Bridge cable pushing and tensioning method in narrow space

Abstract

The present application aims to provide a kind of narrow space bridge cable push-pull tensioning method, comprising the following steps: A, two groups or more than jack are provided between working anchor and tool anchor, each group of jack is evenly arranged, so that when it pushes tool anchor, tool anchor is uniformly stressed;B, intelligent oil pump controls the oil pressure of each group of jack, so that it remains consistent, and simultaneously push tool anchor, and the steel strand is tensioned, when jack pushes to reach the stroke position, anchor nut of working anchor is locked;C, intelligent oil pump returns oil, and tool anchor returns initial position;D, repeat steps A-C, until the cable force reaches the design requirement.The present application aims to provide a kind of narrow space bridge cable push-pull tensioning method, which can well meet the steel strand tensioning demand in narrow space, and the tensioning process is stable, without damaging steel strand twist angle, to ensure tensioning effect.

Description

Technical Field

[0001] This invention relates to the field of bridge cable-stayed technology, and more specifically to a method for pushing and tensioning bridge cables in a narrow space. Background Technology

[0002] The cable-stayed bridge cable is the main load-bearing component that directly transfers the loads of the main girder and bridge deck of a cable-stayed bridge to the towers. The cable material is typically high-strength steel strand or wire, and its form varies depending on its composition, including parallel wires, parallel cables, single cables, wire ropes, enclosed cables, or solid steel bars. Because the cables are placed at an incline, they are called inclined cables. The superstructure of a cable-stayed bridge consists of towers, main girder, and inclined cables. Tower types include A-type, inverted Y-type, H-type, and single-column, and materials include steel, concrete, or a combination of steel and concrete. Cable stays are arranged in single or double rows, each further divided into single-plane, parallel double-plane, and spatial inclined-plane arrangements.

[0003] During the construction of cable-stayed bridges, tensioning devices are used to tension the cables to establish effective cable force. Due to current urban aesthetic and cost considerations, compact cable tower structures are often adopted, characterized by their unique and aesthetically pleasing designs. However, the internal space of a compact cable tower is extremely limited. Traditional tensioning methods and devices require tensioning struts and tension rods. Tensioning struts themselves are 40-120cm long, while tension rods require even greater length, typically equivalent to more than two tensioning struts. Combined with the 60-120cm length of the jacks themselves, this necessitates a substantial amount of space; otherwise, sufficient installation requirements cannot be met. Therefore, these methods cannot be applied to tensioning steel strands in compact cable tower structures. This necessitates the development of a new tensioning device that can overcome the limitations of limited space. Summary of the Invention

[0004] The present invention aims to provide a method for jacking and tensioning bridge stay cables in narrow spaces. This method can better meet the tensioning requirements of steel strands in narrow spaces, especially the tensioning requirements of stay cables in compact cable tower structures. Moreover, the tensioning process is stable and will not damage the twist angle of the steel strands, thus ensuring the tensioning effect.

[0005] The method for jacking and tensioning bridge stay cables in a narrow space includes the following steps:

[0006] A. Two or more sets of jacks are installed between the working anchor and the tool anchor, and the jacks are evenly distributed so that the tool anchor is subjected to uniform force when it pushes the tool anchor.

[0007] B. The intelligent oil pump controls the oil pressure of each group of jacks to keep them consistent, and simultaneously pushes the tool anchor to tension the steel strand. When the jack pushes to the stroke position, it locks the anchoring nut of the working anchor.

[0008] C. The intelligent oil pump returns oil, and the tool anchor returns to its initial position;

[0009] D. Repeat steps AC until the cable tension reaches the design requirements.

[0010] In step A, the axial direction of the working anchor and the tool anchor, as well as the jacking direction, all form an angle of 90° with the end face of the anchor plate.

[0011] In step B, the stroke of the jack is 10mm-200mm.

[0012] The jack is positioned between the anchor plate and the load-bearing plate of the working anchor, and the tool anchor is installed on the load-bearing plate.

[0013] The jacks are set up in four groups, and each group of jacks is arranged in a square.

[0014] The working anchor includes an anchor plate, a working anchor plate, and working clamps. The working anchor plate is fixedly installed on the anchor plate. The working anchor plate has evenly distributed conical holes I, and each conical hole I is provided with a working clamp. The bottom of each set of jacks is fixedly installed on the anchor plate through a fixing plate, located around the working anchor plate.

[0015] The lower part of the outer circle of the working anchor plate is provided with an anchoring nut for locking the working anchor plate after tensioning.

