Strain gauge suitable for bridge floor

Abstract

The utility model relates to the technical field of strain gauges, and discloses a strain gauge suitable for a bridge floor, which comprises a strain gauge body, a substrate is arranged below the strain gauge body, the strain gauge body is adhered to the top surface of the substrate through an adhesive to be fixed, and a plurality of screw rods are arranged on the substrate close to four sides. An embedded sleeve is screwed on the screw rod below the base plate in a threaded manner; and a pentagonal head is mounted at the top end of the screw rod. According to the strain gauge, the substrate is used for carrying the strain gauge, the strain gauge can be directly installed from the position of the substrate during installation, an adhesive does not make contact with the strain gauge in the installation process, the adhesive does not pull the strain gauge to generate deformation stress after being cured, the installed strain gauge does not have installation stress, and therefore the error influence on the subsequent detection result is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of strain gauges, in particular to a strain gauge that can be applied to a bridge deck. Background Art

[0002] Strain gauge is a component used to measure strain, mainly composed of sensitive grids, etc. Its working principle is based on the strain effect, that is, when the conductor or semiconductor material is mechanically deformed under the action of external forces, its resistance value will change accordingly. This change can be measured by special instruments and converted into the strain value of the measuring point.

[0003] In the renovation and reinforcement of bridges, especially old bridges, strain gauges are often used to check the renovation and reinforcement positions of bridges, and to confirm the renovation and reinforcement plan according to the strain conditions. At present, the installation of strain gauges on bridge decks is mainly fixed by adhesives. It is necessary to clean the surface of the bridge deck where it is installed first to ensure that there is no dust or stains on the surface that affect the bonding strength, and then grind and frost the surface to increase the bonding strength. Finally, the adhesive is applied to install the strain gauge. The installation method is cumbersome and has many steps. After the adhesive is cured, it shrinks, causing the strain gauge to deform and generate stress. This stress does not belong to the stress of the bridge itself, which will lead to large errors in subsequent test results. Utility Model Content

[0004] 1. Technical issues to be resolved

[0005] In view of the deficiencies in the prior art, the utility model provides a strain gauge that can be applied to a bridge deck to solve the problems in the background technology.

[0006] (II) Technical solution

[0007] In order to solve the above problems, the utility model provides the following technical solutions:

[0008] A strain gauge applicable to a bridge deck comprises a strain gauge body, a base plate is arranged below the strain gauge body, the strain gauge body is glued to the top surface of the base plate by an adhesive, a plurality of screw rods are installed on four sides of the base plate, a pre-buried sleeve is screwed onto the screw rod below the base plate, and a pentagonal head is installed on the top of the screw rod.

[0009] Preferably, a plurality of arc-shaped sleeves are installed on the top surface of the substrate near the four sides, and spherical cavities are opened on the arc-shaped sleeves and the substrate inside the arc-shaped sleeves. The spherical cavities penetrate the arc-shaped sleeves and the substrate at corresponding positions, and a convex ball is arranged in the spherical cavity. The spherical surface of the convex ball is limited to rotation with the inner wall of the spherical cavity, and the screw is installed on the convex ball.

[0010] Preferably, the inner diameter of the spherical cavity is at least 6 mm larger than the diameter of the convex ball.

[0011] Preferably, a gasket is installed on the bottom surface of the substrate.

[0012] Preferably, a top cover is provided above the base plate, the top cover covers the strain gauge body, and the top cover is fixed to the base plate by bolts.

[0013] Preferably, positioning blocks are installed on the top surface of the substrate near the left and right sides, a threaded hole is opened in the middle position of the positioning block, and a support sleeve is installed on the bottom surface of the top cover corresponding to the position of the positioning block. The bottom surface of the support sleeve is supported by the top surface of the substrate, and the support sleeve is sleeved on the outer periphery of the positioning block. The bolts are passed through the support sleeve threads and screwed into the threaded holes to fix the top cover and the substrate.

