Cable removing method and cable removing device for removing cables of a cable-stayed bridge without support

Abstract

The application relates to the field of bridge body dismantling, and relates to a cable dismantling method for a cable-stayed bridge without support, which is characterized in that a tool anchor ring is connected with an upper end anchor head of a cable, then a jack is arranged at the upper end of the cable; the jack is used to tension the cable until the anchor head is empty; the working anchor ring of the anchor head is cut off and removed; the tool anchor ring is rotated and separated from the anchor head, then the jack is used to release the tension of the cable, until the jack reaches the limit of stroke, then the tool anchor ring is connected with the anchor head again, the jack is reset, the operation is repeated for several times, until the tension of the cable is low; a group of two-circle holes are formed on the upper end and the lower end surfaces of the cable, the two ends of a cable clamp are screwed into bolts and inserted into the hole surfaces of the cable, then the cable clamp is fastened by using the bolts and nuts to tightly adhere to the cable; a traction device is used to apply a close pulling force to the two cable clamps until the tension of the cable between the two cable clamps is zero; the cable between the two cable clamps is cut off, so that the safety of the cable dismantling operation is improved.

Description

Technical Field

[0001] This application relates to the field of bridge demolition, and in particular to a method and equipment for cable-stayed bridge demolition without supports. Background Technology

[0002] The dismantling of a cable-stayed bridge without scaffolding does not require the construction of scaffolding beneath the bridge. Dismantling proceeds directly from both ends of the bridge. As the bridge deck is dismantled down to the lower end of a corresponding cable, the corresponding cable is removed, and simultaneously, the upper part of the tower supporting the cable is dismantled. This dismantling method proceeds from both ends of the bridge towards the tower in the middle. Since the tension of the cables is typically several hundred tons, it is necessary to first reduce the tension of the cables before cutting them.

[0003] For example, the existing construction method for quickly dismantling cable-stayed bridge cables, disclosed in CN101509231A, involves installing a tool anchor ring and a matching through-hole jack at the anchor head of the upper end of the cable. The jack then tensions the cable to disengage the anchor head, creating a gap between the working anchor ring and the anchor plate on the anchor head. At this point, the working anchor ring is no longer under stress and can be cut and removed. After the working anchor ring is removed, the tool anchor ring is unscrewed from the anchor head. The jack then releases tension on the cable until it reaches its travel limit. The tool anchor ring is then screwed back into the anchor head, and the jack is reset. This process is repeated continuously to reduce the tension of the cable to a minimum. Two cable clamps are then used to secure the cable surface, and by moving the two clamps closer together, the tension between the two ends of the cut portion of the cable becomes zero, allowing the cable to be cut.

[0004] Regarding the aforementioned technologies, cable clamps are generally fastened using a series of bolts and nuts. The friction generated by the tight pressure between the cable clamp and the cable sheath surface makes it difficult for the cable clamp to move relative to the cable. However, in order to reduce rain vibration, the cable sheath surface is provided with some particle protrusions, which increases the possibility of slippage between the cable clamp and the cable, reducing the safety of cable dismantling operations. Summary of the Invention

[0005] To improve safety during cable removal operations, this application provides a method and equipment for cable removal without supports in cable-stayed bridges.

[0006] The present application provides a method for dismantling cables of a cable-stayed bridge without supports, which adopts the following technical solution.

[0007] A method for dismantling cables of a cable-stayed bridge without supports includes the following steps.

[0008] Step 1: Connect the tool anchor ring to the upper anchor head of the cable, and then set up the jack at the upper end of the cable to connect it to the cable;

[0009] Step 2: Tension the cable with the jack until the anchor head is free and maintain stable tension;

[0010] Step 3: Cut and remove the working anchor ring of the anchor head;

[0011] Step 4: The tool anchor ring rotates and disengages from the anchor head. Then, the jack releases the tension of the cable until the jack reaches its travel limit. The tool anchor ring is then reconnected to the anchor head, and the jack is reset. This process is repeated several times until the cable tension is reduced to the target value. At the same time, the tension values ​​of several cables close to the cable to be cut are monitored and the cable force is adjusted synchronously.

