Highway negative bending moment bridge flat anchor overall tension structure and tension method

Abstract

This invention relates to the field of transportation bridge engineering technology, and in particular provides a flat anchor integral tensioning structure and tensioning method for highway negative bending moment bridges. The flat anchor integral tensioning structure for highway negative bending moment bridges includes two CNC main units, two anchor plates, and two symmetrically arranged tensioning jacks. This invention implements intelligent and precise construction of bridge prestressing tensioning, enabling real-time tracking and timely error correction throughout the prestressing tensioning process. It essentially eliminates the low measurement accuracy of traditional tensioning methods, effectively controls the magnitude of prestress under the anchor, improves construction technology and standardizes the tensioning process, enhances the quality of prestressing construction, ensures the safety and durability of the bridge structure, and reduces the total life-cycle cost of the bridge. Simultaneously, it achieves rapid, convenient, and quick fixing and clamping of the pre-embedded steel strands, ensuring the stability and reliability of the pre-embedded steel strand tensioning during construction.

Description

Technical Field

[0001] This invention relates to the field of transportation beam bridge engineering technology, and in particular provides a flat anchor integral tensioning structure and tensioning method for highway negative bending moment bridges. Background Technology

[0002] Extensive surveys and inspections of prestressed bridges in service reveal that a significant portion of their quality issues stem from improper prestressing tensioning construction and a lack of effective quality control measures. Improving and refining construction equipment to ensure effective prestressing tensioning, and controlling the entire prestressing process for bridges, have become critical issues requiring urgent attention. However, traditional prestressing tensioning control methods cannot guarantee synchronization accuracy or ensure proper tensioning and tightening of the prestressed steel bars, easily leading to retraction and severely impacting the establishment of effective prestress. Summary of the Invention

[0003] Therefore, it is necessary to provide a flat anchor integral tensioning structure for highway negative bending moment bridges to solve at least one of the technical problems in the background art.

[0004] A flat anchor integral tensioning structure for a negative bending moment bridge on a highway includes two CNC main units, two anchor plates, and two symmetrically arranged tensioning jacks. Each CNC main unit includes a system main unit, an oil pump, and a CNC center. The system main unit is placed on the negative bending moment bridge, and the oil pump and CNC center are located inside the system main unit. The CNC center is used to control the tension force output by the oil pump and automatically record data and generate reports. An oil inlet pipe and an oil return pipe are protruding on one side of the oil pump. The negative bending moment bridge has multiple steel strand channels recessed along its length. Each negative bending moment bridge has two tensioning slots recessed on its top surface, and the two tensioning slots are arranged opposite each other. A grouting port is recessed through the top of each steel strand channel, and pre-embedded steel strands are installed in each of the multiple steel strand channels. Anchors are also installed on the pre-embedded steel strands, and the two ends of the pre-embedded steel strands are respectively protruding into the two tensioning slots. The anchor plate has multiple channels recessed at equal intervals along the length direction. The multiple channels are respectively arranged opposite to multiple pre-embedded steel strands. The anchor plate is installed at one end of multiple pre-embedded steel strands through the multiple channels, and the outer sidewall of the anchor plate abuts against the inner sidewall of the tensioning slot. Each tensioning jack includes a fastener, a hydraulic drive assembly and two clamping assemblies. The fastener has a pad groove recessed on its outer side. The fastener is installed on the inner side of the anchor plate through the pad groove. The hydraulic drive assembly is fixedly installed on the inner side of the fastener. The two clamping assemblies are fixedly installed at both ends of the middle part of the hydraulic drive assembly, and both clamping assemblies are clamped at one end of multiple pre-embedded steel strands.

[0005] As a further improvement of the present invention, the inner sidewall of the anchor plate is provided with a sleeve mounting strip, and the inner sidewall of the sleeve mounting strip is provided with a plurality of mounting sleeves at equal intervals along the length direction. A conical hole is recessed through the middle of the inner sidewall of each mounting sleeve. The plurality of conical holes are respectively arranged opposite to and connected with a plurality of channels, and the cross-sectional area of ​​each conical hole gradually decreases from the outside to the inside. Each mounting sleeve is made of elastic material.

[0006] As a further improvement of the present invention, the fastener includes a fastening plate and two hydraulic mounting plates. A pad groove is recessed in the middle of the outer sidewall of the fastening plate. The pad groove is recessed with multiple sleeve mounting holes at equal intervals along the length direction. The multiple sleeve mounting holes are respectively arranged opposite to multiple mounting sleeves. One end of the two hydraulic mounting plates is fixedly installed in the middle of the top surface and bottom surface of the fastening plate, and the two hydraulic mounting plates are arranged opposite to each other. The bottom ends of the hydraulic mounting plates arranged on the bottom surface of the fastening plate are respectively provided with slide rod mounting plates.

[0007] As a further improvement of the present invention, the hydraulic drive assembly includes an upper hydraulic drive cylinder, a lower hydraulic drive cylinder, and two synchronous hydraulic pipes. The output shaft of the upper hydraulic drive cylinder is fixedly connected to the inner side wall of the hydraulic mounting plate disposed on the top surface of the fastening plate. The output shaft of the lower hydraulic drive cylinder is fixedly connected to the inner side wall of the other hydraulic mounting plate. The two ends of the two synchronous hydraulic pipes are respectively fixedly installed on the two ends of one side wall of the upper hydraulic drive cylinder and the lower hydraulic drive cylinder. The two synchronous hydraulic pipes are arranged opposite to each other, so that the upper hydraulic drive cylinder and the lower hydraulic drive cylinder are interconnected. A connecting valve is protruding from the top of each of the two synchronous hydraulic pipes. One end of the two connecting valves is respectively fixedly installed on one end of the oil inlet pipe and the oil return pipe.