[0014] (III) Beneficial effects

[0015] Compared with the prior art, the utility model provides a strain gauge applicable to bridge decks, which has the following beneficial effects:

[0016] 1. The strain gauge is mounted on a substrate and can be installed directly from the substrate. During the installation process, the adhesive does not contact the strain gauge. The adhesive will not pull the strain gauge to generate deformation stress when it is cured. The strain gauge has no installation stress after installation, so it will not cause errors in subsequent test results.

[0017] 2. The strain gauge is provided with a protrusion on the screw rod, which cooperates with the spherical cavity on the base plate, so that the screw rod can rotate. When the embedded sleeve is slightly offset, it can be adjusted to avoid stress caused by tensioning the base plate.

[0018] 3. The strain gauge is shielded and protected by a top cover, which can reduce the damage and impact caused by environmental or human factors to it, so as to maintain long-term installation and detection requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is the appearance diagram of the utility model;

[0020] Figure 2 It is a schematic diagram of the arrangement of the strain gauge body in the utility model;

[0021] Figure 3 It is a schematic diagram of the arrangement of the screw in the utility model;

[0022] Figure 4 It is a schematic diagram of the arrangement of bolts in the utility model;

[0023] Figure 5 It is a schematic diagram of the arrangement of the gasket in the utility model.

[0024] In the figure: 1. strain gauge body; 2. strain gauge wire; 3. substrate; 4. arc sleeve; 5. spherical cavity; 6. screw; 7. convex ball; 8. pentagonal head; 9. embedded sleeve; 10. gasket; 11. support sleeve; 12. positioning block; 13. bolt; 14. top cover; 15. threaded hole. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0026] See also Figure 1-5 A strain gauge applicable to a bridge deck comprises a strain gauge body 1, a substrate 3 is arranged below the strain gauge body 1, the substrate 3 is made of rubber material, the strain gauge body 1 is glued to the top surface of the substrate 3 by an adhesive, a plurality of arc sleeves 4 are welded and installed at equal intervals on the top surface of the substrate 3 at four sides, a spherical cavity 5 is opened on the arc sleeve 4 and the substrate 3 in the arc sleeve 4, and the spherical cavity 5 passes through the arc sleeve 4 and the substrate 3 at upper and lower positions;

[0027] A convex ball 7 is provided in the spherical cavity 5, and the spherical surface of the convex ball 7 abuts against the inner wall of the spherical cavity 5 to form a limited rotation fixation. The inner diameter of the spherical cavity 5 is larger than the diameter of the convex ball 7, and the difference between the two is at least 6 mm. A screw rod 6 is welded and installed on the convex ball 7, and the upper and lower ends of the screw rod 6 are respectively passed through the top of the arc sleeve 4 and the bottom of the base plate 3. The screw rod 6 below the base plate 3 is threadedly screwed with an embedded sleeve 9, and the end of the screw rod 6 above the arc sleeve 4 is integrally formed with a pentagonal head 8.

[0028] When in use, first drill a hole at the bridge deck installation position to embed the embedded sleeve 9, and inject glue for auxiliary fixation at the same time, so that the embedded sleeve 9 is reliably fixed to the bridge deck, and the top surface of the embedded sleeve 9 is not lower than the highest point of the bridge deck at the installation position. The strain gauge body 1 is bonded to the top surface of the substrate 3 in advance and fixed, and the prestress is removed. Then, the substrate 3 is held, and the screw 6 is moved to align with the embedded sleeve 9 through the limit fixing relationship of the convex ball 7 in the spherical cavity 5. It is first screwed in for pretightening for a certain length. At this time, the strain gauge wire 2 of the strain gauge body 1 is connected to observe whether there is strain. When there is strain, continue to adjust the substrate 3 so that there is no prestress on the substrate 3, and then tighten the screw 6 from the position of the pentagonal head 8 so that the screw 6 is tightened into the embedded sleeve 9 for fixation. There is no need to grind the bridge deck and apply adhesive during installation. There is no prestress on the substrate 3, and there is no prestress on the strain gauge body 1, which ensures the accuracy of the final measured result.

