A cable-girder anchorage structure facilitating maintenance in a steel truss girder cable-stayed bridge

Abstract

The present invention proposes a cable-beam anchoring structure in a steel truss cable-stayed bridge which is easy to maintain, comprising a main body, an anchor pad frame, a sliding column, a notch, a pressure sensor and a steel wire rope; the present invention is provided with an anchor pad frame and a sliding column, and when the pressure sensor is damaged, it is only necessary to lift the steel wire rope through a lifting mechanism to pull the end of the sliding column away from the force measuring end face of the pressure sensor, and then the pressure sensor can be removed from the notch for replacement; therefore, the present invention eliminates the need to pull the vibrating-wire pressure sensor out of the end of the cable during replacement, and there is no need to detach the anchor head from the anchor pad, and the operation is more convenient.

Description

Technical Field

[0001] The invention relates to the technical field of bridges, and in particular to a cable-beam anchoring structure in a steel truss girder cable-stayed bridge which is easy to maintain. Background Art

[0002] A cable-stayed bridge, also known as a cable-tensioned bridge, is a type of bridge in which the main beam is directly pulled onto the cable tower by many cables. It is a structural system composed of pressure-bearing towers, tensioned cables and bending-bearing beams. It has the characteristics of large spanning capacity and beautiful shape, and is the main type of long-span bridges. During the construction of a cable-stayed bridge, the steel truss girder in the main beam is connected to the cable through a cable-beam anchoring structure. As a structure that directly bears and transmits the force of the cable, it is one of the most critical and most complex stress areas of the steel truss girder. According to the structural form, the cable-beam anchoring structure of the steel box main beam is generally divided into three types: ear plate type, anchor plate and anchor box.

[0003] The traditional anchor box cable beam anchoring structure is mainly composed of a pressure plate, a top plate, a bottom plate and a cable sleeve; among them, the pressure plate, the top plate and the bottom plate are welded to the side longitudinal web of the steel truss; and the end of the inclined cable generally passes through the cable sleeve and then is anchored to the anchor pad through the anchor head, and the anchor pad is tightly attached to the pressure plate. At this time, the force transmission path of the inclined cable is: inclined cable → anchor pad → pressure plate → support plate → side longitudinal web → steel truss.

[0004] In order to monitor the cable load in real time for the safety and early warning of the bridge and to facilitate the long-term health monitoring of the bridge, a vibrating string pressure sensor is usually arranged between the anchor plate and the anchor head in the anchor box to monitor the cable load in real time. Since the vibrating string pressure sensor is an electronic component, its life is relatively short compared to the inclined cable or anchor box, and it is easy to be damaged. When the vibrating string pressure sensor is damaged and needs to be replaced, since the cable passes through the middle through hole of the vibrating string pressure sensor, the vibrating string pressure sensor needs to be pulled out from the end of the cable during replacement. At this time, the anchor head needs to be detached from the anchor plate, which is a more troublesome operation. Summary of the invention

[0005] The purpose of the present invention is to design a cable-beam anchoring structure in a steel truss cable-stayed bridge that is easy to maintain, so as to solve the problems raised by the background technology. In order to achieve the above purpose, the present invention provides the following technical solutions: it includes an anchor pad frame that is slidably connected to the main body, and the end of the cable passing through the anchor pad frame is installed on the side of the anchor pad frame away from the main body; there are no less than two sliding columns slidably connected to the main body distributed circumferentially on the anchor pad frame, and the main body is provided with a notch one, and a pressure sensor is detachably connected to the notch one. The end of the sliding column is tightly attached to the force measuring end face of the pressure sensor under the action of the cable, and a steel wire rope is fixed to the end of the anchor pad frame away from the pressure sensor; the steel wire rope can pull the end of the sliding column away from the force measuring end face of the pressure sensor under the action of a lifting mechanism.

[0006] Furthermore, a sliding cavity slidably connected to the sliding column is provided inside the main body, and an elastic member is provided at the end of the sliding column. The elastic member includes a clamping column and a force transmission column slidably connected to the sliding cavity. The clamping column and the force transmission column are connected by a spring, and the end of the force transmission column abuts against the end of the sliding column. One end of the sliding column squeezes the elastic member to transmit the cable force to the pressure sensor, and the steel wire rope is fixedly connected to the clamping column for clamping the pressure sensor. The sliding column is provided with a through hole, and the steel wire rope passes through the through hole.

[0007] Furthermore, a lifting head is fixedly connected to the end of the steel wire rope, and an external thread column and an internal hexagonal hole are provided on the lifting head, and a threaded hole matching with the external thread column is provided at the end of the sliding column.

