Prestressed anchor cable tensioning method and device

Abstract

The present invention discloses a prestressed anchor cable tensioning method and device, which relates to the field of bridge anchor cable construction. The method includes a connection control system, the control system including a control device, the control device controlling an intelligent adjustment device to adjust the tension of a steel wire rope, and the control device including a display screen and a control chip. In the present invention, different sensors and intelligent adjustment devices are circumferentially arranged at different locations inside and outside a pier model to collect and measure the circumferential reinforcement effect of the steel wire rope on the pier model in multiple dimensions. Furthermore, the control system controls the intelligent adjustment device for the steel wire rope force to adjust the force of the steel wire rope, thereby achieving controlled simulation of the effect of the intelligent adjustment of the steel wire rope on the pier model. This provides quantitative and reliable data support and foundation for the actual engineering application of steel wire rope circumferential reinforcement of piers.

Description

Technical Field

[0001] The invention relates to the field of bridge anchor cable construction, and in particular to a prestressed anchor cable tensioning method and a device thereof. Background Art

[0002] Bridge piers are a crucial component of bridge structures, and their stability is directly related to the safety and service life of the bridge. With the rapid development of modern transportation, the loads borne by bridges are constantly increasing. Simultaneously, natural erosion (such as wind, rain, and earthquakes) also places higher demands on the stability of bridge piers. To improve the load-bearing capacity and disaster resistance of bridge piers, prestressed anchor cable reinforcement technology is widely used in bridge pier reinforcement projects.

[0003] The traditional prestressed anchor reinforcement method has the following problems:

[0004] First, stress monitoring is insufficient. Traditional methods have limited means of monitoring the tension of steel wire ropes, internal stress of piers, and surface stress, making it impossible to comprehensively and accurately assess the reinforcement effect.

[0005] Second, the adjustment accuracy is low. In actual engineering, the tension of the wire rope needs to be dynamically adjusted according to the actual stress conditions of the bridge pier. However, the traditional method lacks an effective intelligent adjustment device, making it difficult to achieve accurate cable tension adjustment.

[0006] Third: The construction is complicated. The installation and tensioning process of traditional prestressed anchor cables requires a lot of manual operation, which has low construction efficiency and is prone to uneven tensioning force or unreasonable stress distribution due to human factors.

[0007] Therefore, it is necessary to propose a prestressed anchor cable tensioning method and device to solve the above problems. Summary of the Invention

[0008] The object of the present invention is to provide a prestressed anchor cable tensioning method and device thereof, so as to solve the problems of insufficient stress monitoring, low adjustment accuracy and complex construction.

[0009] To achieve the above object, the present invention provides the following technical solution: a prestressed anchor cable tensioning method, comprising the following steps:

[0010] S101, first tensioning the anchor cables, preparing the bridge pier model, and setting steel wire ropes on the bridge pier model, with the steel wire ropes distributed in a circular shape around the periphery of the bridge pier model;

[0011] S102, arranging a sensor assembly, where the sensor assembly includes a magnetic flux sensor, a pressure sensor, an axial steel bar strain gauge, a radial steel bar strain gauge, a circumferential steel bar strain gauge, and a strain sensor;

[0012] A type A groove is reserved on the outer surface of the pier model, and the type A groove is used to install the magnetic flux sensor;

[0013] A type B groove is provided on the outer surface of the pier model, and the pressure sensor is installed in the type B groove;

[0014] The pier model includes: axial reinforcement, radial reinforcement, and annular reinforcement. Axial reinforcement strain gauges, radial reinforcement strain gauges, and annular reinforcement strain gauges are installed on the axial reinforcement, radial reinforcement, and annular reinforcement respectively.

[0015] A plurality of strain sensors are installed and bonded on the surface of the pier model;

[0016] C-type grooves are reserved at different positions on the surface of the pier model, and reserved intelligent adjustment devices are installed in the C-type grooves;

[0017] S103, tensioning the steel wire rope to the design force F, measuring the tensioning force FC of the steel wire rope wrapped around different locations on the surface of the pier model using a magnetic flux sensor, measuring the normal pressure FY of the steel wire rope wrapped around different locations on the surface of the pier model using a pressure sensor, measuring the axial internal stress FN10, radial internal stress FN11, and circumferential internal stress FN12 of the steel wire rope reinforcement on the pier using axial steel bar strain gauges, radial steel bar strain gauges, and circumferential steel bar strain gauges on the surfaces of the axial steel bars, radial steel bars, and circumferential steel bars, respectively, and measuring the surface stress FB of the steel wire rope wrapped around different locations on the concrete surface of the pier model using a strain sensor;

[0018] S104, connecting a control system, the control system includes a control device, the control device controls the intelligent adjustment device to adjust the tightness of the wire rope, and the control device includes a display screen and a control chip.

[0019] The present invention also discloses a device for tensioning prestressed anchor cables, which is suitable for a prestressed anchor cable tensioning method. One end of the pressure sensor is fixedly provided with an embedded plate, and the other end is rotatably provided with a rotating disk, and an arc-shaped guide plate is slidably provided on the rotating disk. When the wire rope is distributed in a ring around the periphery of the pier model, the wire rope moves through the arc-shaped guide plate.

[0020] Preferably, a cable head rod is fixedly provided at the end of the wire rope, the surface of the cable head rod is smooth, and a threaded rod is provided at one end of the cable head rod away from the wire rope, and a threaded cap is connected to the threaded rod through threaded cooperation.

[0021] Preferably, the intelligent adjustment device includes an anchor, which is a trapezoidal block structure, and one side of the anchor that is movably attached to the outer surface of the pier model is an arc surface, and threaded fixing holes are provided on both sides of the upper and lower surfaces of the anchor, and circular holes are provided on both sides of the anchor, and the circular holes penetrate the trapezoidal inclined surface on the anchor;

[0022] When the steel wire rope is fixed, the cable head rod and the threaded rod at the end of the steel wire rope are moved through the circular hole, and one end of the threaded rod extending out of the circular hole is limited by a threaded cap.

