A deformation monitoring device and a deformation monitoring method

Abstract

The application discloses a deformation monitoring device and a deformation detection method. The deformation monitoring device comprises a first fiber grating, a second fiber grating, a first measuring unit and a second measuring unit. The distal end of the first measuring unit is hinged to the proximal end of the second measuring unit. The second measuring unit can rotate relative to the first measuring unit in a settlement direction. The proximal end of the first fiber grating is closely attached to and fixed on the top of the first measuring unit. The distal end of the first fiber grating is closely attached to and fixed on the top of the second measuring unit. The proximal end of the second measuring unit is closely attached to and fixed on the bottom of the first measuring unit. The distal end of the second fiber grating is closely attached to and fixed on the bottom of the second measuring unit. The deformation monitoring device has high measurement accuracy and wide application range. The deformation monitoring method using the deformation monitoring device can obtain the displacement settlement deformation of each point.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of geotechnical engineering monitoring, in particular to a deformation monitoring device and a deformation monitoring method. BACKGROUND

[0002] Safety monitoring is a basic means for safety state evaluation of various infrastructure construction period and operation period, and is an important part of dynamic design of geotechnical engineering. Traditional geotechnical engineering deformation monitoring mostly uses single sensor measurement technology such as inductance type, resistance type and vibrating wire type strain gauge. There are some disadvantages such as limited sampling quantity, low spatial coverage rate and uncertain data representativeness. With the development of engineering, the requirement for large-scale monitoring sampling of geotechnical engineering is higher and higher. The traditional point monitoring method cannot meet the engineering requirements. The distributed optical fiber displacement monitoring technology uses the wavelength shift characteristics of the grating when the optical fiber is axially stretched to establish the relationship between strain and wavelength, and monitors the position change between two fixed points. However, this method cannot meet the requirement of high precision of geotechnical engineering monitoring. SUMMARY

[0003] The present application aims to at least solve one of the technical problems existing in the prior art, and provides a deformation monitoring device and a deformation monitoring method, wherein the deformation monitoring device has high measurement precision and wide application range, and the deformation monitoring method using the deformation monitoring device can obtain the displacement settlement deformation of each point.

[0004] The technical solution adopted by the present application to solve its technical problems is:

[0005] A deformation monitoring device, comprising a first fiber grating, a second fiber grating, a first measurement unit and a second measurement unit, the distal end of the first measurement unit is hinged to the proximal end of the second measurement unit, the second measurement unit can rotate relative to the first measurement unit in the settlement direction, the proximal end of the first fiber grating is tightly fixed on the top of the first measurement unit, the distal end of the first fiber grating is tightly fixed on the top of the second measurement unit, the proximal end of the second measurement unit is tightly fixed on the bottom of the first measurement unit, and the distal end of the second fiber grating is tightly fixed on the bottom of the second measurement unit.

[0006] In some embodiments of the present application, the first measurement unit comprises a first rod body and a first support part, the distal end of the first rod body is connected to the first support part, the second measurement unit comprises a second rod body and a second support part, the proximal end of the second support part is connected to the second rod body, the first support part is provided with a rotating shaft, and the second support part is provided with a shaft hole matched with the rotating shaft.

[0007] In some embodiments of the present application, the top of the first rod body is provided with a first clamping groove along the length direction thereof, the bottom of the first rod body is provided with a second clamping groove along the length direction thereof, the top of the second rod body is provided with a third clamping groove along the length direction thereof, and the bottom of the second rod body is provided with a fourth clamping groove along the length direction thereof, the first clamping groove and the second clamping groove being used for clamping the first fiber grating, and the third clamping groove and the fourth clamping groove being used for clamping the second fiber grating.

[0008] In some embodiments of the present application, an adhesive is arranged in the first clamping groove, the second clamping groove, the third clamping groove and the fourth clamping groove.

[0009] In some embodiments of the present application, the second support part comprises a sleeve and a support plate, two support plates being arranged on the two sides of the sleeve, and the sleeve and the support plate being provided with the shaft hole.

