A method for dismantling long-span steel strand cable stays

Abstract

This application relates to a method for dismantling a long-span steel strand cable-stayed bridge, belonging to the field of bridge maintenance technology. The method includes tensioning the steel strands using a first traction mechanism to unload the tension at the fixed-end anchorage, cutting the unloaded steel strands, and then tensioning the hoisted steel strands using a second traction mechanism to unload the tension at the tension-end anchorage, cutting the unloaded steel strands, separating the steel strands connected to the second traction mechanism from the tension-end anchorage, dismantling the remaining steel strands, and transporting all dismantled steel strands. This application avoids the need for complex large-scale scaffolding at the tower top, which would otherwise be inconvenient, complex, and inefficient. By cutting the steel strands at the fixed-end anchorage one by one and the steel strands at the tension-end anchorage in groups, the entire steel strand is broken down into smaller parts, reducing hoisting risks and costs.

Description

Technical Field

[0001] This application relates to the field of bridge maintenance technology, and in particular to a method for dismantling long-span steel strand cable stays. Background Technology

[0002] Bridges are widely constructed as an important transportation facility. Among them, cable-stayed bridges, which can achieve large spans, are widely used in various transportation construction projects. The steel strand cable system is widely used in cable-stayed bridge cables, external prestressed tendons, hangers and tie rods due to its advantages such as single cable hanging and tensioning, multiple protection, and miniaturization of construction equipment.

[0003] During operation, cable-stayed bridges are subjected to long-term loads and adverse environmental factors, making them prone to defects such as HDPE sleeve rupture, severe steel strand corrosion, and even cable breakage. These issues seriously threaten bridge safety. Replacing steel strand cable stays is the reverse process of installation, presenting technical challenges such as insufficient length of old steel strands, high safety risks associated with working on high-altitude towers, high construction difficulty, and low economic viability. In particular, during actual operation, operators often cut the steel strands into a "stepped" shape for convenience, resulting in the upper strands being shorter than the normal allowable length, or even shorter than the elastic elongation under tension, making future replacement difficult.

[0004] As mentioned earlier, due to the special structure of its tensioning and anchoring section, it is not possible to directly dismantle it using the single-strand tensioning and releasing technique. It is necessary to release the tension of the entire cable before dismantling. Traditional methods for dismantling steel strand stay cables require the erection of large scaffolds at the top of the tower. The installation and dismantling of these scaffolds are extremely difficult and risky. The lifting weight of the entire stay cable is also quite large, posing a significant instability and safety hazard. Summary of the Invention

[0005] This application provides a method for dismantling long-span steel strand cable stays, in order to solve the problems of low dismantling efficiency, high dismantling risk, and low safety in existing cable stay steel strand dismantling technologies.

[0006] This application provides a method for dismantling a long-span steel strand cable-stayed structure, comprising the following steps:

[0007] The first traction mechanism is connected to the steel strand near the fixed end anchor. The first traction mechanism is used to tension the steel strand so that the steel strand at the fixed end anchor is unloaded.

[0008] Cut the unloading steel strand to separate the steel strand connected to the first traction mechanism from the fixed end anchor.

[0009] The steel strand is hoisted from above the anchor near the tensioning end by the second traction mechanism, and at the same time the second traction mechanism tensions the hoisted steel strand so that the steel strand at the tensioning end anchor is unloaded.

[0010] Cut the unloading steel strand to separate the steel strand connected to the second traction mechanism from the tensioning end anchor.

[0011] Remove the remaining steel strands and move all the removed steel strands.

[0012] In some embodiments, after the steel strand connected to the first traction mechanism is placed horizontally on the main beam, the steel strand placed on the main beam is cut as a whole at the root position of the main tower, separating it from the steel strand that is hanging down and connected to the fixed end anchor.

[0013] Then the steel strands near the anchor at the tensioning end are grouped, hoisted, cut, and lowered.

[0014] In some embodiments, the steel strand that is unloaded near the tensioning end anchor is cut and then continues to be suspended under tension by a second traction mechanism;

[0015] Then, the steel strands near the base of the main tower are cut in the suspended steel strands so that the steel strands falling back onto the main beam are transported.

