A rotating catwalk bearing rope wear rapid test device and test method

Abstract

The application discloses a rotating catwalk bearing cable abrasion rapid test device and a test method, which comprises a motor-driven roller, a rotatable rigid bone wheel, a steel pipe and a rotating speed measuring instrument; the bearing cable to be detected is tensioned and fixed on the outer periphery of the rigid bone wheel; the inner wall surface of the steel pipe is provided with a protective layer; the top surface of the steel pipe relative to the bearing cable is provided with an opening; the steel pipe is installed below the rigid bone wheel; the distance between the steel pipe and the rigid bone wheel is set to be such that the bottom of the bearing cable and the inner wall surface of the steel pipe are in friction when the rigid bone wheel drives the bearing cable to rotate; and the rotating speed measuring instrument is used for measuring the rotating speed of the rigid bone wheel. The application can test the feasibility of the catwalk bearing cable passing through the bridge tower.

Description

Technical Field

[0001] This patent relates to the technology of passing the catwalk load-bearing cable through the bridge tower in the temporary structure of the suspension bridge project, specifically a rotating catwalk load-bearing cable wear rapid testing device and testing method. Background Technology

[0002] For long-span suspension bridges, catwalks are generally arranged in a three-span continuous configuration. During traction, the catwalk cables cross the main towers, typically using a method of bypassing the tower by going around the saddle above the main cable to connect the two main towers. With the development of bridges, new structural forms are constantly emerging. To address construction challenges such as a single span crossing navigable waterways and tower height restrictions due to proximity to an airport, a novel four-main-cable suspension bridge structure with varying sags was proposed for the first time. Considering the stress on the catwalk cables and the installation of the tower-top displacement steel frame during construction, after comprehensive comparison, the lower-level catwalk cables were chosen to pass through the tower using a method of embedding steel pipes inside the tower as ducts for the cables. During the traction process of the cables passing through the pipes, their significant weight causes contact and friction with the duct wall, resulting in wear on the cables and the protective material inside the duct.

[0003] Due to the long traction length, in order to ensure the construction safety and structural stability of the catwalk system, it is necessary to conduct tests and evaluations on the wear of the load-bearing cables and the borehole walls before the specific application of the scheme. At present, there is no complete set of test devices and methods to effectively simulate and evaluate the mutual wear between the load-bearing cables of the catwalk and the borehole walls during the traction process of the catwalk passing through the tower. Therefore, it is urgent to propose a rapid test device and method for the wear of the load-bearing cables of the catwalk when passing through the tower of the catwalk of the large-span suspension bridge, so as to truly reflect the mutual wear between the load-bearing cables and the borehole walls during the actual traction process, and provide a test basis for the diversity of catwalk erection schemes for innovative structural forms of suspension bridges. Summary of the Invention

[0004] The purpose of this invention is to provide a rapid testing device and method for wear of rotating catwalk load-bearing cables, which can verify the feasibility of a scheme where the catwalk load-bearing cables pass through a bridge tower.

[0005] The technical solution adopted by the present invention to solve this technical problem is: a rotating catwalk load-bearing cable wear rapid testing device and testing method, including a rotatable steel wheel, a steel pipe and a speed measuring instrument; The load-bearing cable to be tested is tensioned and fixed to the outer circumference of the steel frame wheel. The inner wall of the steel pipe is provided with a protective layer. The top surface of the steel pipe relative to the load-bearing cable is provided with an opening. The steel pipe is installed below the steel frame wheel. The distance between the steel pipe and the steel frame wheel is set such that when the steel frame wheel drives the load-bearing cable to rotate, the bottom of the load-bearing cable rubs against the inner wall of the steel pipe. The speed measuring instrument is used to measure the speed of the steel frame wheel.

[0006] Preferably, the protective layer is a polytetrafluoroethylene layer.

[0007] Preferably, the steel frame wheel is a roller structure with a notch, and the two ends of the load-bearing cable are tensioned and extended to the notch of the steel frame wheel, and fixed to the steel frame wheel by steel plates and bolts.

[0008] Preferably, the steel frame wheel is coaxially fixed with the roller, and the roller drives the steel frame wheel to rotate.

[0009] Preferably, the system also includes a support frame, which has a sliding groove along its height direction. The height of the steel pipe is adjusted through the sliding groove. Bolt holes are spaced apart on the support frame, and both ends of the steel pipe are fixed to the support frame with bolts.

[0010] Preferably, the bottom of the bracket is fixed to the ground by anchor bolts.

