A high-sensitivity non-contact bridge corner monitoring device

Abstract

The present invention relates to a high-sensitivity non-contact bridge corner monitoring device, comprising: a laser emission device, a reflective component, and a laser reception device. The laser emission device is fixed at the pier of the bridge to be measured; the reflective component is fixed at the bottom of the beam end of the bridge beam to be measured, and the reflective component rotates in the same direction and with the same amplitude as the bridge beam to be measured; the laser reception device is fixed on a fixed object; the laser beam emitted by the laser emission device is reflected by the reflective component to the laser reception device. The beneficial effects are as follows: By converting the measurement of the relatively small beam end corner into the measurement of the relatively large laser travel, the measurement accuracy is greatly improved; once installed, long-term measurement can be carried out, and at the same time, real-time corner monitoring can be achieved; there is no need to erect a bracket, saving the labor and materials required for bracket erection, and it is not restricted by terrain and water flow, and is applicable to long-span bridges spanning wide river surfaces or deep canyons.

Description

Technical Field

[0001] The invention relates to the technical field of bridge angle testing, and in particular to a high-sensitivity contactless bridge angle monitoring device. Background Art

[0002] Due to the bridge collapse incidents in recent years, countries have paid more and more attention to bridge health monitoring. It is an important task of health monitoring to perceive and judge the safety status of bridge structures by measuring various indicators and parameters of bridges. The bridge beam end angle is one of the important indicators of structural safety status.

[0003] The commonly used test instruments at present need to be set up at the test location every time a measurement is made, and cannot be used for long-term online monitoring of the dynamic deflection of some bridges. For large-span bridges across a wide river or deep canyon, the test is more complicated because it is impossible to directly set up observation instruments. At present, there is no mature, high-precision rotation instrument to test the beam end rotation angle. The beam end rotation angle is mainly calculated based on the tested deflection, which has a large error.

[0004] In the test of the rotation angle of the bridge beam end, the total station test method is also one of the commonly used test methods. That is, during the test, by setting up a total station in a place without direct contact with the bridge, the displacement of the main beam end and the change of deflection close to the beam end are tested to deduce the rotation angle of the beam end. When testing with this method, the direct distance between the two measuring points is difficult to determine. When the distance is small, the difference between the two deflections is very small, and the test accuracy is low; when the distance is large, the test accuracy can be improved, but because the deflection curve between the two points is no longer a straight line, it is difficult to deduce the relationship between the deflection and the rotation angle; and the test process is slow, which is not suitable for dynamic rotation angle testing. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a high-sensitivity contactless bridge angle monitoring device to overcome the deficiencies in the above-mentioned prior art.

[0006] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: a high-sensitivity contactless bridge angle monitoring device, comprising: a laser emitting device, a reflective component and a laser receiving device, the laser emitting device is fixed at the pier of the bridge to be measured; the reflective component is fixed at the bottom of the beam end of the bridge beam to be measured, and the reflective component and the bridge beam to be measured rotate in the same direction and with the same amplitude; the laser receiving device is fixed on a fixed object; the laser beam emitted by the laser emitting device is reflected to the laser receiving device by the reflective component.

[0007] Based on the above technical solution, the present invention can also be improved as follows.

[0008] Furthermore, the reflective component is a reflector.

[0009] Furthermore, the laser emitting device emits a single beam or multiple beams of laser beams with adjustable angles; and a plurality of reflective components are installed on a beam of the bridge to be measured.

[0010] Furthermore, the bridge under test is a simply supported beam bridge, and the laser emitting device is fixed at the bottom of the pier of the simply supported beam bridge.

[0011] Furthermore, the bridge under test is a steel structure bridge, and the laser emitting device is fixed on the side of the pier of the steel structure bridge.

[0012] The beneficial effects of the present invention are:

[0013] 1) The measurement accuracy is greatly improved by converting the beam end angle measurement with a smaller amplitude into the laser stroke measurement with a larger amplitude;

[0014] 2) One-time installation allows long-term measurement and real-time corner monitoring;

[0015] 3) No need to erect scaffolds, saving manpower and material investment required for scaffold erection, and not restricted by terrain and water flow, suitable for large-span bridges across wide rivers or deep canyons;

[0016] 4) The structure is designed reasonably, and it is easy to process, manufacture and install. It is small in size, light in weight and easy to carry. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a structural diagram of the high-sensitivity contactless bridge angle monitoring device described in the present invention.

[0018] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0019] 1. Laser emitting device, 2. Reflective component, 3. Beam, 4. Laser receiving device. DETAILED DESCRIPTION

[0020] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0021] Example 1

[0022] like Figure 1 As shown, a high-sensitivity non-contact bridge angle monitoring device comprises: a laser emitting device 1, a reflective component 2 and a laser receiving device 4;

[0023] The laser emitting device 1 is fixed on the pier of the bridge to be measured;

[0024] The reflective component 2 is fixed to the bottom of the beam end of the bridge beam 3 to be measured, and the reflective component 2 and the bridge beam 3 to be measured rotate in the same direction and with the same amplitude, or the reflective component 2 is installed at a position where there is no relative displacement or relative rotation between the bottom of the beam end of the bridge beam 3 to be measured and the beam end;

[0025] The laser receiving device 4 is fixed on a fixed object at a certain distance from the bottom of the beam and is in a horizontal position;

[0026] The laser beam emitted by the laser emitting device 1 is reflected by the reflective component 2 to the laser receiving device 4;

[0027] That is, there is visual access between the laser emitting device 1 and the reflective component 2 without any obstruction;

[0028] There is visual access between the reflective component 2 and the laser receiving device 4, without any obstruction;

[0029] In this embodiment, the laser emitting device 1 and the laser receiving device 4 are both static points. When the beam end turns, the position of the reflected laser on the laser receiving device 4 changes.