[0010] In some embodiments of the present application, an angle limiting assembly is arranged between the first support part and the second support part, the angle limiting assembly comprising a first sector-shaped block fixedly arranged on the first support part and a second sector-shaped block arranged on the support plate, the first sector-shaped block and the second sector-shaped block being limitedly abutted when the first measurement unit and the second measurement unit are relatively rotated by a certain angle.

[0011] In some embodiments of the present application, the first rod body and the first support part are connected by bolts, and the second rod body and the sleeve are connected by bolts.

[0012] In some embodiments of the present application, the length of the first rod body is equal to the length of the second rod body.

[0013] In some embodiments of the present application, a buffer layer is arranged on the outer periphery of the first fiber grating, the second fiber grating, the first measurement unit and the second measurement unit.

[0014] The present application also provides a deformation detection method using the deformation monitoring device.

[0015] The deformation monitoring device is buried in the rock and soil.

[0016] In the monitoring process, the influence of temperature on the strain is eliminated by the second fiber grating, the wavelength of the first fiber grating is obtained, the initial rotation angle of the first measurement unit is θ0, and the deflection angle θ1 of the second measurement unit is obtained.

[0017] The length of the first fiber grating is L, the vertical displacement of the second measuring unit relative to the first measuring unit is Δy, and the displacement settlement deformation of each point (i=1, 2...n) on the second measuring unit is obtained by the following formula

[0018]

[0019] One of the above technical solutions has at least one of the following advantages or benefits: the deformation monitoring device fixes the first fiber grating and the second fiber grating on the top and bottom of the first measuring unit and the second measuring unit respectively, and the first measuring unit and the second measuring unit are connected in rotation, so that only displacement along the foundation settlement direction can be generated, eliminating the influence of lateral deformation, and converting the strain of the first fiber grating and the second fiber grating into the change of the included angle between the first measuring unit and the second measuring unit, and then calculating the deflection displacement of the first measuring unit and the second measuring unit through the change of the included angle, effectively increasing the range of the deformation monitoring device, and through the paired arrangement of the first fiber grating and the second fiber grating on the upper and lower sides, when the first measuring unit and the second measuring unit rotate relative to each other, the fiber grating on one side is stretched, and the fiber grating on the other side naturally relaxes, the stretched fiber grating is converted into an angle, and the relaxed fiber is only affected by temperature, and the wavelength difference between the two is calculated to eliminate the influence of temperature, realize temperature self-compensation, and improve measurement accuracy. When in use, a plurality of first measuring units and second measuring units can be installed in series to realize long-distance and quasi-distributed monitoring. Through the spacing of the fixed points of the first fiber grating and the second fiber grating, different accuracy and range can be realized. The deformation monitoring method using the deformation monitoring device can obtain the displacement settlement deformation of each point.

[0020] Additional aspects and advantages of the application will be in part apparent and in part pointed out hereinafter in the description. BRIEF DESCRIPTION OF DRAWINGS

[0021] The above and / or additional aspects and advantages of the application will become apparent and be readily appreciated from the description of the embodiments, taken in conjunction with the following drawings in which:

[0022] Figure 1 is one of the structural schematic diagrams of an embodiment of the deformation monitoring device of the application;

[0023] Figure 2 is the second structural schematic diagram of an embodiment of the deformation monitoring device of the application;

[0024] Figure 3 is a cross-sectional schematic diagram of an embodiment of the deformation monitoring device of the application;

[0025] Figure 4 is a longitudinal sectional view of an embodiment of the deformation monitoring device of the present application;

[0026] Figure 5 is a structural schematic view III of an embodiment of the deformation monitoring device of the present application. DETAILED DESCRIPTION

[0027] This part will describe the specific embodiments of the present application in detail, the preferred embodiments of the present application are shown in the drawings, the role of the drawings is to supplement the description of the text part with figures, so that people can intuitively and visually understand each technical feature and the overall technical scheme of the present application, but it cannot be understood as a limitation on the protection scope of the present application.

