A method for overall sliding demolition of a catwalk surface layer of a long-span suspension bridge side span

Abstract

This invention proposes a method for the overall sliding removal of the catwalk surface layer of a long-span suspension bridge, belonging to the field of bridge construction technology. This method uses the steel wire ropes of the tower top winch, the anchor winch, and the ear plates to form a whole for the side span catwalk surface layer. The side span catwalk surface layer is then lifted using the steel wire ropes of the tower top winch and the anchor winch, followed by the dismantling of the lifting ropes. After dismantling the lifting ropes, the side span catwalk surface layer is slid down entirely using the steel wire ropes of the tower top winch and the anchor winch. This fundamentally solves the technical problem of overloading the main cable side span caused by raising the lifting ropes in existing technologies, ensuring the construction safety during the removal of the side span catwalk surface layer.

Description

Technical Field

[0001] This invention belongs to the field of bridge construction technology and relates to the construction technology of catwalk removal for long-span suspension bridges, specifically a method for the overall sliding removal of the surface layer of the catwalk on the side span of a long-span suspension bridge. Background Technology

[0002] Long-span suspension bridges refer to suspension bridges with spans exceeding 1000 meters. Due to their extremely large spans, they suffer from poor wind resistance and require high structural stiffness. Existing technologies incorporate side spans to improve the wind resistance and structural stiffness of long-span suspension bridges. This limits the longitudinal slippage of the main cable at the tower top, controls the deformation of the main cable, and ultimately enhances the wind resistance and structural stiffness of the main cable.

[0003] During the construction of the side spans of long-span suspension bridges, a catwalk is required to provide a continuous, safe, and stable high-altitude working platform. This catwalk serves as a temporary access route for construction workers, allowing them to move freely between the two banks for work and the transport of equipment and materials. However, the catwalk is a temporary access route and needs to be dismantled after the main bridge construction is completed. However, due to the catwalk tensioning operation during the steel box girder hoisting phase and the load transfer from the mid-span steel box girder, the main cable of the side span will deform and rise compared to its empty state. If the catwalk surface layer is removed at this time, the load originally shared by multiple lifting points will instantly transfer to the single remaining lifting rope. This sudden concentrated overload can easily cause the lifting rope to break, leading to the collapse of the entire catwalk. Therefore, the existing methods for dismantling the side span catwalk surface layer present a technical problem related to the safety of construction due to the susceptibility of the lifting rope to breakage. Summary of the Invention

[0004] In view of the technical problem described in the background section above, the existing methods for removing the surface layer of the side span catwalk in the prior art have the technical problem that the suspension rope is easily broken, which leads to construction safety issues. In order to address this technical problem, the present invention proposes a construction method for the overall sliding removal of the surface layer of the side span catwalk of a long-span suspension bridge.

[0005] This invention uses the steel wire ropes of the tower top winch, the anchor winch, and the ear plates to form a whole for the side span catwalk surface layer. The steel wire ropes of the tower top winch and the anchor winch are used to lift the side span catwalk surface layer. After the lifting rope is removed, the steel wire ropes of the tower top winch and the anchor winch are used again to allow the side span catwalk surface layer to slide down as a whole. This fundamentally solves the technical problem of overloading the main cable side span caused by excessively high lifting ropes in the existing technology, and ensures the construction safety during the removal of the side span catwalk surface layer.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A method for the overall sliding removal of the surface layer of the catwalk on the side span of a long-span suspension bridge includes: S1: Multiple hoisting points are set up from top to bottom along the extension direction of the side span catwalk surface layer. A pulley system is set at each hoisting point to form a side span catwalk surface layer lifting system. The pulley system is connected to the hoisting rope and the side span main cable clamp respectively. S2: Connect the ear plate to the surface layer of the side catwalk; S3: Pass the anchor winch wire rope through the pulley system at each hoisting point and connect it to the ear plate; pass the tower top winch wire rope through the pulley system at each hoisting point and connect it to the ear plate; S4: Pull the anchor winch wire rope and the tower top winch wire rope, and lift the side span catwalk surface layer through the side span catwalk surface layer lifting system to reduce the distance between the side span catwalk surface layer and the side span main cable, so that the suspension rope becomes unloaded. S5: Remove and modify the hoisting rope; S6: Release the wire ropes of the anchor winch and the tower top winch until the tension of the wire ropes of the anchor winch and the tower top winch is zero. Release the restraints of the side span catwalk surface lifting system, so that the side span catwalk surface slides down as a whole along the anchor winch and the tower top winch wire ropes and toward the anchor under the action of gravity.