[0012] Step 5: Form a set of two rings of holes on the sheath surface at both the upper and lower ends of the cable. Screw bolts into both ends of the cable clamp and insert them into the holes on the cable surface. Then tighten the cable clamp with bolts and nuts to make it fit tightly against the cable.

[0013] Step 6: Use a traction device to apply close tension to the two cable clamps until the tension in the cable between the two clamps is zero;

[0014] Step 7: Cut the cable between the two cable clamps and slowly lower the cut cable to the bridge deck;

[0015] Step 8: After the cable is cut, remove the remaining upper end along with the upper end of the corresponding tower column, and remove the remaining lower end along with the corresponding bridge.

[0016] By adopting the above technical solution, the cable clamps between the two ends of the cut cable are brought close together to reduce the tension of the cut cable to zero, which makes the cable clamps less likely to slip, thus improving operational safety. Furthermore, the tension adjustment of the cables adjacent to the cut cable ensures that the bridge as a whole, which has not been demolished, can still receive good support. In addition, the anchor heads at both ends of the cable can be transported to the ground along with the tower and the bridge for removal, which reduces high-altitude operations and also reduces the possibility of problems during the removal of the cable anchor heads that could affect or endanger normal traffic below the bridge.

[0017] Optionally, before cutting the cable in step 7, an upward lifting force is applied to the upper end of the cable to be cut. When cutting the cable, the cutting starts from the lower part of the cable, and after the upper end of the cable is cut and lowered to the bridge deck, the lower end of the cable is then cut.

[0018] By adopting the above technical solution, the cable used to lift the cable after it is cut is less likely to be subjected to a sudden increase in downward tension, thereby further improving the stability of the cable after cutting. In addition, the two cut sections of the cable are less likely to cause significant inconvenience to the cutting work, so that the cutting work can be carried out smoothly.

[0019] This application also provides a cable removal device using the following technical solution.

[0020] A cable-removal device, used as a cable clamp according to the above-mentioned cable-removal method for dismantling a cable-stayed bridge without supports, includes two sets of fixed half-sleeves, each set consisting of two detachably connected pairs for sleeved on the cable; a sleeve port that is opened through the fixed half-sleeves for bolts to be screwed in and inserted into the cable; and two sets of traction half-sleeves that are detachably connected to the fixed half-sleeves and detachably connected to each other within the same set. The two sets of traction half-sleeves are pulled closer together by a traction device.

[0021] By adopting the above technical solution, the fixed half-set is less likely to move relative to the surface of the cable, so that when the traction half-set is pulled closer, the tension of the cut cable can be stably and safely reduced to zero.

[0022] Optionally, a ring of clamping arc members is fixedly connected to the opposite side of each of the two sets of fixed half-sleeves. Several clamping arc members are provided for each of the two fixed half-sleeves connected to each other. The clamping arc members and the contact side of the traction half-sleeves are inclined so that the clamping arc members can press tightly against the cable when the two sets of traction half-sleeves are close together.

[0023] By adopting the above technical solution, when the two sets of traction half-sleeves are pulled close together, the pressing arc member will be forced to fit tightly against the cable surface. This will increase the friction between the pressing arc member and the cable surface as the tension of the traction half-sleeve increases, making it more difficult for the stationary half-sleeve and the cable to move freely.

[0024] Optionally, the fixed half-sleeve is provided with a guide rod for the traction half-sleeve to slide through, and the end of the guide rod of the fixed half-sleeve away from the fixed half-sleeve is provided with an end half-ring, which can be abutted by the traction half-sleeve, and the two end half-rings are detachably connected.

[0025] By adopting the above technical solution, the movement direction of the traction half-set is stabilized, and the end half-ring can also provide friction.

[0026] Optionally, the end half-ring is detachably connected to the guide rod, and the end half-ring is sleeved on the guide rod to abut against the traction half-ring.

[0027] By adopting the above technical solution, when splicing the two fixed half-sets of corresponding cables, the two end half-rings are sleeved on the corresponding guide rods so that the traction half-set can be pressed against the pressing arc, so that the pressing arc can obtain a preliminary pressing.

