A large-span steel pipe arch bridge unbalanced high-low cable hoisting system and method

Abstract

The present application relates to the technical field of crane, especially to a large-span steel pipe arch bridge unbalanced high-low cable hoisting system and method, the system comprises: anchor box and tower, which are fixedly arranged on one side of the arch bridge; anchor, which is embedded in the mountain on the other side of the arch bridge; main cable, both ends of which are fixed on the anchor box and the anchor, and the middle section is wrapped around the top of the tower; two cranes, each of which is provided with a hoisting pulley block and a traction pulley block; the two cranes are connected by a connecting rope, and a first matching wheel is further arranged; two traction power systems, each of which comprises a traction cable passing through a corresponding traction pulley block and a traction winch; two hoisting power systems, each of which comprises a hoisting cable passing through a corresponding hoisting pulley block and a hoisting winch; wherein the hoisting cable passes through a hoisting pulley block and passes above another first matching wheel. The present application can effectively adapt to the arch bridge unbalanced high-low cable hoisting scene.

Description

Technical Field

[0001] This invention relates to the field of crane technology, and in particular to an unbalanced high-low cable lifting system and method for large-span steel pipe arch bridges. Background Technology

[0002] Cable-stayed bridge systems are core equipment for the installation of superstructures of long-span arch bridges and are widely used in the construction of bridges in mountainous canyons. Traditional cable-stayed bridge systems typically adopt a symmetrical arrangement on both banks. By setting up towers of similar height on both banks of the canyon, the main cable, which bears the load, crosses the canyon in a near-catenary shape. Turning and lateral movement are achieved through cable saddles at the top of the towers, and cranes run along the main cable to lift components.

[0003] However, under certain special environmental conditions (such as high-voltage line clearance requirements, terrain limitations, etc.), it is necessary to use an unbalanced cable hoisting system, where only one bank has a tower and the main cable on the other bank is directly anchored diagonally into the mountainside. If the structure of an existing symmetrical system is directly transplanted into this asymmetrical cable hoisting system, the following problems will arise: First, because the winding and unwinding speeds of each winch cannot be exactly the same, the ends of the traction crane may become loose. In a conventional hoisting system, this slight loosening has little impact, but in an asymmetrical cable hoisting system, the cable is prone to detachment during inclined movement. Second, the fixed-length connecting cable between the two cranes is subjected to alternating impact loads due to asynchronous speeds on the slope, which can easily cause the suspended load to swing violently. Third, the excessive sag of traditional hoisting systems can easily lead to dangerous proximity to the high-voltage lines below. Therefore, a cable hoisting system capable of adapting to unbalanced heights is needed. Summary of the Invention

[0004] This invention provides a lifting and hoisting system and method for unbalanced high and low cables in large-span steel pipe arch bridges, which can effectively solve the problems in the background art.

[0005] This invention provides an unbalanced high-low cable lifting system for large-span steel pipe arch bridges, comprising: Both the anchor box and the tower are fixedly installed on one side of the arch bridge, with the tower located between the anchor box and the arch bridge; The anchorage is buried in the mountainside on the other side of the arch bridge; The main cable is fixed at both ends to the anchor box and the anchorage respectively, and the middle section is wrapped around the top of the tower. Two cranes travel on the main cable at intervals, each crane is equipped with a lifting pulley block and a traction pulley block; the two cranes are connected by a connecting rope; each crane is also equipped with a first matching wheel higher than the lifting pulley block; Two traction power systems are located on both sides of the arch bridge; each traction power system includes a traction cable that winds around a corresponding traction pulley block, and a traction winch for winding and unwinding the traction cable. Two lifting power systems are located on one side of the anchor box; each lifting power system includes a lifting cable that winds around the corresponding lifting pulley block, and a lifting winch for winding and unwinding the lifting cable. The lifting cable passes through a lifting pulley block and goes over another first mating pulley.

[0006] Furthermore, each crane includes a trolley, a lifting frame, and a lifting block, with the trolley hinged to the lifting frame; a traction pulley block is mounted on the trolley, and the lifting pulley block includes a fixed pulley block and a movable pulley block, with the fixed pulley block mounted on the lifting frame and the movable pulley block mounted on the lifting block.

[0007] Furthermore, the fixed pulley block includes a first fixed pulley, a second fixed pulley, a third fixed pulley and a fourth fixed pulley respectively set at the four corners of the same plane of the lifting support, and a central fixed pulley set at the center of the bottom of the lifting support; The movable pulley block includes a first movable pulley, a second movable pulley, a third movable pulley, and a fourth movable pulley, which are respectively installed at the four corners of the same plane of the hoisting block; The first fixed pulley, the second fixed pulley, the third fixed pulley, and the fourth fixed pulley are respectively vertically aligned with the first movable pulley, the second movable pulley, the third movable pulley, and the fourth movable pulley; The lifting cable passes through the first fixed pulley, the first movable pulley, the second fixed pulley, the second movable pulley, the center fixed pulley, the third movable pulley, the third fixed pulley, the fourth movable pulley, and the fourth fixed pulley in sequence.