[0007] Further defined, S1 specifically includes: evenly distributing multiple hoisting points from top to bottom along the extension direction of the side span catwalk surface layer, setting up a pulley system at each hoisting point, and connecting the hoisting rope and the side span main cable clamp through the pulley system to form a side span catwalk surface layer lifting system; wherein, the hoisting rope is one or more catwalk load-bearing cables on the side span catwalk surface layer.

[0008] Further specifying, in S2, the ear plate is positioned in the middle of the side span.

[0009] Further specifying, S3 specifically includes: setting up an anchor winch on the anchor gantry, extending the anchor winch wire rope connected to the anchor winch along one end near the anchor towards the middle of the side span, and connecting it to the ear plate, and passing through the pulley system at each hoisting point in sequence during the extension process; A tower top winch is installed on the main tower. The steel wire rope of the tower top winch, which is connected to the tower top winch, is extended from one end near the main tower to the middle of the side span and connected to the ear plate. During the extension process, it passes through the pulley system at each hoisting point in sequence.

[0010] Further specifying, S5 specifically includes: starting from the installation position of the ear plate, simultaneously and symmetrically advancing the removal of the lifting rope towards the side closer to the main tower and the side closer to the anchorage.

[0011] Furthermore, S5 specifically includes: during the dismantling of the modified lifting rope, using lifting equipment to assist in lifting the modified lifting rope, adjusting the posture of the modified lifting rope, and preventing the modified lifting rope from falling freely during the dismantling process.

[0012] Further specifying, S6 specifically includes: S6.1: Perform rope release operations on the anchor winch wire rope and the tower top winch wire rope until the side span catwalk surface reaches a free-hanging state; S6.2: Continue to release the anchor winch wire rope and the tower top winch wire rope until the tension of the anchor winch wire rope and the tower top winch wire rope is zero, and release the restraints of the side span catwalk surface lifting system. S6.3: The side span catwalk surface layer is dragged by the anchor winch wire rope and the tower top winch wire rope, so that the side span catwalk surface layer slides down along the anchor winch wire rope and the tower top winch wire rope in the direction of the anchor.

[0013] Further specifying S6.3, the dragging operation of the side span catwalk surface layer using the anchor winch wire rope and the tower top winch wire rope specifically includes: during the sliding process of the side span catwalk surface layer, when the side span catwalk surface layer cannot slide down by its own weight, the anchor winch is activated to pull the anchor winch wire rope to drag the side span catwalk surface layer; when the side span catwalk surface layer slides down too fast, the tower top winch wire rope is activated to pull the tower top winch wire rope to drag the side span catwalk surface layer, so that the side span catwalk surface layer slides down as a whole along the anchor winch wire rope and the tower top winch wire rope in the direction of the anchor.

[0014] Further specified, a working platform is set up in front of the anchor saddle. As the side span catwalk surface layer slides down toward the anchor as a whole, the side span catwalk surface layer is removed section by section in a way that every 3 m to 6 m of sliding down is removed.

[0015] Further specifying, in S1, the pulley system at each hoisting point includes two sets of pulley assemblies, wherein one set of pulley assemblies is connected to one side of the side span main cable clamp, and the other set of pulley assemblies is connected to the opposite side of the side span main cable clamp; Protective pads are installed at the connection between the main cable clamp and the pulley assembly in the side span.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention discloses a method for the overall sliding removal of the catwalk surface layer of a long-span suspension bridge. The method involves using the steel wire ropes of the tower top winch, the anchor winch, and the ear plates to form a single unit for the side span catwalk surface layer. The side span catwalk surface layer is then lifted using the steel wire ropes of the tower top winch and the anchor winch, followed by the dismantling of the lifting ropes. After dismantling the lifting ropes, the side span catwalk surface layer is slid down entirely using the steel wire ropes of the tower top winch and the anchor winch. This method fundamentally solves the technical problem of overloading the main cable side span caused by raising the lifting ropes in existing technologies, ensuring construction safety during the removal of the side span catwalk surface layer.