[0008] As a further improvement of the present invention, sliding mounting blocks are respectively provided on both sides of the bottom of the lower hydraulic drive cylinder near the fastener. Each sliding mounting block has a sliding hole through one side wall. Telescopic rod mounting blocks are respectively provided on both sides of the bottom of the lower hydraulic drive cylinder away from the fastener. The two telescopic rod mounting blocks are respectively arranged opposite to the two sliding mounting blocks. Each telescopic rod mounting block is provided with a guide telescopic rod on the side wall near the fastener. The guide telescopic rod is fixedly installed at the bottom of the slide rod mounting plate through the sliding hole at one end near the fastener. An installation ring is provided on the outer wall of the guide telescopic rod near the end of the telescopic rod mounting block.

[0009] As a further improvement of the present invention, each clamp assembly includes a clamp mounting strip, two limiting sliders, and two clamping elements. The top surface of the clamp mounting strip is fixedly mounted at the middle of the bottom end of the upper hydraulic drive cylinder, and the bottom surface of the clamp mounting strip is fixedly mounted at the middle of the top end of the lower hydraulic drive cylinder. A pre-set groove is recessed through one side wall of the clamp mounting strip, and mounting sliding grooves are recessed at the bottom and top of the pre-set groove. Threaded holes and steel rope holes are recessed through the end walls of both ends of the clamp mounting strip, respectively. The threaded holes and steel rope holes are arranged vertically opposite each other, and the two threaded holes are staggered vertically. The two threaded holes and two steel rope holes are respectively connected to the two mounting sliding grooves. The outer sides of the two limiting sliders are slidably mounted in the two mounting sliding grooves. The inner side walls of the two limiting sliders are recessed at the ends away from the threaded holes, and the two clamping elements are respectively mounted in the two clamping mounting grooves.

[0010] As a further improvement of the present invention, a lifting and mounting ring is provided at the middle of both ends of the clamp mounting strip, and a threaded rod is provided in each threaded hole. One end of the threaded rod protrudes outside the clamp mounting strip, and the other end of the threaded rod is rotatably connected to the limiting slider.

[0011] As a further improvement of the present invention, the clamping element includes a clamping mounting slide plate, multiple jaws and multiple pulleys. The outer sidewall of the clamping mounting slide plate is slidably mounted in the clamping mounting groove. The inner sidewall of the clamping mounting slide plate is provided with multiple jaw mounting platforms at equal intervals along the length direction. The multiple jaw mounting platforms are respectively arranged opposite to multiple sleeve mounting holes. The multiple jaws are respectively fixedly mounted on the multiple jaw mounting platforms. The multiple pulleys are respectively installed at intervals along the length direction on the inner sidewall of the clamping mounting slide plate. The pulleys are respectively located between two jaws, and the pulleys on the two clamping elements are staggered.

[0012] As a further improvement of the present invention, each gripper includes a long arc portion and a short arc portion. The long arc portion is fixedly installed on one side of the gripper mounting table, and the short arc portion is fixedly installed on the other side. A smooth transition arc surface is formed between the inner sidewall of the long arc portion and the inner sidewall of the short arc portion. The height of the long arc portion is greater than the height of the short arc portion. The grippers of the two clamping elements are arranged in a circumferential array. The top end of the long arc portion of one gripper abuts against the top end of the short arc portion of the other gripper, so that a circular covering space is formed between the two grippers. The covering space is arranged opposite to the sleeve mounting hole.

[0013] As a further improvement of the present invention, a rope ring is protruding from the end of the clamp mounting slide away from the threaded hole. An elastic rope is provided on the rope ring. The other end of the elastic rope passes through the steel rope hole and is fixedly installed in the mounting ring or the slide bar mounting plate. Each clamp has an arc-shaped groove recessed in it. An elastic band is also provided in the steel rope hole. One end of the elastic band is fixedly installed in the mounting ring or the slide bar mounting plate. The other end of the elastic band passes through the arc-shaped groove on the opposite clamp and the pulley on the same side, and is finally fixedly installed in the arc-shaped groove on the clamp opposite to the side away from the steel rope hole.

[0014] This invention also provides a method for integral tensioning of flat anchors on highway negative bending moment bridges, employing the aforementioned integral tensioning structure for flat anchors on highway negative bending moment bridges.

[0015] The beneficial effects of this invention are as follows:

[0016] 1. This invention can significantly improve construction efficiency, greatly increase the pass rate of effective prestressing force under anchors, ensure construction quality, and avoid economic losses caused by rework due to quality problems requiring negative moment tensioning. It provides a reference for the construction of similar or related structures in the future, especially showing a more significant application effect on negative moment tensioning of box girder top slabs with low prestress, and has good social benefits in accelerating project construction and ensuring project quality.

