A cutting system of externally prestressed steel strands and a cutting method thereof

Abstract

The application discloses a cutting system and a cutting method of an in-vitro prestressed steel beam, and the cutting system comprises a cutting device and a damping system. The cutting device is used for cutting operation on the steel beam at a cutting point of the steel beam to be cut. The damping system comprises two constraint ring buckles, a V-shaped frame and an energy consumption device. The two constraint ring buckles are used for being fixed on the steel beam on both sides of the cutting point. The V-shaped frame comprises two connecting rods. One end of each of the two connecting rods is hingedly connected with a corresponding constraint ring buckle. The other ends of the two connecting rods are hingedly connected with each other. The energy consumption device is hingedly connected with the two connecting rods at two ends thereof. The energy consumption device is used for absorbing the energy released by the steel beam when the steel beam retracts and drives the V-shaped frame to deform. The cutting system can convert the dangerous instantaneous energy released when the steel beam is cut into a smooth, safe, controllable and efficient process, realizes safe and controllable removal of the prestressed steel beam, and can adapt to in-vitro steel beams with different diameters and different beam arrangement forms.

Description

Technical Field

[0001] This invention belongs to the field of bridge engineering and structural construction technology, specifically relating to a system and method for removing externally prestressed steel strands. Background Technology

[0002] External prestressing technology is an important form of modern prestressed concrete structure. Its prestressed steel strands are placed outside the main concrete structure, and the prestress is transferred through deflector blocks and anchor blocks. When demolishing, structurally repairing, or strengthening such structures to increase load capacity after their service life, it is essential to safely release the enormous prestress stored in the steel strands (typically hundreds of tons).

[0003] The removal of external prestressed steel strands is usually done by direct cutting. However, the prestressed steel strands store huge elastic potential energy. The sudden release of energy at the moment of cutting will cause the steel strands to retract violently and swing laterally, which may not only damage the surrounding structure, but also seriously threaten the safety of the operators. Summary of the Invention

[0004] In view of the above-mentioned defects or deficiencies in the prior art, it is desirable to provide a system and method for removing externally prestressed steel strands.

[0005] A first aspect of the present invention provides a system for removing externally prestressed steel strands, comprising: A cutting device for cutting the steel strand at the cutting point to be cut; Vibration damping system, the vibration damping system comprising: Two constraint rings are used to constrain and fix the steel strand on both sides of the cutting point; The V-shaped frame includes two connecting rods, one end of each connecting rod is hinged to a corresponding constraint ring, and the other ends of the two connecting rods are hinged to each other. An energy-dissipating device is provided, with its two ends hinged to the two connecting rods respectively. The energy-dissipating device is used to absorb the energy released by the steel strand when the steel strand retracts and causes the V-shaped frame to deform.

[0006] In addition, the external prestressed steel strand removal system of the present invention may also have the following additional technical features: In some embodiments, the constraint ring includes two semi-circular constraint buckles, one end of which is movably connected, and the other end of which is connected by bolts or clips.

[0007] In some embodiments, a friction washer is provided on the inner wall of the semi-circular constraint buckle, and the semi-circular constraint buckle is connected to the steel strand through the friction washer.

[0008] In some embodiments, the energy-consuming device includes one of a hydraulic damper, a spring damper, a pulse damper, a rotational damper, a magnetorheological damper, or a viscous damper.

[0009] In some embodiments, the cutting system further includes a protective system comprising a protective cylinder with through holes on opposite end walls for the steel strand to pass through. The protective cylinder is used to cover the outside of the steel strand, and the vibration damping system and the cutting device are located inside the protective cylinder.

[0010] In some embodiments, the protective cylinder includes two semi-circular cylinders, one end of which is hinged and the other end of which is detachably connected by bolts or latches. The protective cylinder is provided with a visualization window, which is used to provide a visualization view, and / or the inner wall of the protective cylinder is provided with a fixing hinge for mounting the cutting device, and / or the protective cylinder is provided with an operating hole for the cutting tool of the cutting device to extend into.

[0011] In some embodiments, the cutting device includes one of a hydraulically driven, electrically driven, or gas-driven cutting device.

[0012] In some embodiments, the cutting system further includes a release system for controllably releasing a portion of the prestress in the steel strand prior to cutting, the release system comprising: At least one pair of temporary cable clamps that can be fastened to the steel strand, at least one pair of working anchor plates that can be fastened to the steel strand, a working bundle passing through the working anchor plates and the temporary cable clamps, and a tensioning device for tensioning the working bundle.

[0013] In some embodiments, the cutting system further includes a remote monitoring system and a remote control system, wherein the remote monitoring system is used to monitor the prestress during the prestress release process of the steel strand, and the remote control system is used to remotely control the cutting device and / or the tension release system.