[0023] Preferably, the intelligent adjustment device further includes a positioning base plate, a first sliding plate, a second sliding plate and a positioning card plate, the positioning base plate, the first sliding plate and the second sliding plate are arranged in sequence, the first sliding plate and the second sliding plate are fixedly connected by a supporting connecting rod, a guide support rod is fixedly provided on the positioning base plate, the guide support rod movably passes through the first sliding plate and the second sliding plate, one end of the guide support rod movably passes through the first sliding plate and the second sliding plate and is fixedly connected to the positioning card plate, the positioning card plates are arranged in pairs up and down, the positioning card plate is an L-shaped structure, and the positioning card plate is connected to a threaded fixing rod by threaded cooperation;

[0024] When the wire rope needs to be tightened, a pair of positioning clamps are respectively engaged at the same side corners of the upper and lower surfaces of the anchor, and then the threaded fixing rod is rotated to fix the threaded fixing rod in the threaded fixing hole.

[0025] Preferably, a rotating member is rotatably provided on the second sliding plate, and a threaded fixing sleeve is fixedly provided on the end of the rotating member. The rotating member is operated so that the threaded fixing sleeve is connected to the end of the threaded rod through threaded fitting.

[0026] Preferably, an electric oil pump jack is fixedly provided on the positioning base plate, and a telescopic end of the electric oil pump jack is fixedly connected to the first sliding plate.

[0027] Preferably, the outer surface of the cable head rod and the inner wall of the circular hole are kept smooth.

[0028] Preferably, the steel wire ropes are arranged in pairs, and both ends of the two steel wire ropes are connected to one anchor at the same time.

[0029] Preferably, the outer ring rotating sleeve of the cable head rod is provided with an annular sleeve, and the annular sleeve is movably fitted on the inner wall of the circular hole.

[0030] The technical effects and advantages of the present invention are as follows:

[0031] The present invention deploys different sensors and intelligent adjustment devices in a circumferential manner at different locations inside and outside the pier model to collect and measure the annular reinforcement effect of the steel wire rope on the pier model (including internal and external stresses at different locations, effective tension, and normal pressure) in multiple dimensions. Furthermore, the intelligent adjustment device for the steel wire rope force is controlled by a control system to adjust the force of the steel wire rope, thereby achieving a controlled simulation of the effect of the intelligent adjustment of the steel wire rope on the reinforcement of the pier model. This provides quantitative and reliable data support and foundation for the actual engineering application of steel wire rope circumferential reinforcement of piers.

[0032] When the electric oil pump jack is started, the electric oil pump jack pulls the first sliding plate to move through the telescopic end. At this time, the first sliding plate, the second sliding plate, the rotating member and the threaded fixing sleeve move synchronously, thereby tightening the wire rope, achieving the purpose of adjusting the wire rope tension;

[0033] When the threaded fixing sleeve pulls the threaded rod to move, it can move along the length direction of the circular hole without deviation, ensuring smooth sliding without large resistance affecting the accuracy of cable force adjustment;

[0034] When the wire rope is tightened, the embedded groove will slide on the rotating disk, and the rotating disk will rotate at the end of the pressure sensor, thereby adaptively avoiding the phenomenon of offset stress caused by upward or downward displacement of the wire rope when it is tightened, so that the pressure sensor can accurately measure the positive pressure FY value of the wire rope wrapped around different positions on the surface of the pier model. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic diagram of the prestressed anchor cable tensioning structure of the present invention.

[0036] Figure 2 This is a schematic diagram of the structure of the radial steel bar strain gauge of the present invention.

[0037] Figure 3 Schematic diagram of the control device structure of the present invention.

[0038] Figure 4 Schematic diagram of the pressure sensor structure of the present invention.

[0039] Figure 5 Schematic diagram of the type B groove structure of the present invention.

[0040] Figure 6 It is a schematic diagram of the steel wire rope structure of the present invention.

[0041] Figure 7 It is a schematic structural diagram of the steel wire rope and anchor when they are connected in coordination with each other.

[0042] Figure 8 It is a schematic diagram of the anchor structure of the present invention.

[0043] Figure 9 This is a structural diagram of the intelligent adjustment device of the present invention when used in conjunction with an anchor.

[0044] Figure 10 It is a structural schematic diagram of the intelligent adjustment device of the present invention.

[0045] Figure 11 This is a schematic diagram of the structure of the intelligent adjustment device of the present invention when it is supported at the bottom.

[0046] Figure 12 This is a schematic diagram of the structure of the intelligent adjustment device of the present invention when it is suspended from the top.

[0047] Figure 13 It is a schematic diagram of the internal structure of the electric oil pump jack of the present invention.

[0048] Figure 14 For the present invention Figure 13 A magnified schematic diagram of the structure in the middle.

[0049] Figure 15 For the present invention Figure 13 Enlarged schematic diagram of the structure at point B in the middle.

[0050] Figure 16 This is a schematic diagram of the analysis results of the finite element model of a solid cylinder 1 / 4 of the bridge pier model of the present invention. Figure 16 (a) is the 1 / 4 finite element model diagram, (b) is the radial stress diagram of the loading plane, and (c) is the circumferential stress diagram of the loading plane.

[0051] Figure 17 This is an analytical structural diagram of the vertical distribution of radial stress on the pier model of the present invention.

[0052] Figure 18 This is an analytical structural diagram of the vertical distribution of hoop stress on the pier model of the present invention.

[0053] Figure 19 This is the longitudinal distribution diagram of the edge hoop stress of the present invention.

[0054] Figure 20 This is the vertical stress finite element result diagram of the present invention.

[0055] In the figure: 1. Bridge pier model; 2. Type A groove; 3. Magnetic flux sensor; 4. Type B groove; 5. Pressure sensor; 6. Type C groove; 7. Intelligent adjustment device; 8. Wire rope; 9. Electric cylinder; 10. Axial steel bar strain gauge; 11. Radial steel bar strain gauge; 12. Circumferential steel bar strain gauge; 13. Pier surface strain gauge; 14. Control device; 15. Arc guide plate; 16. Embedded plate; 17. Rotating disk; 18. Cable head rod; 19. Threaded rod; 20. Threaded cap; 21. Anchor; 22. Threaded fixing hole; 23. Circular hole; 24. Positioning base plate; 25. First sliding plate; 26. Second sliding plate; 27. Positioning card plate; 28. Threaded fixing rod; 29. ​​Guide support rod; 30. Electric oil pump jack; 31. support connecting plate; 32. rotating part; 33. threaded fixing sleeve; 34. support connecting rod; 35. first auxiliary pressure sensor; 36. suspension rope; 37. second auxiliary pressure sensor; 38. oil pump housing; 39. oil pump telescopic rod; 40. piston; 41. outer seal; 42. inner seal; 43. first oil inlet and outlet pipes; 44. second oil inlet and outlet pipes; 45. first metal heat exchange tube; 46. second metal heat exchange tube; 47. connecting pipe; 48. discharge pipe; 49. return pipe; 50. infusion hose; 51. liquid storage tank; 52. heat dissipation tank; 53. ring groove; 54. sealing steel ring; 55. sealing rubber ring; 56. first sealing rubber airbag; 57. second sealing rubber airbag; 58. embedded mounting groove. DETAILED DESCRIPTION

[0056] Example 1

[0057] The present invention provides Figures 1-15 A prestressed anchor cable tensioning method and device is shown.