[0017] 2. This invention implements a refined construction technology for intelligent prestressed bridge tensioning, enabling real-time, full-process tracking, intelligent control, and timely error correction of prestressing tensioning. It essentially eliminates the problems associated with low measurement accuracy in manual tensioning, which can lead to personnel injuries and safety accidents. It also reduces the impact of environmental and human factors, effectively controls the magnitude of prestress under the anchor, improves construction techniques and standardizes the tensioning process, enhances the quality of prestressed construction, ensures the safety and durability of the bridge structure, and reduces the total life-cycle cost of the bridge.

[0018] 3. This invention, through the cooperation of a hydraulic drive assembly and two clamping assemblies, achieves rapid, convenient, and quick fixing and clamping of the pre-embedded steel strands, ensuring the stability and reliability of the tensioning of the pre-embedded steel strands during construction, and improving construction efficiency and quality. Simultaneously, the clamping assemblies and elastic bands ensure that the jaws fit more tightly against the outer wall of the pre-embedded steel strands, resulting in a more secure clamping and effectively preventing slippage of the pre-embedded steel strands. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a structure according to an embodiment of the present invention.

[0020] Figure 2 This is a three-dimensional schematic diagram of a tensioning jack in one embodiment of the present invention.

[0021] Figure 3 This is a three-dimensional schematic diagram of a tensioning jack in another embodiment of the present invention.

[0022] Figure 4 This is a schematic diagram of the internal structure of a tensioning jack in one embodiment of the present invention.

[0023] Figure 5 for Figure 4 Enlarged view of point A in the middle.

[0024] Figure 6This is a schematic diagram of the internal structure of a clamping assembly according to an embodiment of the present invention.

[0025] Figure 7 This is a three-dimensional schematic diagram of an anchor plate in one embodiment of the present invention.

[0026] Figure 8 This is a cross-sectional view of a clamp assembly according to an embodiment of the present invention.

[0027] In the picture:

[0028] 10. CNC machine tool; 11. Oil inlet pipe; 12. Oil return pipe; 13. Tensioning slot; 19. Embedded steel strand; 20. Tensioning jack; 60. Anchor plate; 61. Duct; 62. Sleeve installation strip; 63. Installation sleeve; 50. Fastener; 51. Pad groove; 511. Sleeve installation hole; 52. Fastener plate; 53. Hydraulic mounting plate; 54. Slide rod mounting plate; 30. Hydraulic drive assembly; 31. Upper hydraulic drive cylinder; 32. Lower hydraulic drive cylinder; 321. Sliding mounting block; 322. Sliding hole; 323. Telescopic rod mounting block; 324. Guide telescopic rod; 325. Mounting ring; 3 3. Synchronous hydraulic pipe; 331. Connecting valve; 40. Clamp assembly; 41. Clamp mounting strip; 411. Preset groove; 412. Mounting sliding groove; 413. Threaded hole; 414. Steel rope hole; 415. Clamp mounting slide; 416. Lifting mounting ring; 417. Threaded rod; 42. Limiting slider; 43. Clamp element; 431. Clamp mounting slide plate; 432. Gripper; 433. Pulley; 434. Gripper mounting platform; 435. Long arc section; 436. Short arc section; 437. Transition arc surface; 438. Arc-shaped slide; 439. Elastic band; 430. Enclosure space; 441. Rope ring. Detailed Implementation

[0029] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0030] In the description of this invention, it should be noted that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention 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. Therefore, they should not be construed as limitations on this invention.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0032] Please see Figures 1 to 8 A flat anchor integral tensioning structure for a negative bending moment bridge on a highway includes two CNC main units 10, two anchor plates 60, and two symmetrically arranged tensioning jacks 20. Each CNC main unit 10 includes a system main unit, an oil pump, and a CNC center. The system main unit is placed on the negative bending moment bridge, and the oil pump and CNC center are located inside the system main unit. The CNC center is used to control the tension force output by the oil pump and automatically record data and generate reports. An oil inlet pipe 11 and an oil return pipe 12 are respectively protruding on one side of the oil pump. The negative bending moment bridge has multiple steel strand channels recessed along its length. The top surface of the negative bending moment bridge has two tensioning slots 13 recessed, and the two tensioning slots 13 are arranged opposite each other. A grouting port is recessed through the top of each steel strand channel. Pre-embedded steel strands 19 are set in each of the multiple steel strand channels. Anchorages are also set on the pre-embedded steel strands 19. Both ends of the steel strand 19 protrude from the two tensioning slots 13. The anchor plate 60 has multiple recessed channels 61 equidistantly through it along its length. The multiple channels 61 are respectively arranged opposite to the multiple pre-embedded steel strands 19. The anchor plate 60 is clamped and installed at one end of the multiple pre-embedded steel strands 19 through the multiple channels 61, and the outer sidewall of the anchor plate 60 abuts against the inner sidewall of the tensioning slot 13. Each tensioning jack 20 includes a fastener 50, a hydraulic drive assembly 30 and two clamping assemblies 40. The fastener 50 has a recessed pad groove 51 on its outer side. The fastener 50 is sleeved and installed on the inner side of the anchor plate 60 through the pad groove 51. The hydraulic drive assembly 30 is fixedly installed on the inner side of the fastener 50. The two clamping assemblies 40 are fixedly installed at both ends of the middle part of the hydraulic drive assembly 30, and both clamping assemblies 40 are clamped at one end of the multiple pre-embedded steel strands 19.