[0008] Furthermore, a limiting column is provided on the sliding cavity, a limiting ring is provided on the pressing column, and a gap exists between the limiting ring and the limiting column.

[0009] Furthermore, a sealing ring 1 is provided on the clamping column, a sealing ring 2 is provided on the sliding column, the sealing ring 1 and the sealing ring 2 are filled with lubricating oil, the spring 1 is immersed in the lubricating oil, the clamping column is provided with a sliding column, the wire rope is located inside the sliding column, the end of the sliding column passes through the force transmission column and is slidably connected with the through hole, and a sealing ring 3 is provided on the sliding column located inside the through hole.

[0010] Furthermore, the lubricating oil is pressure oil, a damping column fixedly connected to one end of the spring is provided on the clamping column, a plurality of damping holes are provided between the damping column and the force transmission column, and an inert gas is filled between the damping column and the sealing ring.

[0011] Further, an extrusion ring that abuts against the force transmission column is fixedly connected to the end of the sliding column. A plurality of oil passing holes are provided on the extrusion ring, and the pressure oil enters the cavity between the extrusion ring and the second sealing ring through the damping hole and the oil passing holes.

[0012] Further, there are four sliding cavities. Two sliding cavities at the same height are connected through a flow channel. A fuel injection pipe and a pressure relief pipe communicating with the sliding cavity are provided on the side wall of the main body. One-way valves for preventing pressure oil leakage are installed inside the fuel injection pipe and the pressure relief pipe. A plug or a thimble is threadedly connected to the ends of the fuel injection pipe and the pressure relief pipe.

[0013] Further, a chute is provided on the sliding column, and a set screw is threadedly connected to the main body. The end of the set screw abuts against the bottom of the chute.

[0014] Further, a detachable sealing plate is provided in the first notch. An arc-shaped positioning plate that cooperates with the pressure sensor is provided on the inner wall of the sealing plate. A wire outlet is also provided on the sealing plate.

[0015] Further, a rubber ring is embedded at the end of the pressure sensor.

[0016] Further, a cable sleeve is fixedly connected to the main body. The side wall of the cable sleeve is fixedly connected to the inner wall of the main body through a rib plate.

[0017] Further, a drainage channel is provided inside the main body. One end of the drainage channel penetrates through the inner bottom of the main body.

[0018] Further, the thimble includes an external threaded column and the ejector rod fixedly connected to the bottom of the external threaded column. A hexagonal blind hole is provided inside the external threaded column, and a plurality of air passing holes are provided at the bottom of the blind hole.

[0019] Further, an FBG sensor is installed on the anchor pad bracket. The connecting block of the anchor pad bracket is fixedly connected to the sliding column. An FBG strain gauge is pasted on the side wall of one end of each of the four connecting blocks close to the sliding column. The strain values X1 to X4 of the four connecting blocks are measured by the four FBG strain gauges, and the sum of X1 to X4 is obtained as X 总 , and the correction number α = X i / X 总 ; where X i is the measured value of the FBG strain gauge pasted on the connecting block connected to the sliding column that transmits the cable force to the pressure sensor.

[0020] Further, one FBG strain gauge is respectively pasted on one side wall of the four sliding columns close to the connecting block. The strain values Y1 to Y4 of the four connecting blocks are measured by the four FBG strain gauges. The magnitudes of Y1 to Y4 are compared, and the minimum value is determined as Y i 。

[0021] Further, a plurality of support columns are threadedly connected to the end of the main body, and the end face of the support column abutted against the pressing column is flush with the force measuring end face of the pressure sensor.

[0022] Further, a positioning column is fixedly connected to the main body. The inside of the positioning column is connected to a positioning rod through a second spring. The positioning rod is slidably connected to the inside of the positioning column. A positioning hole communicating with the first notch is provided on the positioning column. The positioning rod passes through the positioning hole and inserts into the positioning through hole of the pressure sensor, and the positioning rod is slidably connected to the positioning through hole. A dial rod is fixedly connected to the positioning rod, and the dial rod passes out of the second notch in the positioning column.

