A device for accurately positioning deflection measuring points and strain measuring points in a bridge static load test

Abstract

This invention discloses a device for accurately locating deflection and strain measurement points in bridge static load tests, comprising: a cross-section positioning device and a strain sensor orientation positioning device. The cross-section positioning device consists of a steel plate, a magnetic base, and a laser pointer. The laser pointer is fixed to the bottom surface of the main beam on one side of the test cross-section via the steel plate and magnetic base. The laser emitted by the laser pointer points from one side of the test cross-section to the other side to determine the position of the test cross-section. The strain sensor orientation positioning device consists of an angle disc, a cross-section positioning plate, an orientation positioning rod, and fastening screws. During use, the angle of the orientation pointer is adjusted to match the oblique angle of the test bridge span, and then the cross-section positioning plate is positioned within the test cross-section. At this point, the direction of the orientation positioning rod is the direction of the bridge axis at the strain measurement point. This device can accurately determine the position of the deflection measurement point at the bottom of the beam and the position and bonding direction of the strain sensor during bridge static load tests, avoiding inaccurate measurement results due to inaccurate bonding direction.

Description

Technical Field

[0001] This invention relates to the field of auxiliary devices for bridge static load testing, specifically to a device for accurately locating deflection and strain measuring points in bridge static load testing. Background Technology

[0002] With the continuous development of my country's transportation industry, a large number of bridges have been built on highways. To ensure the safety of the public traveling on these bridges, static and dynamic load tests must be conducted during the completion and operation phases to determine their safety. This has become a crucial issue. The static load test assesses the bridge's load-bearing capacity by comparing the measured strain values ​​and theoretically calculated strain values, as well as the measured deflection values, at the test sections under test loads.

[0003] The accuracy of strain measurements depends not only on the performance of the testing instrument but also on the precise orientation of the strain sensor. In bridge static load tests, numerous strain gauges or strain plates are installed on the bottom of the beam to monitor stress during loading. However, if the strain gauges or strain plates are not precisely positioned during installation, two problems arise: first, the strain measurement points are not located on the test section; second, the strain measurement direction is not parallel to the axis of the main beam. These two problems will result in inaccurate strain test results, potentially leading to errors in the assessment of the bridge's load-bearing capacity.

[0004] In existing technologies, strain sensors are typically positioned visually during static load tests. However, this method introduces two errors: first, the strain measurement point may not fall within the test section, resulting in a strain test result that does not reflect the actual cross-section; second, the strain measurement direction may have an angle α with the beam axis, leading to the measured strain being the actual strain multiplied by cos(α). This deviation between the measured strain value and the theoretically calculated value significantly impacts the assessment of bridge safety. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, the purpose of this invention is to provide a device for accurately locating deflection and strain measuring points in bridge static load tests, so as to solve the problem of the deviation between the measured strain value and the theoretical calculated value caused by the installation position of the strain sensor on the judgment of bridge safety.

[0006] Therefore, this invention proposes a device for accurately locating deflection and strain measurement points in bridge static load tests, comprising: a cross-section positioning device and a strain sensor orientation positioning device. The cross-section positioning device includes a steel plate, a magnetic base, and a laser pointer. The steel plate is fixed to the bottom surface (10) of the bridge at the test section, the magnetic base is adsorbed onto the steel plate, and the laser pointer is fixed to the magnetic base. The strain sensor orientation positioning device includes an angle disk, a cross-section positioning plate, and an orientation positioning rod. The cross-section positioning plate is fixed to the straight edge of the angle disk, and the orientation positioning rod is rotatably connected to the angle disk.

[0007] Furthermore, the laser pointer is located on one side of the test section, and the laser beam emitted by the laser pointer is directed to the other side of the test section, thereby determining the position of the test section along the transverse direction of the bridge.

[0008] Furthermore, the cross-section positioning plate and the laser beam are on the same plane; then the angle of the directional positioning rod is adjusted so that it is equal to the oblique angle of the bridge. At this time, the external direction of the directional positioning rod is the installation direction of the strain sensor, thereby determining the tangent direction of each measuring point of the test section.

[0009] Furthermore, the steel plate is fixedly connected to the bottom surface of the bridge by adhesive bonding.

[0010] Furthermore, the steel plate is bonded and fixed to the bottom surface of the bridge using 502 glue or AB glue.

[0011] Furthermore, the strain sensor orientation positioning device also includes a fastening screw, and the orientation positioning rod and the angle disk are rotatably connected by the fastening screw.

[0012] Furthermore, the angle disc, the cross-sectional positioning plate, and the direction positioning rod are made of stainless steel or polymer plastic.