[0033] An anchor plate 60 has a protruding mounting strip 62 on its inner sidewall. The inner sidewall of the mounting strip 62 has multiple mounting sleeves 63 protruding at equal intervals along its length. Each mounting sleeve 63 has a concave ...

[0034] The fastener 50 includes a fastening plate 52 and two hydraulic mounting plates 53. A pad groove 51 is recessed in the middle of the outer sidewall of the fastening plate 52. The pad groove 51 is recessed with multiple sleeve mounting holes 511 at equal intervals along the length direction. The multiple sleeve mounting holes 511 are respectively arranged opposite to multiple mounting sleeves 63. One end of the two hydraulic mounting plates 53 is fixedly installed in the middle of the top and bottom surfaces of the fastening plate 52, and the two hydraulic mounting plates 53 are arranged opposite to each other. The bottom ends of the hydraulic mounting plates 53 on the bottom surface of the fastening plate 52 are respectively provided with slide rod mounting plates 54.

[0035] The hydraulic drive assembly 30 includes an upper hydraulic drive cylinder 31, a lower hydraulic drive cylinder 32, and two synchronous hydraulic pipes 33. The output shaft of the upper hydraulic drive cylinder 31 is fixedly connected to the inner side wall of the hydraulic mounting plate 53 located on the top surface of the fastening plate 52. The output shaft of the lower hydraulic drive cylinder 32 is fixedly connected to the inner side wall of the other hydraulic mounting plate 53. The two ends of the two synchronous hydraulic pipes 33 are respectively fixedly installed on the two ends of one side wall of the upper hydraulic drive cylinder 31 and the lower hydraulic drive cylinder 32. The two synchronous hydraulic pipes 33 are arranged opposite to each other, so that the upper hydraulic drive cylinder 31 and the lower hydraulic drive cylinder 32 are interconnected. A connecting valve 331 is protruding from the top of each of the two synchronous hydraulic pipes 33. One end of the two connecting valves 331 is respectively fixedly installed on one end of the oil inlet pipe 11 and the oil return pipe 12.

[0036] The lower hydraulic drive cylinder 32 has sliding mounting blocks 321 protruding on both sides of the bottom end near the fastener 50. Each sliding mounting block 321 has a sliding hole 322 recessed through one side wall. The lower hydraulic drive cylinder 32 has telescopic rod mounting blocks 323 protruding on both sides of the bottom end away from the fastener 50. The two telescopic rod mounting blocks 323 are respectively arranged opposite to the two sliding mounting blocks 321. Each telescopic rod mounting block 323 has a guide telescopic rod 324 on the side wall near the fastener 50. The guide telescopic rod 324 is fixedly installed at the bottom of the slide rod mounting plate 54 through the sliding hole 322 at one end near the fastener 50. The outer wall of the guide telescopic rod 324 has a mounting ring 325 protruding at one end near the telescopic rod mounting block 323.

[0037] Each clamp assembly 40 includes a clamp mounting strip 41, two limit sliders 42, and two clamping elements 43. The top center of the clamp mounting strip 41 is fixedly mounted to one bottom end of the upper hydraulic drive cylinder 31, and the bottom center of the clamp mounting strip 41 is fixedly mounted to one top end of the lower hydraulic drive cylinder 32. A pre-set groove 411 is recessed through one side wall of the clamp mounting strip 411, and mounting sliding grooves 412 are recessed at both the bottom and top of the pre-set groove 411. Threaded holes 413 and steel rope holes are respectively recessed through the end walls of both ends of the clamp mounting strip 41. 414, the threaded hole 413 and the steel rope hole 414 are arranged vertically opposite each other, and the two threaded holes 413 are staggered vertically. The two threaded holes 413 and the two steel rope holes 414 are respectively connected to the two mounting sliding grooves 412. The outer sides of the two limiting sliders 42 are slidably installed in the two mounting sliding grooves 412. The inner sidewalls of the two limiting sliders 42 are recessed at the end away from the threaded hole 413, and the two clamping elements 43 are respectively installed in the two clamping mounting grooves 415.

[0038] The clamp mounting strip 41 has a lifting mounting ring 416 protruding from the middle of both ends. Each threaded hole 413 is provided with a threaded rod 417. One end of the threaded rod 417 protrudes from the clamp mounting strip 41, and the other end of the threaded rod 417 is rotatably connected to the limit slider 42.

[0039] The clamping element 43 includes a clamping mounting slide plate 431, multiple jaws 432, and multiple pulleys 433. The outer sidewall of the clamping mounting slide plate 431 is slidably mounted in the clamping mounting groove 415. The inner sidewall of the clamping mounting slide plate 431 is provided with multiple jaw mounting platforms 434 at equal intervals along the length direction. The multiple jaw mounting platforms 434 are respectively arranged opposite to multiple sleeve mounting holes 511. The multiple jaws 432 are respectively fixedly mounted on the multiple jaw mounting platforms 434. The multiple pulleys 433 are respectively installed at intervals along the length direction on the inner sidewall of the clamping mounting slide plate 431. The pulleys 433 are respectively located between two jaws 432, and the pulleys 433 on the two clamping elements 43 are staggered.