[0008] Furthermore, multiple auxiliary fixed pulleys are installed on the lifting support to limit the position of the lifting cable.

[0009] Furthermore, the two lifting pulley blocks are symmetrical in the vertical direction of the main cable.

[0010] Furthermore, the traction pulley assembly includes a first traction wheel and a second traction wheel disposed on both sides of the traction trolley, as well as a fifth fixed pulley, a sixth fixed pulley, and a seventh fixed pulley that are fixed relative to the ground; The traction cable passes sequentially through the fifth fixed pulley, the first traction pulley, the sixth fixed pulley, the second traction pulley, the seventh fixed pulley, and the traction winch.

[0011] Furthermore, the lifting pulley block is located between the first traction wheel and the second traction wheel.

[0012] Furthermore, each crane is equipped with a second mating wheel, which is further away from the other crane than the first mating wheel; each lifting cable passes under the second mating wheel.

[0013] This invention also provides a method for lifting and assembling an unbalanced high-low cable-stayed bridge for a large-span steel pipe arch bridge, using the aforementioned unbalanced high-low cable-stayed bridge lifting and assembling system for large-span steel pipe arch bridges, the steps of which include: S1: First, complete the erection of the main cable, then install the crane on the main cable, and then complete the threading of the lifting cable and traction cable; S2: Connect the two cranes with the connecting rope and keep the connecting rope slack, then move the two cranes to the lifting area; S3: Conduct load tests on the cable hoisting system, gradually loading it to 1.25 times the design lifting weight to verify the system's safety and record the monitoring data at each measuring point; S4: Connect the workpiece to be hoisted to the hoisting blocks of the two cranes, and simultaneously start the two hoisting winches to wind up the hoisting ropes to hoist the workpiece to the set height; S5: Simultaneously start two traction winches to move the two cranes along the main cable and transport the workpiece to the installation position; S6: Start the two hoisting winches in reverse synchronously to unwind the hoisting cable, lower the workpiece to the installation position, disconnect the connection, and complete one hoisting cycle.

[0014] Furthermore, in step S1, the erection of the main cable is specifically as follows: The kite line is pulled by a drone along the main cable path to complete the erection. After the kite line is erected, the kite line is used to pull the guide cable to complete the erection of the guide cable. After the guide cable is erected, the guide cable is used to pull the main cable to complete the erection.

[0015] The technical solution of this invention can achieve the following technical effects: This invention features a first cooperating wheel that allows the lifting cable to pass through the lifting pulley block of one crane and then over the top of another crane, thereby generating oblique pressure that brings the two cranes closer together. This effectively solves the problems of loosening and falling of the traction cable and violent swinging of the suspended load caused by the asynchronous speeds of the traction winches on both sides. At the same time, the use of a structure in which the traction trolley and the lifting support are hinged ensures that the lifting support remains vertically stable during slope movement, improving the stability and safety of the lifting operation. By optimizing the routing of the lifting pulley block (four corner fixed and moving pulleys in conjunction with the central fixed pulley), the lifting block is subjected to uniform force, has strong resistance to crosswinds, and the force on the main cable is distributed, avoiding the risk of deflection and derailment caused by concentrated force in traditional systems. This invention is particularly suitable for asymmetrical cable lifting scenarios in complex terrains such as mountainous canyons. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A schematic diagram of the overall structure of the unbalanced high-low cable lifting and hoisting system for a long-span steel pipe arch bridge. Figure 2 This is a front view of the crane; Figure 3 This is a side view of the crane; Figure 4 A schematic diagram of the wiring for the traction power system and traction pulley block; Figure 5 This is a schematic diagram of the wiring for the lifting power system and the lifting pulley block. Figure 6 This is a schematic diagram of the wiring between the two cranes; Figure 7 This is a wiring diagram for a crane. Figure 8 This is a wiring diagram for another crane.

[0018] Reference numerals: 1. Anchor box; 2. Tower; 3. Anchorage; 4. Main cable; 5. Crane; 51. Traction trolley; 511. First traction wheel; 512. Second traction wheel; 52. Lifting support; 521. First fixed pulley; 522. Second fixed pulley; 523. Third fixed pulley; 524. Fourth fixed pulley; 525. Central fixed pulley; 526. Auxiliary fixed pulley; 53. Lifting block; 531. First movable pulley; 532. Second movable pulley; 533. Third movable pulley; 534. Fourth movable pulley; 54. First matching wheel; 55. Second matching wheel; 6. Connecting rope; 71. Traction cable; 72. Traction winch; 73. Fifth fixed pulley; 74. Sixth fixed pulley; 75. Seventh fixed pulley; 81. Lifting cable; 82. Lifting winch. Detailed Implementation

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0021] This invention relates to an unbalanced high-low cable lifting system for large-span steel pipe arch bridges, such as... Figure 1 As shown, the system mainly includes anchor box 1, tower 2, anchorage 3, main cable 4, two cranes 5, connecting rope 6, two traction power systems, and two lifting power systems. These components enable the unbalanced, high-low cable arrangement from both banks of the arch bridge. The specific structure of each component is as follows: Anchor box 1 is fixedly installed on one side of the arch bridge. Anchor box 1 is made of welded steel plates and has 10 ear plates for installing pins to secure the pulleys of the main cable 4. Anchor box 1 also has 32 reserved holes for passing through 32 φ40mm precision rolled threaded steel bars pre-embedded in the anchorage. The anchorage is completed by locking with double nuts.

