Double-beam stay cable tensioning device and foot bridge stay cable tensioning system

Abstract

The utility model relates to the field of bridge construction equipment, and discloses a double-beam stay cable tensioning device and a foot bridge stay cable tensioning system.The device comprises a pair of counter-force frames, at least two lower anchor heads are connected to one of the counter-force frames, and the lower anchor heads are used for being connected with stay cables; the pair of adjusting devices are mounted on the reaction frames and used for adjusting the distance between the two reaction frames; and the at least one lower fork lug is connected to the other reaction frame. The device improves the construction efficiency, and has the advantages of simplicity in construction operation, high practicability and the like.

Description

Technical Field

[0001] The utility model relates to the field of bridge construction equipment, in particular to a double-beam cable-stayed tensioning device and a cable-stayed tensioning system for a pedestrian bridge. Background Art

[0002] The anti-Fink pedestrian bridge is mainly composed of the main tower, mast, cable, main beam, support, auxiliary facilities and other basic components. The main tower and mast mainly bear axial pressure, the main beam mainly bears its own gravity, the external loads such as crowd load are compression and bending components, and the cable mainly bears the axial tension transmitted by the main beam. The main feature of the cable-stayed bridge is that the main beam is directly pulled on the cable tower with many cables. This structural form can significantly reduce the bending moment on the main beam, reduce the cross-sectional size of the main beam, increase the clear height under the bridge, and reduce the weight of the structure.

[0003] For the anti-Fink type pedestrian cable-stayed bridge, the tensioning of the cable is the core link of the construction. Research on new cable-stayed tensioning construction is of great significance to the development of the anti-Fink type cable-stayed bridge. Although the existing cable-stayed installation and construction can meet the basic construction needs, there are still some problems. Patent CN110184930 A discloses a cable-stayed construction method for a low-tower cable-stayed bridge, which adopts a single steel strand to be tensioned synchronously on the left and right, and uses a single-hole jack for graded symmetrical tensioning. However, this patent can only handle the scenario of a single cable, and the cables need to be initially tensioned one by one, which makes the construction cumbersome and inefficient. Summary of the invention

[0004] The utility model aims to provide a double-beam cable-stayed tensioning device and a cable-stayed tensioning system for a pedestrian bridge, so as to solve the problems in the prior art that the cables need to be initially tensioned one by one, the construction is cumbersome and the efficiency is low.

[0005] In order to achieve the above utility model purpose, the technical solution adopted by the utility model is:

[0006] In a first aspect, the utility model provides a double-beam inclined cable tensioning device, the device comprising:

[0007] A pair of reaction frames, one of which is connected to at least two lower anchor heads, and the lower anchor heads are used to connect the inclined cables;

[0008] A pair of adjustment devices, both mounted on the reaction frames, for adjusting the spacing between the two reaction frames;

[0009] At least one lower fork ear, each of the lower fork ears is connected to another reaction frame.

[0010] Preferably, each adjusting device comprises: a tension rod, each of which is passed through a pair of reaction frames, both ends of the tension rod are provided with limit members to prevent the reaction frames from slipping, one of the reaction frames is provided with a jack, one end of the tension rod is passed through the jack, and the jack is used to push one of the reaction frames to slide back and forth along the tension rod.

[0011] Preferably, two lower fork ears are provided.

[0012] Preferably, at least two sleeves are provided between the two reaction frames, one end of each sleeve is fixedly connected to one of the reaction frames, and the other end of each sleeve is movably connected to an adjusting screw, which is threadedly connected to the other reaction frame.

[0013] Preferably, the reaction frame is provided with a detector for detecting the tensioning force of the inclined cable.

[0014] In a second aspect, the utility model also provides a cable tensioning system for a pedestrian bridge, the system comprising:

[0015] Two sets of the above-mentioned double-beam cable-stayed tensioning devices;

[0016] Two sets of lifting devices are arranged on the left and right sets of the double towers of the pedestrian bridge. The lower fork ears of each set of double-beam cable-stayed tensioning devices are installed on one set of lifting devices. The reaction frame of the double-beam cable-stayed tensioning device is connected to the cable of the pedestrian bridge. The lifting device is used to lift the double-beam cable-stayed tensioning device to a preset height.

[0017] Preferably, the lifting device is a truck crane, a lifting end of the truck crane is connected to a lifting belt, and the lower fork ear of the double-beam inclined cable tensioning device is installed on the lifting end of the truck crane through the lifting belt.