[0013] Furthermore, the magnetic base and the laser pointer in the cross-section positioning device can be removed and recycled after determining the deflection measurement points at the bottom of the beam and the strain measurement points at the bottom and sides of the beam.

[0014] Furthermore, the precise positioning device can be applied to concrete bridges with T-beams, hollow beams, and small box girders.

[0015] Furthermore, the precise positioning device can be applied to straight bridges, skew bridges, and curved bridges.

[0016] The device for precisely positioning deflection and strain measurement points in bridge static load tests provided by this invention can accurately determine the position of the test section and the direction of the strain sensor, avoiding the inaccuracy of test results caused by the randomness of sensor arrangement and the inaccuracy of strain sensor direction during static load tests, thus increasing the accuracy of static load test data. In addition, the device has a simple structure, is convenient and effective, and can provide precise positioning for the installation of strain measurement sensors during bridge static load tests, reducing measurement errors caused by strain sensor installation and greatly improving measurement accuracy.

[0017] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0018] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0019] Figure 1 This is a schematic diagram of the bridge test section in the static load test of the bridge according to the present invention;

[0020] Figure 2 This is a schematic diagram of the installation of the cross-section positioning device in the static load test of the bridge according to the present invention;

[0021] Figure 3 This is a schematic diagram of the orientation positioning device in the static load test of the bridge according to the present invention;

[0022] Figure 4 This is a schematic diagram of the cross-section positioning device and direction positioning device operating under the bridge during the static load test of the bridge according to the present invention; Explanation of reference numerals.

[0023] 1. Steel plate; 2. Magnetic base; 3. Laser pointer; 4. Laser beam; 5. Section positioning plate; 6. Angle disc; 7. Direction positioning rod; 8. Fastening screw; 9. Strain sensor; 10. Bridge bottom surface. Detailed Implementation

[0024] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0025] like Figures 1-4As shown, the device for precise positioning of deflection and strain measurement points in bridge static load tests of the present invention includes: a cross-section positioning device and a strain sensor orientation positioning device; wherein, the cross-section positioning device consists of a steel plate 1, a magnetic base 2 and a laser pointer 3, the steel plate 1 is fixed to the edge of the test cross-section beam, the magnetic base 2 is fixed on the steel plate 1, and the laser pointer 3 is fixed on the magnetic base 2. The fixed laser pointer 3 is located on one side of the test cross-section, and the laser beam emitted by the laser pointer 3 points to the other side of the test cross-section; the strain sensor orientation positioning device consists of an angle disk 6, a cross-section positioning plate 5, an orientation positioning rod 7 and a fastening screw 8, wherein the cross-section positioning plate 5 is fixed on the straight edge of the angle disk 6, and the orientation positioning rod 7 and the angle disk 6 are fixed by the fastening screw 8.

[0026] Specifically, before installing the strain sensor, first determine the location of the test section on both sides of the bridge. Then, use 502 glue (or AB glue) to fix the steel plate to the bottom of the beam at the test section. Next, install the magnetic base, and then adjust the support rod and clamp of the magnetic base to ensure smooth installation of the laser pointer. When installing the laser pointer, first turn on the power switch to light it up. Adjust the direction of the laser pointer. When the laser beam points from one side of the test section to the other, tighten the clamp to fix the laser pointer. The section through which the laser beam passes at this point is the test section.

[0027] When the test section location is accurately determined, the direction plate of the strain sensor directional locator is brought close to the laser beam. When the laser beam just passes close to the direction plate and the pointer angle of the directional locator is the oblique angle of the bridge, the directional locator rod is fixed. At this time, the pointer's external direction indicates the installation direction of the strain sensor. After determining the strain measurement points on the bottom and sides of the beam, the fastening screws 8 can be loosened and the directional locator rod 7 can be removed to prevent damage to the directional locator rod 7.

[0028] In this scheme, the section positioning device can be disassembled and recycled after determining the deflection measuring points at the bottom of the beam and the strain measuring points at the bottom and sides of the beam; among them, the magnetic base 2 and the laser pointer 3 are easy to disassemble and can be directly recycled after disassembly, and the steel plate 1 can be selectively recycled according to the difficulty of disassembly.

[0029] In the section positioning device, the steel plate 1 is made of steel to facilitate the installation and fixation of the magnetic base 2; the section positioning plate 5 and the angle plate 6 in the direction positioning device are made of stainless steel or polymer plastic, which have the characteristics of high flatness, light weight, and easy handling.