[0023] Further, a cable sleeve is fixedly connected to the main body. The side wall of the cable sleeve is fixedly connected to the inner wall of the main body through a rib plate. The end of the cable sleeve is a flared tube. A plurality of groups of limiting components are further provided inside the main body. The limiting component includes four limiting rods fixedly connected to the inside of the main body and distributed in a grid pattern. A roller shaft is rotatably connected to the limiting rod. The cable is located in the square-shaped through hole formed by the four roller shafts, and the sizes of the plurality of square-shaped through holes gradually decrease along the axis of the cable and towards the direction of the cable sleeve.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows: An anchor pad frame and sliding columns are provided in the present invention. When the pressure sensor is damaged, only need to lift the steel wire rope through the lifting mechanism to pull the end of the sliding column away from the force measuring end face of the pressure sensor, and then the pressure sensor can be removed from the first notch for replacement; Therefore, the present invention eliminates the situation that the vibrating wire pressure sensor needs to be drawn out from the end of the cable during replacement in the past, and there is no need to detach the anchor head from the anchor backing plate, and the operation is more convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0026] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0027] Figure 2 A cross-sectional schematic view of a sliding cavity equipped with a wire rope;

[0028] Figure 3 A partial cross-sectional schematic view of the anchor head in the present invention;

[0029] Figure 4 A cross-sectional schematic view of the main body in the present invention;

[0030] Figure 5 An overall structural schematic view of the anchor pad frame;

[0031] Figure 6 A cross-sectional schematic view of the ejector pin;

[0032] Figure 7 A partial cross-sectional schematic view at the positioning rod in the second embodiment;

[0033] Figure 8 A partial cross-sectional schematic view at the support column in the third embodiment.

[0034] Wherein: 1. Main body; 2. Sliding column; 3. Anchor pad frame; 4. Anchor head; 5. Wire rope; 6. Lifting head; 7. Longitudinal support plate; 8. Rib plate; 9. Cable sleeve; 10. Through hole; 11. Seal ring three; 12. Damping hole; 13. Spring one; 14. Ejector pin; 15. Slide column; 16. Sliding cavity; 17. Plug; 18. Check valve; 19. Pressure sensor; 20. Rubber ring; 21. Seal ring one; 22. Damping column; 23. Force transmission column; 24. Extrusion ring; 25. Seal ring two; 26. Set bolt; 27. Chute; 28. Flow channel; 29. Drainage channel; 30. Compression column; 31. Seal plate; 32. Conical rubber pad; 33. Oil passing hole; 34. Cross-shaped reinforcing rib; 35. Hexagonal blind hole; 36. Air passing hole; 37. Thumb rod; 38. Positioning rod; 39. Support column; 40. Flared pipe; 41. Roller; 42. Limit rod. Specific embodiments

[0035] To further elaborate on the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following will, in conjunction with the accompanying drawings and preferred embodiments, describe in detail the specific embodiments, structures, features and their effects of the present invention as follows.

[0036] Embodiment 1: Please refer to Figures 1 - 6, a cable-beam anchoring structure in a steel truss cable-stayed bridge that is easy to maintain, comprises an anchor pad frame 3 slidably connected to a main body 1, and the end of the cable passing through the anchor pad frame 3 is installed on the side of the anchor pad frame 3 away from the main body 1; the installation of the cable end adopts a common installation method, that is, the anchor head 4 is anchored on the anchor pad plate, and the anchor pad plate will be pressed tightly on the anchor pad frame 3, and a conical platform is provided on the anchor head 4, which cooperates with the conical groove on the anchor pad frame 3, thereby increasing the force application area of the cable on the anchor pad frame 3 and effectively preventing the end of the cable from swinging, thereby improving the compactness of the structure; in addition, a cable sleeve 9 is fixedly connected to the main body 1, and the side wall of the cable sleeve 9 is fixedly connected to the inner wall of the main body 1 through a rib plate 8. The cable passes through the cable sleeve 9, which can prevent the end of the cable from swinging and affecting the transmission of the cable force; A drainage channel 29 is provided inside the main body 1, and one end of the drainage channel 29 passes through the inner bottom of the main body 1 to prevent the accumulation of rainwater; longitudinal support plates 7 are welded on both sides of the main body 1, and the longitudinal support plates 7 are respectively welded to the side longitudinal webs and side plates, and top plates are provided on the tops of the side longitudinal webs and side plates, and the side longitudinal webs, side plates and top plates are welded by transverse plates, and the cable sleeve 9 passes through the top plate and is welded to the top plate by a transition plate, thereby realizing a double-cantilever cable-beam anchoring structure, further improving the service life of the anchor box; and a conical platform and a conical groove are also provided between the anchor pad frame 3 and the main body 1, but a conical rubber pad 32 is provided between the two, and maintenance personnel can visually observe the deformation degree of the conical rubber pad 32, thereby intuitively observing the tension of the cable.