[0017] 2. During the sliding process of the side span catwalk surface layer, when the side span catwalk surface layer cannot slide down by its own weight, the anchor winch is activated to pull the anchor winch wire rope to drag the side span catwalk surface layer; when the side span catwalk surface layer slides down too fast, the tower top winch wire rope is activated to pull the tower top winch wire rope to drag the side span catwalk surface layer, so that the side span catwalk surface layer slides down along the anchor winch wire rope and the tower top winch wire rope in the direction of the anchor. That is, during the overall sliding process of the side span catwalk surface layer, the dragging operation of the tower top winch and the anchor winch wire rope can realize the automatic sliding of the side span catwalk surface layer, without the need for construction personnel to enter the catwalk for high-altitude operations, thus reducing construction safety.

[0018] 3. When dismantling the modified lifting rope, the present invention starts from the installation position of the ear plate and simultaneously and symmetrically advances the dismantling of the modified lifting rope towards the side closer to the main tower and the side closer to the anchorage, ensuring that the catwalk is under balanced stress during the dismantling process; at the same time, during the dismantling process, hoisting equipment is used to assist in hoisting the modified lifting rope and adjust the posture of the modified lifting rope to prevent the modified lifting rope from falling freely during the dismantling process, thereby improving construction safety. Attached Figure Description

[0019] Figure 1 This is the main view of the modified lifting point; Figure 2 This is a side view of the modified lifting point; Figure 3 A schematic diagram showing how the winch wire rope passes through the modified lifting point to lift the surface layer of the side span catwalk. Figure 4 A schematic diagram showing the surface layer of the catwalk after the wire rope of the winch is released; Figure 5 This is a schematic diagram showing the complete detachment of the main cable clamps from the catwalk surface after the removal of the catwalk surface layer. Figure 6 A schematic diagram of the segmented sliding of the catwalk surface layer; Explanation of reference numerals in the attached figures: 1-Modify lifting point, 2-Pullover system, 3-Modify lifting rope, 4-Side span catwalk surface layer, 5-Side span main cable clamp, 6-Anchor winch, 7-Tower top winch, 8-Ear plate, 9-Tower top winch wire rope, 10-Anchor winch wire rope, 11-Side span main cable. Detailed Implementation

[0020] The technical solution of the present invention will be further explained and described below with reference to the accompanying drawings and embodiments, but the present invention is not limited to the embodiments described below.

[0021] This invention proposes a method for the overall sliding removal of the surface layer of the catwalk on the side span of a long-span suspension bridge, comprising: S1: See Figure 1 and Figure 2 Multiple lifting points 1 are arranged from top to bottom along the extension direction of the side span catwalk surface layer 4. A pulley system 2 is set at each lifting point 1 to form a side span catwalk surface layer lifting system. The pulley system 2 is connected to the lifting rope 3 and the side span main cable clamp 5 respectively. Specifically, S1 includes: multiple lifting points 1 are evenly arranged from top to bottom along the extension direction of the side span catwalk surface layer 4. A pulley system 2 is set at each lifting point 1. The lifting rope 3 and the side span main cable clamp 5 are connected through the pulley system 2 to form a side span catwalk surface layer lifting system. The lifting rope 3 is one or more catwalk load-bearing cables on the side span catwalk surface layer. As a preferred embodiment of the present invention, the lifting rope 3 is a single catwalk load-bearing cable on the catwalk surface layer.

[0022] S2: Connect ear plate 8 to the side catwalk surface layer 4; see also Figure 3 and Figure 4 In a preferred embodiment of the present invention, the ear plate 8 is set in the middle of the side span to ensure that the suspension rope 3 is removed from the position of the ear plate 8, and the force on the side span catwalk structure is balanced.