[0016] Next, the remaining suspended steel strands are lowered using the second traction mechanism. After lowering one set of steel strands, they are hoisted, cut, and lowered again in sequence with the next set of steel strands.

[0017] In some embodiments, the second traction mechanism groups the steel strands evenly before connecting them to the anchor near the tensioning end, and suspends the suspension platform on the main tower.

[0018] The second traction mechanism is hoisted with each group of steel strands in sequence to unload the steel strands at the tensioning end anchors of each group of steel strands, and at the same time, the unloaded steel strands are cut on the suspension platform.

[0019] The steel strand connected to the second traction mechanism is separated from the tensioning end anchor, and the connected steel strand is lowered to the main beam for transport by the second traction mechanism.

[0020] In some embodiments, the first traction mechanism is located on the side of the main beam near the fixed end anchorage, and the first traction mechanism is a winch. The winch is connected to the steel strand at the fixed end anchorage through a first clamping mechanism.

[0021] The second traction mechanism includes an electric hoist and a support frame installed at the top of the main tower. The electric hoist is located on the main beam and close to the main tower. The suspended platform and the support frame are connected by a lifting rope assembly.

[0022] The electric hoist is provided with a first pulley group on one side, and the support frame is provided with a second pulley group;

[0023] The wire rope of the electric hoist extends past the first pulley block toward the second pulley block, then extends past the second pulley block to the top of the steel strand of the tensioning end anchor, and is hoisted to the steel strand by the second clamping mechanism.

[0024] In some embodiments, both the first clamping mechanism and the second clamping mechanism include a first clamping block and a second clamping block that are connected to each other.

[0025] Both the first clamp block and the second clamp block have wedge-shaped holes inside and are open at both ends;

[0026] Both the first clamp block and the second clamp block have placement openings with connecting wedge-shaped holes on their side walls.

[0027] In some embodiments, the placement opening of the first clamp block and the placement opening of the second clamp block have opposite opening directions;

[0028] The wedge-shaped hole is provided with a tapered clamping plate assembly for clamping the steel strand and cooperating with the wedge-shaped hole.

[0029] In some embodiments, a threaded section is provided on one side of the first clamping block, and an internal thread is provided inside the wedge-shaped hole of the second clamping block to connect with the threaded section;

[0030] The outer side of the first clamp block is provided with a lifting ring that connects to the winch.

[0031] In some embodiments, both the first clamping mechanism and the second clamping mechanism include a first clamping block for fixing and clamping the steel strand, wherein the first clamping block has a wedge-shaped hole inside and both ends are open;

[0032] The wedge-shaped hole contains a tapered clamping plate assembly for clamping the steel strand.

[0033] In some embodiments, the first clamp block is provided with a baffle for limiting the conical clamping plate assembly on the side near the winch;

[0034] The baffle has an opening, the diameter of which is smaller than the diameter at the largest end of the conical clip assembly;

[0035] The outer side of the first clamp block is provided with a lifting ring that connects to the winch.

[0036] The beneficial effects of the technical solution provided in this application include:

[0037] The use of the first and second traction mechanisms avoids the need for complex large-scale scaffolding at the top of the tower, which would otherwise cause inconvenience, complexity, and reduced work efficiency. By cutting the steel strands at the fixed end anchorage one by one and the steel strands at the tensioning end anchorage in groups, the entire steel strand is broken down into smaller parts, reducing hoisting risks and costs. This allows for hoisting with small lifting equipment, and the batch cutting improves worker safety, preventing excessive stress from causing the steel strands to detach due to whole-stretching or hoisting, which would also be inconvenient for workers to operate. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 This is a schematic diagram of the structure provided for an embodiment of this application;

[0040] Figure 2 This is a schematic diagram of the first cutting state provided at the fixed end anchor in the embodiment of this application;

[0041] Figure 3 This is a schematic diagram of the second cutting state provided at the fixed end anchor in the embodiments of this application;

[0042] Figure 4 This is a schematic diagram of the third cutting state provided at the fixed end anchorage in an embodiment of this application;