[0029] In this embodiment, a gasket 10 is adhesively mounted on the bottom surface of the substrate 3 , and the gasket 10 is made of a silicone rubber material. The gasket 10 at the position of the embedded sleeve 9 is not provided.

[0030] When the base plate 3 is fixed, the gasket 10 abuts against the bridge deck, and the slightly raised small stones on the bridge deck surface will squeeze the gasket 10 to deform, so that it will not directly abut against the base plate 3 to cause deformation stress.

[0031] In this embodiment, a top cover 14 is provided above the substrate 3, and the top cover 14 covers the strain gauge body 1. Positioning blocks 12 are welded and installed on the top surface of the substrate 3 near the left and right sides, and a threaded hole 15 is opened in the middle position of the positioning block 12. A support sleeve 11 is welded and installed on the bottom surface of the top cover 14 corresponding to the position of the positioning block 12. The bottom surface of the support sleeve 11 is supported by the top surface of the substrate 3, and the support sleeve 11 is sleeved on the outer periphery of the positioning block 12. A bolt 13 is screwed on the top cover 14 at the position of the support sleeve 11. The bolt 13 passes through the thread of the support sleeve 11 and is screwed into the threaded hole 15 to fix the top cover 14 and the substrate 3. A hole is opened on the side of the top cover 14 corresponding to the position of the strain gauge wire 2, and the strain gauge wire 2 passes through the top cover 14 through the hole.

[0032] The top cover 14 provides direct protection for the entire strain gauge, which can reduce the damage to the strain gauge caused by bridge deck activities or human factors, so as to ensure the continuous and reliable progress of the detection operation.

Claims

1. A strain gauge applicable to a bridge deck, comprising a strain gauge body (1), characterized in that: A base plate (3) is provided below the strain gauge body (1), and the strain gauge body (1) is fixed to the top surface of the base plate (3) by adhesive. A plurality of screw rods (6) are installed on the four sides of the base plate (3), and a pre-buried sleeve (9) is screwed on the screw rod (6) below the base plate (3), and a pentagonal head (8) is installed on the top of the screw rod (6).

2. The strain gauge applicable to a bridge deck according to claim 1, characterized in that: A plurality of arc-shaped sleeves (4) are installed on the top surface of the base plate (3) at four sides. Spherical cavities (5) are opened on the arc-shaped sleeves (4) and the base plate (3) inside the arc-shaped sleeves (4). The spherical cavities (5) penetrate the arc-shaped sleeves (4) and the base plate (3) at corresponding positions. A convex ball (7) is arranged in the spherical cavity (5). The spherical surface of the convex ball (7) and the inner wall of the spherical cavity (5) are limitedly rotated. The screw rod (6) is installed on the convex ball (7).

3. The strain gauge applicable to a bridge deck according to claim 2, characterized in that: The inner diameter of the spherical cavity (5) is at least 6 mm larger than the diameter of the convex ball (7).

4. The strain gauge applicable to a bridge deck according to claim 1, characterized in that: A gasket (10) is installed on the bottom surface of the substrate (3).

5. The strain gauge applicable to a bridge deck according to claim 1, characterized in that: A top cover (14) is provided above the base plate (3), the top cover (14) covers the strain gauge body (1), and the top cover (14) and the base plate (3) are fixed by bolts (13).

6. The strain gauge applicable to a bridge deck according to claim 5, characterized in that: The top surface of the base plate (3) is provided with a positioning block (12) near the left and right sides, a threaded hole (15) is provided in the middle of the positioning block (12), a support sleeve (11) is provided on the bottom surface of the top cover (14) at a position corresponding to the positioning block (12), the bottom surface of the support sleeve (11) is supported against the top surface of the base plate (3), the support sleeve (11) is sleeved on the outer periphery of the positioning block (12), and a bolt (13) is threaded through the support sleeve (11) and screwed into the threaded hole (15) to fix the top cover (14) and the base plate (3).

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