[0018] The beneficial effects of the utility model are mainly embodied in:

[0019] 1. The lower anchor head of the double-beam cable-stayed tensioning device of the utility model can connect the cable-stayed cable, and the spacing between the two reaction frames can be adjusted by the adjustment device, thereby realizing the tensioning adjustment of multiple cables, improving the construction efficiency, and having the advantages of simple construction operation and strong practicality;

[0020] 2. The cable-stayed tensioning system of the pedestrian bridge of the utility model is lifted to the construction position by a lifting device carrying a double-beam cable-stayed tensioning device, thereby improving the convenience and efficiency of construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall structure of a double-beam inclined cable tensioning device provided by one embodiment of the utility model;

[0022] Legend: 1. Lower anchor head; 2. Jack; 3. Reaction frame; 4. Sleeve; 5. Tension rod; 6. Adjusting screw; 7. Lower fork ear. DETAILED DESCRIPTION

[0023] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0024] Figure 1 Schematic diagram of the overall structure of a double-beam cable-stayed tensioning device provided by an embodiment of the utility model. Figure 1 As shown, the utility model provides a double-beam inclined cable tensioning device, the device comprising:

[0025] A pair of reaction frames 3, one of which is connected with at least two lower anchor heads 1, and the lower anchor heads are used to connect the inclined cables;

[0026] A pair of adjustment devices, both mounted on the reaction frames 3, for adjusting the distance between the two reaction frames 3;

[0027] At least one lower fork lug 7 , each of the lower fork lugs 7 is connected to another reaction frame 3 .

[0028] In this embodiment, two lower anchor heads 1 are usually provided, and each lower anchor head 1 can be connected to a stay cable. According to the number of stay cables, a plurality of double-beam stay cable tensioning devices can be arranged to achieve tensioning and adjusting of a plurality of stay cables at the same time.

[0029] In this embodiment, the distance between the two reaction frames 3 is adjusted by the adjustment device, thereby achieving tension adjustment of multiple inclined cables, improving construction efficiency, and having the advantages of simple construction operation and strong practicality.

[0030] As a further optimization of this embodiment, each adjusting device includes: a tension rod 5, each of which is passed through a pair of reaction frames 3, and both ends of the tension rod 5 are provided with limit members to prevent the reaction frames 3 from slipping, one of the reaction frames 3 is provided with a jack 2, one end of the tension rod 5 is passed through the jack 2, and the jack 2 is used to push one of the reaction frames 3 to slide back and forth along the tension rod 5.

[0031] In this embodiment, the tension rod 5 can be a screw rod, the jack 2 is hydraulic, and the limit members can be upper limit nuts set at both ends of the screw rod, which are used to limit the reaction frame 3 and the jack 2. When the jack 2 is started, it can push the reaction frame 3 connected to the lower anchor head 1 to move in the direction close to another reaction frame 3, thereby increasing the tensioning force of the inclined cable.

[0032] As a further optimization of this embodiment, a detector for detecting the tensioning force of the inclined cable is provided on the reaction frame 3. The detector can be a tension sensor. The tensioning force applied to the inclined cable during the adjustment process is monitored in real time by the tension sensor, so as to adjust the tensioning force of the inclined cable to an appropriate value.

[0033] As a further optimization of this embodiment, at least two sleeves 4 are provided between the two reaction frames 3, one end of each sleeve 4 is fixedly connected to one of the reaction frames 3, and the other end of each sleeve 4 is movably connected with an adjusting screw 6, which is screwed to the other reaction frame 3.

[0034] In this embodiment, one end of the adjusting screw 6 is inserted into the corresponding sleeve 4, and the end of the adjusting screw 6 located inside the sleeve 4 is in a T-shaped structure so that the adjusting screw 6 cannot slip out of the sleeve 4. The adjusting screw 6 can slide in the sleeve 4 along the axial direction of the sleeve 4 or along the circumferential direction of the sleeve 4.

[0035] In this embodiment, after the jack 2 is started and the tensioning force of the inclined cable is adjusted to an appropriate value, the adjusting screw 6 is rotated to tighten the two reaction frames 3. With the cooperation of the adjusting screw 6 and the sleeve 4, the jack 2 can be closed at this time. Under the limit of the adjusting screw 6 and the sleeve 4, the tensioning force of the inclined cable is maintained at an appropriate value, and there is no need to start the jack 2 for a long time.

[0036] As an improved optimization of this embodiment, in order to improve the installation stability of the double-beam inclined cable tensioning device, two lower fork ears 7 are provided.