[0028] Optionally, each of the two sets of fixed half-sets is provided with a frame on one side, the frame is slidably connected to a frame slider, the frame slider is provided with a saw section that can cut the cable, and the frame is provided with a saw electric cylinder that keeps the saw section and the cable tightly pressed together.

[0029] By adopting the above technical solution, operators do not need to get too close to the cut cable to carry out the cutting operation, which is safer.

[0030] Optionally, the saw cable electric cylinder power rod is equipped with a cutting pressure sensor, which is connected to the frame slider.

[0031] By adopting the above technical solution, the pressure of the sawing section on the cable is always kept within a suitable range, and the sawing section can be controlled to effectively cut the cable even when the operator is away from the sawing section.

[0032] Optionally, the taller frame has two lifting half-sleeves on the side near the shorter frame that can clamp the cable. The two lifting half-sleeves are detachably connected and can be lifted. A lifting force sensor is provided at the lifting position of the lifting half-sleeve.

[0033] By adopting the above technical solution, the upper end of the cut cable is less likely to fall directly, and it is also convenient to make appropriate adjustments to the pressure applied to the half-span.

[0034] Optionally, the lifting tension sensor is located at one end of the lifting half-set away from the adjacent frame, with the higher saw section cutting the cable from bottom to top and the lower saw section cutting the cable from top to bottom.

[0035] By adopting the above technical solution, the cable portion of the suspended half-set can be made to be more horizontal, so that the two sections at the cable cut point are less likely to be subjected to greater pressure on the cable portion that is being cut by the saw.

[0036] In summary, this application includes at least one of the following beneficial effects:

[0037] 1. When the cable clamps between the two ends of the cable to be cut are brought close together so that the tension of the cable to be cut is zero, the cable clamps are less likely to slip, thus improving operational safety;

[0038] 2. After the cable is cut, the cable used to lift the cable is less likely to be subjected to a sudden increase in downward pressure, so as to further improve the stability of the cable after it is cut. Attached Figure Description

[0039] Figure 1 This is a structural diagram illustrating the relevant configuration between the fixed half-sleeve and the suspended half-sleeve at the upper end of the cable in this application;

[0040] Figure 2 The traction half-set is removed to better show the structural schematic diagram of the clamping arc component.

[0041] Explanation of reference numerals in the attached drawings: 1. Fixed half-set; 2. Sleeve end; 3. Traction half-set; 4. Tightening arc component; 5. Guide rod; 51. End half-ring; 52. Sleeve frame; 53. Frame slider; 54. Saw cable section; 55. Saw cable electric cylinder; 56. Cutting pressure sensor; 57. Lifting half-set; 58. Lifting tension sensor. Detailed Implementation

[0042] The present application will be further described in detail below with reference to the accompanying drawings.

[0043] This application discloses a method for dismantling cables of a cable-stayed bridge without supports, which specifically includes the following steps.

[0044] Step 1: Connect the tool anchor ring to the upper anchor head of the cable, and then set up a jack at the upper end of the cable to connect it to the cable.

[0045] Step 2: Use the jack to tension the cable until the anchor head is free and maintain stable tension.

[0046] Step 3: Cut and remove the working anchor ring of the anchor head.

[0047] Step 4: Rotate the tool anchor ring away from the anchor head, then use the jack to release the tension of the cable until the jack reaches its travel limit. Then reconnect the tool anchor ring to the anchor head, and then reset the jack. Repeat this several times until the cable tension is reduced to the target value, such as 30t to 40t. At the same time, monitor the tension values ​​of several cables close to the cable to be cut and adjust the cable force accordingly.

[0048] The tension adjustment of several cables that have not been cut and are similar to those about to be cut can be carried out using the following method to adjust the cable force of the uncut cables to a stable state for the bridge.

[0049] Under a defined and reasonable bridge condition, the tower and beam can be considered to be under compression only under dead load, with bending moments of zero or close to zero. Under dead load, the cable force can be approximated as the sum of half the dead load of the adjacent beam segment and half the self-weight of the cable, i.e.:

[0050]

[0051] In the formula: T i W i ,α i These represent the cable force, self-weight, and inclination angle of the i-th cable in the mid-span; T i ',α i 'These represent the cable force and inclination angle of the corresponding side span cables; G i G i+1 N i N i+1 ,β i ,β i+1 These represent the gravity, axial force, and inclination angle of the left and right main beams of the i-th cable, respectively.

