Bridge deflection monitoring device and monitoring method

Abstract

The invention relates to a device and method for monitoring the deflection of a bridge, and the device comprises a rectangular medium which is disposed in the middle of the bridge, and the top end of the rectangular medium is connected with the bottom of the bridge; the triangular media are arranged on the two sides of the rectangular medium and extend towards the two sides of the bridge, the tops of the triangular media are connected with the bottom of the bridge, and the right-angle sides of the triangular media face the rectangular medium and a pier on one side of the bridge respectively; the laser generating devices are arranged on bridge piers on the two sides of the bridge, and laser emitted by the output ends of the laser generating devices is emitted to the rectangular medium through the triangular medium. Compared with a traditional light source direct-injection type device, complex mechanical equipment and a control system are not needed, a laser line is adopted, light rays can automatically shift downwards after passing through a triangular medium, the light rays are still horizontal light rays after shift, in addition, the larger the deflection of a current point is, the more the light rays shift downwards, and the higher the deflection of the current point is, the more the light rays shift downwards. And self-adaptive adjustment along with bridge deformation is realized only by means of a light path.

Description

Technical Field

[0001] This application relates to the technical field of bridge deflection monitoring, and particularly to a device and a monitoring method for bridge deflection monitoring. Background Art

[0002] During the long-term use of a bridge, due to the combined action of various factors such as its own gravity, vehicle load, wind force, temperature change, and earthquake, various deformations will inevitably occur. Among them, deflection is one of the important indicators to measure the health status of the bridge structure.

[0003] The Chinese utility model patent with the authorization announcement number CN218297537U discloses a chain-type laser deflection detection system for bridges, which includes a reference station, n monitoring stations, and a calibration station; the reference station is set at one end of the bridge, used to emit light spots, collect the monitoring data of the n monitoring stations, and transmit the monitoring data to the upper computer; the monitoring stations are sequentially set at the points to be monitored on the bridge, and calculate the displacement amount and angle change value of the light spot of the reference station relative to itself; the calibration station is set at the other end of the bridge, used to eliminate the cumulative error of the system, and send the monitoring data of the n monitoring stations to the reference station.

[0004] Although this utility model patent realizes the multi-point synchronous real-time monitoring of bridge deflection, corrects the errors of various monitoring systems, and improves the detection accuracy. However, it is laid on the road surface, and the detectable positions are restricted by the traffic flow. The large number of lasers in the reference station and the monitoring stations will lead to an overly complex heat dissipation system. The laser line emitted by the monitoring station cannot be adjusted adaptively, and when the deflection of the bridge is too large, the phenomenon of being unable to accurately receive the laser at the previous point will occur. Summary of the Invention

[0005] Based on this, it is necessary to provide a device and a method for bridge deflection monitoring to overcome the defects mentioned in the above background art.

[0006] A device for bridge deflection monitoring includes: A rectangular medium, which is arranged in the middle of the bridge, and its top is connected to the bottom of the bridge; Triangular media, a plurality of the triangular media are arranged on both sides of the rectangular medium and extend towards both sides of the bridge, its top is connected to the bottom of the bridge, and its right-angled sides are respectively oriented towards the rectangular medium and one of the bridge piers; As a preference of the device for bridge deflection monitoring in the present invention, the rectangular medium and the triangular media are high-transparency glass.

[0007] As a preference of the device for bridge deflection monitoring in the present invention, the rectangular medium includes a rectangular glass and a double-sided photosensitive device, and the double-sided photosensitive device is arranged between a pair of rectangular glasses, and its photosensitive surface faces the triangular media.

[0008] As a preference for the device for bridge deflection monitoring in the present invention, the triangular medium includes an isosceles right triangle glass and a semi-permeable membrane. A pair of the isosceles right triangle glasses are symmetrically arranged on both sides of the semi-permeable membrane. One right-angled side of the isosceles right triangle glass is connected to the semi-permeable membrane, and a total reflection mirror surface is provided on the other right-angled side.

[0009] As a preference for the device for bridge deflection monitoring in the present invention, on the hypotenuse of the laser incident side of one of the isosceles right triangle glasses, a single-sided photosensitive device is provided, and the photosensitive side of the single-sided photosensitive device faces the isosceles right triangle glass.