[0058] The prestressed anchor cable tensioning method of the present invention comprises the following steps:

[0059] Step 1: First, tension the anchor cable and prepare the pier model 1. Wire ropes 8 are installed on the pier model 1. The wire ropes 8 are distributed in a ring shape around the periphery of the pier model 1. A sensor assembly is used to measure various stresses in the wire ropes 8 and the pier model 1. The sensor assembly includes a magnetic flux sensor 3, a pressure sensor 5, an axial steel bar strain gauge 10, a radial steel bar strain gauge 11, a circumferential steel bar strain gauge 12, and a strain sensor 13. The axial steel bar strain gauge 10, the radial steel bar strain gauge 11, and the circumferential steel bar strain gauge 12 all use fiber Bragg grating sensors.

[0060] The magnetic flux sensor 3 is used to measure the tension force of the steel wire rope 8 at different positions around the circumference. First, a Class A groove 2 is reserved on the outer surface of the pier model 1. The Class A groove 2 is used to install the magnetic flux sensor 3. The magnetic flux sensor 3 is used to measure the tension force FC of the steel wire rope 8 at different positions on the surface of the pier model 1.

[0061] A Class B groove 4 is provided on the outer surface of the pier model 1, and a pressure sensor 5 is installed in the Class B groove 4. An embedded plate 16 is fixedly provided at one end of the pressure sensor 5, and a rotating disk 17 is rotatably provided at the other end. An arc-shaped guide plate 15 is slidably provided on the rotating disk 17. When the steel wire rope 8 is annularly distributed around the outer periphery of the pier model 1, the steel wire rope 8 moves through the arc-shaped guide plate 15, and the pressure sensor 5 measures the positive pressure FY of the steel wire rope 8 wrapped around different positions on the surface of the pier model 1;

[0062] The pier model 1 includes: axial steel bars, radial steel bars, and annular steel bars. Representative axial steel bars, radial steel bars, and annular steel bars are selected (e.g., at equal points in the pier model 1). Axial steel bar strain gauges 10, radial steel bar strain gauges 11, and annular steel bar strain gauges 12 are installed on the steel bar surfaces (the steel bar surfaces need to be polished flat). The axial internal stress FN10, radial internal stress FN11, and annular internal stress FN12 of the steel wire rope 8 used to reinforce the pier are measured using the axial steel bar strain gauges 10, radial steel bar strain gauges 11, and annular steel bar strain gauges 12 on the axial steel bars, radial steel bars, and annular steel bars.

[0063] Strain sensors 13 are installed at different positions on the surface of the pier model 1 to measure the surface stress FB of the steel wire rope 8 wound around the concrete at different positions on the surface of the pier model 1 through the strain sensors 13;

[0064] C-type grooves 6 are reserved at different positions on the surface of the pier model 1 , and reserved intelligent adjustment devices 7 are installed in the C-type grooves 6 ; the intelligent adjustment devices 7 are used to adjust the tightness of the wire rope 8 .

[0065] In the second step, the steel wire rope 8 is tensioned to the design force F (according to the test requirements). The tensioning force FC of the steel wire rope 8 wrapped around different positions on the surface of the pier model 1 is measured by the magnetic flux sensor 3. The normal pressure FY of the steel wire rope 8 wrapped around different positions on the surface of the pier model 1 is measured by the pressure sensor 5. The axial steel bar strain gauge 10, radial steel bar strain gauge 11, and circumferential steel bar strain gauge 12 on the surface of the axial steel bar, radial steel bar, and circumferential steel bar are used to measure the axial internal stress FN10, radial internal stress FN11, and circumferential internal stress FN12 of the steel wire rope 8 in reinforcing the pier respectively. The surface stress FB of the steel wire rope 8 wrapped around the concrete at different positions on the surface of the pier model 1 is measured by the strain sensor 13.

[0066] The third step is to connect the control system, which includes a control device 14. All sensor data are collected and displayed in the control device 14. The control device 14 can control the intelligent adjustment device 7 to adjust the tightness of the wire rope 8.

[0067] It should be noted that the control device 14 may include a display screen and a control chip; wherein the display screen is used to display all sensor data; the control chip is used to receive data fed back by all sensors, and the control chip can also control the intelligent adjustment device 7; the control chip and the display screen are both existing common technologies and will not be elaborated here.

[0068] In summary, the present invention arranges different sensors and intelligent adjustment devices 7 in a circumferential direction at different positions inside and outside the pier model 1 to collect and measure the annular reinforcement effect of the wire rope 8 on the pier model 1 in multiple dimensions (including internal and external stresses at different positions, effective tension, and positive pressure). The intelligent adjustment device 7 of the wire rope 8 is controlled by the control system to adjust the tension of the wire rope 8, thereby realizing control simulation of the effect of the intelligent adjustment of the wire rope 8 on reinforcing the pier model 1, and providing quantitative and reliable data support and foundation for the actual engineering application of the wire rope cable 8 in circumferential reinforcement of piers.

[0069] refer to Figure 4 As shown in FIG, it is a schematic diagram of the pressure sensor 5 in the present invention, Figure 5 This is a structural diagram of the pressure sensor 5 installed in the Class B groove 4 in the present invention. When the pressure sensor 5 is installed in the Class B groove 4, the steel wire rope 8 wrapped around the outer periphery of the pier model 1 moves through the embedded groove 15 at the end of the pressure sensor 5; when the steel wire rope 8 is tightened, the embedded groove 15 will slide on the rotating disk 17, and the rotating disk 17 will rotate at the end of the pressure sensor 5, thereby adaptively avoiding the phenomenon of offset stress caused by upward or downward displacement of the steel wire rope 8 when it is tightened, so that the pressure sensor 5 can accurately measure the positive pressure FY value of the steel wire rope 8 wrapped around different positions on the surface of the pier model 1.

