A method for installing large-tonnage components of a long-span steel box arch bridge

Abstract

This invention relates to a method for installing heavy-duty components of a long-span steel box arch bridge. Two arch cranes are installed on each of the two arch ribs, each equipped with a lifting winch and a balancing winch. The two arch cranes on the same arch rib are spaced apart and connected by a connecting rope. Adjustable-pitch steel wire ropes are installed between each pair of opposing arch cranes on the two arch ribs, with both ends connected to the balancing winches on the two arch cranes. The four arch cranes are pulled along the arch ribs unloaded by traction winches located at both ends of the bridge. During movement, the adjustable-pitch steel wire ropes are kept slack, allowing the arch cranes on the two arch ribs to automatically adapt to changes in the distance between the two arch ribs. Upon reaching the lifting position, the balancing winch tightens the adjustable-pitch steel wire ropes, and the lifting winch lowers the lifting steel wire ropes to lift the component. This invention is applicable to both constant and variable cross-section arch bridges and can lift large-segment, heavy-duty components, resulting in high construction efficiency.

Description

Technical Field

[0001] This invention belongs to the field of bridge construction technology and relates to a method for installing large-tonnage components of a long-span steel box arch bridge using an arch-mounted crane. Background Technology

[0002] When constructing steel arch bridges using the "arch-beam-first" method, components such as suspenders and steel beams are typically installed sequentially after the arch ribs are closed. Currently, cable cranes are commonly used to lift these components. However, cable crane systems require robust cable towers and anchoring systems, resulting in significant investment in temporary facilities and high costs. Furthermore, cable cranes have limited lifting capacity; when lifting steel box girders, they can only be broken down into smaller segments, which are then assembled after being lifted into place, leading to low construction efficiency.

[0003] For example, patent CN115110420B discloses a hoisting construction equipment for the arch ribs of an arch bridge. A load-bearing vehicle is set on each of the two arch ribs, and a winch is set on each of the two load-bearing vehicles. The two load-bearing vehicles are connected by a truss beam. The load-bearing vehicles lift the components to be installed by the winch and are pulled along the track laid on the arch rib by the ground traction system. The aforementioned arch-mounted hoisting equipment can fully utilize the support and load-bearing function of the installed arch ribs, resulting in lower construction costs. However, it is subject to significant limitations due to the bridge type and arch rib shape. Since the spacing between the load-bearing vehicles on the two arch ribs is fixed, it is only suitable for parallel arch rib arch bridges. For variable cross-section arch bridges such as basket arches and butterfly arches, where the spacing between the two arch ribs varies, the aforementioned equipment is not applicable. Furthermore, because the load-bearing vehicles must adapt to the arch shape of the arch ribs, the front and rear wheel track and the width of the load-bearing vehicles are also relatively small. Therefore, only one winch can be installed at each end of each load-bearing vehicle, resulting in limited lifting capacity and making it unsuitable for lifting large-tonnage components. In addition, the load-bearing vehicle tracks of the aforementioned equipment are laid directly on the arch ribs, so it is only suitable for steel box arches with a flat top surface and is not applicable to steel pipe arches or triangular cross-section arch ribs. Summary of the Invention

[0004] The purpose of this invention is to address the above-mentioned problems by providing a method for installing heavy-tonnage components of long-span steel box arch bridges using an arch-mounted crane. This method is applicable to parallel arch rib arch bridges, basket arch bridges, butterfly arch bridges, and other variable cross-section arch bridges, and improves the lifting capacity of the arch-mounted crane.

[0005] The technical solution of the present invention is as follows:

[0006] A method for installing heavy-duty components of a long-span steel box arch bridge, characterized by the following steps:

[0007] (1) During the installation of the arch ribs of the arch bridge, a track system for the crane to travel on the arch is installed on the two arch ribs. The track system includes track seats and track beams. There are multiple track seats, one of which is set at a certain interval on the two arch ribs. Each track seat is welded to the top of the arch rib. At least two track beams are set on each arch rib. The track beams are welded to each track seat along the axial direction of the arch rib.