[0010] As a preference for the device for bridge deflection monitoring in the present invention, the length of the single-sided photosensitive device is less than the length of the hypotenuse, and one end of it is flush with the bottom end of the hypotenuse.

[0011] As a preference for the device for bridge deflection monitoring in the present invention, the hypotenuse of the triangular medium is connected to the bottom of the bridge, and a counterweight is provided at its bottom end.

[0012] A monitoring method for the device for bridge deflection monitoring includes the following steps: Lay the rectangular medium and the triangular medium along the entire length of the bridge at the bottom of the bridge to ensure that the center lines of the rectangular medium and the triangular medium are parallel to the direction of gravity; Lay the laser generating device at the piers on both sides of the bridge so that the laser emitted by it can be emitted to the rectangular medium through the triangular medium, and obtain the deflection height at each point according to the deflection height calculation formula. The deflection height calculation formula for the outermost point is: h 1 - h 2 (Formula 1) Wherein, h 1 is the height of the laser point emitted by the laser generating device when the bridge has not deflected and falls on the right-angled side of the triangular medium from the bottom edge, h 2 is the height of the laser point emitted by the laser generating device when the bridge has deflected and falls on the right-angled side of the triangular medium from the bottom edge; When calculating the deflection height of the next point, ( h 3 - h 1) should be subtracted for light ray correction, h 3 is the height of the laser point emitted from the triangular medium at the previous point and falling on the right-angled side of the current triangular medium from the bottom edge, which is obtained by the single-sided photosensitive device. ( h 3 - h 1) is the offset height of the laser emitted from the previous point.

[0013] As a preference for the monitoring method in the invention, theh is: (Formula 2) Wherein, h 0 is the height of the triangular medium, b According to the law of refraction: n 1·sin a = n 2·sin b It is obtained that, wherein, a is the incident angle of 45°, n 1 is the refractive index of air, n 2 is the refractive index of the triangular medium.

[0014] As a preference of the monitoring method described in the invention, the h 2 is: (Formula 3) Advantages of the present invention: Compared with the traditional light source direct irradiation device, the present invention does not require complex mechanical equipment and control systems. By using a laser line passing through a triangular medium, the light will automatically deflect downward and remain a horizontal light after deflection. In addition, the greater the deflection of the current point, the more the light deflects downward, and the adaptive adjustment with the bridge deformation is realized only by the optical path.

[0015] Based on the principles of light propagation and reflection, the present invention utilizes the high directivity, high stability and high monochromaticity of laser to provide a stable and accurate benchmark for measurement, can accurately capture the change of light angle caused by the bridge deflection, and thus realizes the accurate measurement of the bridge deflection; through the arranged multiple triangular media, the deflection information of different positions of the bridge can be comprehensively obtained, so as to more accurately depict the deflection curve of the bridge and provide more comprehensive data support for evaluating the overall structural health of the bridge; it belongs to non-contact measurement, will not cause any damage to the bridge structure, nor affect the normal use of the bridge, and can realize real-time monitoring during the operation of the bridge. Description of the Drawings

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required to be used in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to these drawings.

[0017] Figure 1 is the structural schematic diagram when the device in the embodiment of the present application is installed; Figure 2 is the structural schematic diagram of the triangular medium in the embodiment of the present application; Figure 3 Schematic diagram of the structure of the rectangular medium in the embodiment of the present application; Figure 4 Schematic diagram of the optical path in the triangular medium when no downward deflection occurs in the embodiment of the present application; Figure 5 Schematic diagram of the optical path in the triangular medium when downward deflection occurs in the embodiment of the present application; Figure 6 Schematic diagram of the optical path calculation in the triangular medium when no downward deflection occurs in the embodiment of the present application; Figure 7 Schematic diagram of the optical path calculation in the triangular medium when downward deflection occurs in the embodiment of the present application; Explanation of reference numerals: 1. Triangular medium; 2. Semi-transparent film; 3. Single-sided photosensitive device; 4. Schematic optical path; 5. Rectangular medium; 6. Double-sided photosensitive device; 7. Laser generating device; 8. Counterweight; 9. Total reflection mirror. Detailed implementation manners

[0018] To make the above objects, features, and advantages of the present application more apparent and understandable, the following detailed description of the specific implementation manners of the present application is provided in conjunction with the accompanying drawings. Many specific details are set forth in the following description to fully understand the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.