[0040] Each gripper 432 includes a long arc portion 435 and a short arc portion 436. The long arc portion 435 is fixedly installed on one side of the gripper mounting table 434, and the short arc portion 436 is fixedly installed on the other side. A smooth transition arc surface 437 is formed between the inner sidewall of the long arc portion 435 and the inner sidewall of the short arc portion 436. The height of the long arc portion 435 is greater than the height of the short arc portion 436. The grippers 432 of the two clamping elements 43 are arranged in a circumferential array. The top end of the long arc portion 435 of one gripper 432 will abut against the top end of the short arc portion 436 of the other gripper 432, so that a circular covering space 430 is formed between the two grippers 432. The covering space 430 is arranged opposite to the sleeve mounting hole 511.

[0041] The clamp mounting slide plate 431 has a rope ring 441 protruding from one end away from the threaded hole 413. An elastic rope is provided on the rope ring 441. The other end of the elastic rope passes through the steel rope hole 414 and is fixedly installed in the mounting ring 325 or the slide bar mounting plate 54. Each jaw 432 has an arc-shaped groove 438 recessed in it. An elastic band 439 is also provided in the steel rope hole 414. One end of the elastic band 439 is fixedly installed in the mounting ring 325 or the slide bar mounting plate 54. The other end of the elastic band 439 passes through the arc-shaped groove 438 on the opposite jaw 432 and the pulley 433 on the same side, and is finally fixedly installed in the arc-shaped groove 438 on the opposite jaw 432 away from the steel rope hole 414.

[0042] For example, in one embodiment: before tensioning, the anchor plate 60 and the duct 61 should be checked to ensure that the position of the anchor plate 60 is accurate, and that the multiple ducts 61 are respectively set opposite to the multiple pre-embedded steel strands 19 and that the ducts 61 are unobstructed and free of water and other debris. Anchor plates 60 are installed at one end of multiple pre-embedded steel strands 19 through multiple holes 61, with the outer sidewall of anchor plates 60 abutting against the inner sidewall of tensioning slot 13, keeping the ends of the multiple pre-embedded steel strands 19 straight. Tensioning jacks 20 are installed on lifting equipment through the lifting rings 416 at both ends of two clamping assemblies 40. Tensioning jacks 20 are moved into tensioning slot 13, with multiple sleeve mounting holes 511 respectively positioned opposite to multiple mounting sleeves 63, and fasteners 50 positioned adjacent to anchor plates 60. The ends of the pre-embedded steel strands 19 are sequentially passed through the sleeve mounting holes 511 and two covering spaces 430, so that tensioning jacks 20 are fitted onto the ends of the multiple pre-embedded steel strands 19, and the tensioning jacks 20 should only be dragged back and forth, and should not be twisted. Subsequently, the tensioning jack 20 is pushed to one side of the anchor plate 60, so that the mounting strip 62 is fitted into the plate groove 51, and multiple mounting sleeves 63 are fitted into multiple sleeve mounting holes 511.

[0043] Subsequently, a pneumatic wrench is used to simultaneously tighten the two threaded rods 417 on the clamp assembly 40, causing the threaded rods 417 to move along the threaded holes 413 toward the center of the clamp assembly 40. This causes the two limiting sliders 42 to move synchronously and alternately along the mounting sliding grooves 412, causing the two clamping elements 43 to move alternately. Consequently, the two grippers 432 move synchronously and alternately. Since the height of the long arc portion 435 is greater than the height of the short arc portion 436, the grippers 432 of the two clamping elements 43 are arranged in a circumferential array, which causes the covering space 430 to deform. This causes the long arc portion 435 and the transition arc surface 437 on the two grippers 432 to alternately squeeze and cover the pre-embedded steel strands 19, allowing the clamp assembly 40 to quickly and conveniently clamp multiple pre-embedded steel strands 19 simultaneously.

[0044] Subsequently, the oil pump will be started, and high-pressure hydraulic oil will flow from the inlet pipe 11 to one of the connecting valves 331, and then simultaneously enter the upper hydraulic drive cylinder 31 and the lower hydraulic drive cylinder 32 through the connecting valve 331 and the synchronous hydraulic pipe 33. It will then return to the oil pump from the other synchronous hydraulic pipe 33 through the connecting valve 331 and the return pipe 12, causing the two symmetrically arranged tension jacks 20 to generate tension force. This causes the output shafts of the upper hydraulic drive cylinder 31 and the lower hydraulic drive cylinder 32 to extend, thus extending the output shafts of the upper hydraulic drive cylinder 31 and the lower hydraulic drive cylinder 32. The moving cylinder 32 moves the drive fastener 50 away from the hydraulic drive assembly 30, and the tension force is much greater than the anchor plate 60 clamping force, which will gradually tighten the pre-embedded steel strand 19 and make the anchor on the pre-embedded steel strand 19 secure in the steel strand channel until the controlled tension stress value is reached. Then, the actual elongation of the end of the pre-embedded steel strand 19 is measured, and the error between the actual elongation and the design tension value should be controlled within 6%. Otherwise, tensioning should be suspended until the cause is found and measures are taken to adjust it before tensioning can continue.

[0045] After the tension reaches the controlled tension stress value, hold the load for 5 minutes and then anchor, and promptly fill in the tension record. The tension record should be accurate and valid, measured by the on-site operator. After anchoring according to regulations, slowly return the oil and unload the machine, then reset the entire machine for the next tensioning.