[0043] Figure 5 This is a schematic diagram of the cutting state at the tensioning end anchorage in an embodiment of this application;

[0044] Figure 6 A schematic diagram of the completely dismantled state provided in the embodiments of this application;

[0045] Figure 7 This is a schematic diagram of the first structure of the first clamping mechanism in the embodiments of this application;

[0046] Figure 8 This is a schematic diagram of the first structure provided by the first clamping block in the embodiments of this application;

[0047] Figure 9 This is a structural schematic diagram of the second clamping block provided in the embodiments of this application;

[0048] Figure 10 This is a structural schematic diagram of the tapered clip assembly provided in the embodiments of this application;

[0049] Figure 11This is a schematic diagram of the second structure provided by the first clamping mechanism in the embodiments of this application;

[0050] Figure 12 This is a schematic diagram of the second structure provided by the first clamping block in the embodiments of this application.

[0051] 1. Main beam; 2. Main tower; 4. Fixed end anchorage; 5. Second clamping mechanism; 8. Steel strand; 10. Tensioning end anchorage; 25. Winch; 27. First clamping mechanism; 271. Baffle; 2711. Opening; 272. Lifting ring; 273. First clamping block; 2731. Threaded section; 274. Conical clamping plate assembly; 275. Second clamping block; 2751. Internal thread; 277. Wedge hole; 278. Placement opening; 28. Electric hoist; 281. First pulley block; 282. Second pulley block; 35. Support frame; 36. Suspended platform; 37. Lifting rope assembly. Detailed Implementation

[0052] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0053] This application provides a method for dismantling long-span steel strand cable stays, which can solve the problems of low dismantling efficiency, high dismantling risk, and low safety of existing cable stay steel strand dismantling.

[0054] See Figure 1-12 As shown in the figure, this application provides a method for dismantling a long-span steel strand cable stay, including the following steps:

[0055] Step 1: Connect the first traction mechanism to the steel strand 8 near the fixed end anchor 4, and tension the steel strand 8 through the first traction mechanism so that the steel strand 8 at the fixed end anchor 4 is unloaded.

[0056] Before the first traction mechanism connects to the steel strand 8, the outer sheath of the steel strand needs to be pulled out first, and the outer sheath of the steel strand needs to be circumferentially cut near the fixed end anchor 4. A power device, such as a traction vehicle, is set on the main beam 1. The power device is connected to the circumferentially cut end of the outer sheath of the steel strand through a steel wire rope. A cutting machine is set below the circumferentially cut end of the outer sheath of the steel strand. When the power device pulls out the outer sheath of the steel strand, the outer sheath of the steel strand will be cut by the cutting device, so that the outer sheath of the steel strand can be pulled out and divided along the length direction at the same time, so that the outer sheath of the steel strand can be separated from the steel strand 8.

[0057] By pre-connecting the first traction mechanism to the segment of the steel strand 8 near the fixed end anchor 4, the first traction mechanism pulls the steel strand 8 toward the fixed end anchor 4, thereby unloading the stress on the segment of the steel strand 8 between the fixed end anchor 4 and the connection between the first traction mechanism and the steel strand 8. This avoids the inconvenience of cutting due to stress at this point, and the sudden unloading after cutting would cause the steel strand 8 to swing due to the reaction force, which could easily cause injury to workers and reduce construction safety.

[0058] Step 2: Cut the unloading steel strand 8 to separate the steel strand 8 connected to the first traction mechanism from the fixed end anchor 4.

[0059] When the first traction mechanism connects to the steel strand 8 at the fixed end anchor 4, it prioritizes connecting one steel strand 8 at a time. After each steel strand 8 is connected, it is tensioned and then cut to separate the steel strand 8 connected by the first traction mechanism from the fixed end anchor 4. Then, the connected single steel strand 8 is slowly lowered by the first traction mechanism, using the gravity and inertia of the steel strand 8, and falls back towards the root of the main tower 2 until all the single steel strand 8 has fallen back onto the main beam 1. Then, the first traction mechanism is released so that the first traction mechanism can connect to another steel strand 8 and the above process is repeated until all the steel strand 8 at the fixed end anchor 4 are cut and separated.