[0011] This invention also provides a testing method using the aforementioned rotary catwalk load-bearing cable wear rapid testing device, wherein the wire rope wear detection includes: A1. The rotation speed of the steel frame wheel can be converted into the traction distance of the load-bearing cable. When the traction length of the load-bearing cable is four times the length of the steel pipe embedded in the bridge tower on one side (for two bridge towers, considering the friction length during installation and removal), stop the rotation of the steel frame wheel and remove the load-bearing cable. A2. Evaluate the wear condition of the load-bearing cable after it simulates traction through the steel pipe. The evaluation indicators are: Wear condition of the steel wire surface of the outer strands of the load-bearing cable; Nominal diameter test: Determine whether the cross-sectional area of ​​the load-bearing cable has been significantly reduced. When the diameter of the load-bearing cable is reduced by 7% or more relative to the nominal diameter, the load-bearing cable is unusable even if no wire breaks have occurred. Breaking strength test: Use professional instruments to test the tensile strength of the worn wire rope to see if the strength has been reduced. If the strength is less than the minimum breaking strength of the wire rope of this specification in the standard, even if no wire breaks, this load-bearing rope cannot be used.

[0012] This invention also provides a testing method using the aforementioned rotary catwalk load-bearing cable wear rapid testing device, wherein the steel pipe wear detection includes: B1. Rotate the steel frame wheel until all the load-bearing cables are pulled through the steel pipe, then stop rotating the steel frame wheel and remove the load-bearing cables; B2. Take photos of the appearance of the protective layer of the steel pipe, conduct a preliminary assessment of the wear condition, and test the friction coefficient of the protective layer.

[0013] Preferably, if during the traction process of the load-bearing cable in step B1, the external wear of the load-bearing cable and the protective layer is continuously observed, and when visible fuzzing, scratches and wear appear on the surface, the rotation of the steel roller is paused, the friction coefficient of the protective layer is tested, the rotation speed and rotation time of the steel roller are recorded, and converted into the number of rotations of the steel roller, which is then converted into the traction distance of the wire rope to evaluate the durability of the protective layer.

[0014] The present invention provides at least the following beneficial effects: the wear test device and method for the load-bearing cable of a suspension bridge catwalk passing through the tower can provide a process feasibility basis for the scheme of load-bearing cable passing through the tower. This device is not only simple in structure, easy to operate, and saves floor space, but also solves the problems of the long actual traction length of the load-bearing cable being inconvenient to simulate, and the durability test of the steel pipe protective layer, by utilizing the rotation of the motor.

[0015] It has the following characteristics: (1) It can realistically simulate the traction process of the load-bearing cable of the catwalk of a long-span cantilever bridge by controlling the speed and number of rotations of the rollers and the tension of the load-bearing cable; (2) It can perform wear tests on the protective material of the inner wall of the steel pipe, evaluate the durability and stability of the protective layer, and determine when it is necessary to replace it; (3) It can use economical and convenient test equipment to simulate long-distance traction of load-bearing cables and achieve different test objectives.

[0016] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the rotary catwalk load-bearing cable wear rapid testing device of the present invention.

[0018] Explanation of reference numerals in the attached drawings: 1-roller, 2-steel frame wheel, 3-load-bearing cable, 4-steel plate, 5-steel pipe, 6-support, 7-anchor bolt. Detailed Implementation

[0019] The present invention will now be described in detail and completely with reference to the accompanying drawings. Those skilled in the art will be able to implement the present invention based on these descriptions. Before describing the present invention with reference to the accompanying drawings, it should be particularly noted that the technical solutions and features provided in various parts of the present invention, including the following description, can be combined with each other without conflict.

[0020] Furthermore, the embodiments of the present invention described below are generally only some, not all, of the embodiments of the present invention. Therefore, all other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

[0021] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. The specific implementation process is as follows: Example 1 The actual traction distance of the load-bearing cable 3 of the catwalk of the long-span suspension bridge is relatively long, reaching 3,000 meters, and it occupies a large area, making it impossible to simulate the entire traction process. In order to save the land area and realistically simulate the traction process, this device is used to simulate the traction of the entire line, while also testing the durability of the protective measures.

[0022] like Figure 1 As shown, the rotary catwalk support cable 3 wear rapid testing device includes a rotatable steel wheel 2, a steel pipe 5, and a speed measuring instrument. The steel wheel 2 is coaxially welded and fixed to the roller 1, and the roller 1 drives the steel wheel 2 to rotate. The roller 1 is driven by a motor. The steel wheel 2 is designed to facilitate the winding of the support cable 3. The support cable 3 is tensioned and wound tightly around the steel wheel 2 and fixed to the steel wheel 2 by a steel plate 4 and bolts. Then, the rotation of the roller simulates the traction process of the support cable 3.