[0022] Tower 2 is fixedly installed on one side of the arch bridge, located between anchor box 1 and the arch bridge. Tower 2 adopts a portal lattice structure, mainly composed of load-bearing columns, connecting beams, a transverse beam at the top of the tower, and diagonal bracing. The load-bearing columns are four-limb lattice structures, with one set on each side. The load-bearing columns are divided into standard segments (3m high) and irregular segments (0.8m high), both using φ820×14mm steel pipes. Tower 2 is equipped with a cable saddle at the top, and a rolling transverse mechanism is installed below the cable saddle to realize the transverse movement of the cable saddle on the transverse beam at the top of the tower. After transverse movement into place, it is locked with a pin.

[0023] Anchorage 3 is embedded in the mountainside on the other side of the arch bridge. Anchorage 3 employs a combination of rock anchors, gravity anchors, and pile foundations. Anchorage 3 features a raised support seat, three sliding tracks (2cm thick Q345 steel plates with a flatness error ≤±2mm), detachable sliders and sliding shoes, a counter-pressure frame, and a lateral movement reaction frame. The slider is secured to the support seat, and the cable is anchored to the U-shaped sliding seat. Lateral movement is achieved by pushing the slider with jacks. At the front end of anchorage 3, there is a row of seven piles running transversely towards the bridge, each with a diameter of 1.8m and embedded 4.5m into moderately weathered rock. Anchorage 3 also contains 63 pre-embedded anchor cables, each group consisting of nine φ15.2mm steel strands.

[0024] Main cable 4 is fixed at both ends to anchor box 1 and anchor 3 respectively, and the middle section is wrapped around the cable saddle at the top of tower 2. Main cable 4 consists of 10 φ60mm steel wire ropes, with a single cable breaking strength of 2510kN. The span arrangement of main cable 4 is 216m (side span) + 735.8m (main span). The sag of the unloaded cable is controlled at 1 / 27.5 of the span, and the maximum sag during hoisting is controlled at 1 / 17 of the span.

[0025] Two cranes 5 travel on the main cable 4 at intervals; the structure of each crane 5 is as follows: Figures 2-3 As shown, the crane 5 is equipped with a lifting pulley block and a traction pulley block; the two cranes 5 are connected by a connecting rope 6, which is used to prevent the distance between the two cranes 5 from exceeding the allowable range; each crane 5 is also equipped with a first mating wheel 54 that is higher than the lifting pulley block.

[0026] Two traction power systems are located on either side of the arch bridge. Each traction power system includes a traction cable 71 that winds around a corresponding traction pulley block, and a traction winch 72 for winding and unwinding the traction cable 71. The traction cable 71 is made of φ36mm steel wire rope with a single-strand breaking strength of 582kN. The traction winch 72 is a 35-ton winch. Each traction power system is used to move one crane 5, such as... Figure 4 As shown.

[0027] Two lifting power systems are located on one side of the anchor box 1. Each lifting power system includes a lifting cable 81 that winds around a corresponding lifting pulley block, and a lifting winch 82 for winding and unwinding the lifting cable 81. The lifting cable 81 is made of φ26mm steel wire rope with a single-strand breaking strength of 472kN. The lifting winch 82 is a 20-ton winch. The lifting cable 81 winds around the lifting pulley block of one crane 5 and passes over the first mating pulley 54 of the other crane 5. Each lifting power system is used to realize the lifting and lowering action of one crane 5, such as... Figure 5 As shown.

[0028] The working principle of this system is as follows: Figure 6 As shown, after the lifting cable 81 exits from the lifting pulley block of a crane 5, it rests on the first mating pulley 54. The lifting cable 81 is vertical at the exit end of the lifting pulley block. The workpiece being lifted exerts a downward pulling force F1 on the lifting cable 81 within the lifting pulley block. Because the lifting cable 81 is raised by the first mating pulley 54, it forms an obtuse angle at the exit end, exerting a force F1 on the exit end of the lifting pulley block. Figure 6 The inclined pressure F2 causes crane 5 to tend to lean towards another crane 5, while the traction cable 71 pulls on the outer side of each crane 5 (i.e., Figure 4(The left crane 5 is pulled by the traction cable 71, while the right crane 5 is pulled by another traction cable 71.) Throughout the lifting process, because the two cranes 5 tend to move closer together, the traction cables 71 on both sides remain taut. Even if the winding and unwinding speeds of the traction cables 71 on both sides are inconsistent, the oblique pressure F2 allows the two cranes 5 to automatically adjust to a balanced state. For example, if the unwinding speed of the left traction cable 71 is greater than the winding speed of the right traction cable 71 during the rightward movement of the crane 5, the traction cable 71 will gradually loosen. Without this structure, the loose traction cable 71 would easily fall off. However, the oblique pressure F2 generated by this structure causes the two cranes 5 to move closer together, thereby re-tautting the traction cable 71 and effectively ensuring the connection between the traction cable 71 and the crane 5.