[0014] A second aspect of the present invention provides a method for removing externally prestressed tendons, implemented based on the externally prestressed tendon removal system described in any embodiment of this application, the removal method comprising: A vibration damping system is installed on the steel strand to be cut, and two constraint rings are fixed to both sides of the steel strand cutting point. A V-shaped frame is installed between the two constraint rings, and an energy dissipation device is installed between the two connecting rods of the V-shaped frame. The steel strand is cut at the cutting point using a cutting device to sever the steel strand.

[0015] According to the present invention, the external prestressed steel strand removal system and method transform the dangerous instantaneous energy release into a stable, safe, controllable, and efficient process through the synergistic effect of the internal constraint ring, V-shaped frame, and energy dissipation device of the vibration damping system. By combining active constraint and energy dissipation, the system achieves safe and controllable removal of the prestressed steel strand and can adapt to external steel strands of different diameters and different strand arrangements, and can operate in narrow spaces. Attached Figure Description

[0016] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 An overall structural diagram of the external prestressed steel strand removal system provided in the embodiments of this application; Figure 2 This is an overall structural diagram of the vibration reduction system provided in the embodiments of this application; Figure 3 This is a cross-sectional structural diagram of the vibration reduction system provided in the embodiments of this application; Figure 4 This is an overall structural diagram of the protection system provided in the embodiments of this application; Figure 5 This is a first cross-sectional structural diagram of the protection system provided in an embodiment of this application; Figure 6 This is a second cross-sectional structural diagram of the protection system provided in an embodiment of this application; Figure 7 A structural diagram of a first type of cutting device for a protective system provided in this application embodiment; Figure 8 A structural diagram of a second cutting device for a protective system provided in this application embodiment; Figure 9 This is an overall structural diagram of the tensioning system provided in the embodiments of this application; Figure 10 This is a structural diagram of a temporary cable clamp with an anchor plate provided in an embodiment of this application; Figure 11 A structural diagram of the working anchor plate provided in the embodiments of this application; Figure 12 for Figure 11 Diagram of the semi-circular plate structure of the working anchor plate; Figures 13 to 20 An exemplary flowchart of a method for removing externally prestressed steel strands provided in an embodiment of this application.

[0017] In the above image: 10 Cutting device; 110 Cutting air gun; 111 Fixing device; 120 Cutting blade; 130 Self-adjusting pressure device; 20 Vibration damping system; 210 Constraint ring; 211 Semi-circular constraint buckle; 212 Bolt; 220 Connecting rod; 230 Energy dissipation device; 231 Spherical bearing; 240 Friction washer; 30 Protective system; 310 Protective cylinder; 311 Semi-circular cylinder body; 312 Semi-circular end plate; 313 Working hole; 320 Fixed hinge; 330 Visual window; 340 Rotating shaft; 40 Tensioning system; 410 Temporary cable clamp; 420 Working anchor plate; 421 Semi-circular plate; 422 Sleeve; 430 Tensioning equipment; 440 Working bundle; 50. Remote monitoring system; 60. Remote control system; 70 steel strands. Detailed Implementation

[0018] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0019] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0020] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The singular forms “a,” “the,” and “the” as used in this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0021] Unless the context otherwise requires, throughout the specification and claims, the term "comprising" is interpreted as open and encompassing, that is, "including, but not limited to".

[0022] In the description of this specification, the terms "one embodiment," "some embodiments," "exemplary embodiment," "example," "specific example," or "some examples," etc., are intended to indicate that a particular feature, structure, material, or characteristic associated with that embodiment or example is included in at least one embodiment or example of this disclosure. The illustrative representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics mentioned may be included in any suitable manner in any one or more embodiments or examples.

[0023] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of this disclosure, unless otherwise stated, "a plurality of" means two or more.

[0024] Traditional extracorporeal shock wave resection (ESR) methods have the following main problems: 1) Poor safety: Cutting is typically done directly using an acetylene torch or an abrasive saw. At the moment of cutting, the steel strand 70 will violently retract and swing, generating enormous impact kinetic energy, which can easily cause serious damage to operators, surrounding equipment, and the structure itself. 2) Low controllability: The prestress release process is instantaneous and uncontrollable, making slow, staged release impossible. This results in significant secondary impact on the structure and may cause unpredictable stress redistribution. 3) Low efficiency: To ensure safety, operators must operate remotely from the work site using long poles or other tools, resulting in poor precision. Furthermore, only a single steel strand 70 can be cut at a time, making it extremely inefficient for multi-strand anchorage systems. 4) Weak adaptability: Traditional methods are difficult to implement for steel strands 70 located in complex, confined, or severely corroded spaces, posing even higher risks.

[0025] To at least partially solve the above problems, the first aspect of the present invention, as follows: Figures 1 to 3 As shown, a system for cutting off externally prestressed steel strands is provided for use in the demolition, reinforcement, or renovation of externally prestressed concrete structures (such as bridges, buildings, etc.). The system includes: Cutting device 10, the cutting device 10 is used to cut the steel strand 70 at the cutting point of the steel strand 70 to be cut; Vibration damping system 20, the vibration damping system 20 comprising: Two constraint rings 210 are used to constrain and fix the steel strand 70 on both sides of the cutting point; The V-shaped frame includes two connecting rods 220, one end of each connecting rod 220 is hinged to a corresponding constraint ring 210, and the other ends of the two connecting rods 220 are hinged to each other. Energy dissipation device 230, the two ends of which are respectively hinged to the two connecting rods 220, the energy dissipation device 230 is used to absorb the energy released by the steel strand 70 when the steel strand 70 retracts and causes the V-shaped frame to deform.