[0023] S3: Pass the anchor winch wire rope 10 through the pulley system 2 at each re-lifting point 1 and connect it to the ear plate 8; pass the tower top winch wire rope 9 through the pulley system 2 at each re-lifting point 1 and connect it to the ear plate 8; S3 specifically includes: setting up an anchor winch 6 on the anchor gantry, extending the anchor winch wire rope 10 connected to the anchor winch 6 from one end near the anchor towards the middle of the side span, passing it through the pulley system 2 at each re-lifting point 1 in sequence during the extension process, and then passing the anchor winch wire rope 10 through the pulley system 2 at each re-lifting point 1. The tail end is temporarily anchored to the ear plate 8 with high-strength bolts; a tower top winch 7 is installed on the main tower, and the tower top winch wire rope 9 connected to the tower top winch 7 is extended from one end near the main tower to the middle of the side span. During the extension, it passes through the pulley system 2 at each modified lifting point 1 in sequence. Then, the tail end of the tower top winch wire rope 9 is temporarily anchored to the ear plate 8 with high-strength bolts, so that all modified lifting points 1 are connected in series to form an integral load-bearing structure, avoiding local overload and improving the common load-bearing capacity of multiple modified lifting points 1.

[0024] S4: After the construction personnel evacuate, the anchor winch 6 pulls the anchor winch wire rope 10, and at the same time, the tower top winch 7 pulls the tower top winch wire rope 9. The side span catwalk surface layer lifting system lifts the side span catwalk surface layer 4, reducing the distance between the side span catwalk surface layer 4 and the side span main cable 11, so that the distance is reduced to a safe distance. At the same time, the lifting rope 3 becomes unloaded, that is, the lifting rope 3 is in a completely slack state. At this time, the anchor winch wire rope 10 near the anchor is temporarily fixed to the anchor, and the tower top winch wire rope 9 near the main tower is temporarily fixed to the main tower, so that the attitude of the side span catwalk is locked.

[0025] S5: Remove the lifting rope 3; S5 specifically includes: starting from the installation position of the ear plate 8, simultaneously and symmetrically remove the lifting rope 3 towards the side closer to the main tower and the side closer to the anchorage, maintaining symmetrical removal operations to prevent the side span main cable clamp 5 from deviating due to unilateral force; during the removal of the lifting rope 3, use hoisting equipment to assist in hoisting the lifting rope 3, adjust the posture of the lifting rope 3, and prevent the lifting rope 3 from falling freely during the removal process. The hoisting equipment can be a hand chain hoist, electric hoist, or other equipment.

[0026] S6: After the removal of the suspension rope 3, check the integrity of the connection nodes of the side span catwalk surface layer 4. (See below) Figure 6 The anchor winch wire rope 10 and the tower top winch wire rope 9 are released until the tension of the anchor winch wire rope 10 and the tower top winch wire rope 9 is zero. The restraint of the side span catwalk surface layer lifting system is released, so that the side span catwalk surface layer 4 slides down along the anchor winch wire rope 10 and the tower top winch wire rope 9 in the direction of the anchor under the action of gravity.

[0027] S6 specifically includes: S6.1: Slowly release the steel wire rope 10 of the anchor winch and the steel wire rope 9 of the tower top winch until the side span catwalk surface layer 4 reaches a free drooping state; S6.2: Continue to release the anchor winch wire rope 10 and the tower top winch wire rope 9 until the tension of both the anchor winch wire rope 10 and the tower top winch wire rope 9 is zero, and release the restraints of the side span catwalk surface lifting system. S6.3: The side span catwalk surface layer 4 is dragged by the anchor winch wire rope 10 and the tower top winch wire rope 9, so that the side span catwalk surface layer 4 slides down as a whole along the anchor winch wire rope 10 and the tower top winch wire rope 9 in the direction of the anchor under the action of gravity.

[0028] In a preferred embodiment of the present invention, in S6.3, the dragging operation of the side span catwalk surface layer 4 by the anchor winch wire rope 10 and the tower top winch wire rope 9 specifically includes: during the sliding process of the side span catwalk surface layer 4, when the side span catwalk surface layer 4 cannot slide down by its own weight, the anchor winch 6 is started to pull the anchor winch wire rope 10 to drag the side span catwalk surface layer 4; when the side span catwalk surface layer 4 slides down too fast, the tower top winch wire rope 9 is started to pull the tower top winch wire rope 9 to drag the side span catwalk surface layer 4, so that the side span catwalk surface layer 4 slides down as a whole along the anchor winch wire rope 10 and the tower top winch wire rope 9 in the direction of the anchor. Specifically, the tower top winch wire rope 9 is used to prevent the side span catwalk surface layer 4 from sliding down too quickly, and the anchor winch wire rope 10 is used to prevent the side span catwalk surface layer 4 from becoming stuck. When the side span catwalk surface layer 4 stops sliding down, the anchor winch 6 can pull it; when the side span catwalk surface layer 4 slides down too quickly, the tower top winch 7 can pull it. The overall sliding speed of the side span catwalk surface layer 4 should ideally be controlled between 0.1 m / s and 0.2 m / s. A sliding speed exceeding 0.2 m / s is considered too fast.