[0029] Preferably, each crane 5 includes a traction trolley 51, a lifting support 52, and a lifting block 53. The traction trolley 51 is hinged to the lifting support 52, and the lifting block 53 is directly connected to the workpiece being lifted. The traction pulley group is set on the traction trolley 51, and the lifting pulley group includes a fixed pulley group and a movable pulley group. The fixed pulley group is set on the lifting support 52, and the movable pulley group is set on the lifting block 53. When the crane 5 is working, the trolley 51 travels on the main cable 4. Due to this unbalanced lifting scenario, the main cable 4 will have different inclinations in some positions. If the trolley 51 and the lifting bracket 52 are fixed as one unit, the lifting bracket 52 will rotate with the trolley 51, thus affecting the overall stability of the lifting system. Therefore, this system connects the trolley 51 and the lifting bracket 52 in a hinged manner. Under the pull of the lifted workpiece, no matter where the trolley 51 moves to, the lifting bracket 52 can always remain in a vertical position, effectively ensuring the stability of the lifting system. Furthermore, the fixed pulley group of the lifting pulley block is set on the stable lifting bracket 52, thereby ensuring the stability of the lifting block 53 and preventing large swaying during the lifting process.

[0030] Preferably, the fixed pulley group includes a first fixed pulley 521, a second fixed pulley 522, a third fixed pulley 523 and a fourth fixed pulley 524 respectively arranged in a circumferential order at the four corners of the same plane of the lifting support 52, and a central fixed pulley 525 arranged at the center of the bottom of the lifting support 52. The movable pulley block includes a first movable pulley 531, a second movable pulley 532, a third movable pulley 533, and a fourth movable pulley 534, which are respectively arranged in a circumferential order at the four corners of the same plane of the hoisting block 53; The first fixed pulley 521, the second fixed pulley 522, the third fixed pulley 523 and the fourth fixed pulley 524 correspond vertically to the first movable pulley 531, the second movable pulley 532, the third movable pulley 533 and the fourth movable pulley 534, respectively.

[0031] To correspond to the positions of the two cranes 5, the first fixed pulley 521, the second fixed pulley 522, the third fixed pulley 523, and the fourth fixed pulley 524 of one crane 5 are distributed in a counterclockwise direction when viewed from above, as follows: Figure 7 As shown, the first movable pulley 531, the second movable pulley 532, the third movable pulley 533, and the fourth movable pulley 534 are arranged accordingly; the first fixed pulley 521, the second fixed pulley 522, the third fixed pulley 523, and the fourth fixed pulley 524 of the other crane 5 are distributed clockwise in a top-down view, as shown... Figure 8 As shown, the first movable pulley 531, the second movable pulley 532, the third movable pulley 533, and the fourth movable pulley 534 are arranged accordingly. The two lifting pulley groups are symmetrical in the vertical direction of the main cable 4.

[0032] Both cranes 5 have the following characteristics: the lifting cable 81 enters from the first fixed pulley 521 and exits from the fourth fixed pulley 524. The first fixed pulley 521 and the fourth fixed pulley 524 are both located on one side of the crane 5, while the second fixed pulley 522 and the third fixed pulley 523 are both located on the other side of the crane 5. The lifting cable 81 passes sequentially through the first fixed pulley 521, the first movable pulley 531, the second fixed pulley 522, the second movable pulley 532, the center fixed pulley 525, the third movable pulley 533, the third fixed pulley 523, the fourth movable pulley 534, and the fourth fixed pulley 524.

[0033] Under the above wiring method, such as Figures 7-8 As shown, the lifting cable 81 can directly form a symmetrical inclined tension structure in the direction of travel of the crane 5 by the second movable pulley 532, the central fixed pulley 525 and the third movable pulley 533. The lifting cable 81 forms a symmetrical inclined tension structure in the direction of travel of the crane 5 between the first movable pulley 531 and the second fixed pulley 522, and between the third fixed pulley 523 and the fourth movable pulley 534. The two inclined tension structures are in opposite directions, so that both sides of the lifting block 53 can receive oblique tension. During the formation of the crane 5, even if there is a side wind, the lifting block 53 can be kept in a stable state by the two inclined tension structures, thereby ensuring the stability of the lifting system.

[0034] In addition, from the perspective of force, the above-mentioned wiring method can enable the first movable pulley 531, the second movable pulley 532, the third movable pulley 533 and the fourth movable pulley 534 on the lifting block 53 to be connected to the two lifting cables 81 (the section is the part between the movable pulley and the fixed pulley). In this way, the force on each movable pulley will be more consistent, effectively avoiding the lifting block 53 from overturning and affecting the normal operation of the lifting system.