[0026] Specifically, the cutting system includes a cutting device 10 and a vibration damping system 20. The cutting device 10 is used to achieve precise cutting of the externally prestressed steel strand 70 at a designated cutting point. The vibration damping system 20 is used to clamp and constrain the steel strand 70 on both sides of the cutting point before the cutting device 10 cuts the steel strand 70, so as to reduce the stress released at the moment of cutting the steel strand 70.

[0027] The vibration damping system 20 includes two constraint rings 210, which are respectively constrained and fixed to the steel strand 70 on both sides of the cutting point to ensure that the vibration damping system 20 and the steel strand 70 move synchronously and avoid relative sliding. A V-shaped frame is hinged between the two constraint rings 210 and located on the upper and / or lower side of the steel strand 70. That is, the V-shaped frame can be arranged on the upper side of the cutting point or on the lower side of the cutting point, or multiple V-shaped frames can be arranged at intervals in the circumferential direction in combination with the cable force. The V-shaped frame rotates around its apex, causing the energy-dissipating device 230 to gradually release the stress on the steel strands 70. The V-shaped frame includes two hinged connecting rods 220, which together form a V-shaped structure. Each connecting rod 220 is hinged to a corresponding constraint ring 210. The energy-dissipating device 230 is hinged between the two connecting rods 220. As the steel strands 70 retract, the V-shaped frame undergoes hinge deformation, converting the axial rebound energy of the steel strands 70 into the opening or closing motion of the two connecting rods 220. The energy-dissipating device 230 does work when the V-shaped frame deforms, absorbing and dissipating the huge elastic potential energy released by the prestress, significantly reducing the rebound impact, vibration, and noise of the steel strands 70, and improving the safety of the cutting operation.

[0028] Among them, the two connecting rods 220 can be I-beam structures, so that the cross-section of the connecting rod 220 is I-shaped. That is, the connecting rod 220 includes a top plate and a bottom plate arranged in parallel, and a waist plate located between the top plate and the bottom plate. The waist plate is set perpendicular to the top plate and the bottom plate. The two ends of the connecting rod 220 have connecting lugs extending outward from the top plate and the bottom plate with I-shaped cross-section. The connecting lugs are provided with pin holes, and pins are installed in the pin holes. The two connecting rods 220 located on the same side of the steel strand 70 are hinged through the cooperation of the pin holes on the connecting lugs and the pins. Similarly, the rod body of the connecting rod 220 located in the middle area can also extend outward from the top plate and the bottom plate to form a connecting lug plate. The connecting lug plate has a pin hole. The left and right ends of the energy dissipation device 230 can be provided with spherical bearings 231. The spherical bearing 231 includes an inner ring and an outer ring. The outer ring is fixedly connected to the energy dissipation device 230, and the inner ring has an inner ring hole. The pin passes through the pin hole of the connecting lug plate on one side of the connecting rod 220, the inner ring hole in the spherical bearing 231, and the pin hole of the connecting lug plate on the other side of the connecting rod 220 in sequence, so as to realize the hinge connection between the energy dissipation device 230 and the connecting rod 220. When the V-shaped frame deforms, the inner ring of the spherical bearing 231 can swing in the spherical surface of the outer ring to adapt to the change of the angle between the connecting rod 220 and the energy dissipation device 230.

[0029] In the external prestressed steel strand cutting system provided in this application embodiment, the steel strand 70 is fixed at both sides of the cutting point by the constraint rings 210 set on both sides of the cutting point, providing a constraint basis for subsequent energy release and preventing the steel strand 70 from going out of control as a whole; the set V-shaped frame is used to convert the retraction motion of the steel strand 70 into the deformation motion of the V-shaped frame, realizing the guiding control of the movement trajectory of the steel strand 70 and avoiding lateral swinging; the energy dissipation device 230 set between the two connecting rods 220 of the V-shaped frame is used to convert the kinetic energy of the steel strand 70 into the working stroke of the damper, realizing the active absorption of energy and changing the instantaneous burst into a slow release.

[0030] The removal system transforms the dangerous instantaneous energy release into a stable, safe, controllable, and efficient process through the synergistic effect of the internal constraint ring 210, V-shaped frame, and energy dissipation device 230 within the vibration damping system 20. By combining active constraint with energy dissipation, it achieves safe and controllable removal of the prestressed steel strands 70 and can adapt to external steel strands 70 with different diameters and different bundle configurations, allowing for operation in confined spaces.