[0060] Step 3: The steel strand 8 is hoisted from above the steel strand 8 near the tensioning end anchor 10 using the second traction mechanism. At the same time, the second traction mechanism tensions the hoisted steel strand 8 so that the steel strand 8 at the tensioning end anchor 10 is unloaded.

[0061] Step 4: Cut the unloading steel strand 8 to separate the steel strand 8 connected to the second traction mechanism from the tensioning end anchor 10.

[0062] First, group the steel strands 8 near the anchor 10 at the tensioning end. Preferably, five steel strands 8 are grouped together, but not limited to five. Any group can be arranged within the force range of the second traction mechanism.

[0063] The second traction mechanism is connected to a set of steel strands 8, and then the set of steel strands 8 is tensioned, so that the segments of steel strands 8 near the tensioning end anchor 10 are unloaded.

[0064] Then, the unloading steel strand 8 is cut into sections to separate the steel strand 8 connected to the second traction mechanism from the tensioning end anchor 10. Then, the second traction mechanism lowers the steel strand 8 and places it on the main beam 1 for transport.

[0065] After the lowering is completed, the second traction mechanism is connected to the next group of steel strands 8. The above operation is repeated until all the steel strands 8 at the tensioning end anchor 10 are lowered.

[0066] Step 5: Remove the remaining steel strands 8 and move all the removed steel strands 8 away.

[0067] After the steel strands 8 connected to the first traction mechanism and the second traction mechanism are removed, the remaining steel strands 8 in the tensioning end anchorage 10 and the fixed end anchorage 4 are removed, taken out and transported.

[0068] By using the first and second traction mechanisms, the need for complex large-scale scaffolding at the top of the tower is avoided, which would lead to inconvenience, complexity, and reduced work efficiency. By cutting the steel strands 8 at the fixed end anchor 4 one by one and cutting the steel strands 8 at the tensioning end anchor 10 in groups, the entire steel strand 8 is broken down into parts, reducing hoisting risks and costs. Smaller hoisting tools can be used for hoisting, and batch cutting improves worker safety, avoiding excessive stress caused by cutting or removing the entire strand, which could lead to the steel strand 8 detaching and make it inconvenient for workers to operate.

[0069] In some alternative embodiments, see Figure 1-6 As shown, in the dismantling method of the large-span steel strand cable, in step 2, after the first traction mechanism places all the steel strands 8 near the fixed end anchor 4 completely horizontally on the main beam 1, the steel strands 8 placed on the main beam 1 are cut as a whole near the main tower 2, and the cutting position is preferably 50cm above the main beam 1.

[0070] After the steel strands 8 placed on the main beam 1 are cut, the cut and separated steel strands 8 are transported, and then the steel strands 8 near the tensioning end anchor 10 are grouped, hoisted, cut and lowered, and finally all are removed and transported.

[0071] By cutting the steel strands into sections multiple times, the steel strands 8 are separated, which avoids the steel strands 8 being too long and heavy to handle during transportation, and also avoids the steel strands 8 being too long and heavy to dismantle, which would lead to difficulties in dismantling and low dismantling efficiency. This improves the safety of the workers and also prevents the steel strands 8 from becoming tangled after dismantling, which would cause difficulties in subsequent transportation and disassembly.

[0072] In some alternative embodiments, see Figure 1-6 As shown, in the dismantling method of the large-span steel strand cable, after the steel strand 8 near the tensioning end anchor 10 is cut, it continues to be suspended by tension through the second traction mechanism. Then, the steel strand 8 near the root of the main tower 2 among the suspended steel strands 8 is cut so that the steel strand 8 falling back onto the main beam 1 is transported. Then, the remaining suspended steel strands 8 are lowered using the second traction mechanism. After lowering the first set of steel strands 8, they are hoisted, cut and lowered again in sequence with the next set of steel strands 8.