[0037] Since the vibrating wire pressure sensor senses external pressure through the change in the vibration frequency of the metal wire, and its vibration frequency is positively correlated with the tension (similar to the relationship between the string tension and the pitch of a string), it can convert mechanical deformation into an electrical signal output, thereby achieving high-precision capture of micron-level deformation. Compared with resistive or capacitive sensors, the vibrating wire pressure sensor is less sensitive to electromagnetic interference and temperature and humidity changes. Therefore, it is more suitable for long-term monitoring in complex electromagnetic environments and harsh climate conditions such as bridge anchor boxes. Usually, vibrating wire pressure sensors are arranged between the anchor backing plate and the anchor head 4 in the anchor box to monitor the load of the cable force in real time. However, since the vibrating wire pressure sensor is an electronic component, its lifespan is relatively short compared to the stay cable or the anchor box, and it is relatively easy to be damaged compared to other welded parts. Therefore, when the vibrating wire pressure sensor is damaged and needs to be replaced, since the stay cable passes through the middle through hole 10 of the vibrating wire pressure sensor, during replacement, the vibrating wire pressure sensor needs to be withdrawn from the end of the stay cable. At this time, the anchor head 4 needs to be detached from the anchor backing plate, and the operation is rather troublesome. Therefore, in the anchor pad frame 3 of the present invention, four sliding columns 2 slidably connected to the main body 1 are circumferentially distributed. The anchor pad frame 3 is fixedly connected to the sliding columns 2 through connecting blocks, and cross-shaped reinforcing ribs 34 are fixedly connected to both sides of the connecting blocks. A notch one is provided on the main body 1, and a pressure sensor 19 is detachably connected in the notch one. The end of one sliding column 2 is in close contact with the force-measuring end face of the pressure sensor 19 under the action of the stay cable, and the other three sliding columns 2 are in close contact with the limiting table inside the main body 1. A steel wire rope 5 is fixedly connected to the end of the anchor pad frame 3 away from the pressure sensor 19. Under the action of the lifting mechanism, the steel wire rope 5 can pull the end of the sliding column 2 away from the force-measuring end face of the pressure sensor 19. Among them, the lifting mechanism can be in the form of a combination of a jack and a support frame, that is, the support frame is supported on the end wall of the main body 1, and the end of the steel wire rope 5 is fixed on the telescopic rod of the jack. Starting the jack can lift the steel wire rope 5. So far, other specific details of the lifting mechanism are not elaborated too much in this article. Those skilled in the art can make adaptive adjustments according to the above process or the on-site environment. Therefore, when the pressure sensor 19 is damaged, only need to lift the steel wire rope 5 through the lifting mechanism to make the end of the sliding column 2 pull away from the force-measuring end face of the pressure sensor 19, and then the pressure sensor 19 can be removed from the notch one for replacement. It eliminates the situation that the vibrating wire pressure sensor 19 needs to be withdrawn from the end of the stay cable during previous replacement, and there is no need to detach the anchor head 4 from the anchor backing plate, and the operation is more convenient.

[0038] In this embodiment, a detachable sealing plate 31 is provided in the first notch. An arc-shaped positioning plate cooperating with the pressure sensor 19 is provided on the inner wall of the sealing plate 31. A wire outlet is also provided on the sealing plate 31. A rubber ring 20 is embedded at the end of the pressure sensor 19. The resistance generated by the slight deformation of the rubber ring 20 initially embeds the pressure sensor 19 in the first notch, preventing the pressure sensor 19 from slipping and falling due to gravity. Subsequently, the sealing plate 31 can be installed to position and fix the pressure sensor 19. The positioning process is that the arc-shaped positioning plate pushes the pressure sensor 19 to a suitable position. Among them, the installation method of the sealing plate 31 and the first notch can adopt the form of bolt connection.

[0039] Due to processing accuracy issues, the four sliding columns 2 may not be pressed on the limiting table and the pressure sensor 19 simultaneously; or in order to be pressed on the limiting table and the pressure sensor 19 simultaneously, a very high processing accuracy requirement for the main body 1 is needed. For this problem, in the present invention, a sliding cavity 16 slidably connected to the sliding column 2 is provided inside the main body 1. An elastic member is provided at the end of the sliding column 2. The elastic member includes a pressing column 30 and a force transmission column 23 slidably connected to the sliding cavity 16. The pressing column 30 and the force transmission column 23 are connected by a first spring 13, and the end of the force transmission column 23 abuts against the end of the sliding column 2. The end of one of the sliding columns 2 transmits the cable force to the pressure sensor 19 by squeezing the elastic member. Therefore, by adopting the elastic member as a transition form, the processing accuracy is converted into the deformation accuracy of the first spring 13, and this deformation accuracy is insignificant for the force transmission. Therefore, while reducing the processing accuracy of the main body 1, it can ensure that the cable force can be accurately transmitted to the pressure sensor 19, thereby improving the detection accuracy of the pressure sensor 19.