[0052] Step 5: Form a set of two rings of holes on the sheath surface at both the upper and lower ends of the cable. Screw bolts into both ends of the cable clamp and insert them into the holes on the cable surface. Then, use bolts and nuts to tighten the cable clamps so that they fit tightly against the cable.

[0053] Step 6: Use a traction device to apply close tension to the two cable clamps until the tension of the cable between the two clamps is zero.

[0054] Step 7: Cut the cable between the two cable clamps and slowly lower the cut cable to the bridge deck. Before cutting the cable, apply an upward lifting force to the upper end of the cable to be cut. When cutting the cable, start cutting upward from the lower part of the cable. After the upper end of the cable is cut and lowered to the bridge deck, cut the lower end of the cable.

[0055] Step 8: After the cable is cut, remove the remaining upper end along with the upper end of the corresponding tower column, and remove the remaining lower end along with the corresponding bridge.

[0056] The principle of the cable removal method for cable-stayed bridge without support in this application embodiment is that the two cable clamps are less likely to slip when they are close to each other, so as to improve the safety performance of the cable cutting operation.

[0057] This application also discloses a cable-removal device, which replaces cable clamps in the above-described method for dismantling a cable-stayed bridge without supports. (Refer to...) Figure 1 It includes two sets of two fixed half-sleeves 1 in each set. The fixed half-sleeves 1 can be ordinary cable clamps. The two fixed half-sleeves 1 are fastened together by bolts and nuts to press tightly against the cable. The circumferential surface of the fixed half-sleeves 1 is evenly provided with several sleeve ports 2 around its own axis. Each sleeve port 2 is provided with a bolt threaded in so that the bolt of the sleeve port 2 can be inserted into the hole pre-drilled on the sheath surface of the cable.

[0058] Reference Figure 1 and Figure 2Two sets of fixed half-sleeves 1 are fixedly connected to a ring of clamping arc members 4 at their far ends. Several clamping arc members 4 are evenly arranged around the axis of each set of fixed half-sleeves 1, and the number of clamping arc members 4 in each set of fixed half-sleeves 1 is consistent. The circumferential surface of the clamping arc members 4 away from the axis of the set of fixed half-sleeves 1 is inclined. The closer the inclined surface of the clamping arc members 4 is to the outer diameter of the set of fixed half-sleeves 1, the larger it is. Each set of clamping arc members 4 is coaxially fitted with a set of two traction half-sleeves 3. The two traction half-sleeves 3 in the same set are fastened together by bolts and nuts. The traction half-sleeves 3 can be pulled by the steel strand of the external traction equipment so that the two sets of traction half-sleeves 3 are brought closer together, so that the two sets of fixed half-sleeves 1 tend to be closer together, so that the tension of the cable to be cut between the two sets of fixed half-sleeves 1 becomes zero. The inner wall of the traction half-set 3 is inclined, and the inclined inner wall of the traction half-set 3 can fit against the inclined outer wall of the pressing arc member 4, so that when the two sets of traction half-sets 3 are close to each other, the pressing arc member 4 can also press against the surface of the cable at the same time, which increases the friction between the pressing arc member 4 and the cable, making the fixed half-set 1 less likely to move at will.

[0059] Reference Figure 1 and Figure 2 Two sets of fixed half-sleeves 1 are fixedly connected to guide rods 5 on opposite sides. The length direction of the guide rods 5 is the same as the axial direction of the fixed half-sleeves 1. The traction half-sleeves 3 are slidably connected to the guide rods 5 along the length direction of the guide rods 5. The ends of all the guide rods 5 connected to the same fixed half-sleeves 1 that are away from the fixed half-sleeves 1 are inserted with the same end half-ring 51, so that a set of two fixed half-sleeves 1 corresponds to a set of two end half-rings 51. The two end half-rings 51 in the same set can be fastened together with bolts and nuts to be tightly fitted to the cable. The end half-rings 51 can be detachably connected to the cable by bolts. Before the two traction half-sleeves 3 in the same group are connected, the bolts of the end half-ring 51 corresponding to the guide rod 5 are only initially fixed. After the two traction half-sleeves 3 in the same group are connected, the bolts of the end half-ring 51 corresponding to the guide rod 5 are tightened again so that the end half-ring 51 can press the traction half-sleeve 3 against the clamping arc 4 initially. On the one hand, this facilitates the connection between the traction half-sleeves 3, and on the other hand, it also makes it less likely that the traction half-sleeve 3 will move to a large extent after the end half-ring 51 is finally tightened.