[0016] The tool anchor includes a tool anchor plate, tool clamps, and a limiting plate. The tool anchor plate is installed in the middle of the load-bearing plate. Conical holes II, each corresponding to a conical hole I, are evenly distributed on the tool anchor plate. Each conical hole II is provided with a tool clamp. A limiting plate is provided on the middle of the bottom surface of the load-bearing plate. The limiting plate has limiting holes corresponding to conical holes II. The diameter of the limiting holes is smaller than the diameter of the tail end of the tool clamp after installation. The top of each set of jacks is fixedly connected to the load-bearing plate, and the connection position is located around the tool anchor plate.

[0017] The load-bearing plate has an anchor plate mounting hole in the middle, and a support ring is provided at the bottom of the side wall of the anchor plate mounting hole. The tool anchor plate has a corresponding anchor plate mounting hole, and a limiting ring corresponding to the support ring is provided on the upper part of its side wall. The support ring supports the limiting ring, so that the tool anchor plate is positioned and installed in the anchor plate mounting hole.

[0018] The installation process for the working anchor and tool anchor is as follows:

[0019] Anchor plates are cast onto the beam, and working anchor plates, working clamps, and jacks are installed on the anchor plates; then load-bearing plates, limit plates, tool anchor plates, and tool clamps are installed.

[0020] The working process of this invention is as follows:

[0021] The method of this invention uses multiple sets of jacks to simultaneously push and tension the cable multiple times. Compared with the existing tensioning jacks and tensioning operation methods, this structure does not require tensioning support feet and tensioning rods. It only requires the length of the jacks and their pushing stroke, which greatly saves the required space. Moreover, based on the setting of multiple sets of jacks, the volume of the jacks can be effectively reduced, and the length of the jacks can be shortened to the extreme, so that they can be installed in narrow spaces while ensuring the tensioning effect, so that the cable force of each cable fully meets the design requirements.

[0022] This invention utilizes anchor plates and a uniquely structured load-bearing plate, along with a jack layout, to achieve a method for tensioning steel strands within confined spaces through multiple, gradual tensioning operations. The method's optimized jack arrangement ensures consistent thrust from each jack onto the load-bearing plate, resulting in a more stable tensioning process that avoids damaging the strand's twist angle and affecting the tensioning effect, thus demonstrating promising application prospects. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the method for jacking and tensioning bridge stay cables in a narrow space, as described in Example 1.

[0024] The numbers and names in the diagram are as follows:

[0025] 1-Jack, 2-Anchor plate, 3-Working anchor plate, 4-Working clamp, 5-Conical hole I, 6-Fixing disc hole, 7-Anchor nut, 8-Tool anchor plate, 9-Bearing plate, 10-Tool clamp, 11-Limiting plate, 12-Conical hole II, 13-Limiting hole, 14-Anchor plate mounting hole, 15-Support ring, 16-Limiting ring. Detailed Implementation

[0026] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. Example 1

[0027] like Figure 1 As shown, a bridge cable-stayed bridge tensioning device in a narrow space includes a working anchor, a tool anchor, and jacks 1. Two or more sets of jacks 1 are provided between the working anchor and the tool anchor. Each set of jacks 1 works together to push the tool anchor, and the distribution of the jacks 1 ensures that the tool anchor is subjected to uniform force. Four sets of jacks 1 are provided, and each set of jacks 1 is arranged in a square.

[0028] The working anchor includes an anchor plate 2, a working anchor plate 3, and a working clamping piece 4. The working anchor plate 3 is fixedly installed on the anchor plate 2. The working anchor plate 3 has evenly distributed conical holes I5, and each conical hole I5 is provided with a working clamping piece 4. The bottom of each set of jacks 1 is fixedly installed on the anchor plate 2 through a fixing plate 6, and is located around the working anchor plate 3.

[0029] An anchoring nut 7 is provided on the lower part of the outer side wall of the working anchor plate 3, which is used to lock the working anchor plate 3 after tensioning.

[0030] The tool anchor includes a tool anchor plate 8, a load-bearing plate 9, a tool clamping piece 10, and a limiting plate 11. The tool anchor plate 8 is installed in the middle of the load-bearing plate 9. The tool anchor plate 8 has conical holes II 12 that correspond one-to-one with the conical holes I 5. Each conical hole II 12 is provided with a tool clamping piece 10. The limiting plate 11 is provided in the middle of the bottom surface of the load-bearing plate 9. The limiting plate 11 has limiting holes 13 that correspond one-to-one with the conical holes II 12. The diameter of the limiting holes 13 is smaller than the diameter of the tail end of the tool clamping piece 10 after installation. The top of each set of jacks 1 is fixedly connected to the load-bearing plate 9, and the connection position is located around the tool anchor plate 8.

[0031] The load-bearing plate 9 has an anchor plate mounting hole 14 in the middle. The bottom of the side wall of the anchor plate mounting hole 14 is provided with a support ring 15. The tool anchor plate 8 is provided with a corresponding anchor plate mounting hole 14. The upper part of its side wall is provided with a limiting ring 16 corresponding to the support ring 15. The support ring 15 supports the limiting ring 16, so that the tool anchor plate 8 is positioned and installed in the anchor plate mounting hole 14.