[0073] After the steel strand 8 near the tensioning end anchor 10 is unloaded and cut, the second traction mechanism continues to pull the steel strand 8. Then, the steel strand 8 on the main beam 1 is cut as a whole at a position close to the main tower 2 and at a height of 50cm. First, the steel strand 8 on the main beam 1 is cut and transported. Then, the steel strand 8 connected to the second traction mechanism is hoisted and lowered, and then transported away.

[0074] In some alternative embodiments, see Figure 1-6 As shown, in the dismantling method of the large-span steel strand cable, the second traction mechanism makes the steel strand 8 evenly grouped before connecting the steel strand 8 near the tensioning end anchor 10, and suspends the suspension platform 36 on the main tower 2.

[0075] The second traction mechanism hoists each group of steel strands 8 in sequence, so that the steel strands 8 at the tensioning end anchor 10 corresponding to each group of steel strands 8 are unloaded. At the same time, the unloaded steel strands 8 are cut on the suspension platform 36, so that the steel strands 8 connected to the second traction mechanism are separated from the tensioning end anchor 10. The connected steel strands 8 are then lowered to the main beam 1 by the second traction mechanism for transport.

[0076] Before being connected to the second traction mechanism, the steel strands 8 near the tensioning end anchor 10 are evenly grouped. In this embodiment, it is preferred that there are five strands per group. Each second traction mechanism is connected to a group of steel strands 8. Then, they are cut and lowered. A suspension platform 36 is provided on one side of the main tower 2. The suspension platform 36 allows the workers to move to a higher cutting position and then cut the steel strands 8.

[0077] In some alternative embodiments, see Figure 1-12 As shown, in the dismantling method of the large-span steel strand cable, the first traction mechanism is set on the side of the main beam 1 near the fixed end anchor 4. The first traction mechanism is a winch 25. The winch 25 is connected to the steel strand 8 at the fixed end anchor 4 through the first clamping mechanism 27.

[0078] The second traction mechanism includes an electric hoist 28 and a support frame 35 set on the top of the main tower 2. The electric hoist 28 is located on the main beam 1 and close to the main tower 2. The suspended platform 36 and the support frame 35 are connected by a lifting rope assembly 37.

[0079] The electric hoist 28 is provided with a first pulley block 281 on one side, and a second pulley block 282 is provided on the support frame 35. The wire rope of the electric hoist 28 passes around the first pulley block 281 and extends towards the second pulley block 282, then passes around the second pulley block 282 and extends to the top of the steel strand 8 of the tensioning end anchor 10, and is hoisted to the steel strand 8 through the second clamping mechanism 5.

[0080] A winch 25 is installed near the fixed end anchor 4 of the main beam 1 to connect the steel strand 8 near the fixed end anchor 4. An electric hoist 28 and a first pulley block 281 are installed near the main tower 2 of the main beam 1. A support frame 35 is fixed at the top of the main tower 2 and a second pulley block 282 is fixed on the support frame 35. The wire rope of the electric hoist 28 passes through the first pulley block 281 and changes direction to extend toward the second pulley block 282. Then it passes through the second pulley block 282 and changes direction again to extend toward the steel strand 8 until it is connected to the steel strand 8.

[0081] The support frame 35 is equipped with a lifting rope assembly 37 for suspending the suspension platform 36. The winch 25 is connected to the steel strand 8 through the first clamping mechanism 27, and the electric hoist 28 is connected to the steel strand 8 through the second clamping mechanism 5.

[0082] In some alternative embodiments, see Figure 1 and Figure 7-10 As shown, in the dismantling method of the long-span steel strand cable, the first clamping mechanism 27 and the second clamping mechanism 5 both include a first clamping block 273 and a second clamping block 275 connected to each other. The first clamping block 273 and the second clamping block 275 are both provided with wedge-shaped holes 277 and open at both ends. The side walls of the first clamping block 273 and the second clamping block 275 are both provided with placement openings 278 that connect to the wedge-shaped holes 277.

[0083] In this embodiment, the placement opening 278 of the first clamp block 273 and the placement opening 278 of the second clamp block 275 have opposite opening directions, and a conical clamping plate assembly 274 for clamping the steel strand 8 and cooperating with the wedge hole 277 is provided in the wedge hole 277.