[0060] Reference Figure 1Two lifting half-sleeves 57 are provided at the higher end of the cable, on the side of the end half-ring 51 away from the guide rod 5. The lifting half-sleeves 57 are fastened together by bolts and nuts to fit tightly onto the cable. The lifting half-sleeves 57 are detachably connected to a lifting force sensor 58 that can be connected to the hook cable of an external crane. The lifting force sensor 58 detects the upward tension applied to the cable by the lifting half-sleeves 57 and sends the corresponding signal to the external controller, which then displays it on the external display screen. This allows the operator to control the external crane so that the lifting half-sleeves 57 apply a tension close to the weight of the cable to be cut between the two end half-rings 51. This ensures that when the higher end of the cable is cut, even if a large downward pressure is suddenly applied to the lifting half-sleeves 57 and the external crane, the lifting half-sleeves 57 and the external crane can remain in a relatively stable state.

[0061] Reference Figure 2 Each of the two sets of end half-rings 51 can be detachably connected to a sleeve 52 by bolts on one side. The sleeve 52 is slidably connected to a frame slider 53. The frame slider 53 is equipped with a sawing cable part 54 that can cut the cable with a wire saw. The sleeve 52 is fixedly connected to a sawing cable electric cylinder 55 that pushes the frame slider 53 away from the cable. A cutting pressure sensor 56 is provided between the power rod of the sawing cable electric cylinder 55 and the frame slider 53. The cutting pressure sensor 56 detects the cutting pressure between the rope chain of the sawing cable part 54 and the cable and sends a signal to an external controller so that the cutting pressure between the rope chain of the sawing cable part 54 and the cable is maintained within a suitable range, so that the operator does not need to approach the cable cutting point to perform cutting operations.

[0062] Reference Figure 1 The lifting tension sensor 58 is located at the end of the lifting half-sleeve 57 furthest from the adjacent end half-ring 51. The taller saw section 54 cuts the cable from bottom to top, allowing the lifting half-sleeve 57 to separate the cut end of the cable. This reduces the possibility of excessive pressure on the section of the cable cut by the saw section 54, and also makes the cable cutting operation smoother. Conversely, the shorter saw section 54 cuts the cable from top to bottom, allowing for better separation of the cut ends of the shorter cable.

[0063] The implementation principle of a cable dismantling device according to an embodiment of this application is as follows: the corresponding cables of two fixed half-sets 1 in the same group are fastened together, and then the two end half-rings 51 are fastened together. Then, the two traction half-sets 3 in the same group are spliced ​​together to be fitted onto a tight-fitting arc member 4. After the two traction half-sets 3 are fastened together, the bolts of the end half-rings 51 corresponding to the guide rod 5 are tightened so that the end half-rings 51 abuts against the traction half-sets 3 and the traction half-sets 3 are pressed against the tight-fitting arc member 4. Then, the external traction device pulls the two traction half-sets 3 together, so that the tension of the cable between the two fixed half-sets 1 becomes zero.

[0064] Next, the sleeve 52 and the suspended half-sleeve 57 at the higher end of the cable are installed. Then, an external crane applies external force to the suspended half-sleeve 57, and the cable sawing unit 54 cuts the upper end of the cable from bottom to top. After the upper end of the cable is cut, the external crane lowers the upper end of the cable to the bridge deck, and then the sleeve 52 is installed at the lower end of the cable. Then, the cable sawing unit 54 cuts the cable from top to bottom.