[0008] (2) After the arch ribs are closed, two arch cranes are installed on each of the two arch ribs. Each arch crane has a track wheel at its bottom, which supports it on the track beam on the arch rib and allows it to travel along the track beam. Each arch crane is equipped with a lifting winch and a balancing winch. Each arch crane has a first fixed pulley at the end facing the outside of the arch rib and a second fixed pulley at the end facing the inside of the arch rib. The two arch cranes on the same arch rib are spaced apart and connected by a connecting rope. Two arch cranes on each arch rib are transversely opposite to two arch cranes on another arch rib. An adjustable wire rope is installed between each pair of transversely opposite arch cranes on the two arch ribs. The two ends of the adjustable wire rope pass over the second fixed pulleys on the two arch cranes and are connected to the balance winches on the two arch cranes. The lifting winch on each arch crane is connected to a lifting wire rope. One end of the lifting wire rope passes over the first fixed pulley, hangs down on the outside of the arch rib, and is connected to a hook.

[0009] (3) At both ends of the bridge, a traction winch is set up for each arch crane. The traction winch is connected to the side of the arch crane facing the traction winch by a traction cable.

[0010] (4) Transport the bridge components to be installed to the installation position under the bridge using a transport ship; start the traction winch, control the traction winch at one end of the bridge to retract the cable, and control the traction winch at the other end of the bridge to release the cable, and pull the four arch cranes to move on the arch ribs. During the movement of the arch cranes, the winch that releases the cable provides a certain counter-tension while releasing the cable, so that the connecting wire rope between the two arch cranes on the same arch rib is always taut. At the same time, control the balance winch on each arch crane to keep the adjusting wire rope in a relaxed state, so that the arch cranes on the two arch ribs can automatically adapt to the change in the distance between the two arch ribs; after the arch cranes move to the top of the transport ship, stop, control the balance winch to tighten the adjusting wire rope, and the lifting winch lowers the lifting wire rope to connect with the components to be installed on the ship, and lifts the components to the installation position for installation; after one component is installed, repeat the above process to lift the next bridge component until all bridge components are lifted.

[0011] This invention features two overhead cranes on each arch rib, spaced a certain distance apart and connected by a connecting rope. This allows for the lifting of large-segment, heavy-tonnage steel box girders, improving construction efficiency. The overhead cranes on the two arch ribs are connected by an adjustable-pitch steel wire rope. The length and tension of the adjustable-pitch steel wire rope are controlled by a balancing winch, which can adapt to changes in the spacing between the two arch ribs of a variable cross-section arch bridge. Therefore, it is applicable to both constant and variable cross-section arch bridge construction, expanding the scope of use of overhead cranes and reducing construction costs. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the transverse bridge layout of the arch-mounted crane used in this invention;

[0013] Figure 2 This is a schematic diagram of the arch-mounted crane's layout along the bridge direction as used in this invention;

[0014] Figure 3 This is a schematic diagram of the structure of a track seat used in this invention;

[0015] Figure 4 This is a side view of the overall structure along the bridge direction of the arch-mounted suspension system used in this invention;

[0016] Figure 5 This is a schematic diagram of the state of the hoisting boom of the present invention;

[0017] Figure 6 This is a schematic diagram showing the hoisting of the steel box girder according to the present invention;

[0018] Figure 7 This is a schematic diagram showing the state of the bridge after construction is completed. Detailed Implementation

[0019] The specific embodiments of the present invention are as follows:

[0020] (1) such as Figure 1 , Figure 2 As shown, during the installation of the arch ribs of the arch bridge, a track system for the crane to travel on the arch is installed on the two arch ribs 100. The track system includes track seats 1 and track beams 2. There are multiple track seats, one of which is set at a certain interval on the two arch ribs. Each track seat 1 is welded to the top of the arch rib 100. At least two track beams are set on each arch rib. The track beams 2 are welded to each track seat 1 along the axial direction of the arch rib 100.