[0028] In the present application, if there is a description of direction (up, down, left, right, front and back), it is only for the convenience of describing the technical scheme of the present application, and it is not intended or implied that the indicated technical features must have a specific orientation, be constructed and operated in a specific orientation, therefore it cannot be understood as a limitation on the present application.

[0029] In the present application, the meaning of "several" is one or more, the meaning of "multiple" is two or more, "greater than", "less than", "more than" and the like are understood as not including the number; "above", "below", "within" and the like are understood as including the number. In the description of the present application, if there is a description of "first" and "second", it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features or implicitly indicating the sequence of indicated technical features.

[0030] In the present application, unless otherwise explicitly limited, the words "set", "install", "connect" and the like should be broadly understood, for example, they can be directly connected, or indirectly connected through an intermediate medium; can be fixedly connected, or can be detachably connected, or can be integrally formed; can be mechanically connected, or can be electrically connected or capable of communicating with each other; can be the internal communication of two elements or the interaction relationship of two elements. The skilled in the art can reasonably determine the specific meaning of the above words in the present application in combination with the specific content of the technical scheme.

[0031] wherein, Figure 1 The reference direction coordinate system of the embodiment of the present application is given, and the embodiments of the present application are described below in combination with the directions shown in Figure 1

[0032] The embodiment of the present application provides a deformation monitoring device, referring to Figures 1 to 5 ​, comprising a first fiber grating 100, a second fiber grating 200, a first measuring unit 300 and a second measuring unit 400, the distal end of the first measuring unit 300 is hinged to the proximal end of the second measuring unit 400, the second measuring unit 400 can rotate relative to the first measuring unit 300 in the settlement direction, the proximal end of the first fiber grating 100 is close to and fixed on the top of the first measuring unit 300, the distal end of the first fiber grating 100 is close to and fixed on the top of the second measuring unit 400, the proximal end of the second measuring unit 400 is close to and fixed on the bottom of the first measuring unit 300, and the distal end of the second fiber grating 200 is close to and fixed on the bottom of the second measuring unit 400.

[0033] The deformation monitoring device can only produce displacement along the foundation settlement direction by fixing the first fiber grating 100 and the second fiber grating 200 on the top and bottom of the first measuring unit 300 and the second measuring unit 400 respectively, and the first measuring unit 300 and the second measuring unit 400 are connected in rotation, thereby eliminating the influence of lateral deformation, converting the strain of the first fiber grating 100 and the second fiber grating 200 into the change of the included angle between the first measuring unit 300 and the second measuring unit 400, and subsequently calculating the deflection displacement of the first measuring unit 300 and the second measuring unit 400 through the change of the included angle, thereby effectively increasing the range of the deformation monitoring device, and through the paired arrangement of the first fiber grating 100 and the second fiber grating 200 on the upper and lower sides, when the first measuring unit 300 and the second measuring unit 400 rotate relative to each other, the fiber grating on one side is stretched, and the fiber grating on the other side naturally relaxes, the stretched fiber grating is converted into a rotation angle, and the relaxed fiber is only affected by temperature, the wavelength difference between the two is calculated to eliminate the influence of temperature, realize temperature self-compensation, and improve measurement accuracy, in use, a plurality of first measuring units 300 and second measuring units 400 can be connected in series to realize long-distance and quasi-distributed monitoring, and different accuracy and range can be realized through the spacing between the fixed points of the proximal end and the distal end of the first fiber grating 100 and the second fiber grating 200.

[0034] Referring to Figure 4 The first measuring unit 300 comprises a first rod body 310 and a first support portion 320, the distal end of the first rod body 310 is connected to the first support portion 320, the second measuring unit 400 comprises a second rod body 410 and a second support portion 420, the proximal end of the second support portion 420 is connected to the second rod body 410, the first support portion 320 is provided with a rotating shaft 600, and the second support portion 420 is provided with a shaft hole matched with the rotating shaft 600.