[0029] A working platform is set up in front of the anchor saddle. As the side span catwalk surface layer 4 slides down towards the anchor as a whole, it is removed section by section, in increments of 3-6 meters. See Figure 5 This represents the state after the removal of the side span catwalk surface layer 4, where the main cable clamp 5 of the side span is completely detached from the side span catwalk surface layer 4. Figure 5 The side span of the main cable 11 is not shown in the diagram.

[0030] See Figure 1 and Figure 2The pulley system 2 at each hoisting point 1 includes two sets of pulley assemblies. One set of pulley assemblies is connected to one side of the main cable clamp 5 of the side span, and the other set of pulley assemblies is connected to the opposite side of the main cable clamp 5 of the side span. The pulley assembly includes three pulley steering wheels. One pulley steering wheel is connected to the side of the main cable clamp 5 of the side span by a high-strength bolt, and the other two pulley steering wheels are connected to the corresponding positions of the hoisting rope 3 by high-strength bolts, so that the three pulley steering wheels are arranged in an isosceles triangle.

[0031] In a preferred embodiment of the present invention, a protective pad is provided at the connection between the side span main cable clamp 5 and the pulley assembly. The protective pad is preferably a rubber pad. The protective pad protects the connection between the side span main cable clamp 5 and the pulley assembly, preventing damage to the anti-corrosion coating on the main cable clamp.

[0032] In a preferred embodiment of the present invention, the modified suspension point 1 is set at the transverse position of the side span catwalk, and the distance between two adjacent modified suspension points 1 is about 50 meters.

[0033] The above description is only used to illustrate the technical solutions of the present invention, and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing, those skilled in the art should understand that modifications can still be made to the technical solutions described above, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present invention.

Claims

1. A method for the integral sliding demolition of the deck of a catwalk of a side span of a long-span suspension bridge, characterized in that, include: S1: Multiple lifting points (1) are set up from top to bottom along the extension direction of the side span catwalk surface layer (4). A pulley system (2) is set at each lifting point (1) to form a side span catwalk surface layer lifting system. The pulley system (2) is connected to the lifting rope (3) and the side span main cable clamp (5) respectively. S2: Connect ear plates (8) to the side catwalk surface (4); S3: Pass the anchor winch wire rope (10) through the pulley system (2) at each hoisting point (1) and connect it to the ear plate (8); Pass the tower top winch wire rope (9) through the pulley system (2) at each hoisting point (1) and connect it to the ear plate (8); S4: Pull the anchor winch wire rope (10) and the tower top winch wire rope (9), and lift the side span catwalk surface layer (4) through the side span catwalk surface layer lifting system, reduce the distance between the side span catwalk surface layer (4) and the side span main cable (11), so that the lifting rope (3) becomes unstressed; S5: Remove the modified hoisting rope (3); S6: Perform rope release operation on the anchor winch wire rope (10) and the tower top winch wire rope (9) until the tension of the anchor winch wire rope (10) and the tower top winch wire rope (9) is zero, release the restraint of the side span catwalk surface lifting system, so that the side span catwalk surface (4) slides down along the anchor winch wire rope (10) and the tower top winch wire rope (9) and towards the anchor under the action of gravity.

2. The catwalk deck integral sliding demolition construction method for the side span of a long-span suspension bridge according to claim 1, characterized in that, The S1 specifically includes: a number of hoisting points (1) are evenly arranged from top to bottom along the extension direction of the side span catwalk surface layer (4), and a pulley system (2) is set at each hoisting point (1). The hoisting rope (3) and the side span main cable clamp (5) are connected through the pulley system (2) to form a side span catwalk surface layer lifting system; wherein, the hoisting rope (3) is one or more catwalk load-bearing cables on the side span catwalk surface layer.