[0030] Example 2

[0031] like Figure 1 As shown, this embodiment is a further improvement on the basis of embodiment 1, and the details are as follows:

[0032] The reflective component 2 is preferably a reflector, but other devices with reflective function are certainly not excluded.

[0033] Example 3

[0034] like Figure 1 As shown, this embodiment is a further improvement on the basis of Embodiment 1 or 2, and the details are as follows:

[0035] According to the test requirements, the laser emitting device 1 emits a single beam or multiple beams of laser beams with adjustable angles;

[0036] A plurality of reflective components 2 are installed on a beam body 3 of the bridge to be tested, and the installation position of the reflective components 2 is the position where the turning angle needs to be tested.

[0037] Example 4

[0038] like Figure 1 As shown, this embodiment is a further improvement on the basis of Embodiment 1, 2 or 3, and the details are as follows:

[0039] The bridge under test is a simply supported beam bridge, and the laser emitting device 1 is fixed at the bottom of the pier of the simply supported beam bridge.

[0040] Alternatively, the bridge to be measured is a steel structure bridge, and the laser emitting device 1 is fixed on the side of a pier of the steel structure bridge.

[0041] When the beam end of the bridge beam 3 under test turns, the beam 3 will drive the reflective component 2 to turn. Since the reflective component 2 is fixed on the beam end, the turning angle of the reflective component 2 and the beam 3 is the same.

[0042] The incident angle between the laser beam emitted by the laser emitting device 1 and the reflective component 2 will change, resulting in a change in the position of the laser beam on the laser receiving device 4 after reflection. By measuring the change in the position of the laser beam on the laser receiving device 4, the rotation angle of the beam end can be calculated;

[0043] It should be noted that since the installation position of the reflective component 2 is sometimes difficult to ensure at the support, when the beam end turns, the reflective component 2 not only causes an angular displacement, but also generates a certain deflection. Therefore, the relationship between the laser point change distance obtained by the test and the actual rotation angle of the structure is:

[0044] S 1 =H cot(b)

[0045] S 2 =H cot(b+2a)

[0046] S 3 =L sin(a)cot(b)

[0047] S=S 1 -S 2 +S 3 =H[cot(b)-cot(b+2a)]+L sin(a)cot(b)

[0048] in:

[0049] L is the distance from the reflective component 2 to the center of the support;

[0050] H is the vertical distance from the laser receiving device 4 to the reflective component 2;

[0051] a is the top turning angle;

[0052] b is the angle between the laser emitting device 1 and the horizontal plane.

[0053] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A high-sensitivity non-contact bridge corner monitoring device, characterized in that, it includes: a laser emission device (1), a reflective component (2) and a laser reception device (4). The laser emission device (1) is fixed at the pier of the bridge to be measured; the reflective component (2) is fixed at the bottom of the beam end of the beam body (3) of the bridge to be measured, and the reflective component (2) rotates in the same direction and with the same amplitude as the beam body (3) of the bridge to be measured; the laser reception device (4) is fixed on a fixed object at a certain distance from the beam bottom and is in a horizontal position; the laser beam emitted by the laser emission device (1) is reflected by the reflective component (2) to the laser reception device (4). Both the laser emission device (1) and the laser reception device (4) are static points. When the beam end of the beam body (3) of the bridge to be measured undergoes a corner rotation, the beam body (3) will drive the reflective component (2) to undergo a corner rotation, the incident angle between the laser beam emitted by the laser emission device (1) and the reflective component (2) will change, the position of the laser light reflected onto the laser reception device (4) will change, and the corner rotation occurring at the beam end is deduced by measuring the change in the position of the laser on the laser reception device (4); Since it is difficult to ensure that the installation position of the reflective component (2) is at the support, when the beam end undergoes a corner rotation, it drives the reflective component (2) not only to undergo a corner displacement, but also to generate a certain deflection. Therefore, the relationship between the measured change distance S of the laser point and the top corner a of the beam body of the bridge to be measured is: S 1 =H cot(b) S 2 =H cot(b + 2a) S 3 = L sin(a) cot(b) S = S 1 -S 2 +S 3 = H [cot(b) - cot(b + 2a)] + L sin(a) cot(b) where: L is the distance from the reflective component (2) to the center of the support; H is the vertical distance from the laser reception device (4) to the reflective component (2); a is the top corner; b is the angle between the laser emission device (1) and the horizontal plane.

2. A high-sensitivity non-contact bridge corner monitoring device according to claim 1, characterized in that: the reflective component (2) is a mirror.

3. A high-sensitivity non-contact bridge corner monitoring device according to claim 1, characterized in that: the laser emission device (1) emits a single beam or multiple beams of laser beams with adjustable angles; multiple reflective components (2) are installed on one beam body (3) of the bridge to be measured.

4. A high-sensitivity non-contact bridge corner monitoring device according to claim 1, characterized in that: the bridge to be measured is a simply supported beam bridge, and the laser emission device (1) is fixed at the bottom of the pier of the simply supported beam bridge.

5. A high-sensitivity non-contact bridge corner monitoring device according to claim 1, characterized in that: the bridge to be measured is a steel structure bridge, and the laser emission device (1) is fixed on the side of the pier of the steel structure bridge.

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