[0031] In some implementations, such as Figure 2 and Figure 3 As shown, the constraint ring buckle 210 includes two semi-circular constraint buckles 211, one end of the two semi-circular constraint buckles 211 is movably connected, and the other end of the two semi-circular constraint buckles 211 is connected by a bolt 212 or a snap fastener.

[0032] Specifically, the constraint ring 210 includes two interlocking semi-circular constraint buckles 211. The shape of the semi-circular constraint buckles 211 matches the shape of the steel strand 70. That is, one end of the two semi-circular constraint buckles 211 is hinged or rotatably connected by a pivot 340. The hinge can be connected by a pin or a screw. The other end of the two semi-circular constraint buckles 211 is connected by a bolt 212, a snap-fit ​​or a lock. It can also be connected by multiple bolts 212 to further improve the fixing firmness of the constraint ring 210.

[0033] In this example, two interlocking semi-circular constraint buckles 211 are used to quickly snap and fix the steel strand 70, which is used to fix the steel strand 70 during the cutting operation and prevent the steel strand 70 from flying around and injuring people; and the shape of the semi-circular constraint buckle 211 matches the shape of the steel strand 70, clamping it evenly and stably, avoiding local damage to the steel strand 70.

[0034] In some implementations, such as Figure 3 As shown, a friction washer 240 is provided on the inner wall of the semi-circular constraint buckle 211, and the semi-circular constraint buckle 211 is connected to the steel strand 70 through the friction washer 240.

[0035] Specifically, a friction washer 240 is provided on the inner wall of the semi-circular constraint buckle 211. The shape of the friction washer 240 matches the shape of the steel strand 70. The friction washer 240 increases the friction between the constraint buckle 210 and the steel strand 70, prevents the constraint buckle 210 from slipping when the steel strand 70 rebounds, and avoids damage to the surface of the steel strand 70 by rigid clamping, thus protecting the strength of the steel strand 70.

[0036] In some embodiments, the energy-consuming device 230 includes one of a hydraulic damper, a spring damper, a pulse damper, a rotational damper, a magnetorheological damper, or a viscous damper.

[0037] Specifically, the energy dissipation device 230 is flexible and versatile, and various dampers can achieve continuous and stable energy dissipation, effectively suppressing the rebound impact and vibration of the steel strand 70. Different dampers can be matched according to the prestress and the specifications of the steel strand 70, and the damping effect is adjustable and has a wide range of applications. When the stress of the steel strand 70 is released, it pushes the piston, and the energy is dissipated by the damping force generated by the flow of hydraulic oil or magnetofluid through the small hole.

[0038] In some implementations, such as Figures 4 to 6 As shown, the cutting system also includes a protective system 30, which includes a protective cylinder 310. The protective cylinder 310 has a through hole on its opposite end wall for the steel strand 70 to pass through. The protective cylinder 310 is used to cover the outside of the steel strand 70, and the vibration damping system 20 and the cutting device 10 are located inside the protective cylinder 310.

[0039] Specifically, the protective cylinder 310 has two opposing circular end plates along the axial direction of the steel strand 70. Each circular end plate is formed by two semi-circular end plates 312, with a through hole at the center for the steel strand 70 to pass through. The protective cylinder 310 covers the working section of the steel strand 70, allowing cutting operations to be performed within this section. The protective cylinder 310 forms a physical isolation barrier, confining fragments and energy of the steel strand 70 within the protective cylinder 310 even in the event of accidental loss of control, ensuring operational safety. Furthermore, the cutting device 10 and vibration damping system 20 are all located within the protective cylinder 310, achieving integrated vibration damping, cutting, and protection, thus improving on-site construction safety.

[0040] In some implementations, such as Figures 4 to 6 As shown, the protective cylinder 310 includes two semi-circular cylinders 311, one end of the two semi-circular cylinders 311 is hinged, and the other end of the two semi-circular cylinders 311 is detachably connected by bolts 212 or locks. The protective cylinder 310 is provided with a visualization window 330, which is used to provide visualization. The inner wall of the protective cylinder 310 is provided with a fixing hinge 320 for mounting the cutting device 10. The protective cylinder 310 is provided with an operating hole for the cutting tool of the cutting device 10 to extend into.

[0041] Specifically, the protective cylinder 310 includes oppositely arranged annular end walls and two oppositely arranged semi-circular cylinders 311 located between the two annular end walls. Each semi-circular cylinder 311 is fixedly connected to a corresponding annular end wall, so that the annular end walls and the semi-circular cylinders 311 together form a closed cylindrical protective cylinder 310. One end of each semi-circular cylinder 311 is rotatably connected along the generatrix of the protective cylinder 310 via a pivot 340 or hinged, while the other ends of each semi-circular cylinder 311 are connected via bolts 212 or locking clips. This connection method facilitates on-site installation and assembly of the protective cylinder 310, improving construction efficiency.

[0042] The protective cylinder 310 can be equipped with a visualization window 330 in the middle, such as using explosion-proof glass or explosion-proof plastic, to provide a display of cutting-related effects, realize visual monitoring of the cutting process, and facilitate the judgment of the cutting status and the retraction of the steel strand 70.

