.

[0051] It should be noted that the parts in this embodiment that are the same or similar to those in the first embodiment can be referenced to each other and will not be described in detail in this application.

[0052] Embodiment 3

[0053] As another embodiment, this embodiment 3 is proposed on the basis of embodiments 1 and 2. The multi-tower cable-stayed bridge repair and reinforcement tower top steel structure construction platform obtained by this method is installed on the top of the main tower 1 of the cable tower. Specifically:

[0054] A bottom hoop structure 3 is installed at the side end of the top of the main tower 1 of the cable tower, and a safety protection enclosure bottom platform 4 is supported on the bottom hoop structure 3; a temporary hoisting structure is installed on the top of the main tower 1 of the cable tower, which is used to hoist the hoisting objects 17 outside the tower and assist in hoisting the cantilever steel truss construction platform;

[0055] The cantilever steel truss construction platform forms a symmetrical structure on both sides of the middle part of the top of the cable tower main tower 1. Both ends of the cantilever steel truss construction platform are cantilevered to the outside of the cable tower main tower 1 and are respectively provided with a second pulley block 37 and a construction hanging basket 38.

[0056] A lightning rod 2 is installed in the middle of the main tower 1 of the cable tower, and a bottom hoop structure 3 is installed at the side end of the top of the main tower 1 of the cable tower. The bottom hoop structure 3 is connected to the bottom platform 4 of the safety protection enclosure. The four corners of the bottom platform 4 of the safety protection enclosure are installed with safety protection enclosure vertical connecting columns 5. The safety protection enclosure vertical connecting columns 5 are equipped with tower top lighting lamps 9. The adjacent safety protection enclosure vertical connecting columns 5 are connected by three-layer safety protection enclosure horizontal connecting rods 6. A plurality of safety protection enclosure vertical connecting rods are installed between the adjacent safety protection enclosure vertical connecting columns 5. A safety protection fence 8 is installed on the inner side of the enclosure frame composed of a safety protection fence vertical connecting column 5, a safety protection fence transverse connecting rod 6 and a safety protection fence vertical connecting rod 7. A closed canopy 10 is installed on the upper safety protection fence transverse connecting rod 6. The safety protection fence 8 is larger than the tower top steel structure construction platform in terms of length, width and height. Closing the closed canopy 10 on rainy days can protect the tower top steel structure construction platform and the staff. The closed canopy 10 is in a closed state on non-rainy days.

[0057] The first chemical bolt 11, the first hoist 12, the first hoist limit groove 13, the steel temporary hanger 14, the first hoist hoisting wire rope 15 and the first pulley block 16 are transported from the cable tower main tower 1 to the top of the cable tower main tower 1, and the steel temporary hanger 14, the first hoist 12, the first hoist hoisting wire rope 15 and the first pulley block 16 are installed on the top of the cable tower main tower 1. The steel temporary hanger 14 is fixed to the top of the cable tower main tower 1 by means of the first chemical bolt 11 embedding reinforcement, and the first hoist 12 is limited by the first hoist limit groove 13. The temporary hoisting structure composed of the first chemical bolt 11, the first hoist 12, the first hoist limit groove 13, the steel temporary hanger 14, the first hoist hoisting wire rope 15 and the first pulley block 16 is used to hoist the hoisting object 17 outside the tower, and assists in hoisting the cantilever steel truss construction platform.

[0058] Embodiment 4

[0059] As another embodiment, this embodiment 4 proposes, on the basis of the embodiment 3, a more specific construction platform for repairing and reinforcing the tower top steel structure of a multi-tower cable-stayed bridge:

[0060] The temporary lifting structure includes a temporary steel hanger 14, a first winch 12, a first winch lifting wire rope 15 and a first pulley block 16. The temporary steel hanger 14 is fixed to the top of the cable tower main tower 1 by means of a first chemical bolt 11 embedded reinforcement. The first winch 12 is limited by a first winch limiting groove 13. A welded base 19 and a stiffening plate 20 are provided on the top of the cable tower main tower 1 by a second chemical bolt 18 as embedded parts of a cantilever steel truss construction platform. The cantilever steel truss construction platform forms a symmetrical structure on both sides of the middle part of the top of the cable tower main tower 1, and the cantilever steel truss construction platform is welded and fixed on the base 19. The cantilever steel truss construction platform includes a second winch 33, a second winch limiting groove 34, a second winch lifting wire rope 39, a second pulley block 37 and a construction hanging basket 38.

[0061] The hoisting objects 17 outside the tower include: a second chemical bolt 18, a base 19, a stiffening plate 20, a cushion beam 21, a lower chord 22, an upper chord 23, a diagonal web 24, a vertical pole 25, a pin 26, a lower crossbeam 28, an upper crossbeam 29, a second winch 33, a second winch limit groove 34, a safety net 35, a weight bag water 36, a second pulley block 37, a construction hanging basket 38 and a second winch hoisting wire rope 39.

[0062] The cantilever steel truss construction platform includes a middle part, a left cantilever part and a right cantilever part, which are assembled and constructed in three times; specifically, the parts that are hoisted above the main tower 1 of the cable tower but have not been used are used as counterweights to press the end of the cantilever steel truss construction platform close to the center of the main tower 1 when the cantilever steel truss construction platform is assembled section by section, such as Figure 6 The first counterweight 28 or Figure 8 The second counterweight 32 in the.