[0037] Embodiment 2

[0038] This embodiment provides a cable-stayed tensioning system for a pedestrian bridge, the system comprising:

[0039] Two sets of double-beam stay cable tensioning devices of embodiment 1;

[0040] Two sets of lifting devices are arranged on the left and right sets of the double towers of the pedestrian bridge. The lower fork ears 7 of each set of double-beam inclined cable-stayed tensioning devices are installed on one set of lifting devices. The reaction frame 3 of the double-beam inclined cable-stayed tensioning device is connected to the inclined cable of the pedestrian bridge. The lifting device is used to lift the double-beam inclined cable-stayed tensioning device to a preset height.

[0041] As a further optimization of this embodiment, the lifting device is a truck crane, a lifting end of the truck crane is connected with a lifting belt, and the lower fork ear 7 of the double-beam inclined cable tensioning device is installed on the lifting end of the truck crane through the lifting belt.

[0042] In this embodiment, the construction steps of the cable-stayed tensioning system of the pedestrian bridge are as follows:

[0043] 1. Preparation for installation of the cable-stayed cable

[0044] 1.1 Material preparation

[0045] (1) Equipment: According to the specifications of the inclined cables determined by the design and construction units, the corresponding reaction frames 3 and tension rods 5 are processed.

[0046] (2) Finished cables: The performance of the cables should be inspected before leaving the factory. After the cables are transported to the site, the specifications, models and integrity of the cables should be checked.

[0047] 1.2 Equipment preparation

[0048] (1) Tensioning equipment: jack 2, oil pump, etc.

[0049] (2) Lifting equipment: 350kN truck crane.

[0050] (3) Transportation equipment: forklift.

[0051] 2. Cable transportation

[0052] According to the construction schedule, the inclined cables are transported to the construction site. In order to avoid damage to the PE of the inclined cables during the lifting process, large-diameter fiber ropes or slings are used for lifting. When the inclined cables are stored, square wood pads should be provided at the lower end of the cable tray. Fire sources are strictly prohibited within 10m around the cable body. Each inclined cable should be separated by number to avoid confusion.

[0053] 3. Exhibition

[0054] In order to eliminate the torsional force generated when the cable is coiled, the cable needs to be extended. During the extension process, sleeper blocks need to be placed under the cable, and sleeper blocks and rubber skins need to be placed every 1m along the straight direction of the cable to protect the cable from damage.

[0055] 4. Hanging rope and traction anchor

[0056] When hanging at the tower end, use a soft lifting belt to set a traction point at the upper fork ear of the inclined cable, connect the lifting belt to the car crane, then lift the upper fork ear to the anchor point of the tower end ear plate, and use the pin to fix the upper fork ear to the tower end ear plate. After the tower end is hung, fully unfold the beam end inclined cable to confirm that the cable body is smooth. When hanging at the beam end, use the car crane to lift the lower fork ear 7 to the anchor point of the beam end ear plate, and use the pin to fix the lower fork ear 7 to the beam end ear plate.

[0057] 5. Tension

[0058] The construction plan for synchronous tensioning of the cables of the double towers of the anti-Fink pedestrian bridge is to symmetrically and synchronously tension the cables on the left and right sides of the double towers. For the tensioning project of a row of double-beam cables, due to the narrow gap between the double-beam cables, it is necessary to customize a special reaction frame 3 according to the design and construction requirements to tension the double-beam cables so that the double-beam cables can be tensioned at the same time. The following tensioning steps are all synchronous construction of the cables on the left and right sides of the double towers. First, the cables are symmetrically and collaboratively pre-tensioned row by row. After all the cables are pre-tensioned, they are tensioned row by row symmetrically and collaboratively. The specific tensioning construction steps are as follows:

[0059] (1) Before the cable is tensioned, a technical briefing should be conducted to confirm the tensioning force and elongation of the cable, check whether the tensioning jack 2 is centered and adjusted, check the serial number of the supporting equipment of jack 2, connect the oil pump and the oil pipe of jack 2, run the precision pressure gauge for two strokes under no-load condition, check whether the oil pump is leaking and whether jack 2 can work normally.

[0060] (2) Install the reaction frame 3, tension rod 5 and jack 2 at the tension reaction position of the sleeve 4 at the end of the beam to keep the force balance on the left and right ends of the reaction frame 3 and ensure that the center of gravity of the system of reaction frame 3, tension rod 5 and jack 2 coincides.

[0061] (3) In order to give full play to the elastic support effect of the cable on the main beam, the cable needs to be in a tensioned state at all times. Therefore, the cable must be pre-tensioned before being loaded to eliminate non-elastic deformation. Pre-tensioning can make the cable bear force evenly in the bridge structure, reduce deformation and stress concentration, and improve the bearing capacity and stability of the bridge. Use the jack 2 to apply force to the reaction frame 3 and the tension rod 5, and at the same time adjust the adjustment screw 6 of the cable to cooperate with the jack 2 to make the cable taut, that is, complete the pre-tensioning. After the pre-tensioning is completed, tighten the adjustment screw 6 to fix the cable.