[0043] like Figures 4 to 7 As shown, multiple fixed hinges 320 can be arranged at intervals along the circumferential direction on the inner wall of the protective cylinder 310. The fixed hinges 320 are used to hinge with the cutting device 10 (such as the subsequent electrically driven cutting device 10), which can effectively support the cutting device 10 while moving the cutting blade 120 of the cutting device 10, so as to facilitate remote control of the cutting device 10 to perform the cutting operation of the steel strand 70.

[0044] like Figure 8 As shown, the protective cylinder 310 also has an operating hole on its side wall for the cutting tool of the cutting device 10 to extend into. For example, for the subsequent gas-driven cutting device 10, the cutting air gun 110 of the gas-driven cutting device 10 can pass through the operating hole and extend into the protective cylinder 310. The nozzle of the cutting air gun 110 can spray high-temperature gas to melt and cut the steel strand 70. It is understood that a fixing device 111 is also provided at the operating hole to fix the cutting air gun 110. The fixing device 111 includes one or more combinations of clamping sleeve, locking bolt 212, clamp, threaded connection seat, elastic claw, adjustable clamping bracket or magnetic fixing seat.

[0045] Of course, under certain special working conditions, the protective cylinder 310 can also adopt a semi-circular structure. For example, under certain working conditions, the steel strand 70 is close to the concrete structure and the protective cylinder 310 does not have enough installation space. The protective cylinder 310 can be made into a semi-circular structure to adapt to the requirements of extremely narrow installation space.

[0046] In some embodiments, the cutting device 10 includes one of a hydraulically driven, electrically driven, or gas-driven cutting device 10.

[0047] Specifically, the hydraulically driven, electrically driven, or gas-driven cutting device 10 can be configured with a remote control system 60 to enable remote control of the cutting device 10 and improve operator safety. The hydraulically driven cutting device 10 may include a ring-shaped hydraulic shear; the electrically driven cutting device 10 may include a multi-blade diamond saw assembly; and the gas-driven cutting device 10 may include an oxygen-acetylene cutting device 10. The cutting device 10 includes at least two cutting heads arranged circumferentially around the steel bundle 70, each capable of simultaneously acting on the steel bundle 70 to achieve synchronous cutting. Figure 7 As shown, there are two cutting devices 10, which are respectively arranged on the upper side of the steel strand 70 and the cutting device 10. Each cutting device 10 includes a cutting blade 120, which is circular and has a serrated surface. The cutting blade 120 can rotate to cut the steel strand 70. A support rod is hinged to the cutting blade 120, and the support rod can be hinged to a fixed hinge 320 on the inner wall of the protective cylinder 310. A self-adjusting pressure device 130 is hinged to the support rod. The self-adjusting pressure device 130 can drive the cutting blade 120 to move linearly along an axis perpendicular to the steel strand 70 to complete the cutting operation of the steel strand 70. The self-adjusting pressure device 130 can be a hydraulic cylinder or an electric push rod, etc.

[0048] For example, a multi-blade diamond saw assembly can consist of multiple diamond saw blades arranged at intervals around the steel bundle 70 in the circumferential direction. Each diamond saw blade is independently equipped with a hydraulic rod, and all hydraulic rods are activated synchronously. This allows each diamond saw blade to simultaneously cut the steel bundle 70 from multiple working surfaces at the same cutting point, ensuring simultaneous energy release and avoiding uneven force release caused by unilateral cutting. Similarly, an oxygen-acetylene cutting device 10 arranged at intervals around the steel bundle 70 in the circumferential direction can also simultaneously cut the steel bundle 70 from multiple working surfaces at the same cutting point. Of course, it is also possible to simultaneously cut the steel bundle 70 from multiple working surfaces at different cutting points. Multiple different working surfaces refer to cutting surfaces that are cut vertically from top to bottom, or cutting surfaces that are cut at an angle from top to bottom (which can be at different angles), or cutting surfaces that are cut vertically from bottom to top, or cutting surfaces that are cut at an angle from bottom to top (which can be at different angles). At the same cutting point, all cutting surfaces are located on the same plane; at different cutting points, all cutting surfaces are located on different planes.

[0049] Furthermore, the cutting device 10 is equipped with a fracture monitoring sensor, which includes one or more combinations of fiber optic grating sensors, acoustic emission sensors, or high-speed camera devices; the fracture monitoring sensor is used to monitor the fracture propagation status in real time during the cutting process and to issue a prompt signal when the steel strand 70 is completely cut off.

[0050] In this example, the cutting progress can be judged in real time to avoid incomplete or excessive cutting, and the acoustic emission signal can provide an early warning of when the steel strand 70 is about to break, providing a trigger signal for the start-up of the energy-consuming device 230.