[0084] In this embodiment, a threaded section 2731 is provided on one side of the first clamping block 273, and an internal thread 2751 connected to the threaded section 2731 is provided inside the wedge-shaped hole 277 of the second clamping block 275. A lifting ring 272 connected to the winch 25 is provided on the outside of the first clamping block 273.

[0085] The steel strand 8 is inserted through the placement opening 278 into the wedge-shaped hole 277 of the first clamping block 273, so that the first clamping block 273 is fitted onto the outside of the steel strand 8. Then, the tapered clamping plate assembly 274 is inserted into the wedge-shaped hole 277 from the opening on the side of the first clamping block 273 near the threaded section 2731, and fitted onto the outside of the steel strand 8. The tapered clamping plate assembly 274 clamps the steel strand 8 within the wedge-shaped hole 277. Then, the second clamping block 275 is fitted onto the outside of the steel strand 8 through the placement opening 278, so that the steel strand 8 is located within the wedge-shaped hole 277 of the second clamping block 275. Then, the second clamping block 275 uses its internal thread 2751 to engage with the threaded section 2731 of the first clamping block 273, so that the second clamping block 275 is screwed onto the threaded section 2731 of the first clamping block 273, connecting the first clamping block 273 and the second clamping block 275 together. After the second clamping block 275 is installed, the placement opening 278 of the second clamping block 275 is in the opposite direction to the placement opening 278 of the first clamping block 273, so that the steel strand 8 is clamped alternately with the first clamping block 273 and the second clamping block 275, further improving the clamping force of the first clamping mechanism 27 and the second clamping mechanism 5.

[0086] After the first and second traction mechanisms cut the connected steel strand 8, the steel strand 8, being spirally wound together, will rotate after cutting, causing the conical clamp assembly 274 to rotate. The second clamp block 275 provides secondary positioning and clamping for the steel strand 8, preventing the rotating steel strand 8 from causing the conical clamp assembly 274 to generate centrifugal force and fly out of the first clamp block 273. The second clamp block 275 limits the conical clamp assembly 274 within the first clamp block 273 to prevent detachment, thus improving safety.

[0087] The conical clamping plate assembly 274 consists of two arc-shaped clamping plates. The shape of the conical clamping plate assembly 274 is adapted to match the wedge-shaped hole 277. The conical clamping plate assembly 274 inside the first clamping block 273 and the second clamping block 275 are in the same direction, so that the second clamping block 275 can limit the conical clamping plate assembly 274 in the first clamping block 273.

[0088] The diameter of the wedge-shaped hole 277 on the side closer to the threaded section 2731 is larger than the diameter on the side farther from the threaded section 2731. The lifting ring 272 is U-shaped and is located on the outside of the first clamping block 273 and facing the second clamping block 275. It can also be understood that the second clamping block 275 is inside the U-shaped lifting ring 272.

[0089] In some alternative embodiments, see Figure 1 and Figure 9-12As shown, in the dismantling method of the long-span steel strand cable, both the first clamping mechanism 27 and the second clamping mechanism 5 include a first clamping block 273 for fixing and clamping the steel strand 8. The first clamping block 273 has a wedge-shaped hole 277 inside and both ends are open. The wedge-shaped hole 277 contains a tapered clamping plate assembly 274 for clamping the steel strand 8.

[0090] In this embodiment, a baffle 271 for limiting the conical clamping plate assembly 274 is provided on the side of the first clamping block 273 near the winch 25. An opening 2711 is provided on the baffle 271, and the diameter of the opening 2711 is smaller than the diameter at the largest end of the conical clamping plate assembly 274. A lifting ring 272 connected to the winch 25 is provided on the outer side of the first clamping block 273.

[0091] The diameter of the wedge-shaped hole 277 on the side closer to the baffle 271 is larger than the diameter on the side farther from the baffle 271. The lifting ring 272 is U-shaped and is located on the outside of the first clamping block 273 and facing the baffle 271. It can also be understood that the baffle 271 is inside the U-shaped lifting ring 272. The conical clamping plate assembly 274 is composed of two arc-shaped clamping plates, and the shape of the conical clamping plate assembly 274 is adapted to match the wedge-shaped hole 277.