[0040] In addition, the elastic member can well convert the pressure on the pressure sensor 19 into one-fourth of the cable force, thereby increasing the service life of the pressure sensor 19. The steel wire rope 5 is fixedly connected to the pressing column 30 for pressing the pressure sensor 19. A through hole 10 is provided on the sliding column 2, and the steel wire rope 5 passes through the through hole 10. At this time, the lifting mechanism does not need to lift the entire cable force, but only needs to lift one-fourth of the cable force, which is convenient for the operation of maintenance personnel. The form of separating the elastic member from the sliding column 2 is beneficial to the processing of the structure of the present invention and the guarantee of precision. The end of the steel wire rope 5 is fixedly connected with a lifting head 6. The lifting head 6 is provided with an external threaded column and an internal hexagonal hole. The end of the sliding column 2 is provided with a threaded hole matching the external threaded column. When the pressure sensor 19 does not need to be replaced, the lifting head 6 is screwed into the threaded hole, so as to prevent dust and rainwater from flowing into the inside of the sliding cavity 16 and rusting the first spring 13, and increasing the service life of the first spring 13. The sliding cavity 16 is provided with a limiting column, and the pressing column 30 is provided with a limiting ring. There is a gap between the limiting ring and the limiting column to prevent the elastic member from colliding greatly when the lifting assembly is damaged or placed unstably.

[0041] In this embodiment, a first sealing ring 21 is provided on the pressing column 30, a second sealing ring 25 is provided on the sliding column 2, lubricating oil is filled in the first sealing ring 21 and the second sealing ring 25, the first spring 13 is immersed in the lubricating oil, a sliding column 15 is provided on the pressing column 30, the steel wire rope 5 is located inside the sliding column 15, the end of the sliding column 15 passes through the force transmission column 23 and is slidably connected to the through hole 10, and a third sealing ring 11 is provided on the sliding column 15 located inside the through hole 10, thereby further improving the service life of the first spring 13 and preventing the first spring 13 from rusting; since the cable will shake during use (when the vehicle is driving or in windy weather), the previous anchor box was only simply installed with shock pads, and the shock absorption effect was limited. In this embodiment, the lubricating oil is pressure oil, a damping column 22 fixedly connected to the end of the first spring 13 is provided on the pressing column 30, and a number of damping holes 12 are provided between the damping column 22 and the force transmission column 23. Inert gas is filled between the damping column 22 and the first sealing ring 21. Therefore, the first spring 13 converts the shake into reciprocating motion. During the reciprocating motion, the process of the pressure oil passing through the damping holes 12 and the process of the pressure oil compressing the inert gas will generate damping, thereby playing a role in shock absorption and buffering for the shake of the cable; an extrusion ring 24 abutting against the force transmission column 23 is fixedly connected to the end of the sliding column 2, and a number of oil passing holes 33 are provided on the extrusion ring 24. The pressure oil enters the cavity between the extrusion ring 24 and the second sealing ring 25 through the damping holes 12 and the oil passing holes 33; the extrusion ring 24 can fully abut against the force transmission column 23 without hindering the pressure oil from flowing into the cavity between the extrusion ring 24 and the second sealing ring 25, thereby increasing the volume of the pressure oil, improving the damping effect while enhancing the anti-corrosion effect of the first spring 13; there are four sliding cavities 16, and two sliding cavities 16 at the same height are connected by a flow channel 28. A pressure oil injection pipe and a pressure relief pipe communicating with the sliding cavity 16 are provided on the side wall of the main body 1. The pressure relief pipe is located between the pressure oil injection pipe and the pressure sensor 19. Check valves 18 for preventing pressure oil leakage are installed inside the pressure oil injection pipe and the pressure relief pipe. Plug heads 17 are threadedly connected to the ends of the pressure oil injection pipe and the pressure relief pipe, thereby realizing the filling of the pressure oil and the stability of the internal oil circuit; in addition, during the installation process, the side of the main body 1 with the first notch is located below, which is convenient for the replacement and maintenance of the pressure sensor 19; a sliding groove 27 is provided on the sliding column 2, and a set screw 26 is threadedly connected to the main body 1. The end of the set screw 26 abuts against the bottom of the sliding groove 27, which is convenient for the installation of the structure and prevents the sliding column 2 from detaching from the sliding cavity 16.