[0051] In some implementations, such as Figures 9 to 12 As shown, the cutting system further includes a tension release system 40, which is used to controllably release part of the prestress in the steel strand 70 before cutting. The tension release system 40 includes: At least one pair of temporary cable clamps 410 that can be fastened to the steel strand 70, at least one pair of working anchor plates 420 that can be fastened to the steel strand 70, a working bundle 440 passing through the working anchor plates 420 and the temporary cable clamps 410, and a tensioning device 430 for tensioning the working bundle 440.

[0052] Specifically, the tension release system 40 is optional and is mainly for external strands with large cable forces. It pre-releases a portion of the internal force to reduce the danger caused by stress cutting. The tension release system 40 is used to actively and controllably release the prestress in the steel strand 70 before cutting. As a controllable release actuator, it is linked with the protection system 30 and the vibration reduction system 20. Before the steel strand 70 is cut, the actuator applies a precisely controllable pre-pressure to the steel strand 70, thereby achieving a low-stress state during cutting.

[0053] The tensioning system 40 includes: temporary cable clamps 410 and working anchor plates 420 arranged sequentially on both sides of the cutting point, and tensioning equipment 430, such as jacks, located between the temporary cable clamps 410 and working anchor plates 420. The temporary cable clamps 410 and working anchor plates 420 each have steel strand 70 holes at their centers for steel strands 70 to pass through, and the end faces of the temporary cable clamps 410 and working anchor plates 420 are circumferentially arranged with multiple working strand holes 313 for working strands 440 to pass through.

[0054] like Figure 10 As shown, the temporary cable clamp 410 with anchor plate is used to temporarily anchor the working bundle 440 and provide a support surface for the jack. The temporary cable clamp 410 includes two semi-circular cable clamps 411, which can be directly fastened to the steel bundle 70. One end of the two semi-circular cable clamps 411 can be hinged by bolts 212 or locks, and the other end can also be opened or closed by bolts 212, etc., which is the same as the structural setting principle of the constraint ring 210. Friction washers 240 can also be set on the inner wall of the semi-circular cable clamp 411. The structure of the anchor plate on the temporary cable clamp 410 is the same as that of the working anchor plate 420.

[0055] like Figure 11 and Figure 12 As shown, the working anchor plate 420 includes two semi-annular plates 421. The mating surfaces of the two semi-annular plates 421 are provided with multiple sleeves 422. When the two semi-annular plates 421 are fastened together, the corresponding sleeves 422 are mated together to form a through hole. A pin can be inserted into the through hole to detachably connect and fix the two semi-annular plates 421. The anchor plates of the semi-annular plates 421 and the temporary cable clamp 410 are provided with multiple working bundle holes 313 along the circumferential direction for the working bundle 440 to pass through. The working bundle 440 can pass through the working bundle holes 313, preferably steel strands or special tensioning bundles, etc., to pre-tighten the steel bundle 70 and transfer the internal force of the steel bundle 70 to be cut to the working bundle 440. It can be gradually released later. Among them, the working anchor plate 420 is the final locking device of the external prestressing system. Its core function is to firmly lock the prestressed steel strand 70 after it is tensioned to the design value through the internal wedge-shaped clamps and other anchoring elements, and transfer the tension stored in the steel strand 70 to the working strand 440. The tensioning device 430 uses jacks and supporting equipment, which are set around the periphery of the working anchor plate 420 and the working bundle 440 to realize the transfer of internal force, and then release the internal force step by step through the jacks.

[0056] In this example, by adding a tensioning system 40, some of the prestress in the steel strand 70 is transferred to the working strand 440 through internal force transfer before cutting, thereby reducing the stress level of the section to be cut and avoiding a huge impact caused by a sudden one-time cut. This method is particularly suitable for ultra-large tonnage steel strands 70.

[0057] It is understandable that the protective cylinder 310 is also provided with a working bundle hole 313 for the working bundle 440 to pass through on the annular end wall opposite to it. The temporary cable clamp 410 with anchor plate, the working anchor plate 420 and the tensioning equipment 430 of the tensioning system 40 are located outside the protective cylinder 310.

[0058] It should be noted that those skilled in the art can also choose to use only the tensioning system 40, without the vibration damping system 20, to achieve efficient and safe cutting of the steel strand 70, based on the actual needs of steel strand 70 cutting.

[0059] In some embodiments, the cutting system further includes a remote monitoring system 50 and a remote control system 60, wherein the remote monitoring system 50 is used to monitor the prestress during the prestress release process of the steel strand 70, and the remote control system 60 is used to remotely control the cutting device 10 and / or the tension release system 40.

[0060] Specifically, such as Figure 4 , Figure 7 and Figure 8 As shown, the protective casing 310 is externally equipped with a remote monitoring system 50 and a remote control system 60. The remote monitoring system 50 includes force sensors, a pressure gauge, and a camera, used to monitor the prestress release process of the steel strand 70 and visual information about the cutting of the steel strand 70, displaying prestress release data in real time, making the release process visual and quantifiable, and providing a basis for construction control decisions. The remote control system 60 includes a display or control buttons, relying on the visual information and prestress provided by the remote monitoring system 50 to remotely control the cutting device 10 or the tensioning system 40, enabling automatic or semi-automatic control of the cutting and energy release process, reducing the risk of injury to personnel in case of emergencies.