[0035] Furthermore, assuming the weight of the suspended object is G, then the force exerted on the lifting cable 81 by each of the first movable pulley 531, the second movable pulley 532, the third movable pulley 533, and the fourth movable pulley 534 is G / 4. When evenly distributed across each lifting cable 81, this equals G / 8. Figures 7-8 As can be seen, the first fixed pulley 521 and the fourth fixed pulley 524 are each connected to a lifting cable 81 section, and their stress is G / 8; the second fixed pulley 522 and the third fixed pulley 523 are each connected to two lifting cable 81 sections, and their stress is G / 4; the central fixed pulley 525 is connected to two lifting cable 81 sections, and its stress is G / 4. It can be seen that during lifting, the force applied to the main cable 4 of the crane 5 will be slightly greater on one side and slightly less on the other side, and the weight of the two cranes 5 will be exactly opposite on opposite sides. When the crane 5 is placed on the main cable 4, the two symmetrical cranes 5 will be in a balanced state. However, compared with the traditional form of concentrating all the weight in the middle, the force applied to the main cable 4 by the two cranes in this system will be more dispersed, so that the stress of the multiple cables of the main cable 4 can be distributed more evenly, making the lifting system run more smoothly, especially in the scenario of unbalanced high and low cables, effectively preventing the crane 5 from deviating to both sides.

[0036] Preferably, multiple auxiliary fixed pulleys 526 are also provided on the lifting support 52 to limit the position of the lifting cable 81, prevent the lifting cable 81 from touching and rubbing against each other inside the lifting support 52, and ensure the normal operation of the lifting system.

[0037] Preferably, the traction pulley block includes a first traction wheel 511 and a second traction wheel 512 disposed on both sides of the traction trolley 51, and a fifth fixed pulley 73, a sixth fixed pulley 74, and a seventh fixed pulley 75 fixed relative to the ground; the traction cable 71 passes sequentially through the fifth fixed pulley 73, the first traction wheel 511, the sixth fixed pulley 74, the second traction wheel 512, the seventh fixed pulley 75, and the traction winch 72. With this structure, the traction cable 71 and the main cable 4 can be kept relatively parallel, so that when the traction cable 71 pulls the crane 5, the crane 5 is less likely to detach from the main cable 4, thus improving the safety of the lifting system.

[0038] Preferably, the lifting pulley block is positioned between the first traction wheel 511 and the second traction wheel 512. Since the tension of the traction cable 71 on the crane 5 mainly acts on the first traction wheel 511 and the second traction wheel 512, the above design allows the tension of the traction cable 71 on the crane 5 to be located outside the two sides of the lifting pulley block, thereby effectively reducing the impact of the tension of the traction cable 71 on the lifting pulley block and avoiding the deflection of the lifting pulley block due to uneven tension of the traction cable 71, which would affect the lifting function.

[0039] Preferably, each crane 5 is also provided with a second mating wheel 55, which is further away from the other crane 5 than the first mating wheel 54; each lifting cable 81 passes under the second mating wheel 55. The second mating wheel 55 enables the lifting cable 81 to also provide some support to the crane 5, especially to prevent the crane 5 from deflecting too much when the main cable 4 is subjected to unbalanced force as described above.

[0040] This invention also relates to a method for lifting and assembling an unbalanced high-low cable-stayed bridge with a large span steel pipe arch bridge, using the aforementioned unbalanced high-low cable-stayed bridge lifting and assembling system for large span steel pipe arch bridges, the steps of which include: S1: First, complete the erection of the main cable 4, then install the crane 5 on the main cable 4, and then complete the threading of the lifting cable 81 and the traction cable 71. S2: Connect the two cranes 5 with the connecting rope 6 and keep the connecting rope 6 in a slack state, then move the two cranes 5 to the lifting area; S3: Conduct load tests on the cable hoisting system, gradually loading it to 1.25 times the design lifting weight to verify the system's safety and record the monitoring data at each measuring point; S4: Connect the workpiece to be hoisted to the hoisting blocks 53 of the two cranes 5, and simultaneously start the two hoisting winches 82 to wind up the hoisting ropes 81 to hoist the workpiece to the set height; S5: Simultaneously start the two traction winches 72 to move the two cranes 5 along the main cable 4 and transport the workpiece to the installation position; S6: Start the two hoisting winches 82 in reverse synchronous mode to unwind the hoisting cable 81, lower the workpiece to the installation position, disconnect the connection, and complete one hoisting cycle.

[0041] Preferably, in step S1, the erection of the main cable 4 is specifically as follows: First, a drone is used to pull the kite line along the main cable path 4. After the kite line is erected, it is used to pull the guide cable to complete the guide cable erection. Specifically, a 16t guide pulley is fixed near the bridge's centerline at the wet joint between the first and second spans of the approach bridge on the tower-side bank, and another 16t guide pulley is fixed at the centerline of anchorage 3 on the towerless bank. A 10t winch is fixed on each approach bridge deck. The drone, carrying a kite line with a diameter of 0.5–1mm, is then repeatedly flown from the tower-side bank to the towerless bank, allowing the kite line to cross the canyon. One end of the kite line is connected to a 6mm diameter hemp rope, and the kite line is used to pull the hemp rope across the span. Next, connect one end of the hemp rope to a 16mm diameter guide cable. Use a winch on the towerless bank to pull the hemp rope, while simultaneously releasing the rope with a winch on the tower bank. This causes the hemp rope to pull the guide cable over the cable saddle pulley at the top of the tower 2 on the tower bank, pulling it from the tower bank to the anchorage 3 on the towerless bank. The guide cable then passes over the traction pulley on the block slide on the towerless bank and enters the traction winch on the towerless bank. Then, start the winches on both banks to tension and tighten the guide cable. Use two total stations to measure the mid-span sag of the guide cable. When the sag reaches 1 / 27.5 of the span, temporarily anchor both ends of the guide cable to the anchorages on both banks.