3. The method for integral sliding demolition of the catwalk surface layer of a long-span suspension bridge as described in claim 1, characterized in that, In S2, the ear plate (8) is positioned in the middle of the side span.

4. The method for integral sliding demolition of the catwalk surface layer of a long-span suspension bridge as described in claim 1, characterized in that, The S3 specifically includes: setting up an anchor winch (6) on the anchor gantry, extending the anchor winch wire rope (10) connected to the anchor winch (6) from one end close to the anchor to the middle of the side span, and connecting it to the ear plate (8), and passing through the pulley system (2) at each hoisting point (1) in sequence during the extension process. A tower top winch (7) is installed on the main tower. The tower top winch wire rope (9) connected to the tower top winch (7) is extended from one end close to the main tower to the middle of the side span and connected to the ear plate (8). During the extension process, it passes through the pulley system (2) at each hoisting point (1).

5. The method for integral sliding demolition of the catwalk surface layer of a long-span suspension bridge as described in claim 1, characterized in that, S5 specifically includes: starting from the installation position of the ear plate (8), simultaneously and symmetrically advancing the removal of the hoisting rope (3) towards the side closer to the main tower and the side closer to the anchor.

6. The method for integral sliding demolition of the catwalk surface layer of a long-span suspension bridge as described in claim 5, characterized in that, S5 further includes: during the dismantling of the modified lifting rope (3), using lifting equipment to assist in the lifting of the modified lifting rope (3), adjusting the posture of the modified lifting rope (3), and preventing the modified lifting rope (3) from falling freely during the dismantling process.

7. The method for integral sliding demolition of the catwalk surface layer of a long-span suspension bridge as described in claim 4, characterized in that, S6 specifically includes: S6.1: Perform rope release operation on the anchor winch wire rope (10) and the tower top winch wire rope (9) until the side span catwalk surface layer (4) reaches a free drooping state; S6.2: Continue to release the anchor winch wire rope (10) and the tower top winch wire rope (9) until the tension of the anchor winch wire rope (10) and the tower top winch wire rope (9) is zero, and release the restraint of the side span catwalk surface lifting system. S6.3: The side span catwalk surface layer (4) is dragged by the anchor winch wire rope (10) and the tower top winch wire rope (9), so that the side span catwalk surface layer (4) slides down along the anchor winch wire rope (10) and the tower top winch wire rope (9) in the direction of the anchor under the action of gravity.

8. The method for integral sliding demolition of the catwalk surface layer of a long-span suspension bridge as described in claim 7, characterized in that, In S6.3, the dragging operation of the side span catwalk surface layer (4) by the anchor winch wire rope (10) and the tower top winch wire rope (9) specifically includes: during the process of the side span catwalk surface layer (4) sliding down, when the side span catwalk surface layer (4) cannot slide down by its own weight, the anchor winch (6) is started to pull the anchor winch wire rope (10) to drag the side span catwalk surface layer (4); when the side span catwalk surface layer (4) slides down too fast, the tower top winch wire rope (9) is started to pull the tower top winch wire rope (9) to drag the side span catwalk surface layer (4), so that the side span catwalk surface layer (4) slides down along the anchor winch wire rope (10) and the tower top winch wire rope (9) and towards the anchor as a whole.

9. The method for integral sliding demolition of the catwalk surface layer of a long-span suspension bridge according to claim 8, characterized in that, A working platform is set up in front of the anchor saddle. As the side span catwalk surface layer (4) slides down toward the anchor as a whole, the side span catwalk surface layer (4) is removed section by section in the manner of removing a section of the side span catwalk surface layer (4) every 3 m to 6 m of sliding down.

10. The method for integral sliding demolition of the catwalk surface layer of a long-span suspension bridge according to claim 1, characterized in that, In S1, the pulley system (2) at each hoisting point (1) includes two sets of pulley assemblies, wherein one set of pulley assemblies is connected to one side of the side span main cable clamp (5), and the other set of pulley assemblies is connected to the opposite side of the side span main cable clamp (5). A protective pad is provided at the connection between the main cable clamp (5) and the pulley assembly in the side span.

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