[0061] The external prestressed steel strand removal system provided in this application has the following advantages: Intrinsic safety: Through the coordinated operation of the vibration damping system 20 and the tension release system 40, and the principle of post-cutting and protection, the risk of uncontrolled retraction of the steel strand 70 is fundamentally eliminated, ensuring the safety of personnel and equipment.

[0062] Controlled release: This achieves the transformation of prestress from instantaneous burst to slow release, reducing the impact on the original structure and helping to control the impact of demolition.

[0063] Highly adaptable: The system can be modularly designed to adapt to external steel bundles 70 with different diameters and different bundle forms, and can operate in narrow spaces.

[0064] The process is monitorable: The integrated sensor and other monitoring systems make the entire release process visible and quantifiable, providing data support for construction monitoring and subsequent research.

[0065] The second aspect of the invention, as Figures 13 to 20 As shown, a method 200 for removing externally prestressed steel strands is provided, implemented based on the externally prestressed steel strand removal system described in any embodiment of this application. The removal method includes: S210: Install a vibration damping system 20 on the steel strand 70 to be cut, constrain and fix two constraint rings 210 to both sides of the cutting point of the steel strand 70, install a V-shaped frame between the two constraint rings 210, and install an energy dissipation device 230 between the two connecting rods 220 of the V-shaped frame. Specifically, such as Figure 13 As shown, before installing the vibration damping system 20, the anti-corrosion layer of the cutting area of ​​the steel strand 70 is cleaned to expose the metal surface of the steel strand 70.

[0066] like Figure 14 As shown, the vibration damping system 20 is then installed: The initial calculation of the tension elongation of the steel strand 70 is used to determine the stroke of the energy dissipation device 230 (e.g., a damper), the type of energy dissipation device 230 is determined, and the size of the friction washer 240 is determined according to the diameter of the steel strand 70. Two constraint rings 210 are fixed to both sides of the predetermined cutting point of the steel strand 70 and locked in place with bolts 212, etc. A V-frame is then installed between the two constraint rings 210, and the energy dissipation device 230 is installed between the two connecting rods 220 of the V-frame. For example, based on the specifications of the steel strand 70 (e.g., each strand consists of 19 φ15.2mm steel strands), constraint rings 210 and a V-frame of corresponding dimensions, as well as a hydraulic damper of corresponding tonnage, are designed and manufactured. The constraint rings 210 are installed at appropriate positions on the steel strand 70, and then the V-frame is installed, with the energy dissipation device 230 installed in the middle of the V-frame.

[0067] S240: The steel strand 70 is cut at the cutting point using the cutting device 10 to sever the steel strand 70.

[0068] Specifically, such as Figure 18As shown, the cutting device 10 is activated, causing multiple cutting devices 10 to simultaneously cut from multiple working surfaces at the same cutting point; or, the cutting device 10 is activated, causing multiple cutting devices 10 to simultaneously cut from multiple working surfaces at different cutting points. Figure 19 As shown, after the steel strand 70 is cut, it retracts, causing the V-shaped frame to deform, which in turn drives the energy dissipation device 230 to absorb the energy released by the steel strand 70.

[0069] Further preferred, such as Figure 15 and Figure 16 As shown, the procedure before step S240 also includes: S220: Install the protective system 30: After opening the protective system 30, install the selected cutting device 10, and at the same time set up the remote monitoring system and the visualization window 330 (transparent glass or plastic), and set up the remote control system 60 (wireless or wireless connection between the cutting device 10 and the tensioning system 40). After completion, fasten the protective system 30 onto the cleaned steel strand 70 and lock it in place with bolts 212.

[0070] Further preferred, such as Figure 17 As shown, the process between step S220 and step S240 further includes: S230: Install tension release system 40: Calculate the internal force required to release the stress of the steel strand 70, and install tension release system 40 on both sides of the steel strand 70 to be cut, including temporary cable clamps 410 with anchor plates, working anchor plates 420, tensioning equipment 430 and working bundle 440. According to the requirements, use tensioning equipment 430 and working bundle 440 to gradually transfer the internal force of the steel strand 70 to the working bundle 440.

[0071] like Figure 18 As shown, after the working bundle 440 is tensioned, the operator, located in a safe area, remotely starts the cutting device 10. (As indicated...) Figure 19 and Figure 20 As shown, when the steel strand 70 is cut, the stress in the steel strand 70 is released, and the steel strand 70 begins to retract under the action of prestress. However, its movement is immediately restricted by the vibration damping system 20 and the tension release system 40. A portion of its kinetic energy is absorbed by the energy dissipation device 230, thereby achieving a slow and stable release of prestress rather than an instantaneous burst. At the same time, it forms a constraint on the cut steel strand 70. The tension release system 40 still has some residual stress, which can be gradually released to a stress-free state through the jack. The whole process is free from violent impact, vibration and swaying.