[0019] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present application.

[0020] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of this application, "a plurality of" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0021] In this application, unless otherwise clearly defined and limited, terms such as "installed", "connected", "linked", "fixed", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two components or the interaction relationship between two components, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0022] In this application, unless otherwise clearly defined and limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0023] It should be noted that when an element is referred to as "fixed to" or "disposed on" 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 an intermediate element at the same time. The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation.

[0024] Embodiment This embodiment provides a device for bridge deflection monitoring, such as Figure 1As shown in the figure, it includes a triangular medium 1, a rectangular medium 5 and a laser generating device 7 provided at the bottom of the bridge. The rectangular medium 5 is provided in the middle of the bridge, and its photosensitive surfaces on the opposite sides face the bridge piers on both sides. The laser generating device 7 is provided at the bridge piers on both sides, and its output end for emitting laser light faces the rectangular medium 5. The triangular medium 1 is provided between the rectangular medium 5 and the laser generating device 7. A plurality of the triangular media 1 are arranged at intervals along the entire length of the bridge. The laser incident side of the triangular medium 1 faces the output end of the laser generating device 7, and the laser emitting side of the triangular medium 1 faces the rectangular medium 5. The laser light emitted by the laser generating device 7 is directed towards the rectangular medium 5 through the triangular medium 1.

[0025] As Figure 2 shown in the figure, the triangular medium 1 includes a pair of symmetrically arranged isosceles right-angled triangular glasses. A large isosceles right-angled triangle is formed by the pair of isosceles triangular glasses. A semi-permeable membrane 2 for receiving laser light is provided between the pair of isosceles right-angled triangular glasses, and its light-transmitting surface faces the laser incident side of the triangular medium 1.

[0026] In this embodiment, a total reflection mirror surface 9 is provided at the top (hypotenuse) of the triangular medium 1, and the total reflection mirror surface 9 points to the bottom end of the triangular medium 1. A single-sided photosensitive device 3 is provided on the laser incident side of the triangular medium 1, and the photosensitive surface of the single-sided photosensitive device 3 faces the isosceles right-angled triangular glass. The length of the single-sided photosensitive device 3 is less than the length of the hypotenuse of the isosceles right-angled triangular glass. One end of the single-sided photosensitive device 3 is flush with the bottom end of the hypotenuse, and the other end is located on the laser light path when the bridge does not deflect after installation. The single-sided photosensitive device 3 uses a position-sensitive detector to detect the laser position point.

[0027] As Figure 3 shown in the figure, the rectangular medium 5 includes a rectangular glass and a double-sided photosensitive device 6. The double-sided photosensitive device 6 is provided between a pair of rectangular glasses, and its photosensitive surface faces the triangular medium 1.

[0028] In this embodiment, both the triangular medium 1 and the rectangular medium 5 are high-transparency glasses to ensure a high transmittance of the laser light.

[0029] In this embodiment, the hypotenuse of the triangular medium 1 is connected to the bottom of the bridge, and a counterweight 8 is provided at its bottom end. The counterweight 8 is installed below the triangular medium 1 and the rectangular medium 5 to ensure that the center lines of the triangular medium 1 and the rectangular medium 5 are parallel to the direction of gravity (perpendicular to the horizontal plane).

[0030] As Figure 4As shown, when there is no vehicle passing on the bridge, i.e., the initial installation state of the device, the light ray 4 emits from the pier side, enters through the optical fiber incident side of the triangular medium 1, refracts to the middle of the bottom side of the triangular medium 1, and after being reflected by the total reflection mirror 9, symmetrically emits from the triangular medium 1. That is, the light ray 4 after passing through the triangular medium 1 is on the same horizontal plane as the incident light ray, and the light ray 4 does not shift.