[0070] refer to Figure 6 As shown in the figure, it is a structural schematic diagram of the end of the wire rope cable 8. A cable head rod 18 is fixedly provided at the end of the wire rope cable 8. The surface of the cable head rod 18 is smooth. A threaded rod 19 is provided at the end of the cable head rod 18 away from the wire rope cable 8. A threaded cap 20 is connected to the threaded rod 19 through threaded cooperation. The wire rope cables 8 on the surface of the pier model 1 are arranged in groups of two. After the two wire rope cables 8 are wrapped around the pier model 1 for one week, the head and tail ends pass through the intelligent adjustment device 7. The intelligent adjustment device 7 includes an anchor 21.

[0071] refer to Figure 7 and Figure 8As shown in the figure, the anchor 21 is a trapezoidal block structure. One side of the anchor 21 that is movably fitted to the outer ring surface of the pier model 1 is an arc surface. Threaded fixing holes 22 are provided on both sides of the upper and lower surfaces of the anchor 21, and circular holes 23 are provided on both sides of the anchor 21. The circular holes 23 pass through the trapezoidal inclined surface on the anchor 21; when fixing the wire rope 8, the cable head rod 18 and the threaded rod 19 at the end of the wire rope 8 are moved through the circular hole 23, and one end of the threaded rod 19 extending out of the circular hole 23 is limited by the threaded cap 20; after tightening the threaded cap 20, the wire rope 8 can be tightened.

[0072] refer to Figure 9 and Figure 10 As shown in, the intelligent adjustment device 7 also includes a positioning base plate 24, a first sliding plate 25, a second sliding plate 26 and a positioning card plate 27. The positioning base plate 24, the first sliding plate 25 and the second sliding plate 26 are arranged in sequence, and the first sliding plate 25 and the second sliding plate 26 are fixedly connected by a supporting connecting rod 34. A guide support rod 29 is fixedly provided on the positioning base plate 24, and the guide support rod 29 movably passes through the first sliding plate 25 and the second sliding plate 26. The guide support rod 29 movably passes through one end of the first sliding plate 25 and the second sliding plate 26 and is fixedly connected to the positioning card plate 27. The positioning card plates 27 are arranged in pairs up and down, and the positioning card plates 27 are L-shaped structures. A threaded fixing rod 28 is connected to the positioning card plates 27 by threaded cooperation. When it is necessary to tighten the wire rope cable 8, a pair of positioning card plates 27 can be respectively engaged at the same side corners of the upper and lower surfaces of the anchor 21, and then the threaded fixing rod 28 is rotated to make The screw fixing rod 28 is fixed in the screw fixing hole 22, completing the relative fixation of the positioning card plate 27 and the anchor 21; a rotating member 32 is rotatably provided on the second sliding plate 26, and a screw fixing sleeve 33 is fixedly provided on the end of the rotating member 32. Operating the rotating member 32 can make the screw fixing sleeve 33 be connected to the end of the threaded rod 19 by threaded cooperation, thereby achieving relative fixation of the screw fixing sleeve 33 and the end of the wire rope cable 8, and an electric oil pump type jack 30 is fixedly provided on the positioning base plate 24, and the telescopic end of the electric oil pump type jack 30 is fixedly connected to the first sliding plate 25; when the electric oil pump type jack 30 is started, the electric oil pump type jack 30 pulls the first sliding plate 25 to move through the telescopic end. At this time, the first sliding plate 25, the second sliding plate 26, the rotating member 32 and the screw fixing sleeve 33 move synchronously, thereby tightening the wire rope cable 8, achieving the purpose of adjusting the rope force of the wire rope cable 8.

[0073] It should be noted that a positioning base plate 24, a first sliding plate 25, a second sliding plate 26 and a positioning clamping plate 27 are also provided on the opposite sides of the upper and lower surfaces of the anchor 21. However, since the ends of the two steel wire rope cables 8 are connected to one anchor 21 at the same time, the positions of the two steel wire rope cables 8 connected to the anchor 21 are staggered with each other. Therefore, the other first sliding plate 25 and the second sliding plate 26 are fixedly connected by a support connecting plate 31. There are two support connecting plates 31 and two support connecting rods 34. The two support connecting rods 34 are arranged between the corresponding two rotating parts 32. The two support connecting plates 31 are arranged on the side away from the corresponding two rotating parts 32. This is an operation that can be adjusted by technical personnel in this field according to actual needs and will not be elaborated here.

[0074] Furthermore, the outer surface of the cable head rod 18 and the inner wall of the circular hole 23 remain smooth. When the cable head rod 18 passes through the circular hole 23, the cable head rod 18 is coaxial with the circular hole 23, and the threaded fixing sleeve 33 is connected to the end of the threaded rod 19. The threaded fixing sleeve 33 is also coaxial with the cable head rod 18 and the threaded rod 19. Therefore, when the threaded fixing sleeve 33 pulls the threaded rod 19 to move, it can move along the length direction of the circular hole 23 without deviation, ensuring smooth sliding without the presence of large resistance affecting the accuracy of the cable force adjustment.

[0075] Furthermore, because the steel wire ropes 8 are arranged in pairs, but both ends of the two steel wire ropes 8 are simultaneously connected to an anchor 21, the steel wire ropes 8 are wound around the periphery of the pier model 1 with a certain offset angle, that is, a spiral distribution. Therefore, when the steel wire ropes 8 are tightened, it is inevitable that the steel wire ropes 8 will be subjected to upward or downward stress. At this time, the cable head rod 18 will apply upward or downward stress to the inner wall of the circular hole 23. If the stress is too large, it will increase the resistance between the circular hole 23 and the cable head rod 18. The cable head rod 18 is excessively pressed against the inner wall of the circular hole 23, causing a jamming phenomenon, which affects the adjustment of the cable force. Therefore, an annular sleeve is provided on the outer ring rotating sleeve of the cable head rod 18, and the annular sleeve is movably fitted on the inner wall of the circular hole 23, so that the cable head rod 18 and the circular hole 23 are connected through the annular sleeve. In this way, the inner ring and the outer ring of the annular sleeve can slide or rotate relative to each other, instead of the original cable head rod 18 being able to slide or rotate only through the outer ring contact. By increasing the sliding or rotating surface, the jamming phenomenon is minimized and the smoothness of the cable force adjustment is improved.