[0046] Subsequently, cement grout is mixed at the grouting port and poured into the steel strand duct for grouting. Grouting should be carried out slowly and evenly without interruption. A piston-type grouting pump should be used to pump the cement grout into the steel strand duct. Grouting should continue until the duct is full and grout discharge occurs, with the discharge grout having the same consistency as the specified cement grout. To ensure the pipeline is filled with cement grout, a stabilization period of not less than 2 minutes should be maintained after closing the grouting port. The grout stop nozzle can only be removed after the cement grout has solidified for 10 minutes.

[0047] Meanwhile, during and within 48 hours after grouting, the temperature of the bridge under negative bending moment must not be lower than 5℃. When the air temperature is higher than 35℃, grouting work should be carried out at night. After grouting, the compactness of the grout should be checked promptly; any deficiencies should be addressed and corrected immediately. During grouting, at least three sets of test specimens should be taken from each work shift, cured under standard conditions for 28 days, and their compressive strength should be checked as a basis for evaluating the quality of the cement grout. Anchor sealing should be carried out after grouting.

[0048] For example, in one embodiment: when the drive latch 50 moves away from the hydraulic drive assembly 30, the elastic rope extends synchronously, causing the two clamp mounting slides 431 to continue to generate an alternating force, further increasing the alternating force of the two grippers 432, making the two grippers 432 clamp the pre-embedded steel bundle 19 more securely, and causing the elastic band 439 to move outward synchronously. Furthermore, because the other end of the elastic band 439 repeatedly passes through the arc on the opposite gripper 432... The shaped groove 438 and the pulley 433 on the same side are finally fixedly installed in the arc-shaped groove 438 on the gripper 432 on the opposite side away from the steel rope hole 414. When the elastic band 439 moves outward, the elastic band 439 will cover the long arc portion 435 through the arc-shaped groove 438 and generate an upward pulling force, so that the long arc portion 435 fits more tightly against the outer wall of the pre-embedded steel strand 19, and the gripper 432 clamps the pre-embedded steel strand 19 more firmly, effectively preventing the pre-embedded steel strand 19 from slipping.

[0049] For example, in one embodiment: before tensioning, the concrete records of the negative bending moment bridge need to be checked. The concrete age of the negative bending moment bridge should be no less than 7 days, and the concrete strength should be no less than 90% of the design strength, and the elastic modulus should be no less than 90% of the 28-day elastic modulus of the concrete before tensioning can proceed. Subsequently, tensioning parameters are input at the CNC center. These parameters include the number of pre-embedded steel strands 19, the regression equation of the tensioning jack, the tension force of a single pre-embedded steel strand 19, and the theoretical elongation of the pre-embedded steel strand 19. The computer system automatically calculates the tension force to obtain the control tension stress value.

[0050] During tensioning, two tensioning jacks 20 should be started simultaneously, and both jacks 20 should be under dual control: primarily controlling the tension stress value, and secondarily controlling the elongation value of the embedded steel strand 19, with mutual verification. The relative error between the measured elongation value and the theoretical elongation value should be controlled within ±6%, and the tension force should meet the design requirements. Otherwise, tensioning should be stopped immediately, the cause analyzed, and appropriate measures taken to resolve the issue.

[0051] Installation process: Anchor plates 60 are installed at one end of multiple pre-embedded steel strands 19 through multiple holes 61, with the outer sidewall of anchor plates 60 abutting against the inner sidewall of tensioning slots 13. Installation strips 62 are fitted into the pad grooves 51, and multiple installation sleeves 63 are fitted into multiple sleeve installation holes 511. Two hydraulic mounting plates 53 are fixedly installed at one end on the top and bottom surfaces of the fastening plate 52, respectively, with the two hydraulic mounting plates 53 facing each other. The output shaft of the upper hydraulic drive cylinder 31 is fixedly connected to the inner sidewall of the hydraulic mounting plate 53 located on the top surface of the fastening plate 52. The output shaft of the lower hydraulic drive cylinder 32 is connected to another hydraulic mounting plate 53. The inner sidewall of the mounting plate 53 is fixedly connected. The two ends of the two synchronous hydraulic pipes 33 are respectively fixedly installed on the two ends of one sidewall of the upper hydraulic drive cylinder 31 and the lower hydraulic drive cylinder 32. The two synchronous hydraulic pipes 33 are arranged opposite to each other, so that the upper hydraulic drive cylinder 31 and the lower hydraulic drive cylinder 32 are interconnected. One end of the two connecting valves 331 is respectively fixedly installed on one end of the oil inlet pipe 11 and the oil return pipe 12. The guide telescopic rod 324 is passed through the sliding hole 322 and fixedly installed on the bottom of the slide rod mounting plate 54 near the fastener 50. The middle of the top surface of the clamp mounting strip 41 is fixedly installed on one end of the bottom of the upper hydraulic drive cylinder 31. The middle of the bottom surface of the clamp mounting strip 41 is fixedly installed on the bottom of the upper hydraulic drive cylinder 31. Fixedly installed at one end of the top of the lower hydraulic drive cylinder 32, two limiting sliders 42 are slidably installed in two mounting sliding grooves 412 on their outer sides. One end of the threaded rod 417 is rotatably connected to the limiting slider 42, and the outer sidewall of the clamp mounting slide plate 431 is slidably installed in the clamp mounting groove 415. Multiple pulleys 433 are installed at intervals along the length direction on the inner sidewall of the clamp mounting slide plate 431. The pulleys 433 are located between the two grippers 432, and the pulleys 433 on the two clamping elements 43 are staggered. The long arc portion 435 is fixedly installed on one side of the gripper mounting platform 434, and the short arc portion 436 is fixedly installed on the other side. A smooth transition arc surface 437 is formed between the inner sidewall of the long arc portion 435 and the inner sidewall of the short arc portion 436. The height of the long arc portion 435 is greater than the height of the short arc portion 436. The top of the long arc portion 435 in one of the grippers 432 will abut against the top of the short arc portion 436 in the other gripper 432. One end of the elastic rope is threaded through the steel rope hole 414 and fixedly installed in the mounting ring 325 or the slide bar mounting plate 54. One end of the elastic band 439 is repeatedly threaded through the arc-shaped groove 438 on the opposite gripper 432 and the pulley 433 on the same side, and finally fixedly installed in the arc-shaped groove 438 on the gripper 432 on the opposite side away from the steel rope hole 414.