[0031] As Figure 5 shown, when there is a vehicle passing on the bridge, the bridge deflects downward, the position of the triangular medium 1 drops, the position where the light ray 4 enters the triangular medium 1 from the pier side rises, refracts to the bottom side of the triangular medium 1, and after being reflected by the total reflection mirror 9, the light ray 4 passes through the semi-permeable membrane 2. The light ray 4 is divided into two parts. One part is reflected onto the single-sided photosensitive device 3, and the position of the laser spot (which is also the position where the light ray emits from the triangular medium 1) is accurately sensed through the single-sided photosensitive device 3, so as to accurately calculate the position where the light ray 4 enters the triangular medium 1, and then obtain the deflection at this position. The other part of the light ray passes through the semi-permeable membrane 2 and emits from the other right-angled side of the triangular medium 1. The emitted light ray is still parallel to the incident light ray 4. The emitted light ray shoots towards the next triangular medium 1.

[0032] The light ray 4 emitted from this triangular medium 1 shoots towards the next triangular medium 1. By calculating the height difference between the position where the light ray emits from the current triangular medium 1 and the position where the light ray enters the next triangular medium 1, it is the deflection of the next triangular medium 1 relative to the current triangular medium 1. Calculate step by step until reaching the rectangular medium 5 in the middle, so as to calculate the deflections of each measuring point of the bridge.

[0033] Since the closer to the middle, the greater the deflection of the bridge. When the bridge undergoes flexural deformation, every time the device passes through a triangular medium 1, the light ray moves downward by a certain part, and the self-adaptive adjustment with the bridge deformation is realized by relying on the optical path, ensuring the transmission of the light ray towards the middle of the bridge.

[0034] This embodiment also provides a monitoring method for a device for bridge deflection monitoring, including the following steps: Lay the rectangular medium 5 and the triangular medium 1 along the full length of the bridge at the bottom of the bridge, ensuring that the center lines of the rectangular medium 5 and the triangular medium 1 are parallel to the direction of gravity; Lay the laser generating device 7 at the piers on both sides of the bridge, so that the laser emitted by it can be emitted to the rectangular medium 5 through the triangular medium 1, and obtain the deflection height of each point according to the deflection height calculation formula; The deflection height calculation formula for the outermost point is: h 1 - h 2 (Formula 1) Where h1 is the height of the laser point emitted by the laser generating device above the base along the right-angled side of the triangular medium when the bridge has no downward deflection. h 2 is the height of the laser point emitted by the laser generating device above the base along the right-angled side of the triangular medium when the bridge has downward deflection. As Figure 6 shown, the incident angle of light ray 4 on the triangular medium 1 a = 45°, and the exit angle from the triangular medium 1 is also a = 45°; the refraction angle of light ray 4 after passing through point A on the incident interface is b , the incident angle a and the refraction angle b satisfy the refraction law: n 1·sin a = n 2·sin b , n 1 and n 2 represent the refractive indices of air and the triangular medium 1 respectively, a and b represent the incident angle and the refraction angle respectively. h The calculation formula for 1 is: (Formula 2) where h 0 is the height of the triangular medium.

[0035] As Figure 7 shown, when a vehicle passes over the bridge, the bridge deflects downward, the position of the triangular medium 1 drops, the position where the light ray 4 enters the triangular medium 1 from the pier side rises, changing from point A to point D, and the height of point D above the base is h 2, the incident angle a and the refraction angle b satisfy the refraction law: n 1·sin a = n 2·sin b , and the incident angle a = 45°.

[0036] The refracted light ray 4 is incident on point E on the base, reflected by the total reflection mirror 9, passes through point F on the semi-permeable membrane 2, and the light ray 4 is divided into two parts. One part is reflected onto point G on the single-sided photosensitive device 3, and the other part of the light ray passes through the semi-permeable membrane 2, is refracted after passing through point H on the other right-angled side of the triangular medium 1, and the emitted light ray is parallel to the initial light ray. The heights of points G and H above the base are the same, and this height is h 3. By accurately sensing the position of the laser point G through the single-sided photosensitive device 3, h 3 is obtained, then the calculation formula for the height h 2 of point D above the base is: (Formula 3) Thus, the deflection height at this point is ( h 1 - h 2).