[0030] Furthermore, the positioning device of this application is applicable to different types of bridges such as T-beams and hollow beams; at the same time, the positioning device of this application is applicable to bridges with different installation angles such as straight bridges, skew bridges and curved bridges; therefore, the positioning device is not only simple in structure, convenient and effective, but also has the characteristics of strong applicability and can be widely promoted and used.

[0031] The working principle and process of the device for precise positioning of deflection and strain measuring points in bridge static load tests according to the present invention are briefly described below with reference to the accompanying drawings.

[0032] like Figure 1 As shown, the positions of the test section on both sides of the beam are first determined using tools such as a measuring tape and a plumb bob;

[0033] like Figure 2 As shown, during the static load test, the steel plate 1 is fixed to the bridge bottom surface 10 of the side beam of the test section with 502 glue or AB glue. Then, the magnetic base 2 is fixed, the laser pointer 3 is placed on the magnetic base, the laser pointer is turned on, the direction of the laser pointer is adjusted, and the laser pointer is fixed when the laser beam 4 emitted by the laser pointer points from one side of the test section to the other side of the section. At this time, the laser line along the bridge width direction is the position of the test section.

[0034] like Figure 3 As shown, the strain sensor direction positioning device consists of a cross-section positioning plate 5, an angle disk 6, a direction positioning rod 7, and fastening screws 8. In use, the angle of the direction positioning rod 7 is adjusted to match the oblique angle of the test bridge span. Then, the fastening screws 8 are tightened to fix the direction positioning rod 7 on the angle disk. Next, when the angle disk 6 is close to the bottom of the beam, the cross-section positioning plate 5 is slowly rotated so that the laser beam 4 passes close to the cross-section positioning plate 5. At this time, the direction of the direction positioning rod is the direction of the bridge axis at the strain measurement point, which is the installation position of the strain sensor 9.

[0035] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A device for precise positioning of deflection and strain measuring points in a bridge static load test, characterized in that, Includes a cross-section positioning device and a strain sensor orientation positioning device. The cross-section positioning device includes a steel plate (1), a magnetic base (2), and a laser pointer (3). The steel plate (1) is fixed on the bottom surface (10) of the bridge at the test section, the magnetic base (2) is adsorbed on the steel plate (1), and the laser pointer (3) is fixed on the magnetic base (2). The strain sensor orientation positioning device includes an angle disk (6), a cross-sectional positioning plate (5), and an orientation positioning rod (7); the cross-sectional positioning plate (5) is fixed on the straight edge of the angle disk (6), and the orientation positioning rod (7) is rotatably connected to the angle disk (6); The laser pointer (3) is located on one side of the test section, and the laser beam (4) emitted by the laser pointer (3) points to the other side of the test section, thereby determining the position of the test section along the transverse direction of the bridge; the section positioning plate (5) and the laser beam (4) are on the same plane; then the angle of the direction positioning rod (7) is adjusted so that it is equal to the oblique angle of the bridge. At this time, the external direction of the direction positioning rod (7) is the installation direction of the strain sensor, thereby determining the tangent direction of each measuring point of the test section.

2. The device for precise positioning of deflection and strain measuring points in bridge static load tests according to claim 1, characterized in that, The steel plate (1) is fixedly connected to the bottom surface (10) of the bridge by adhesive bonding.

3. The device for precise positioning of deflection and strain measuring points in bridge static load tests according to claim 2, characterized in that, The steel plate (1) is bonded and fixed to the bottom surface (10) of the bridge using 502 glue or AB glue.

4. The device for precise positioning of deflection and strain measuring points in bridge static load tests according to claim 1, characterized in that, The strain sensor orientation positioning device also includes a fastening screw (8), and the orientation positioning rod (7) and the angle disk (6) are rotatably connected by the fastening screw (8).

5. The device for precise positioning of deflection and strain measuring points in bridge static load tests according to claim 1, characterized in that, The angle disc (6), the cross-section positioning plate (5), and the direction positioning rod (7) are made of stainless steel or polymer plastic.

6. The device for precise positioning of deflection and strain measuring points in bridge static load tests according to claim 1, characterized in that, The magnetic base (2) and the laser pointer (3) in the cross-section positioning device can be removed and recycled after determining the deflection measurement points at the bottom of the beam and the strain measurement points at the bottom and sides of the beam.

7. The device for precise positioning of deflection and strain measuring points in bridge static load tests according to claim 1, characterized in that, The precise positioning device can be applied to concrete bridges with T-beams, hollow beams, and small box girders.

8. The device for precise positioning of deflection and strain measuring points in bridge static load tests according to claim 1, characterized in that, The precise positioning device is applicable to straight bridges, skew bridges, and curved bridges.

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