[0063] It should be noted that the parts in this embodiment that are the same or similar to those in Embodiment 3 can be referenced to each other and will not be described in detail in this application.

[0064] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

Claims

1. A method for assembling and disassembling a construction platform for repairing and reinforcing a tower top steel structure of a multi-tower cable-stayed bridge, characterized in that: The following steps are involved: Step 1: Install the bottom hoop structure at the side end of the top of the main tower, install the bottom platform of the safety protection enclosure, install the enclosure frame around the bottom platform of the safety protection enclosure, and install a closed canopy on the top of the enclosure frame; Step 2: Install a temporary hoisting structure on the top of the main tower of the cable tower to hoist the components of the cantilever steel truss construction platform; Step 3: Set the cantilever steel truss construction platform embedded parts on both sides of the top of the cable tower main tower, lay a cushion beam in the center of the top of the cable tower main tower, and assemble the middle part of the cantilever steel truss construction platform; Step 4: Push the middle part of the assembled cantilever steel truss construction platform to the left to assemble the right cantilever part; push the assembled cantilever steel truss construction platform part to the right to assemble the left cantilever part; Step 5: Move the cantilever steel truss construction platform to both sides of the middle part of the top of the main tower to form a symmetrical structure; Step 6. Install the pulley block and lifting system on the left cantilever and the right cantilever.

2. The method for assembling and disassembling a construction platform for repairing and reinforcing a multi-tower cable-stayed bridge tower top steel structure according to claim 1, characterized in that: The cantilever steel truss construction platform includes a middle part, a left cantilever part and a right cantilever part, which are assembled in three times; in step three, a cushion beam is laid in the center of the top of the main tower of the cable tower, and the rods and parallel connection structure of the middle part of the cantilever steel truss construction platform are assembled above the cushion beam, and the rods are bolted together by pins; in steps four and five, the assembled cantilever steel truss construction platform part is translated so that the left cantilever part or the right cantilever part to be assembled is located above the main tower of the cable tower.

3. The method for assembling and disassembling a construction platform for repairing and reinforcing a multi-tower cable-stayed bridge tower top steel structure according to claim 1, characterized in that: In step 4, when assembling the right cantilever part of the tower top cantilever steel truss construction platform, push the completed cantilever steel truss construction platform part to the left, so that the right end of the middle part of the cantilever steel truss construction platform is moved above the pad beam, and a first counterweight is set above the right end of the middle part of the cantilever steel truss construction platform, and the middle part of the cantilever steel truss construction platform is temporarily welded and fixed to the embedded parts of the cantilever steel truss construction platform on the left side, and then assemble the right cantilever part at the right end of the middle part of the cantilever steel truss construction platform; assemble the left cantilever part in the same way, but in the opposite direction.

4. The method for assembling and disassembling a construction platform for repairing and reinforcing a multi-tower cable-stayed bridge tower top steel structure according to claim 1, characterized in that: In step four, when the cantilever steel truss construction platform is pushed to the left or right side, one end of the assembled cantilever steel truss construction platform part is moved to above the pad beam in the middle of the top of the main tower of the cable tower, and a counterweight is arranged above the end of the cantilever steel truss construction platform here. The counterweight is specifically a rod that has been transported to the top of the tower and has not yet been installed.

5. The method for assembling and disassembling a construction platform for repairing and reinforcing a multi-tower cable-stayed bridge tower top steel structure according to claim 1, characterized in that: In step six, the pulley block includes a second pulley block, the lifting system includes a second winch, a second winch limiting groove, a second winch lifting wire rope and a construction hanging basket, and weight bags are symmetrically arranged on the cantilever steel truss construction platform for horizontal balancing weights, and a safety net is laid on the left and right cantilevers of the cantilever steel truss construction platform.

6. The method for assembling and disassembling a construction platform for repairing and reinforcing a multi-tower cable-stayed bridge tower top steel structure according to claim 1, characterized in that: In step one, a lightning rod is installed on the middle part of the main tower of the cable tower, and a bottom clamp structure is installed on the side end of the top of the main tower of the cable tower. The bottom clamp structure is connected to the bottom platform of the safety protection enclosure, and vertical connecting columns of the safety protection enclosure are installed at the four corners of the bottom platform of the safety protection enclosure. The vertical connecting columns of the safety protection enclosure are equipped with tower top lighting lamps. The adjacent vertical connecting columns of the safety protection enclosure are connected by three-layer horizontal connecting rods of the safety protection enclosure. Several vertical connecting rods of the safety protection enclosure are installed between the adjacent vertical connecting columns of the safety protection enclosure. The safety protection enclosure is installed on the inner side of the enclosure frame composed of the vertical connecting columns of the safety protection enclosure, the horizontal connecting rods of the safety protection enclosure and the vertical connecting rods of the safety protection enclosure, and a closed canopy is installed on the upper horizontal connecting rods of the safety protection enclosure. The length, width and height dimensions of the safety protection enclosure are all larger than the steel structure construction platform on the top of the tower.

7. The method for assembling and disassembling a construction platform for repairing and reinforcing a multi-tower cable-stayed bridge tower top steel structure according to claim 1, characterized in that: After the tower top cantilever steel truss construction platform is installed and inspected to be qualified, the tower top cantilever steel truss construction platform operation starts. After the tower top cantilever steel truss construction platform operation is completed, the cantilever steel truss construction platform is dismantled. The dismantling sequence is opposite to the assembly and shifting installation sequence of the cantilever hanger auxiliary lifting tower top.

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