[0065] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A method for dismantling cables of a cable-stayed bridge without supports, characterized in that: Specifically, the following steps are included: Step 1: Connect the tool anchor ring to the upper anchor head of the cable, and then set up the jack at the upper end of the cable to connect it to the cable; Step 2: Tension the cable with the jack until the anchor head is free and maintain stable tension; Step 3: Cut and remove the working anchor ring of the anchor head; Step 4: The tool anchor ring rotates and disengages from the anchor head. Then, the jack releases the tension of the cable until the jack reaches its travel limit. The tool anchor ring is then reconnected to the anchor head, and the jack is reset. This process is repeated several times until the cable tension is reduced to the target value. At the same time, the tension values ​​of several cables close to the cable to be cut are monitored and the cable force is adjusted synchronously. The cable force is equal to the sum of half of the dead load of the adjacent beam segment and half of the cable's own weight. Step 5: Form a set of two rings of holes on the sheath surface at both the upper and lower ends of the cable. Screw bolts into both ends of the cable clamp and insert them into the holes on the cable surface. Then tighten the cable clamp with bolts and nuts to make it fit tightly against the cable. Step 6: Use a traction device to apply close tension to the two cable clamps until the tension in the cable between the two clamps is zero; Step 7: Apply an upward lifting force to the upper end of the cable to be cut. When cutting the cable, start cutting upward from the lower part of the cable. After the upper end of the cable is cut and lowered to the bridge deck, then cut the lower end of the cable. Step 8: After the cable is cut, remove the remaining upper end along with the upper end of the corresponding tower column, and remove the remaining lower end along with the corresponding bridge.

2. A cable-removal device, used as a cable clamp according to the cable-removal method for dismantling a cable-stayed bridge without supports as described in claim 1, characterized in that: It includes two sets of fixed half sleeves (1) with two phases detachably connected to be fitted onto the cable, a sleeve port (2) that is opened through the fixed half sleeve (1) and for bolts to be screwed in to be inserted into the cable, and two sets of traction half sleeves (3) that are detachably connected to the fixed half sleeve (1) and detachably connected to each other in the same set. The two sets of traction half sleeves (3) tend to move closer together when pulled by the traction equipment.

3. The cable-removing device according to claim 2, characterized in that: Each of the two sets of fixed half-sleeves (1) is fixedly connected to a ring of pressing arc members (4) on the opposite side. Each ring of pressing arc members (4) is provided with several corresponding to the two fixed half-sleeves (1). The pressing arc members (4) and the traction half-sleeves (3) are inclined so that when the two sets of traction half-sleeves (3) are close to each other, the pressing arc members (4) can press tightly against the cable.

4. The cable-removing device according to claim 3, characterized in that: The fixed half-sleeve (1) is provided with a guide rod (5) through which the traction half-sleeve (3) slides. The end of the guide rod (5) of the fixed half-sleeve (1) away from the fixed half-sleeve (1) is provided with an end half-ring (51). The end half-ring (51) can be abutted by the traction half-sleeve (3). The two end half-rings (51) can be detachably connected.

5. The cable-removing device according to claim 4, characterized in that: The end half ring (51) is detachably connected to the guide rod (5), and the end half ring (51) is sleeved on the guide rod (5) to abut against the traction half ring (3).

6. A cable-removing device according to claim 2, characterized in that: Both sets of fixed half-sets (1) are provided with a frame (52) on the side close to each other. The frame (52) is slidably connected to a frame slider (53). The frame slider (53) is provided with a saw section (54) that can cut the cable. The frame (52) is provided with a saw cylinder (55) that moves the saw section (54) to keep it pressed tightly against the cable.

7. A cable-removing device according to claim 6, characterized in that: The power rod of the saw cable electric cylinder (55) is equipped with a cutting pressure sensor (56), which is connected to the frame slider (53).

8. A cable-removing device according to claim 6, characterized in that: The taller frame (52) has two lifting half-sleeves (57) on the side near the shorter frame (52) that can clamp the cable. The two lifting half-sleeves (57) are detachably connected. The lifting half-sleeves (57) can be lifted. A lifting force sensor (58) is provided at the lifting position of the lifting half-sleeves (57).

9. A cable-removing device according to claim 8, characterized in that: The lifting tension sensor (58) is located at one end of the lifting half-set (57) away from the adjacent set (52). The higher saw section (54) cuts the cable from bottom to top, and the lower saw section (54) cuts the cable from top to bottom.

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