[0072] After the sensor indicates that the prestress has been fully released (or the retraction displacement has stopped), remove the tensioning system 40, the cutting device 10, and the protective system 30. After disconnecting the vibration damping system 20 from the cable force, the cutting work is completed, and the machine moves to the next working point. In this application, the two major functions of constraint guidance and energy dissipation are integrated into a dedicated system. Before cutting, a controlled, energy-dissipating path is prepared in advance for the elastic retraction of the steel strand 70. This is an active safety design concept. At the same time, a traditional passive protection system 30 is added to ensure absolute safety. Meanwhile, the combination of synchronous cutting and controlled release not only solves the problem of low efficiency in single-strand cutting, but also ensures the symmetrical release of energy of the entire steel strand 70 through synchronous cutting. Then, through energy dissipation by the energy dissipation device 230 and the internal force transfer and release by the tensioning system 40, a smooth and safe cutting effect is achieved.

[0073] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A system for removing externally prestressed steel strands, characterized in that, include: A cutting device (10) is used to cut the steel strand (70) at the cutting point of the steel strand (70) to be cut; Vibration damping system (20), the vibration damping system (20) includes: Two constraint rings (210) are used to constrain and fix the steel strand (70) on both sides of the cutting point; The V-shaped frame includes two connecting rods (220), one end of each connecting rod (220) is hinged to a corresponding constraint ring (210), and the other ends of the two connecting rods (220) are hinged to each other. Energy dissipation device (230), the two ends of which are respectively hinged to the two connecting rods (220), the energy dissipation device (230) is used to absorb the energy released by the steel strand (70) when the steel strand (70) retracts and causes the V-shaped frame to deform.

2. The external prestressed steel strand removal system according to claim 1, characterized in that, The constraint ring (210) includes two semi-circular constraint buckles (211), one end of the two semi-circular constraint buckles (211) is movably connected, and the other end of the two semi-circular constraint buckles (211) is connected by a bolt (212) or a snap fastener.

3. The external prestressed steel strand removal system according to claim 2, characterized in that, A friction washer (240) is provided on the inner wall of the semi-circular constraint buckle (211), and the semi-circular constraint buckle (211) is connected to the steel bundle (70) through the friction washer (240).

4. The external prestressed steel strand removal system according to claim 1, characterized in that, The energy-consuming device (230) includes one of a hydraulic damper, a spring damper, a pulse damper, a rotary damper, a magnetorheological damper, or a viscous damper.

5. The external prestressed steel strand removal system according to claim 1, characterized in that, The cutting system also includes a protective system (30), which includes a protective cylinder (310). The protective cylinder (310) has a through hole on the opposite end wall for the steel strand (70) to pass through. The protective cylinder (310) is used to cover the outside of the steel strand (70), and the vibration damping system (20) and the cutting device (10) are located inside the protective cylinder (310).

6. The external prestressed steel strand removal system according to claim 5, characterized in that, The protective cylinder (310) includes two semi-circular cylinders (311), one end of the two semi-circular cylinders (311) is hinged, and the other end of the two semi-circular cylinders (311) is detachably connected by bolts (212) or buckles; The protective cylinder (310) is provided with a visualization window (330) for providing visualization, and / or the inner wall of the protective cylinder (310) is provided with a fixing hinge (320) for mounting the cutting device (10), and / or the protective cylinder (310) is provided with an operating hole for the cutting tool of the cutting device (10) to extend into.

7. The external prestressed steel strand removal system according to claim 1, characterized in that, The cutting device (10) includes one of hydraulically driven, electrically driven or gas-driven cutting devices (10).

8. The external prestressed steel strand removal system according to claim 1, characterized in that, The cutting system further includes a release system (40) for controllably releasing part of the prestress in the steel strand (70) before cutting, the release system (40) comprising: At least one pair of temporary cable clamps (410) that can be fastened to the steel strand (70), at least one pair of working anchor plates (420) that can be fastened to the steel strand (70), a working bundle (440) that passes through the working anchor plates (420) and the temporary cable clamps (410), and a tensioning device (430) for tensioning the working bundle (440).

9. The external prestressed steel strand removal system according to claim 8, characterized in that, The cutting system further includes a remote monitoring system (50) and a remote control system (60), wherein the remote monitoring system (50) is used to monitor the prestress of the steel strand (70) during the prestress release process, and the remote control system (60) is used to remotely control the cutting device (10) and / or the tension release system (40).

10. A method for removing an externally prestressed tendon (70) using an externally prestressed tendon removal system as described in any one of claims 1-9, comprising: A vibration damping system (20) is installed on the steel strand (70) to be cut, and two constraint rings (210) are fixed to both sides of the cutting point of the steel strand (70). A V-shaped frame is installed between the two constraint rings (210), and an energy dissipation device (230) is installed between the two connecting rods (220) of the V-shaped frame. The steel bundle (70) is cut at the cutting point using a cutting device (10) to cut the steel bundle (70).

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