[0052] This invention can achieve:

[0053] 1. This invention can significantly improve construction efficiency, greatly increase the pass rate of effective prestressing force under anchors, ensure construction quality, and avoid economic losses caused by rework due to quality problems requiring negative moment tensioning. It provides a reference for the construction of similar or related structures in the future, especially showing a more significant application effect on negative moment tensioning of box girder top slabs with low prestress, and has good social benefits in accelerating project construction and ensuring project quality.

[0054] 2. This invention implements a refined construction technology for intelligent prestressed bridge tensioning, enabling real-time, full-process tracking, intelligent control, and timely error correction of prestressing tensioning. It essentially eliminates the problems associated with low measurement accuracy in manual tensioning, which can lead to personnel injuries and safety accidents. It also reduces the impact of environmental and human factors, effectively controls the magnitude of prestress under the anchor, improves construction techniques and standardizes the tensioning process, enhances the quality of prestressed construction, ensures the safety and durability of the bridge structure, and reduces the total life-cycle cost of the bridge.

[0055] 3. This invention, through the cooperation of the hydraulic drive assembly 30 and two clamping assemblies 40, achieves rapid, convenient, and quick fixing and clamping of the pre-embedded steel strand 19, ensuring the stability and reliability of the tensioning of the pre-embedded steel strand during construction, and improving construction efficiency and quality. Simultaneously, the clamping assembly 40 and the elastic band 439 ensure that the grippers 432 fit more tightly against the outer wall of the pre-embedded steel strand 19, making the clamping of the pre-embedded steel strand 19 more secure and effectively preventing slippage of the pre-embedded steel strand 19.