[0092] The steel strand 8 is inserted into the wedge-shaped hole 277 of the first clamp block 273 through the placement port 278, and the first clamp block 273 is fitted onto the outside of the steel strand 8. Then, the conical clamping plate assembly 274 is inserted into the wedge-shaped hole 277 from the opening of the first clamp block 273 near the threaded section 2731, and fitted onto the outside of the steel strand 8. The conical clamping plate assembly 274 clamps the steel strand 8 in the wedge-shaped hole 277. After the first traction mechanism and the second traction mechanism are connected and the steel strand 8 is cut, because the steel strand 8 is spirally wound together, the steel strand 8 will rotate after cutting. Therefore, it is necessary to fix a baffle 271 at the end near the largest diameter of the wedge-shaped hole 277 in the first clamp block 273. The diameter of the opening 2711 of the baffle 271 is larger than the diameter of the steel strand 8 but smaller than the maximum diameter of the conical clamping plate assembly 274, so that the conical clamping plate assembly 274 can be prevented from flying out and detaching.

[0093] The baffle 271 and the first clamp block 273 are fixed in a detachable manner. The outer wall of the first clamp block 273 is provided with a first bolt hole, and the baffle 271 is provided with a second bolt hole corresponding to the first bolt hole. The baffle 271 is removed before the conical clamp assembly 274 is installed. After the conical clamp assembly 274 is installed, the baffle 271 and the first clamp block 273 are connected and fixed by bolts passing through the first bolt hole and the second bolt hole.

[0094] The working principle and process of this application:

[0095] The first traction mechanism is connected to the steel strand 8 near the fixed end anchor 4. The steel strand 8 is tensioned by the first traction mechanism so that the steel strand 8 at the fixed end anchor 4 is unloaded.

[0096] Cut the unloading steel strand 8 to separate the steel strand 8 connected to the first traction mechanism from the fixed end anchor 4.

[0097] The steel strand 8 is hoisted from above the anchor 10 near the tensioning end by the second traction mechanism, and at the same time the second traction mechanism tensions the hoisted steel strand 8 so that the steel strand 8 at the tensioning end anchor 10 is unloaded.

[0098] Cut the unloading steel strand 8 to separate the steel strand 8 connected to the second traction mechanism from the tensioning end anchor 10.

[0099] Remove the remaining steel strands 8 and move all the removed steel strands 8.

[0100] After the steel strands 8 connected to the first traction mechanism and the second traction mechanism are removed, the remaining steel strands 8 in the tensioning end anchorage 10 and the fixed end anchorage 4 are removed, taken out and transported.

[0101] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0102] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0103] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for dismantling a long-span steel strand cable-stayed bridge, characterized in that, include: The first traction mechanism is connected to the steel strand (8) near the fixed end anchor (4), and the steel strand (8) is tensioned by the first traction mechanism so that the steel strand (8) at the fixed end anchor (4) is unloaded. Cut the unloading steel strand (8) to separate the steel strand (8) connected to the first traction mechanism from the fixed end anchor (4); The steel strand (8) is hoisted from above the steel strand (8) near the tensioning end anchor (10) by the second traction mechanism, and at the same time the second traction mechanism tensions the hoisted steel strand (8) so that the steel strand (8) at the tensioning end anchor (10) is unloaded. Cut the unloading steel strand (8) to separate the steel strand (8) connected to the second traction mechanism from the tensioning end anchor (10); Remove the remaining steel strands (8) and move all the removed steel strands (8); The first traction mechanism is located on the side of the main beam (1) near the fixed end anchor (4). The first traction mechanism is a winch (25). The winch (25) and the steel strand (8) at the fixed end anchor (4) are connected by the first clamping mechanism (27). The second traction mechanism includes an electric hoist (28) and a support frame (35) set on the top of the main tower (2). The electric hoist (28) is located on the main beam (1) and close to the main tower (2). A suspension platform (36) is suspended on the main tower (2). The suspension platform (36) and the support frame (35) are connected by a lifting rope assembly (37). The electric hoist (28) is provided with a first pulley group (281) on one side, and the support frame (35) is provided with a second pulley group (282). The wire rope of the electric hoist (28) extends from the first pulley group (281) toward the second pulley group (282), then extends from the second pulley group (282) to the top of the steel strand (8) of the tensioning end anchor (10), and is hoisted to the steel strand (8) by the second clamping mechanism (5); The first clamping mechanism (27) and the second clamping mechanism (5) both include a first clamping block (273) and a second clamping block (275) that are connected to each other; Both the first clamp block (273) and the second clamp block (275) have wedge-shaped holes (277) inside and are open at both ends; The first clamp block (273) and the second clamp block (275) are both provided with placement openings (278) for connecting wedge-shaped holes (277) on their side walls. The placement opening (278) of the first clamp block (273) has the opposite opening direction to the placement opening (278) of the second clamp block (275); The wedge hole (277) is provided with a tapered clamping plate assembly (274) for clamping the steel strand (8) and cooperating with the wedge hole (277).