[0076] refer to Figure 11 and Figure 12As shown in , when the steel wire rope 8 is tensioned, it is first necessary to preliminarily fix the position of the intelligent adjustment device 7 according to the tensioning position; for example, when the steel wire rope 8 at the upper and middle parts of the outer ring of the pier model 1 is tensioned, the intelligent adjustment device 7 is fixed in a suspended manner. The specific method includes: a suspension rope 36 is connected to the positioning base plate 24, and a second auxiliary pressure sensor 37 and a stretching mechanism are arranged above the suspension rope 36. The second auxiliary pressure sensor 37 can monitor the force of the suspension rope 36 suspending the positioning base plate 24. Considering that the intelligent adjustment device 7 will increase the gravity of the steel wire rope 8 when it is connected to the steel wire rope 8, affecting the steel wire rope The stress monitoring of the wire rope 8 and the pier model 1 is carried out by stretching the suspension rope 36 upwards through the stretching mechanism until the value monitored by the second auxiliary pressure sensor 37 is consistent with the sum of the gravity of the positioning base plate 24, the first sliding plate 25, the second sliding plate 26, the positioning clamping plate 27, the threaded fixing rod 28, the guide support rod 29, the electric oil pump jack 30, the support connecting plate 31, the rotating part 32, the threaded fixing sleeve 33 and the support connecting rod 34 on the intelligent adjustment device 7. In this way, the influence of the gravity of the intelligent adjustment device 7 on the wire rope 8 is avoided, so that the stress monitoring values ​​of the pier model 1 and the wire rope 8 are accurate;

[0077] It should be noted that the stretching mechanism can use an electric cylinder or other mechanism, which will not be described in detail here.

[0078] When the steel wire rope 8 at the lower part of the outer ring of the pier model 1 is tensioned, the intelligent adjustment device 7 is fixed in a supporting manner. The specific method includes: an electric cylinder 9 is connected to the bottom of the positioning base plate 24, and a first auxiliary pressure sensor 35 is also provided on the electric cylinder 9. The first auxiliary pressure sensor 35 is used to monitor the gravity generated by the intelligent adjustment device 7, and start the electric cylinder 9 to push up. When the pressure value monitored by the first auxiliary pressure sensor 35 is consistent with the sum of the gravity of the positioning base plate 24, the first sliding plate 25, the second sliding plate 26, the positioning card plate 27, the threaded fixing rod 28, the guide support rod 29, the electric oil pump jack 30, the support connecting plate 31, the rotating part 32, the threaded fixing sleeve 33 and the support connecting rod 34 on the intelligent adjustment device 7, the influence of the gravity of the intelligent adjustment device 7 on the steel wire rope 8 is avoided, so that the stress monitoring values ​​of the pier model 1 and the steel wire rope 8 are accurate.

[0079] Furthermore, the first auxiliary pressure sensor 35, the second auxiliary pressure sensor 37, the stretching mechanism and the electric cylinder 9 are connected through a controller, the input end of the controller is connected to the output end of the first auxiliary pressure sensor 35 and the second auxiliary pressure sensor 37, and the output end of the controller is connected to the input end of the stretching mechanism and the electric cylinder 9. The controller is used to receive data monitored by the first auxiliary pressure sensor 35 and the second auxiliary pressure sensor 37, and the controller is used to control the operation of the electric cylinder 9 or the stretching mechanism.

[0080] Since the two ends of the annularly arranged wire rope 8 have a certain offset angle in the height direction, the intelligent adjustment device 7 will inevitably be subjected to stress changes in the up and down directions during the process of tensioning the wire rope 8. If the pressure values ​​monitored by the first auxiliary pressure sensor 35 and the second auxiliary pressure sensor 37 change after the wire rope 8 is tensioned, this information can be fed back to the controller, and the controller controls the operation of the electric cylinder 9 or the stretching mechanism to adjust the support force or suspension force on the positioning substrate 24, so that the pressure values ​​of the first auxiliary pressure sensor 35 and the second auxiliary pressure sensor 37 are restored, thereby eliminating the error caused by adjusting the tension of the wire rope 8.

[0081] Example 2

[0082] refer to Figures 13 to 15 As shown in the figure, the electric oil pump jack 30 includes an oil pump housing 38, an oil pump telescopic rod 39 and a piston 40. The oil pump telescopic rod 39 is a solid cylindrical structure, and the oil pump housing 38 is a hollow cylindrical structure. The piston 40 is slidably arranged in the oil pump housing 38 and divides the interior of the oil pump housing 38 into a first oil chamber and a second oil chamber; the oil pump telescopic rod 39 moves through one end of the oil pump housing 38 and is fixedly connected between the piston 40. A first inlet and outlet oil pipe 43 and a second inlet and outlet oil pipe 44 are provided on the oil pump housing 38. The first inlet and outlet oil pipe 43 and the second inlet and outlet oil pipe 44 are connected to the first oil chamber and the second oil chamber respectively. It is connected to an external electric oil pump through the inlet and outlet oil pipes. The electric oil pump is not shown in the figure. It is a supporting power mechanism of the electric oil pump type jack 30 and will not be described here. The end of the oil pump telescopic rod 39 away from the piston 40 is fixedly connected to the first sliding plate 25. When oil is injected into the first oil chamber through the electric oil pump and the oil in the second oil chamber is pumped out, the piston 40 will move in the direction away from the oil pump telescopic rod 39, which can tension the wire rope 8. When oil is injected into the second oil chamber through the electric oil pump and the oil in the first oil chamber is pumped out, the piston 40 will move in the direction close to the oil pump telescopic rod 39, which can reset the wire rope 8, making it easy to use.

[0083] It should be noted that electromagnetic valves are provided in both the first oil inlet and outlet pipes 43 and the second oil inlet and outlet pipes 44 to facilitate the on-off control of the channels.

[0084] The traditional electric oil pump jack 30 has the following disadvantages:

[0085] First, the piston does not rise actively;

[0086] Causes: Insufficient oil supply from the oil pump, damaged sealing, large piston resistance;

[0087] Second, the seal is aged or damaged;

[0088] Reason: After long-term use, the seals may lose their sealing performance due to wear, aging or corrosion.