[0042] Since the cable will sway during use, the original cable was directly led out from the cable sleeve 9 during installation. When the cable sways, the rubber layer on the surface of the cable will be scratched over a large area at the outlet of the cable sleeve 9, thus damaging the rubber layer on the surface of the cable and reducing the service life of the cable. Therefore, in this embodiment, a flared pipe 40 is provided at the end of the cable sleeve 9, and several groups of limiting components are further provided inside the main body 1. The limiting components include four limiting rods 42 fixedly connected inside the main body 1 and distributed in a cross shape. A roller shaft 41 is rotatably connected to the limiting rod 42. The cable is located in the square-shaped through hole 10 formed by the four roller shafts 41, and the sizes of several square-shaped through holes 10 gradually decrease along the axis of the cable and in the direction towards the cable sleeve 9. Therefore, when the cable sways, the outer circle of the cable will successively lean against the roller shafts 41 in the square-shaped through hole 10. Since the size of the square-shaped through hole 10 gradually decreases, the swaying angle of the cable is gradually reduced, and thus the swaying angle of the cable at the outlet of the cable sleeve 9 is greatly reduced, thereby improving the service life of the cable.

[0043] The process of assembling the cable-beam anchoring structure that is convenient for maintenance in the above-mentioned steel truss girder cable-stayed bridge is as follows: Install the pressure sensor 19 in notch one and fix it through the sealing plate 31; then slide the four elastic members into the sliding cavity 16 respectively, and then slide the sliding column 2 in the anchor pad frame 3 into the sliding cavity 16, so that the end of the sliding column 2 abuts against the force-transmitting column 23. Then, turn the set screw 26 so that the end of the set screw 26 abuts against the bottom of the chute 27; then invert the main body 1, that is, make the anchor pad frame 3 abut against the ground, place the cable sleeve 9 vertically upward, so that the end of the pressing column 30 presses against the pressure sensor 19. Screw the thimble 14 into the internal injection oil pipe, and screw the plug 17 into the pressure relief pipe. The ejector rod 37 in the thimble 14 will open the one-way valve 18 in the injection oil pipe. Then, connect the three-way pipe with the injection oil pipe. Among them, the other two ends of the three-way pipe are provided with valves and are respectively connected with the nitrogen supply system and the negative pressure extraction system; both the nitrogen supply system and the negative pressure extraction system adopt common systems, and will not be elaborated too much in this article; start the negative pressure extraction system to extract air from the two connected sliding cavities 16, and extract the remaining air inside through the air holes 36 in the thimble 14; then close the valve connected to the negative pressure extraction system after extraction, open the other valve, and fill the inside with nitrogen through the nitrogen supply system. When the pressure inside the sliding cavity 16 is slightly higher than the external pressure, stop inflation, and remove the three-way pipe, the thimble 14 and the plug 17, and screw the thimble 14 into the internal pressure relief pipe. The ejector rod 37 in the thimble 14 will open the one-way valve 18 in the pressure relief pipe; then pour the pressure oil into the sliding cavity 16 through the oil pressure system. When the liquid level leaks out from the pressure relief pipe, remove the thimble 14; then continue to input the pressure oil until it submerges the damping column 22 and then stop. In this process, the debugging of the pressure sensor 19 is completed; then remove the oil pressure system, and block the injection oil pipe and the pressure relief pipe with the plug 17, thus completing the assembly; and the above-mentioned thimble includes an external thread column and an ejector rod fixed to the bottom of the external thread column. The inside of the external thread column is provided with a hexagonal blind hole for facilitating the screwing of the thimble; the bottom of the hexagonal blind hole 35 is provided with several air holes for facilitating the flow of gas.