2. The method for dismantling long-span steel strand cable stays as described in claim 1, characterized in that: After the steel strand (8) connected to the first traction mechanism is placed horizontally on the main beam (1), the steel strand (8) placed on the main beam (1) is cut off at the root position of the main tower (2) and separated from the steel strand (8) in a hanging state connected to the fixed end anchor (4). Then the steel strands (8) near the tensioning end anchor (10) are grouped, hoisted, cut and lowered.

3. The method for dismantling long-span steel strand cable stays as described in claim 1, characterized in that: The steel strand (8) that is unloaded near the tensioning end anchor (10) is cut and then continues to be suspended by tension through the second traction mechanism; Then, the steel strand (8) near the root of the main tower (2) in the suspended steel strand (8) is cut so that the steel strand (8) falling back onto the main beam (1) is transported; Next, the remaining suspended steel strands (8) are lowered using the second traction mechanism. After lowering one set of steel strands (8), they are hoisted, cut and lowered again in sequence with the next set of steel strands (8).

4. The method for dismantling long-span steel strand cable stays as described in claim 1, characterized in that: Before connecting the steel strands (8) near the tensioning end anchor (10), the second traction mechanism makes the steel strands (8) evenly grouped and suspends the suspension platform (36) on the main tower (2). The second traction mechanism is hoisted with each group of steel strands (8) in sequence so that the steel strands (8) at the tensioning end anchor (10) corresponding to each group of steel strands (8) are unloaded, and the unloaded steel strands (8) are cut on the suspension platform (36). The steel strand (8) connected to the second traction mechanism is separated from the tensioning end anchor (10), and the connected steel strand (8) is lowered to the main beam (1) by the second traction mechanism.

5. The method for dismantling long-span steel strand cable stays as described in claim 1, characterized in that: The first clamping block (273) has a threaded section (2731) on one side, and the wedge-shaped hole (277) of the second clamping block (275) has an internal thread (2751) that connects to the threaded section (2731). The outer side of the first clamp block (273) is provided with a lifting ring (272) that is connected to the winch (25).

6. The method for dismantling long-span steel strand cable stays as described in claim 1, characterized in that: The first clamping mechanism (27) and the second clamping mechanism (5) both include a first clamping block (273) for fixing and clamping the steel strand (8). The first clamping block (273) has a wedge-shaped hole (277) inside and both ends are open. The wedge-shaped hole (277) contains a tapered clamping plate assembly (274) for clamping the steel strand (8).

7. The method for dismantling long-span steel strand cable stays as described in claim 6, characterized in that: The first clamp block (273) is provided with a baffle (271) for limiting the conical clamp assembly (274) on the side near the winch (25). The baffle (271) has an opening (2711) with a diameter smaller than the diameter at the largest end of the conical clip assembly (274). The outer side of the first clamp block (273) is provided with a lifting ring (272) that is connected to the winch (25).

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