[0089] The electric oil pump jack 30 designed in the present invention effectively solves the disadvantages of the traditional electric oil pump jack 30, including:

[0090] First, the piston 40 can move smoothly;

[0091] Second, the sealing performance is improved;

[0092] Specifically:

[0093] An inner seal 42 is fixedly provided on the outer periphery of the piston 40. The inner seal 42 includes an annular groove 53. A sealing steel ring 54 is slidably provided in the annular groove outside the annular groove 53. The outer ring of the sealing steel ring 54 slides and fits with the inner wall of the oil pump housing 38. A sealing rubber ring 55 is fixedly provided on the outer ring edge of the annular groove 53. The outer ring of the sealing rubber ring 55 movably fits on the inner wall of the oil pump housing 38. An outer seal 41 is also provided at the position where the oil pump telescopic rod 39 moves through the oil pump housing 38. The outer seal 41 includes a first sealing rubber airbag 56 and a second sealing rubber airbag 57. An inner seal 41 is provided on the inner wall of the oil pump housing 38. The second sealing rubber airbag 57 is embedded in the embedded mounting groove 58, and the first sealing rubber airbag 56 is arranged inside the oil pump housing 38 and fits on the outer surface of the oil pump telescopic rod 39. The first sealing rubber airbag 56 and the second sealing rubber airbag 57 are connected to each other; when the oil pressure in the first oil chamber increases, the oil will squeeze the first sealing rubber airbag 56, and the gas in the first sealing rubber airbag 56 will enter the second sealing rubber airbag 57, thereby increasing the pressure of the gas in the second sealing rubber airbag 57 to improve the sealing effect. In other words, the higher the oil pressure, the better the sealing effect, and there will be no leakage problem.

[0094] When the oil is injected into the first chamber or the second chamber to push the piston 40 to move, the sealing steel ring 54 slides in the annular groove 53, with a small contact area and small resistance, thus avoiding the phenomenon that the piston 40 cannot slide smoothly, and the sealing rubber ring 55 has the effect of real-time sealing between the outer ring of the piston 40 and the inner wall of the oil pump housing 38.

[0095] It should be noted that, in the present invention, since the sealing steel ring 54 is slidably arranged on the inner wall of the annular groove 53, even if oil leaks into the annular groove 53 at the contact position between the sealing rubber ring 55 and the oil pump housing 38, the oil will only push the sealing steel ring 54 to slide, achieving a certain degree of redundancy effect, and will not cause the oil in the first chamber and the second chamber to mix with each other.

[0096] In the present invention, a second metal heat exchange cylinder 46 is fixedly provided on both sides of the piston 40, and a first metal heat exchange cylinder 45 is fixedly provided on the inner walls of both ends of the oil pump housing 38. The second metal heat exchange cylinder 46 is slidably provided inside the first metal heat exchange cylinder 45, and the second metal heat exchange cylinder 46 and the first metal heat exchange cylinder 45 are communicated with each other. There are at least two first metal heat exchange cylinders 45 and second metal heat exchange cylinders 46. The multiple first metal heat exchange cylinders 45 on the same side of the piston 40 are communicated with each other through a connecting pipe 47. The lowermost first metal heat exchange cylinder 45 is connected to a discharge pipe 48 and a return pipe 49. A liquid storage tank 51 and a heat dissipation tank 52 are provided on the outside of the electric oil pump jack 30. The heat dissipation tank 52 is communicated with the liquid storage tank 51. The liquid storage tank 51 and the heat dissipation tank 52 are respectively connected to the return pipe 49 and the discharge pipe through the infusion hose 50. 48 is connected, and coolant is stored in the liquid storage tank 51, the heat dissipation tank 52, the liquid infusion hose 50, the discharge pipe 48 and the return pipe 49; when the piston 40 moves back and forth in the oil pump housing 38, the coolant will circulate in the second metal heat exchange cylinder 46, the first metal heat exchange cylinder 45, the connecting pipe 47, the discharge pipe 48, the return pipe 49, the liquid infusion hose 50, the heat dissipation tank 52 and the liquid storage tank 51. The coolant located in the first metal heat exchange cylinder 45 and the second metal heat exchange cylinder 46 can fully absorb the heat of the oil inside the oil pump housing 38, and achieve a good heat dissipation effect. When the coolant is discharged into the heat dissipation tank 52, it is dissipated by a fan or other heat dissipation mechanism. The cooled coolant enters the liquid storage tank 51 for storage and then flows back for utilization, which can fully reduce the heat of the oil and reduce the phenomenon of reduced sealing and reduced service life caused by overheating of the oil.

[0097] Based on the first metal heat exchange tube 45 and the second metal heat exchange tube 46 provided in the present invention, the limited space in the first oil chamber and the second oil chamber is fully utilized for heat dissipation; and the amount of oil in the first oil chamber and the second oil chamber is reduced, ensuring sufficient oil pressure and oil supply; and the first metal heat exchange tube 45 and the second metal heat exchange tube 46 also have coolant, which also provides stable strength support for the piston 40, achieving the purpose of taking into account heat dissipation, sufficient support strength and sufficient oil pressure and oil supply.

[0098] Experiments have shown that:

[0099] In the present invention, two bridge pier models 1 can be prepared, namely a solid bridge pier with a diameter of 2m and a hollow bridge pier with a diameter of 1.2m; both are 2m in height;

[0100] According to the original design drawings of the bridge pier, the diameter of the vertical steel bars of the solid pier is 28 mm, and the diameter of the annular stirrups is 8 mm, which is convenient for installing the pressure sensor. According to the sensor size requirements, the distance between the two steel bars near the sensor is adjusted to 17 cm.

[0101] Table 1 shows the design parameters of solid piers

[0102] bridge piers solid Outer diameter / m 2 Height / m 2 Vertical steel bar diameter / mm 28 Total length of vertical reinforcement / m 84 Ring reinforcement diameter / mm 42 Total length of ring reinforcement / m 8.53

[0103] The diameter of the vertical steel bars on the outer surface of the hollow pier is 25 mm, the diameter of the vertical steel bars on the inner surface is 12 mm, and the diameter of the annular stirrups is 8 mm, which is convenient for installing the pressure sensor. According to the sensor size requirements, the distance between the two steel bars near the sensor is adjusted to 17 cm.