[0023] Below roller 1 is a steel pipe 5 with the same diameter and material as the pre-embedded pipes inside the actual tower. For ease of observation and operation, the upper part of the steel pipe 5 is open. Referring to the construction plan, the inner wall of the steel pipe 5 is covered with a polytetrafluoroethylene (PTFE) protective layer used in actual construction. The relative position of roller 1 and steel pipe 5 is controlled by supports 6 on both sides to ensure contact between the load-bearing cable 3 and the inner side of the steel pipe 5, simulating the friction between the load-bearing cable 3 and the inner wall of the steel pipe 5 as it passes through. The supports are fixed to the ground by anchor bolts 7.

[0024] In this embodiment, the traction length of the load-bearing cable 3 at a single point is 40 meters, which is the length of the pre-embedded steel pipe 5 passing through the two bridge towers (the length of the pre-embedded steel pipe 5 for a single bridge tower is 10 meters, considering installation and removal). However, the actual length of the load-bearing cable 3 is 3000 meters, which means that the single point of the protective layer of the steel pipe 5 will undergo 3000 meters of continuous friction. Therefore, in addition to judging the wear degree of the load-bearing cable 3 after passing through the tower, this test focuses on the fatigue test of the inner wall of the steel pipe 5 to determine the timing of replacing the protective layer of the steel pipe 5. Among them, the structural factors affecting the wear test system between the load-bearing cable 3 of the catwalk of the long-span suspension bridge and the pre-embedded steel pipe 5 in the tower are mainly: 1. Traction tension of load-bearing cable 3: In actual operation, the load-bearing cable 3 has a certain internal tension during traction. In the test, the end of the load-bearing cable 3 was tensioned by a winch and fixed to the roller 1 frame with bolts and steel plates 4.

[0025] 2. Specifications of load-bearing cable 3: The specifications of the steel wire rope shall be selected according to the actual specifications of the load-bearing cable 3 of the catwalk, and a steel wire rope with a diameter of 60mm and a strength of 2160MPa shall be selected.

[0026] 3. Roller 1 rotation speed: Control the rotation speed of roller 1 to keep the linear speed consistent with the actual traction speed of the load-bearing cable 3.

[0027] 4. Dimensions of steel pipe 5: The diameter of steel pipe 5 is 100mm, the upper opening is in contact with the steel wire rope, and the inner wall is lined with a 3mm thick polytetrafluoroethylene protective layer.

[0028] The rotary catwalk load-bearing cable 3 wear rapid testing device was processed and installed according to the corresponding dimensions. The position of the steel pipe 5 was adjusted by the slide groove to ensure continuous contact with the wire rope. The rotation speed of the roller 1 was adjusted, and the number of rotations of the roller 1 was recorded by a speed measuring instrument during the test.

[0029] Wire rope wear detection Wire rope wear detection includes: A1. By detecting the rotation speed of the steel frame wheel 2, the traction distance of the load-bearing cable 3 can be converted. When the traction length of the load-bearing cable 3 is four times the length of the pre-embedded steel pipe 5 of a single bridge tower, that is, 40 meters, stop the rotation of the steel frame wheel 2 and remove the load-bearing cable 3. A2. Evaluate the wear condition of the load-bearing cable 3 after it simulates traction through the steel pipe 5. The evaluation indicators are: Wear condition of the steel wire surface of the outer strand of the load-bearing cable 3; Nominal diameter test: Determine whether the cross-sectional area of ​​load-bearing cable 3 has decreased significantly. When the diameter of load-bearing cable 3 is reduced by 7% or more relative to the nominal diameter, even if no wire breakage has occurred, this load-bearing cable 3 is unusable. Breaking strength test: Use professional instruments to test the tensile strength of the worn wire rope to see if the strength has been reduced. If the strength is less than the minimum breaking strength of the wire rope of this specification in the standard, even if no wire breaks, this load-bearing cable 3 is not usable.

[0030] Wear inspection of steel pipe 5 includes: B1. When the steel frame wheel 2 is rotated until all the load-bearing cables 3 have passed through the steel pipe 5 and completed the traction, that is, the traction length of 3000 meters, stop rotating the steel frame wheel 2 and remove the load-bearing cables 3. B2. Take photos of the appearance of the protective layer of steel pipe 5, and conduct a preliminary assessment of the wear condition (such as surface roughness, scratches or grooves) and test the friction coefficient of the protective layer.