[0056] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. A flat anchor integral tensioning structure for a highway negative bending moment bridge, characterized in that: The system includes two CNC main units (10), two anchor plates (60), and two symmetrically arranged tensioning jacks (20). Each CNC main unit (10) includes a system main unit, an oil pump, and a CNC center. The system main unit is placed on the negative moment bridge. The oil pump and CNC center are located inside the system main unit. The CNC center is used to control the tension force output by the oil pump and automatically record data and generate reports. An oil inlet pipe (11) and an oil return pipe (12) are respectively protruding on one side of the oil pump. The negative moment bridge has multiple steel strand channels recessed along its length. The top surface of the negative moment bridge has two tensioning slots (13) recessed, and the two tensioning slots (13) are arranged opposite to each other. A grouting port is recessed through the top of each steel strand channel. Pre-embedded steel strands (19) are set in multiple steel strand channels. Anchors are also set on the pre-embedded steel strands (19), and the two ends of the pre-embedded steel strands (19) are respectively protruding in the two tensioning slots (13). Anchor plate (60) has multiple recessed channels (61) equidistantly through it along its length. The multiple channels (61) are respectively arranged opposite to multiple pre-embedded steel strands (19). Anchor plate (60) is installed at one end of multiple pre-embedded steel strands (19) through the multiple channels (61), and the outer sidewall of anchor plate (60) abuts against the inner sidewall of tensioning slot (13). Each tensioning jack (20) includes a fastener (50) and a hydraulic drive assembly (30). The fastener (50) and two clamping assemblies (40) are provided with a pad groove (51) on the outside of the fastener (50). The fastener (50) is sleeved and installed on the inside of the anchor plate (60) through the pad groove (51). The hydraulic drive assembly (30) is fixedly installed on the inside of the fastener (50). The two clamping assemblies (40) are fixedly installed at both ends of the middle part of the hydraulic drive assembly (30), and both clamping assemblies (40) are clamped at one end of multiple pre-embedded steel strands (19). An anchor plate (60) has a sleeve installation strip (62) protruding on its inner side wall. The sleeve installation strip (62) has multiple installation sleeves (63) protruding at equal intervals along its length. Each installation sleeve (63) has a concave ... The fastener (50) includes a fastening plate (52) and two hydraulic mounting plates (53). A pad groove (51) is recessed in the middle of the outer sidewall of the fastening plate (52). The pad groove (51) is recessed with multiple sleeve mounting holes (511) at equal intervals along the length direction. The multiple sleeve mounting holes (511) are respectively arranged opposite to multiple mounting sleeves (63). One end of the two hydraulic mounting plates (53) is fixedly installed in the middle of the top and bottom surfaces of the fastening plate (52), and the two hydraulic mounting plates (53) are arranged opposite to each other. The bottom ends of the hydraulic mounting plates (53) on the bottom surface of the fastening plate (52) are respectively provided with sliding rod mounting plates (54). The hydraulic drive assembly (30) includes an upper hydraulic drive cylinder (31), a lower hydraulic drive cylinder (32), and two synchronous hydraulic pipes (33). The output shaft of the upper hydraulic drive cylinder (31) is fixedly connected to the inner side wall of the hydraulic mounting plate (53) located on the top surface of the fastening plate (52). The output shaft of the lower hydraulic drive cylinder (32) is fixedly connected to the inner side wall of the other hydraulic mounting plate (53). The two ends of the two synchronous hydraulic pipes (33) are respectively fixedly installed on the two ends of one side wall of the upper hydraulic drive cylinder (31) and the lower hydraulic drive cylinder (32). The two synchronous hydraulic pipes (33) are arranged opposite to each other, so that the upper hydraulic drive cylinder (31) and the lower hydraulic drive cylinder (32) are connected to each other. A connecting valve (331) is protruding from the top of each of the two synchronous hydraulic pipes (33). One end of the two connecting valves (331) is fixedly installed on one end of the oil inlet pipe (11) and the oil return pipe (12). Each clamp assembly (40) includes a clamp mounting strip (41), two limit sliders (42), and two clamping elements (43). The top center of the clamp mounting strip (41) is fixedly mounted to one end of the bottom of the upper hydraulic drive cylinder (31), and the bottom center of the clamp mounting strip (41) is fixedly mounted to one end of the top of the lower hydraulic drive cylinder (32). A pre-set groove (411) is recessed through one side wall of the clamp mounting strip (411). The bottom and top of the pre-set groove (411) are both recessed with mounting sliding grooves (412). Threaded holes (413) and steel rope holes are respectively recessed through the end walls of both ends of the clamp mounting strip (41). (414), the threaded hole (413) and the steel rope hole (414) are arranged opposite each other, and the two threaded holes (413) are staggered. The two threaded holes (413) and the two steel rope holes (414) are respectively connected to the two mounting sliding grooves (412). The outer sides of the two limiting sliders (42) are slidably installed in the two mounting sliding grooves (412). The inner sidewalls of the two limiting sliders (42) are recessed at the end away from the threaded hole (413) and the two clamping elements (43) are respectively installed in the two clamping mounting grooves (415). The clamping element (43) includes a clamping mounting slide plate (431), multiple jaws (432) and multiple pulleys (433). The outer sidewall of the clamping mounting slide plate (431) is slidably mounted in the clamping mounting groove (415). The inner sidewall of the clamping mounting slide plate (431) is provided with multiple jaw mounting platforms (434) at equal intervals along the length direction. The multiple jaw mounting platforms (434) are respectively arranged opposite to multiple sleeve mounting holes (511). The multiple jaws (432) are respectively fixedly mounted on the multiple jaw mounting platforms (434). The multiple pulleys (433) are respectively installed at intervals along the length direction on the inner sidewall of the clamping mounting slide plate (431). The pulleys (433) are respectively located between two jaws (432), and the pulleys (433) on the two clamping elements (43) are staggered. Each gripper (432) includes a long arc portion (435) and a short arc portion (436). The long arc portion (435) is fixedly installed on one side of the gripper mounting table (434), and the short arc portion (436) is fixedly installed on the other side. A smooth transition arc surface (437) is formed between the inner sidewall of the long arc portion (435) and the inner sidewall of the short arc portion (436). The height of the long arc portion (435) is greater than the height of the short arc portion (436). The grippers (432) of the two clamping elements (43) are arranged in a circumferential array. The top end of the long arc portion (435) of one of the grippers (432) will abut against the top end of the short arc portion (436) of the other gripper (432), so that a circular covering space (430) is formed between the two grippers (432). The covering space (430) is arranged opposite to the sleeve mounting hole (511).

2. The integral tensioning structure of the flat anchor for a highway negative bending moment bridge according to claim 1, characterized in that: The lower hydraulic drive cylinder (32) has sliding mounting blocks (321) protruding on both sides of the bottom end near the fastener (50). Each sliding mounting block (321) has a sliding hole (322) through one side wall. The lower hydraulic drive cylinder (32) has telescopic rod mounting blocks (323) protruding on both sides of the bottom end away from the fastener (50). The two telescopic rod mounting blocks (323) are respectively arranged opposite to the two sliding mounting blocks (321). Each telescopic rod mounting block (323) has a guide telescopic rod (324) on the side wall near the fastener (50). The guide telescopic rod (324) is fixedly installed at the bottom of the slide rod mounting plate (54) through the sliding hole (322) at one end near the fastener (50). The outer wall of the guide telescopic rod (324) has a mounting ring (325) protruding at one end near the telescopic rod mounting block (323).

3. The integral tensioning structure of the flat anchor for a highway negative bending moment bridge according to claim 2, characterized in that: The clamp mounting strip (41) has a lifting mounting ring (416) protruding from the middle of both ends. Each threaded hole (413) is provided with a threaded rod (417). One end of the threaded rod (417) protrudes from the clamp mounting strip (41), and the other end of the threaded rod (417) is rotatably connected to the limiting slider (42).

4. A method for integral tensioning of flat anchors for highway negative bending moment bridges, using the integral tensioning structure of flat anchors for highway negative bending moment bridges as described in any one of claims 1 to 3.

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