[0021] The function of the track support is to provide stable support and a welding surface for the track beam. For example... Figure 3 As shown, to accommodate arch ribs with different cross-sectional shapes, a plane supporting the track beam and welded to the track beam can be provided at the top of each track seat. The bottom of the track seat 1 has a groove 11 that matches the shape of the top of the arch rib. The groove 11 at the bottom of the track seat is fastened to the top of the arch rib 100 and welded to the arch rib. Figure 1 , Figure 2 In the embodiment shown, the arch rib has a triangular cross section, and the bottom of the track seat can be provided with a V-shaped groove that matches the top of the triangular arch rib. Similarly, for the steel pipe arch rib, the bottom of the track seat can be provided with an arc-shaped groove that matches the curvature of the top of the steel pipe arch rib.

[0022] During actual construction, the track seat and track beam can be welded to each arch rib segment before the arch rib is installed. After the arch rib segments are installed and closed, the track system is also installed synchronously with the arch rib.

[0023] To facilitate the installation of the track beams, each track beam can be divided into multiple segments. Each segment is welded between the top surfaces of two adjacent track seats. The ends of multiple track beam segments are welded sequentially, and an arc-shaped track beam with the same shape as the arch rib is formed by replacing curves with straight lines.

[0024] (2) After the arch ribs are installed and closed, two arch cranes 3 are installed on the two arch ribs respectively. Each arch crane 3 has a track wheel 31 at the bottom, which supports the track beam 2 on the arch rib and can travel along the track beam. Each arch crane is equipped with a lifting winch 32 and a balancing winch 33. Each arch crane has a first fixed pulley 34 at the outer end facing the arch rib and a second fixed pulley 35 at the inner end facing the arch rib. The two arch cranes 3 on the same arch rib 100 are spaced apart and connected by a connecting rope 4. The connection is as follows: two arch cranes on each arch rib are horizontally opposite to two arch cranes on another arch rib. An adjustable wire rope 5 is installed between each pair of horizontally opposite arch cranes 3 on the two arch ribs. The two ends of the adjustable wire rope 5 pass over the second fixed pulleys 35 on the two arch cranes and are connected to the balance winches 33 on the two arch cranes respectively. The lifting winch 32 on each arch crane is connected to the lifting wire rope 6. One end of the lifting wire rope 6 passes over the first fixed pulley 34 and hangs down on the outside of the arch rib and is connected to the hook.

[0025] (3) such as Figure 4 and Figure 2 As shown, a traction winch 7 is installed at each end of the bridge corresponding to each arch crane. Each traction winch 7 is connected to the side of the arch crane 3 on the arch rib facing the traction winch via a traction cable 8.

[0026] (4) such as Figure 5 , Figure 6As shown, the bridge components to be installed, such as the gantry cranes and steel box girders, are transported to the installation location below the bridge using transport ship 9. The traction winches at both ends of the bridge are started, controlling the winch at one end to retract the cable while the winch at the other end releases the cable, thus pulling four arch-mounted cranes 3 to travel unloaded on the arch ribs. During the movement of the arch-mounted cranes, the winch releasing the cable provides a certain counter-tension while releasing the cable, ensuring that the connecting steel wire rope 4 between two arch-mounted cranes on the same arch rib remains taut. Simultaneously, the balancing winches on each arch-mounted crane are controlled to adjust the pitch of the steel wire rope. 5. The system is in a relaxed state, allowing the arch cranes on the two arch ribs to automatically adapt to changes in the spacing between the two arch ribs. After the arch cranes travel above the transport ship, the traction winches at both ends of the bridge are controlled to stop the arch cranes. The balance winches are then controlled to tighten the adjusting wire ropes. The lifting winches then vertically lower the lifting wire ropes to connect with the components to be installed on the ship, lifting the components to their installation positions. Because the adjusting wire ropes remain taut during lifting, the arch cranes on the two arch ribs remain stable and balanced during the lifting process. After one component is installed, the above process is repeated to lift the next bridge component until all bridge components are installed.

[0027] According to standard construction procedures, the lifting rods are usually installed first, such as... Figure 5 As shown, the 200mm gantry crane is used to symmetrically lift the gantry bars from both ends of the bridge towards the middle; after all the gantry bars are installed, the steel box girder is then lifted, as shown. Figure 6 As shown, steel box girders 300 mm long were symmetrically hoisted from the middle of the bridge to both ends using an arch crane.