[0044] Due to the manufacturing precision of the elastic blocks, for example, the lengths of different springs - 13 may be inconsistent during the processing, or the material properties of different springs - 13 may also have some differences, which easily leads to different degrees of elastic deformation of the springs - 13. Or after long - term use, the fatigue generated by the four springs - 13 is different, thus resulting in different forces on the four springs - 13; the above - mentioned situations will all cause the pressure acting on the pressure sensor 19 not to be accurately regarded as one - quarter of the cable force; at this time, if the value of the pressure sensor 19 is multiplied by four to be used as the actual cable force, a certain measurement error will occur; based on the above - mentioned problem of measurement accuracy, a correction value is introduced in the present invention to correct the test value of the pressure sensor 19. The maintenance personnel only need to correct it regularly during maintenance to obtain a more accurate cable force. Specifically, an FBG sensor is installed on the anchor pad holder 3. Among them, the FBG sensor is a fiber Bragg grating sensor, and the FBG sensor does not need to be started in real - time and can be started during maintenance; the FBG sensor has a high measurement accuracy for strain and thus feeds back the corresponding stress (force) value; in the present invention, the connecting block of the anchor pad holder 3 is fixedly connected to the sliding column 2, and an FBG strain gauge is pasted on the side wall of each of the four connecting blocks near one end of the connecting block. The reason for selecting this position is that in the entire anchor pad holder 3 and the sliding column 2, the strain at the connection between the connecting block and the sliding column 2 is larger, which is more conducive to the measurement of the FBG sensor; subsequently, the strain values X1 to X4 of the four connecting blocks are measured by the four FBG strain gauges, and the sum of X1 to X4 is obtained as X 总 , and the correction number α = X i / X 总 ; where X i is the measurement value of the FBG strain gauge pasted on the connecting block connected to the sliding column 2 that transmits the cable force to the pressure sensor 19, so as to obtain the proportion of the stress at the connection between the connecting block and the sliding column 2 to the total stress, and then the proportion of the value measured by the pressure sensor 19 to the cable force can be obtained; at this time, the cable force is: the value obtained by dividing the value measured by the pressure sensor 19 by the correction number α.

[0045] Embodiment 2: Please refer to Figure 7 , the difference from Embodiment 1 is that a positioning column is fixedly connected to the main body 1. Inside the positioning column, a positioning rod 38 is connected to a spring two. The positioning rod 38 is slidably connected inside the positioning column. The positioning column is provided with a positioning hole communicating with the notch one. The positioning rod 38 passes through the positioning hole and is inserted into the positioning through - hole 10 of the pressure sensor 19, and the positioning rod 38 is slidably connected to the positioning through - hole 10. A dial rod is fixedly connected to the positioning rod 38, and the dial rod passes through the notch two in the positioning column; thus, it is convenient for the accurate positioning during the installation of the pressure sensor 19 and prevents the uneven force on the pressure sensor 19 from affecting the test data.

[0046] Embodiment 3: Please refer toFigure 8 , different from the first embodiment, a number of support columns 39 are threadedly connected to the end of the main body 1. An internal hexagonal threaded hole is provided inside the support column 39. The end face of the support column 39 in contact with the pressing column 30 is flush with the force-measuring end face of the pressure sensor 19. Therefore, the elastic member can be replaced or the spring force can be adjusted; since the main body 1 is usually inclined upward after welding, the pressure oil will not leak during replacement; when the cable shakes less, the value of the pressure sensor 19 will only fluctuate around the standard value. However, if the value of the pressure sensor 19 is too large at this time, it means that one of the other three elastic members has been damaged. At this time, it is necessary to determine which elastic member is damaged so as to replace it; when determining which specific spring member is damaged, a method can be adopted in which an FBG strain gauge is respectively pasted on one side wall of the four sliding columns 2 close to the connection block. The strain values Y1 to Y4 of the four connection blocks are measured by the four FBG strain gauges. Compare the magnitudes of Y1 to Y4 and determine the minimum value as Y i , then Y i The corresponding elastic member is the damaged elastic member, and only need to replace it; the purpose of selecting the FBG strain gauge pasted on the side wall of the sliding column 2 close to the connection block is that since the connection block is plate-shaped, that is, permanent deformation is likely to occur at the connection block, this permanent deformation will affect the measurement of the FBG strain gauge, and will narrow the difference in strain between this position and other positions, and then it is easy to make a wrong judgment of Y i ; but on the side wall of the sliding column 2 close to the connection block (that is, the inner side of the sliding column 2), first, the force here is greater than that on the side wall of the sliding column 2 away from the connection block (that is, the outer side of the sliding column 2), which is convenient for collecting strain data; second, the permanent deformation occurring on the sliding column 2 is less, thereby improving the accurate discrimination accuracy of Y i , and then the damaged elastic member can be accurately replaced.

[0047] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be intermediate elements at the same time. The terms "upper", "lower", "left", "right", "front", "rear" and similar expressions used in this article are only for the purpose of illustration.