[0104] Table 2 Design parameters of hollow piers

[0105] bridge piers solid Outer diameter / m 1.2 Inner diameter / m 0.63 Height / m 2 External vertical steel bar diameter / mm 25 Internal vertical steel bar diameter / mm 12 Total length of external vertical reinforcement / m 37.8 Total length of internal vertical reinforcement / m 33.6 Ring reinforcement diameter / mm 8 Total length of ring reinforcement / m 53.04

[0106] According to the research on the mechanism of action of prestressed steel wire rope, the arrangement spacing of the steel wire rope cables 8 is set to 20 cm.

[0107] Table 3 Dimensional design table of anchor 21

[0108] model 26 specifications 22 specifications Total length / mm 435 435 Total width / mm 336 250 Total height / mm 257 252 Opening size / mm Diameter 60 Diameter 58 Maximum center distance between two holes / mm 225 225

[0109] The size specifications of the anchor 21 are divided into 26 specifications and 22 specifications.

[0110] Table 4 Measurement content and arrangement

[0111] project Solid piers Hollow bridge piers Number of wire ropes / piece 6 6 Number of steel bar strain gauges 16 8 Pressure sensor / piece 3 3 Magnetic flux sensor / piece 3 3

[0112] A magnetic flux sensor is nested and installed on the surface of the wire rope 8 (the installation position needs to be grooved in advance on the surface of the pier model 1) to measure the prestress loss during the tensioning process.

[0113] 8 Specifications of Wire Rope Cable Selection:

[0114] 6×36WS steel core wire rope, nominal diameter φ26mm, strength 1870MPa, nominal breaking force 450kN.

[0115] 6×36WS steel core wire rope, nominal diameter Φ22mm, strength 1770MPa, nominal breaking force 305kN.

[0116] refer to Figure 16 Figure 3 shows a schematic diagram of the finite element model analysis results for a solid cylinder 1 / 4 of the pier model 1. Finite element analysis was used to determine the load required to reinforce the pier model 1 with prestressed steel wire ropes 8. When a single-ring prestress acts on a structure such as a pier, the internal stress will be affected vertically by the structure. Finite element analysis was conducted to explore the effect of single-ring prestressing on the structure. A finite element model of a solid cylinder 1 / 4 with a height of 5 m and a diameter of 2 m was established, and a circumferentially uniformly distributed pressure was applied to the middle of the column. Based on the size of the steel wire ropes 8, a loading width of 20 mm and a pressure of 10 MPa were proposed, and C50 concrete was used as the column material.

[0117] refer to Figures 16 to 20 , Figure 16 (a) is the 1 / 4 finite element model diagram, (b) is the radial stress diagram of the loading plane, and (c) is the circumferential stress diagram of the loading plane; Figure 17 The middle one is the analysis diagram of the vertical distribution of radial stress. Figure 18 The figure in the middle is an analysis diagram of the vertical distribution of hoop stress; the finite element analysis results show that, compared with the plane structure, when a single-ring annular uniformly distributed load acts on a cylindrical structure, the stress in the loaded section is weakened to a certain extent and is unevenly distributed, gradually weakening toward the center of the circle. At the same time, the stress will be transmitted along the vertical direction. As it moves away from the loading position, the transmitted stress becomes smaller and smaller. Considering the need for reinforcement, the hoop stress at the edge of the structure plays an important role.

[0118] It should be noted that Figure 16 and Figure 17 S11 represents the stress in the X-axis direction, with positive values ​​being tensile stress and negative values ​​being compressive stress;

[0119] Figure 16 and Figure 18 S22 represents the stress in the Y-axis direction, with positive values ​​being tensile stress and negative values ​​being compressive stress;

[0120] Figure 20 The S33 in the figure represents the stress in the Z-axis direction, where a positive value indicates tensile stress and a negative value indicates compressive stress.

[0121] Figures 16 to 18 The CSYS-1 in the figure is an identifier representing the coordinate system in the finite element analysis software; the coordinate system (CSYS for short) is the coordinate system.

[0122] Figures 16 to 18 and Figure 20 Average: 75% represents the average stress threshold; the blue area in the figure represents the part with lower stress, and the yellow and red areas represent the part with higher stress; Figure 16 The "e-03" here means multiplying by 10 to the power of -3; "e-01" means multiplying by 10 to the power of -1; "e+00" means multiplying by 10 to the power of 0; and so on; among them, "e" is a representation in scientific notation in finite element analysis, which stands for "multiplying by the power of 10".

[0123] When a single ring 10MPa uniformly distributed load is applied, the circumferential compressive stress at the edge of the loading plane is 3.43MPa. As the distance from the loading position increases, the stress decreases rapidly to both sides. When the distance from the loading position is 15mm, the circumferential stress at the edge has dropped to 1.16MPa. When the distance from the loading position is 100mm, the stress has dropped to 0.2MPa, and the effect is very weak. Figure 19As shown in , when hoop prestressing is applied, vertical tensile stress is generated along the outer edge of the structure.

[0124] From the analysis results, it can be seen that the vertical tensile stress generated is no more than 0.5MPa.

[0125] The load was changed to 8MPa, 6MPa, 4MPa, and 2MPa respectively; the stress distribution was the same as that when loading 10MPa, indicating that the stress distribution was independent of the load size; the maximum value of the edge circumferential compressive stress was shown in Table 4 below: Finite element results for different loads.

[0126] Table 5 Finite element results of different loads

[0127] Uniformly distributed load 10MPa 8MPa 6MPa 4MPa 2MPa Maximum circumferential compressive stress at the edge 3.43MPa 2.73MPa 2.1MPa 1.36MPa 0.68MPa

[0128] Since the standard value of the tensile strength of C50 concrete is 2.65 MPa, to suppress the occurrence of vertical cracks in the piers, the hoop stress at the outer edge of the structure should be no less than 2.65 MPa. Combined with the data in Table 5, considering the effect of interval reinforcement, the effective uniformly distributed load should not be less than 10 MPa.

[0129] Test steps:

[0130] A steel wire rope cable 8 with a diameter of 26 mm and a steel wire rope cable 8 with a diameter of 22 mm are prepared. The two specifications of steel wire rope cables 8 are divided into initial tensioning and formal tensioning. In the case of initial tensioning, the two specifications of steel wire rope cables 8 are tensioned step by step from 10 KN to 50 KN; in the case of formal tensioning, the steel wire rope cable 8 with a diameter of 26 mm is loaded step by step from 10 KN to 300 KN; the steel wire rope cable 8 with a diameter of 22 mm is loaded step by step from 10 KN to 200 KN.