[0062] (4) In order to ensure that the stress and deformation of the cable are within a reasonable range, avoid excessive stress and deformation of the cable during the tensioning process, reduce stress relaxation and creep of the cable, optimize the stress distribution of the cable, and ensure the safety and stability of the anti-Fink pedestrian bridge, the cable needs to be tensioned in stages. The cable tensioning construction should be carried out in accordance with the principle of "uniform, symmetrical, staged, and cyclic". Start the oil pump and jack 2, and perform the tensioning construction in stages according to the monitoring cable force at each stage. When the target tensioning force is reached, stabilize the oil pressure to stop tensioning and tighten the adjusting screw 6, observe the oil gauge reading and the cable force sensor reading on the cable body, and record the tensioning cable force values, oil gauge readings and cable elongation at each stage on the cable force monitoring table. When the tensioning force reaches the target cable force, the oil pressure needs to be released, and the cable force sensor reading is observed to see whether it is maintained at the target tensioning force. If the tensioning force reading fluctuates beyond the error range, the cable needs to be tensioned again.

[0063] (5) After the current cable tension is completed, in order to understand the changing state of the cable tension during the construction process, a cable tension tester is used to test the surrounding cables at the same time. If there is any inconsistency with the predicted law, jack 2 is required to re-tension and observe the tension situation.

[0064] 6. Transport of tensioning equipment

[0065] After the current cable tension reaches the target cable tension, the tensioning equipment needs to be removed and the above equipment installation, pre-tensioning operation and graded tensioning operation need to be repeated for the next row of inclined cables.

[0066] It should be noted that, for the above-mentioned various method embodiments, for the sake of simplicity of description, they are all expressed as a series of action combinations, but those skilled in the art should be aware that this application is not limited by the order of the actions described, because according to this application, some steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and units involved are not necessarily required by this application.

Claims

1. A double-beam cable tensioning device, characterized in that: The device comprises: A pair of reaction frames (3), wherein at least two lower anchor heads (1) are connected to one of the reaction frames (3), and the lower anchor heads (1) are used to connect the inclined cables; A pair of adjustment devices, both mounted on the reaction frames (3), for adjusting the distance between the two reaction frames (3); At least one lower fork ear (7), each of the lower fork ears (7) is connected to another reaction frame (3).

2. The double-beam cable-stayed tensioning device according to claim 1, characterized in that: Each adjusting device comprises: a tension rod (5), each of the tension rods (5) is passed through a pair of reaction frames (3), both ends of the tension rod (5) are provided with limit members to prevent the reaction frames (3) from sliding off, one of the reaction frames (3) is provided with a jack (2), one end of the tension rod (5) is passed through the jack (2), and the jack (2) is used to push one of the reaction frames (3) to slide back and forth along the tension rod (5).

3. The double-beam cable-stayed tensioning device according to claim 2, characterized in that: The lower fork ears (7) are provided with two.

4. The double-beam cable-stayed tensioning device according to claim 2, characterized in that: At least two sleeves (4) are provided between the two reaction frames (3), one end of the sleeve (4) is fixedly connected to one of the reaction frames (3), and the other end of each sleeve (4) is movably connected to an adjusting screw (6), and the adjusting screw (6) is screwed to the other reaction frame (3).

5. The double-beam stay cable tensioning device according to claim 1, characterized in that: The reaction frame (3) is provided with a detector for detecting the tensioning force of the inclined cable.

6. A cable-stayed tensioning system for a pedestrian bridge, characterized in that: The system comprises: Two sets of double-beam cable-stayed tensioning devices according to any one of claims 1 to 5; Two sets of lifting devices are arranged on the left and right sets of the double towers of the pedestrian bridge, the lower fork ears (7) of each set of double-beam inclined cable-stayed tensioning devices are installed on one set of lifting devices, and the reaction frame (3) of the double-beam inclined cable-stayed tensioning devices is connected to the inclined cables of the pedestrian bridge; the lifting devices are used to lift the double-beam inclined cable-stayed tensioning devices to a preset height.

7. The cable-stayed tensioning system for a pedestrian bridge according to claim 6, characterized in that: The lifting device is a truck crane, a lifting end of the truck crane is connected with a lifting belt, and the lower fork ear (7) of the double-beam inclined cable tensioning device is installed on the lifting end of the truck crane through the lifting belt.

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