[0042] After the guide cable is erected, the main cable 4 is pulled by the guide cable to complete the erection. Specifically, a 32t tensioning pulley block (line 4) is set up at the anchor box 1 on the tower bank, and the pulley block is connected to the balance wheel on the anchor box 1 on the tower bank. One end of the main cable 4 to be erected is fixed to the 32t tensioning pulley block with cable clamps, and the free end of the other end of the main cable 4 is connected to the guide cable with 7 to 10 cable clamps. The guide cable traction winch is started, so that the winch on the towerless bank retracts the rope and the winch on the tower bank releases the rope, driving the front end of the main cable 4 to move towards the towerless bank at a speed controlled within 5m / min. When the front end of the main cable 4 reaches the top of the tower 2 on the tower bank, the main cable 4 is manually assisted into the cable saddle pulley groove, and the temporary connection between the main cable 4 and the guide cable is released. The main cable 4 is lifted by the tower crane and passed through the load-bearing pulley on the crane 5, and then the main cable 4 is temporarily reconnected to the guide cable. Continue operating the winch to move the front end of main cable 4 along with the guide cable towards the towerless bank until the front end of main cable 4 reaches the balance wheel at the slider of anchorage 3 on the towerless bank. Anchor the end of main cable 4 to the balance wheel. Then, use the 32t pulley block at anchorage box 1 on the towered bank to tighten main cable 4 in the reverse direction. Use two total stations to measure the mid-span sag of main cable 4. When the sag reaches 1 / 27.5 of the span, anchor the end of main cable 4 at the towered bank to anchorage box 1 on the towered bank. Repeat the above steps to install the remaining main cables 4 one by one.

[0043] Preferably, the specific operation of step S2 is as follows: Take a steel wire rope with a length equal to the design distance between the two cranes 5 (approximately 1.5 times the crane length) as the connecting rope 6. Connect both ends of the connecting rope 6 to the frames of the two cranes 5 respectively. After connection, allow the connecting rope 6 to be in a naturally slack state (the middle of the connecting rope 6 should be able to form a noticeable sag when lifted by hand). Start the traction winch 72 on the tower bank to wind up the traction cable 71, and simultaneously loosen the traction winch 72 on the towerless bank, so that the two cranes 5 move along the main cable 4 towards the tower bank, with a moving speed not exceeding 10m / min. Stop traction when they are directly above the lifting platform 45m in front of the tower 2 on the tower bank. Lower the lifting blocks 53 of the two cranes 5 to both sides of the arch rib segment on the lifting platform, stopping the bottom of the lifting blocks 53 about 10cm away from the lifting lugs of the arch rib segment.

[0044] Preferably, the specific operation of step S3 is as follows: A load-bearing platform was constructed using steel sections and Bailey bridge segments, with platform dimensions comparable to the arch rib segments. Counterweights were stacked on the platform, with the total weight calculated based on the design lifting capacity P = 160t. Loading was performed in stages: 0.5P, 0.75P, 1.0P, 1.1P, and 1.25P. After each stage, a static load test was conducted: the load was lifted 10cm off the ground and held for at least one hour, with displacement, cable force, and tower deflection data measured and recorded at each measuring point. After the static load test, a dynamic load test was conducted in the same stages: 0.5P, 0.75P, 1.0P, and 1.1P. The load was moved across the entire span, stopping at one-quarter of the span (approximately 184m from the tower on the anchored bank), one-half (approximately 367.9m), three-quarters (approximately 552m), and 75m before the anchorage on the bank without a tower, with data measured and recorded at each measuring point.

[0045] During the test, the following were monitored simultaneously: longitudinal bridge displacement (allowable ±30mm) and settlement (overall settlement ±30mm, differential settlement between left and right spans ±5mm) of the tower-bank anchor box 1 and the towerless bank anchor 3; cable force of main cable 4 (<836kN), cable force of traction cable 71 (<194kN), cable force of lifting cable 81 (<94.4kN); mid-span sag of main cable 4; relative height difference between high-voltage line and cable system (≥20m); root stress of tower 2 (<220MPa), tower top displacement (<237mm), and wind cable force (<1170kN); travel speed (5-20m / min) and lifting speed (0.5-16m / min) of crane 5; deformation and wear of crane 5 and lifting equipment; jamming of cable saddle and slider during lateral movement and deformation of lateral reaction frame.