[0028] This invention, by installing two overhead cranes on each arch rib with a certain distance between them, not only significantly increases lifting capacity but also allows for the lifting of longer steel box girder segments. This enables the increase in the length of steel box girder segments during fabrication, thereby improving installation efficiency. The distance between the two overhead cranes on the same arch rib can be set according to the length of the steel box girder segment.

[0029] like Figure 7 As shown, after all components such as the bridge suspender 200 and steel box girder 300 are hoisted, the arch crane and traction system can be dismantled, and the bridge deck ancillary facilities can be constructed.

Claims

1. A method for installing a large-tonnage component of a long-span steel box arch bridge, characterized in that, The method comprises the following steps: (1) installing a track system for the arch crane to walk on the two arch ribs during the installation of the arch ribs of the arch bridge, the track system comprising track bases and track beams, the track bases being multiple, one being arranged on each arch rib at a certain interval, each track base being welded to the top of the arch rib, at least two track beams being arranged on each arch rib, the track beams being welded to the track bases in the axial direction of the arch rib; (2) after the closure of the arch ribs, two arch cranes are arranged on each of the two arch ribs, each arch crane being provided with track wheels at the bottom, supported on the track beams on the arch ribs and capable of walking along the track beams, each arch crane being provided with a hoisting winch and a balancing winch, the first fixed pulley being arranged on the side of each arch crane facing the outer side of the arch rib, and the second fixed pulley being arranged on the side of each arch crane facing the inner side of the arch rib; the two arch cranes on the same arch rib are spaced apart and connected by a connecting rope, the two arch cranes on each arch rib being opposite to the two arch cranes on the other arch rib in the transverse direction of the bridge, a distance-adjusting steel wire rope being arranged between each two arch cranes opposite to each other in the transverse direction of the bridge on the two arch ribs, the distance-adjusting steel wire rope being wound around the second fixed pulleys on the two arch cranes at both ends and connected to the balancing winches on the two arch cranes, the hoisting winch on each arch crane being connected to a hoisting steel wire rope, one end of the hoisting steel wire rope being wound around the first fixed pulley and hanging down on the outer side of the arch rib and connected to a hook; (3) a traction winch is arranged on each end of the bridge corresponding to each arch crane, the traction winch being connected to the side of the arch crane facing the traction winch through a traction rope; (4) a transport ship is used to transport the bridge components to be installed to the position below the bridge, the traction winches are started, the traction winches on one end of the bridge are controlled to take in the traction rope, the traction winches on the other end of the bridge are controlled to pay out the traction rope, the four arch cranes are walked on the arch ribs, in the walking process of the arch cranes, the winch paying out the traction rope provides a certain counter-tension at the same time, the connecting steel wire rope between the two arch cranes on the same arch rib is always in a taut state, at the same time, the balancing winches on the arch cranes are controlled to make the distance-adjusting steel wire rope in a relaxed state, so that the arch cranes on the two arch ribs can automatically adapt to the change in the interval of the two arch ribs, the arch cranes stop after walking above the transport ship, the balancing winches are controlled to take in the distance-adjusting steel wire rope, the hoisting winch lowers the hoisting steel wire rope to be connected to the component on the ship, the component is hoisted to the installation position for installation, after the installation of the component is completed, the above process is repeated to hoist the bridge component at the next position, until all the bridge components are hoisted.

2. The method for installing large-tonnage components of a long-span steel box arch bridge according to claim 1, characterized in that: The top of each track base is provided with a flat surface supporting the track beam and welded to the track beam, and the bottom is provided with a notch matching the shape of the top of the arch rib, the notch at the bottom of the track base is buckled to the top of the arch rib and welded to the arch rib.

3. The method for installing large-tonnage components of a long-span steel box arch bridge according to claim 1 or 2, characterized in that: Each track beam comprises multiple segments, each segment being welded between the top surfaces of two adjacent track bases, the end portions of the multiple track beam segments being sequentially welded, and the track beams are formed in a straight-to-curved manner to form arc-shaped track beams consistent with the line type of the arch rib.

Images