[0048] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Although the present invention has been disclosed above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to the equivalent embodiments of equivalent changes within the scope of the technical solution of the present invention by using the above-disclosed technical content. However, as long as it does not depart from the content of the technical solution of the present invention, any brief modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A cable-beam anchorage structure for facilitating maintenance in a steel truss girder cable-stayed bridge, characterized in that: It comprises an anchor pad frame connected to the main body in a sliding manner and to the end of the cable; the anchor pad frame has no less than two sliding columns connected to the main body in a sliding manner distributed circumferentially, the main body is provided with a notch one, a pressure sensor is detachably connected to the notch one, the end of the sliding column is in close contact with the force measuring end face of the pressure sensor under the action of the cable, and a steel wire rope is fixedly connected to the end of the anchor pad frame away from the pressure sensor; the steel wire rope can pull the end of the sliding column away from the force measuring end face of the pressure sensor under the action of a lifting mechanism; The interior of the main body is provided with a sliding cavity slidably connected to the sliding column, and an elastic member is provided at the end of the sliding column. The elastic member includes a clamping column and a force transmission column slidably connected to the sliding cavity. The clamping column and the force transmission column are connected by a spring, and the end of the force transmission column abuts against the end of the sliding column. The end of the sliding column squeezes the elastic member to transmit the cable force to the pressure sensor. The steel wire rope is fixedly connected to the clamping column for clamping the pressure sensor. The sliding column is provided with a through hole, and the steel wire rope passes through the through hole. The sliding chambers are provided with four, and two sliding chambers at the same height are connected through a flow channel. The side wall of the main body is provided with an oil injection pipe and a pressure relief pipe connected with the sliding chamber. The pressure relief pipe is located between the oil injection pipe and the pressure sensor. The inside of the oil injection pipe and the pressure relief pipe is installed with a one-way valve to prevent leakage of pressure oil. The ends of the oil injection pipe and the pressure relief pipe are threadedly connected with a plug or an ejector pin; A positioning column is fixedly connected to the main body, and the interior of the positioning column is connected to the positioning rod through spring 2. The positioning rod is slidably connected to the interior of the positioning column. A positioning hole connected to the notch 1 is provided on the positioning column. The positioning rod passes through the positioning hole and is inserted into the positioning through hole of the pressure sensor. The positioning rod is slidably connected to the positioning through hole. A shift rod is fixedly connected to the positioning rod, and the shift rod passes through the notch 2 in the positioning column.

2. The cable-beam anchorage structure facilitating maintenance in the steel truss girder cable-stayed bridge according to claim 1, wherein: The clamping column is provided with a sealing ring 1, the sliding column is provided with a sealing ring 2, the sealing ring 1 and the sealing ring 2 are filled with lubricating oil, the spring 1 is immersed in the lubricating oil, the clamping column is provided with a sliding column, the wire rope is located inside the sliding column, the end of the sliding column passes through the force transmission column and is slidably connected with the through hole, and the sliding column located inside the through hole is provided with a sealing ring 3.

3. The cable-beam anchorage structure facilitating maintenance in the steel truss girder cable-stayed bridge according to claim 2, characterized in that: The lubricating oil is pressure oil, a damping column fixedly connected to one end of the spring is provided on the compression column, a plurality of damping holes are provided between the damping column and the force transmission column, and an inert gas is filled between the damping column and the sealing ring.

4. The cable-girder anchorage structure facilitating maintenance in the steel truss girder cable-stayed bridge according to claim 1, wherein: The anchor pad frame is equipped with an FBG sensor. The connecting block of the anchor pad frame is fixedly connected to the sliding column. An FBG strain gauge is attached to the side wall of one end of the four connecting blocks close to the sliding column.

5. The cable-beam anchorage structure facilitating maintenance in the steel truss girder cable-stayed bridge according to claim 1, characterized in that: The anchor pad frame is equipped with an FBG sensor, the connection block of the anchor pad frame is fixedly connected to the sliding column, and a FBG strain gauge is respectively attached to one side wall of the four sliding columns close to the connection block.

6. The cable-girder anchorage structure facilitating maintenance in the steel truss girder cable-stayed bridge according to claim 5, characterized in that: The end of the main body is threadedly connected with a plurality of support columns, and the end face of the support column in contact with the pressing column is flush with the force-measuring end face of the pressure sensor.

7. The cable-girder anchorage structure facilitating maintenance in the steel truss girder cable-stayed bridge according to claim 1, characterized in that: A cable sleeve is fixedly connected to the main body. The side wall of the cable sleeve is fixedly connected to the inner wall of the main body through a rib plate. The end of the cable sleeve is a flared pipe. A plurality of groups of limiting components are further arranged inside the main body. The limiting components include four limiting rods fixedly connected inside the main body and distributed in a cross shape. A roller shaft is rotatably connected to the limiting rod. The cable is located in a square-shaped through hole formed by the four roller shafts, and the sizes of a plurality of the square-shaped through holes gradually decrease along the axis of the cable and in the direction towards the cable sleeve.

Images