[0046] Preferably, the specific operation of step S5 is as follows: Simultaneously start the traction winches 72 on both the tower-supported and towerless banks. The tower-supported bank winds the rope while the towerless bank winds the rope, moving crane 5 towards the towerless bank at a speed controlled between 5-20 m / min, adjusted according to the lifting weight and wind speed. During transport, the following real-time monitoring and automatic control are continuously implemented: Pin-type force sensors are installed on the connecting steel belt between the upper and lower lifting devices of each crane 5 to read the lifting weight at each lifting point in real time. If the lifting weight at any lifting point exceeds 110% of the designed lifting weight, the power supply to the hoisting winch 82 is automatically cut off; pin-type strain sensors are installed on the balance wheel of the main cable 4 to read the cable force of each main cable 4 in real time. If the cable force of any main cable 4 exceeds 836 kN, an alarm is automatically triggered and the machine stops; a Beidou mobile station is installed at the top of the tower to read the tower top deviation in real time. If the deviation along the bridge direction exceeds 240 mm, an automatic alarm is triggered; a movable pressure gauge sensor is installed at the rope exit point of the traction winch 72 to read the traction cable 7... 1. The cable force is set to automatically alarm and stop when it exceeds 194kN. A Beidou positioning terminal is installed on each of the two cranes 5 to read the crane's moving speed, displacement, and synchronization in real time. The PLC control system automatically adjusts the speed of the traction winches 72 on both sides based on the Beidou positioning data, ensuring that the difference in moving speed between the two cranes 5 does not exceed 0.2m / min. Automatic adjustment is made when the actual distance between the two cranes 5 deviates from the theoretical distance by more than ±100mm. If the deviation continues to increase or either traction winch 72 overspeeds, the power is automatically cut off and the crane stops. A laser rangefinder is installed at the bottom of each crane 5, working in conjunction with a pre-set reflective target. A stop signal is automatically issued when the laser rangefinder reading reaches the design value. Traction stops when the laser rangefinder or Beidou positioning indicator reaches directly above the installation position.

[0047] Preferably, step S6 is performed as follows: Two hoisting winches 82 are started in reverse synchronous motion to unwind the lifting cable 81, with the unwinding speed controlled between 0.5 m / min and 1 m / min. During the lowering process, surveyors use a total station to monitor the axial deviation and elevation of the arch rib segment in real time, reporting the data every 10 cm of lowering. When the segment is less than 10 cm from the top surface of the installed segment, the unwinding speed is reduced to 0.2 m / min, and the lifting and lowering team, in conjunction with the hand-operated hoist, performs fine-tuning adjustments in the lateral and longitudinal directions to align the mating flange on the segment with the flange hole positions on the installed segment. Two symmetrically positioned punch pins are inserted for temporary fixation, and then the segment is lowered further to stabilize it. The flange fitting gap is checked; if the gap is less than 2 mm, all connecting bolts are tightened. The pin connection between the arch rib segment lifting lug and the lifting block 53 is released, completing one lifting cycle. The two cranes 5 are returned along the main cable 4 to the lifting area on the tower bank to prepare for the lifting of the next segment. After all arch rib segments are hoisted and joined, the cable saddle and slider are moved laterally to the centerline of the bridge. Then, the arch columns, steel cap beams, composite bridge deck beams, and bridge panels are hoisted sequentially using the method described above. During the entire hoisting process, operations should be stopped in the event of winds of level 5 or above, heavy rain, dense fog, or thunderstorms, and crane 5 should be moved to the vicinity of tower 2 and locked.

[0048] Although this application has been described in conjunction with specific features and embodiments, it is obvious that various modifications and combinations can be made thereto without departing from the spirit and scope of this application. Accordingly, this specification and drawings are merely exemplary illustrations of the application as defined herein, and are to be considered as covering any and all modifications, variations, combinations, or equivalents within the scope of this application. Clearly, those skilled in the art can make various alterations and modifications to this application without departing from its scope. Thus, if such modifications and modifications fall within the scope of this application and its equivalents, this application intends to include such modifications and modifications.

Claims

1. A lifting and hoisting system for unbalanced high-low cable-stayed bridges with large spans, characterized in that, include: Anchor box (1) and tower (2) are both fixedly installed on one side of the arch bridge, and the tower (2) is located between the anchor box (1) and the arch bridge; Anchorage (3) is buried on the mountainside on the other side of the arch bridge; The main cable (4) is fixed at both ends to the anchor box (1) and the anchor (3) respectively, and the middle section is wrapped around the top of the tower (2); Two cranes (5) travel on the main cable (4) at intervals from each other. Each crane (5) is equipped with a lifting pulley block and a traction pulley block. The two cranes (5) are connected by a connecting rope (6). Each crane (5) is also equipped with a first matching wheel (54) higher than the lifting pulley block. Two traction power systems are respectively set on both sides of the arch bridge; each traction power system includes a traction cable (71) that passes through the corresponding traction pulley block, and a traction winch (72) for winding and unwinding the traction cable (71); Two lifting power systems are located on one side of the anchor box (1); each of the lifting power systems includes a lifting cable (81) that passes through a corresponding lifting pulley block, and a lifting winch (82) for winding and unwinding the lifting cable (81); The lifting cable (81) passes through one of the lifting pulley groups and goes over the other first mating pulley (54).