[0037] When calculating the deflection height at the next point, ( h 3 - h 1) should be subtracted for ray correction. h 3 is the height of the laser spot emitted from the triangular medium at the previous point and landing on the right - angled side of the current triangular medium from the bottom edge, which is obtained by the single - sided photosensitive device. ( h 3 - h 1) is the height by which the laser deviates when emitted from the previous point.

[0038] Among them, h 3 is the height of the laser spot emitted from the triangular medium at the previous point and landing on the right - angled side of the current triangular medium from the bottom edge, which is obtained by the single - sided photosensitive device.

[0039] The technical features of the above - described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above - described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0040] The above - described embodiments only represent several implementation manners of the present application. Their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A device for monitoring bridge deflection, characterized in that: include: A rectangular medium, wherein the rectangular medium is arranged in the middle of the bridge, and the top end of the rectangular medium is connected to the bottom of the bridge; Triangular media, a plurality of said triangular media are arranged on both sides of the rectangular media and extend to both sides of the bridge, with the tops thereof connected to the bottom of the bridge, and the right-angled sides thereof facing the rectangular media and the piers on one side of the bridge respectively; A laser generating device is arranged on the piers on both sides of the bridge, and the laser emitted from the output end thereof is directed toward the rectangular medium via the triangular medium.

2. The device for monitoring bridge deflection according to claim 1, characterized in that: The rectangular medium and the triangular medium are high light-transmittance glass.

3. The device for monitoring bridge deflection according to claim 1, characterized in that: The rectangular medium includes rectangular glass and a double-sided photosensitive device. The double-sided photosensitive device is arranged between a pair of rectangular glasses, and its photosensitive surface faces the triangular medium.

4. The device for monitoring bridge deflection according to claim 1, characterized in that: The triangular medium comprises an isosceles right triangle glass and a semi-permeable membrane. A pair of the isosceles right triangle glasses are symmetrically arranged on both sides of the semi-permeable membrane. One right-angled side of the isosceles right triangle glass is connected to the semi-permeable membrane, and the other right-angled side is provided with a total reflection mirror.

5. The device for monitoring bridge deflection according to claim 4, characterized in that: A single-sided photosensitive device is provided on the hypotenuse of the laser incident side of one of the isosceles right-angled triangle glasses, and the photosensitive side of the single-sided photosensitive device faces the isosceles right-angled triangle glass.

6. The device for monitoring bridge deflection according to claim 5, characterized in that: The length of the single-sided photosensitive device is smaller than the length of the hypotenuse, and one end of the single-sided photosensitive device is flush with the bottom end of the hypotenuse.

7. The device for monitoring bridge deflection according to claim 4, characterized in that: The hypotenuse of the triangular medium is connected to the bottom of the bridge, and a counterweight is arranged at the bottom end thereof.

8. A monitoring method for the device for monitoring bridge deflection according to any one of claims 1 to 7, characterized in that: The steps include: Arrange the rectangular medium and the triangular medium at the bottom of the bridge along the entire length of the bridge, and ensure that the center lines of the rectangular medium and the triangular medium are parallel to the direction of gravity; The laser generating device is arranged at the piers on both sides of the bridge, so that the laser emitted by it can be emitted to the rectangular medium through the triangular medium, and the deflection height of each point is obtained according to the deflection height calculation formula; The calculation formula for the deflection height at the outermost point is: h 1- h 2 (Official 1) in, h 1 is the height from the bottom edge to the right angle side of the triangular medium when the laser point emitted by the laser generating device falls on the bridge without deflection. h 2 is the height from the bottom edge to the right angle side of the triangular medium where the laser point emitted by the laser generating device falls when the bridge deflects downward; When calculating the deflection height of the next point, subtract ( h 3- h 1) Perform light correction, h 3 is the height of the right angle side of the triangle medium from the bottom side of the laser point emitted by the laser from the previous point, which is obtained by the single-sided photosensitive device. ( h 3- h 1) The height that the laser is offset from the previous point.

9. The method according to claim 8, characterized in that Said h 1 is: (Formula 2) in, h 0 is the height of the triangular medium, b According to the law of refraction: n 1. sin a = n 2. sin b Find, among which, a The incident angle is 45°, n 1 is the refractive index of air, n 2 is the refractive index of the triangular medium.

10. The method according to claim 8, characterized in that Said h 2 is: (Formula 3).

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