[0031] If, during the traction process in step B1, the external wear of the load-bearing cable 3 and the protective layer is continuously observed, and visible wear such as fuzzing or scratches appears on the surface, the rotation of the steel roller 2 is paused, the friction coefficient of the protective layer is tested, the rotation speed and rotation time of the steel roller 1 are recorded, and converted into the number of revolutions of the steel roller 2, which is then converted into the traction distance of the wire rope to evaluate the durability of the protective layer.

[0032] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and embodiments shown and described herein.

Claims

1. A rapid testing device for wear of rotating catwalk support cables, characterized in that, Includes a rotatable steel wheel, steel pipe, and a speed measuring instrument; The load-bearing cable to be tested is tensioned and fixed to the outer circumference of the steel frame wheel. The inner wall of the steel pipe is provided with a protective layer. The top surface of the steel pipe relative to the load-bearing cable is provided with an opening. The steel pipe is installed below the steel frame wheel. The distance between the steel pipe and the steel frame wheel is set such that when the steel frame wheel drives the load-bearing cable to rotate, the bottom of the load-bearing cable rubs against the inner wall of the steel pipe. The speed measuring instrument is used to measure the speed of the steel frame wheel.

2. The rapid wear testing device for rotary catwalk support cables as described in claim 1, characterized in that, The protective layer is a polytetrafluoroethylene layer.

3. The rapid wear testing device for rotary catwalk support cables as described in claim 1, characterized in that, The steel frame wheel is a roller structure with a notch. The two ends of the load-bearing cable are tensioned and extended to the notch of the steel frame wheel, and are fixed to the steel frame wheel by steel plates and bolts.

4. The rapid wear testing device for rotary catwalk load-bearing cables as described in claim 1 or 3, characterized in that, The steel frame wheel is fixed coaxially with the roller, and the roller drives the steel frame wheel to rotate.

5. The rapid wear testing device for rotary catwalk support cables as described in claim 1, characterized in that, It also includes a support frame, which has a sliding groove along the height direction and bolt holes spaced apart on the support frame. The two ends of the steel pipe are fixed to the support frame by bolts.

6. The rapid wear testing device for rotary catwalk support cables as described in claim 5, characterized in that, The bottom of the bracket is fixed to the ground by anchor bolts.

7. A test method using the rapid wear test device for rotating catwalk load-bearing cables as described in any one of claims 1 to 6, characterized in that, Load-bearing cable wear detection includes: A1. When the steel frame wheel is rotated to four times the length of the steel pipe embedded in the bridge tower on one side, stop rotating the steel frame wheel and remove the load-bearing cable. A2. Evaluate the wear condition of the load-bearing cable after it simulates traction through the steel pipe. The evaluation indicators are: Nominal diameter inspection: Determine whether the cross-sectional area of ​​the load-bearing cable has been significantly reduced. When the diameter of the load-bearing cable is reduced by 7% or more relative to the nominal diameter, the load-bearing cable is unusable even if no wire breakage has occurred. Breaking tensile test: Use professional instruments to conduct a tensile test on the worn load-bearing cable to see if the strength has been reduced. If the strength is less than the minimum breaking force of the same specification load-bearing cable before wear in the specification, even if no wire breaks, this load-bearing cable is not usable.

8. A test method using the rapid wear test device for rotating catwalk load-bearing cables as described in any one of claims 1 to 6, characterized in that, Steel pipe wear detection includes: B1. Rotate the steel frame wheel until all the load-bearing cables are pulled through the steel pipe, then stop rotating the steel frame wheel and remove the load-bearing cables; B2. Take photos of the appearance of the protective layer of the steel pipe, conduct a preliminary assessment of the wear condition, and test the friction coefficient of the protective layer.

9. The test method of the rapid wear test device for rotating catwalk load-bearing cables as described in claim 8, characterized in that, If, during the traction process in step B1, the external wear of the load-bearing cable and the protective layer is continuously observed, and visible fuzzing, scratches, or wear appear on the surface, the rotation of the steel frame wheel is paused, the friction coefficient of the protective layer is tested, the rotation speed and rotation time of the roller fixed coaxially with the steel frame wheel are recorded, and converted into the number of rotations of the steel frame wheel, which is then converted into the traction distance of the load-bearing cable to evaluate the durability of the protective layer.

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