2. The unbalanced high-low cable lifting system for large-span steel pipe arch bridges according to claim 1, characterized in that, Each of the cranes (5) includes a trolley carriage (51), a lifting frame (52), and a lifting block (53), wherein the trolley carriage (51) is hinged to the lifting frame (52); the traction pulley assembly is disposed on the trolley carriage (51), and the lifting pulley assembly includes a fixed pulley assembly and a movable pulley assembly, wherein the fixed pulley assembly is disposed on the lifting frame (52), and the movable pulley assembly is disposed on the lifting block (53).

3. The unbalanced high-low cable lifting system for large-span steel pipe arch bridges according to claim 2, characterized in that, The fixed pulley group includes a first fixed pulley (521), a second fixed pulley (522), a third fixed pulley (523) and a fourth fixed pulley (524) respectively set at the four corners of the same plane of the lifting bracket (52), and a central fixed pulley (525) set at the center of the bottom of the lifting bracket (52); The movable pulley group includes a first movable pulley (531), a second movable pulley (532), a third movable pulley (533) and a fourth movable pulley (534) respectively set at the four corners of the same plane of the hoisting block (53); The first fixed pulley (521), the second fixed pulley (522), the third fixed pulley (523) and the fourth fixed pulley (524) are respectively vertically corresponding to the first movable pulley (531), the second movable pulley (532), the third movable pulley (533) and the fourth movable pulley (534); The lifting cable (81) passes sequentially through the first fixed pulley (521), the first movable pulley (531), the second fixed pulley (522), the second movable pulley (532), the center fixed pulley (525), the third movable pulley (533), the third fixed pulley (523), the fourth movable pulley (534), and the fourth fixed pulley (524).

4. The unbalanced high-low cable lifting system for large-span steel pipe arch bridges according to claim 3, characterized in that, The lifting support (52) is also provided with multiple auxiliary fixed pulleys (526) to limit the position of the lifting cable (81).

5. The unbalanced high-low cable lifting system for large-span steel pipe arch bridges according to claim 3, characterized in that, The two lifting pulley assemblies are symmetrical in the vertical direction of the main cable (4).

6. The unbalanced high-low cable lifting system for large-span steel pipe arch bridges according to claim 2, characterized in that, The traction pulley assembly includes a first traction wheel (511) and a second traction wheel (512) disposed on both sides of the traction trolley (51), and a fifth fixed pulley (73), a sixth fixed pulley (74) and a seventh fixed pulley (75) fixed relative to the ground; The traction cable (71) passes in sequence through the fifth fixed pulley (73), the first traction wheel (511), the sixth fixed pulley (74), the second traction wheel (512), the seventh fixed pulley (75), and the traction winch (72).

7. The unbalanced high-low cable lifting system for large-span steel pipe arch bridges according to claim 6, characterized in that, The lifting pulley block is located between the first traction wheel (511) and the second traction wheel (512).

8. The unbalanced high-low cable lifting system for large-span steel pipe arch bridges according to claim 1, characterized in that, Each of the cranes (5) is also provided with a second mating wheel (55), which is further away from the other crane (5) than the first mating wheel (54); each of the lifting cables (81) passes under the second mating wheel (55).

9. A method for lifting and hoisting unbalanced high-low cable-stayed bridges with long spans, characterized in that... Using the unbalanced high-low cable lifting system for large-span steel pipe arch bridges as described in any one of claims 1 to 8, the steps include: S1: First, complete the erection of the main cable (4), then install the crane (5) on the main cable (4), and then complete the winding of the lifting cable (81) and the traction cable (71); S2: Connect the two cranes (5) with the connecting rope (6) and keep the connecting rope (6) in a slack state, and move the two cranes (5) to the lifting area; S3: Conduct load tests on the cable hoisting system, loading it in stages up to 1.25 times the design lifting weight to verify the system's safety and record the monitoring data at each measuring point; S4: Connect the workpiece to be hoisted to the hoisting blocks (53) of the two cranes (5), and start the two hoisting winches (82) simultaneously to wind up the hoisting ropes (81) and hoist the workpiece to the set height; S5: Simultaneously start the two traction winches (72) to move the two cranes (5) along the main cable (4) and transport the workpiece to the installation position; S6: Start the two hoisting winches (82) in reverse synchronous mode to unwind the hoisting cable (81), lower the workpiece to the installation position, disconnect the connection, and complete one hoisting cycle.

10. The method for lifting and hoisting an unbalanced high-low cable-stayed bridge with a large span steel pipe arch bridge according to claim 9, characterized in that, In step S1, the erection of the main cable (4) is specifically as follows: The kite line is pulled by a drone to erect the main cable (4). After the kite line is erected, the kite line is used to pull the guide cable to complete the erection of the guide cable. After the guide cable is erected, the guide cable is used to pull the main cable (4) to complete the erection.

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