[0032] The process of tensioning the stay cables using the aforementioned cable-stayed bridge cable-pushing and tensioning device in a narrow space is as follows:

[0033] A. Two or more sets of jacks 1 are provided between the working anchor and the tool anchor. Each set of jacks 1 is evenly distributed so that the tool anchor is subjected to uniform force when it pushes the tool anchor. The axial direction of the working anchor and the tool anchor and the pushing direction of the jacks 1 are all 90° with the end face of the anchor plate.

[0034] B. The intelligent oil pump controls the oil pressure of each group of jacks 1 to keep them consistent, and simultaneously pushes the tool anchor to tension the steel strand. When jack 1 pushes to the stroke position, the working anchor plate 3 of the working anchor is locked. In the implementation case, the stroke of jack 1 is 100mm.

[0035] C. The intelligent oil pump returns oil, and the tool anchor returns to its initial position;

[0036] D. Repeat steps AC until the cable tension reaches the design requirements.

Claims

1. A method for jacking and tensioning bridge stay cables in a narrow space, comprising the following steps: A. Two or more sets of jacks (1) are provided between the working anchor and the tool anchor. Each set of jacks (1) is evenly arranged so that the tool anchor is subjected to uniform force when it pushes the tool anchor. B. The intelligent oil pump controls the oil pressure of each group of jacks (1) to keep them consistent, and pushes the tool anchor at the same time to tension the steel strand. When the jack (1) pushes to the stroke position, the anchoring nut (7) of the working anchor is locked. C. The intelligent oil pump returns oil, and the tool anchor returns to its initial position; D. Repeat steps AC until the cable tension reaches the design requirements; The jack (1) is located between the anchor plate (2) and the bearing plate (9) of the working anchor, and the tool anchor is installed on the bearing plate (9); The working anchor includes an anchor plate (2), a working anchor plate (3), and a working clamp (4). The working anchor plate (3) is fixedly installed on the anchor plate (2). Conical holes I (5) are evenly distributed on the working anchor plate (3), and each conical hole I (5) is provided with a working clamp (4). The bottom of each set of jacks (1) is fixedly installed on the anchor plate (2) through a fixing plate (6) and is located around the working anchor plate (3). The lower part of the outer wall of the working anchor plate (3) is provided with an anchoring nut (7) for locking the working anchor plate (3) after tensioning. The tool anchor includes a tool anchor plate (8), a tool clamp (10), and a limiting plate (11). The tool anchor plate (8) is installed in the middle of the load-bearing plate (9). The tool anchor plate (8) has conical holes (12) that correspond one-to-one with the conical holes (5). Each conical hole (12) is provided with a tool clamp (10). The load-bearing plate (9) is provided with a limiting plate (11) in the middle of the bottom surface. The limiting plate (11) is provided with limiting holes (13) that correspond one-to-one with the conical holes (12). The diameter of the limiting holes (13) is smaller than the diameter of the tail end of the tool clamp (10) after installation. The top of each set of jacks (1) is fixedly connected to the load-bearing plate (9). The connection position is located around the tool anchor plate (8). The bearing plate (9) is provided with an anchor plate mounting hole (14) in the middle. The bottom of the side wall of the anchor plate mounting hole (14) is provided with a support ring (15). The tool anchor plate (8) is provided with a corresponding anchor plate mounting hole (14). The upper part of its side wall is provided with a limiting ring (16) corresponding to the support ring (15). The support ring (15) supports the limiting ring (16), so that the tool anchor plate (8) is positioned and installed in the anchor plate mounting hole (14).

2. The method for jacking and tensioning bridge stay cables in a narrow space as described in claim 1, characterized in that: In step A, the axial direction of the working anchor and the tool anchor, as well as the jacking direction of the jack (1), are all 90° with the end face of the anchor plate.

3. The method for jacking and tensioning bridge stay cables in a narrow space as described in claim 1, characterized in that: In step B, the stroke of the jack (1) is 10mm-200mm.

4. The method for jacking and tensioning bridge stay cables in a narrow space as described in claim 1, characterized in that: The jacks (1) are set up in four groups, and the jacks (1) in each group are arranged in a square.

5. The method for jacking and tensioning bridge stay cables in a narrow space as described in claim 1, characterized in that: The installation process for the working anchor and tool anchor is as follows: Anchor plate (2) is cast onto beam body, and working anchor plate (3), working clamp (4), and jack (1) are assembled on anchor plate (2); then load-bearing plate (9), limiting plate (11), tool anchor plate (8), and tool clamp (10) are assembled.

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