Claims

1. A prestressed anchor cable tensioning method, characterized in that: The following steps are involved: S101, first tensioning the anchor cable, preparing the bridge pier model (1), setting the steel wire rope cable (8) on the bridge pier model (1), and the steel wire rope cable (8) is distributed in a ring shape on the outer periphery of the bridge pier model (1); S102, arranging a sensor assembly, wherein the sensor assembly includes a magnetic flux sensor (3), a pressure sensor (5), an axial steel bar strain gauge (10), a radial steel bar strain gauge (11), a circumferential steel bar strain gauge (12), and a strain sensor (13) installed on the pier model (1); C-type grooves (6) are reserved at different positions on the surface of the pier model (1), and a reserved intelligent adjustment device (7) is installed in the C-type groove (6); S103, tensioning the steel wire rope (8) to a design force F, and measuring the tension force, internal stress, and surface stress of the pier model (1) through a sensor assembly; S104, connecting a control system, the control system including a control device (14), the control device (14) controlling the intelligent adjustment device (7) to adjust the tightness of the wire rope (8), the control device (14) including a display screen and a control chip; The prestressed anchor cable tensioning method uses a prestressed anchor cable tensioning device to tension the pier model (1), and the prestressed anchor cable tensioning device includes: a steel wire rope (8) distributed in an annular manner on the periphery of the pier model (1) and a pressure sensor (5) arranged on the outer surface of the pier model (1), one end of the pressure sensor (5) is fixedly provided with an embedded plate (16), and the other end is rotatably provided with a rotating disk (17), and an arc-shaped guide plate (15) is slidably provided on the rotating disk (17), and the steel wire rope (8) moves through the arc-shaped guide plate (15); The end of the steel wire rope (8) is fixedly provided with a cable head rod (18), the surface of the cable head rod (18) is smooth, and the end of the cable head rod (18) away from the steel wire rope (8) is provided with a threaded rod (19), and the threaded rod (19) is connected to a threaded cap (20) through threaded engagement; The intelligent adjustment device (7) includes an anchor (21), the anchor (21) is a trapezoidal block structure, one side of the anchor (21) that is movably attached to the outer surface of the pier model (1) is an arc surface, both sides of the upper and lower surfaces of the anchor (21) are provided with threaded fixing holes (22), both sides of the anchor (21) are provided with circular holes (23), and the circular holes (23) pass through the trapezoidal inclined surface on the anchor (21); When the steel wire rope (8) is fixed, the cable head rod (18) and the threaded rod (19) at the end of the steel wire rope (8) are moved through the circular hole (23), and one end of the threaded rod (19) extending out of the circular hole (23) is limited by the threaded cap (20); The intelligent adjustment device (7) further comprises a positioning substrate (24), a first sliding plate (25), a second sliding plate (26) and a positioning card plate (27). The positioning substrate (24), the first sliding plate (25) and the second sliding plate (26) are arranged in sequence. The first sliding plate (25) and the second sliding plate (26) are fixedly connected via a supporting connecting rod (34). A guide support rod (29) is fixedly arranged on the positioning substrate (24). The guide support rod (29) moves through the first sliding plate (25) and the second sliding plate (26). One end of the guide support rod (29) moves through the first sliding plate (25) and the second sliding plate (26) and is fixedly connected to the positioning card plate (27). The positioning card plates (27) are arranged in pairs up and down. The positioning card plates (27) are L-shaped structures. The positioning card plates (27) are connected to a threaded fixing rod (28) via threaded engagement. When the wire rope (8) needs to be tightened, a pair of positioning clamps (27) are respectively engaged at the same side corners of the upper and lower surfaces of the anchor (21), and then the threaded fixing rod (28) is rotated so that the threaded fixing rod (28) is fixed in the threaded fixing hole (22).

2. A prestressed anchor cable tensioning method according to claim 1, characterized in that: A type A groove (2) is reserved on the outer surface of the pier model (1), and the type A groove (2) is used to install a magnetic flux sensor (3); A type B groove (4) is provided on the outer surface of the pier model (1), and a pressure sensor (5) is installed in the type B groove (4); The bridge pier model (1) includes: axial reinforcement, radial reinforcement, and annular reinforcement, and an axial reinforcement strain gauge (10), a radial reinforcement strain gauge (11), and annular reinforcement strain gauge (12) are installed on the axial reinforcement, radial reinforcement, and annular reinforcement, respectively; A plurality of strain sensors (13) are mounted on the surface of the pier model (1); The tension FC of the steel wire rope (8) wound around the surface of the pier model (1) at different positions is measured by the magnetic flux sensor (3), the positive pressure FY of the steel wire rope (8) wound around the surface of the pier model (1) at different positions is measured by the pressure sensor (5), the axial internal stress FN10, radial internal stress FN11 and circumferential internal stress FN12 of the steel wire rope (8) reinforcing the pier are measured by the axial steel bar strain gauge (10), radial steel bar strain gauge (11) and circumferential steel bar strain gauge (12) on the surface of the axial steel bar, radial steel bar and circumferential steel bar respectively, and the surface stress FB of the steel wire rope (8) wound around the concrete at different positions on the surface of the pier model (1) is measured by the strain sensor (13).

3. A prestressed anchor cable tensioning method according to claim 1, characterized in that: A rotating member (32) is rotatably provided on the second sliding plate (26), and a threaded fixing sleeve (33) is fixedly provided at the end of the rotating member (32). When the rotating member (32) is operated, the threaded fixing sleeve (33) is connected to the end of the threaded rod (19) through threaded engagement.

4. A prestressed anchor cable tensioning method according to claim 3, characterized in that: An electric oil pump type jack (30) is fixedly arranged on the positioning base plate (24), and a telescopic end of the electric oil pump type jack (30) is fixedly connected to the first sliding plate (25).

5. A prestressed anchor cable tensioning method according to claim 3, characterized in that: The outer surface of the cable head rod (18) and the inner wall of the circular hole (23) are both kept smooth.

6. A prestressed anchor cable tensioning method according to claim 3, characterized in that: The steel wire ropes (8) are arranged in pairs, and both ends of the two steel wire ropes (8) are simultaneously connected to an anchor (21); The outer ring rotating sleeve of the cable head rod (18) is provided with an annular sleeve, and the annular sleeve is movably fitted on the inner wall of the circular hole (23).

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