[0035] In some embodiments, the top of the first rod body 310 is provided with a first clamping groove along the length direction thereof, the bottom of the first rod body 310 is provided with a second clamping groove along the length direction thereof, the top of the second rod body 410 is provided with a third clamping groove along the length direction thereof, and the bottom of the second rod body 410 is provided with a fourth clamping groove along the length direction thereof, the first clamping groove and the second clamping groove are used for clamping the first fiber grating 100, facilitating the pasting and fixing of the first fiber grating 100, and the third clamping groove and the fourth clamping groove are used for clamping the second fiber grating 200, facilitating the pasting and fixing of the second fiber grating 200, thereby solving the problem of easy breakage and low survival rate of the bare fiber grating when directly used.

[0036] The first clamping groove, the second clamping groove, the third clamping groove and the fourth clamping groove are all provided with adhesive 500.

[0037] Referring to Figure 4 The second support part 420 comprises a sleeve 422 and a support plate 421, two support plates 421 are arranged on the two sides of the sleeve 422, and the sleeve 422 and the support plate 421 are both provided with an axle hole.

[0038] In some embodiments, an angle limiting assembly is arranged between the first support part 320 and the second support part 420, the angle limiting assembly comprises a first sector-shaped block fixedly arranged on the first support part 320 and a second sector-shaped block arranged on the support plate 421, when the first measuring unit 300 and the second measuring unit 400 rotate by a certain angle, the first sector-shaped block and the second sector-shaped block limit and abut, when the fiber grating reaches the maximum deflection angle, the angle limiting assembly can be locked, so that the first rod body 310 and the second rod body 410 cannot rotate relative to each other, thereby preventing the fiber grating from being broken due to excessive stretching.

[0039] The first rod body 310 is connected with the first support part 320 through a bolt, and the second rod body 410 is connected with the sleeve 422 through a bolt, so that the standardized production and installation mode makes the range and precision of the deformation monitoring device not affected by the installation form.

[0040] The length of the first rod body 310 is equal to that of the second rod body 410, that is, the first rod body 310 and the second rod body 410 serve as a basic measuring unit, a plurality of basic measuring units are connected in series to form a quasi-distributed measuring line, the measuring line is arranged on the surface of the rock-soil body, the middle part of each basic measuring unit is fixed with an anchor pile in the rock-soil body, and any position of the measuring line is arranged on a fixed point, taking the fixed point as a starting point, the angular displacement of each measuring unit is sequentially accumulated, and the displacement is the displacement distribution of the rock-soil body along the measuring line, when the basic measuring unit rotates, the change of the arc length corresponding to the central angle of the rotating shaft 600 corresponds to the change of the fiber length of a measuring unit, so that the measuring unit is in a modular form, the length of the measuring line can be increased or decreased in the number of measuring units according to the measurement requirement, and is not limited by the limit tensile strain of the fiber grating.

[0041] The deformation monitoring device further comprises a buffer layer, which is arranged on the outer periphery of the first fiber grating 100, the second fiber grating 200, the first measuring unit 300 and the second measuring unit 400, that is, after the fiber grating is pasted, a layer of foam glue is sprayed on the surface of the deformation monitoring device, thereby playing a buffering and shock isolation role.

[0042] A deformation detection method using the deformation monitoring device in any one of the above embodiments, comprising the following steps:

[0043] The rotating shaft 600, the first rod body 310 and the second rod body 410 are assembled through connecting screws, and the first fiber grating 100 and the second fiber grating 200 are pasted at the first clamping groove, the second clamping groove, the third clamping groove and the fourth clamping groove on the surface; the strain coefficient, the sensitivity, the hysteresis and other parameters of the whole monitoring device are calibrated in the laboratory

[0044] The deformation monitoring device is buried in the rock and soil;

[0045] In the monitoring process, the temperature influence on the strain is eliminated through the second fiber grating 200 (specifically, at all times, one of the first fiber grating 300 and the second fiber grating 200 on the upper side and the lower side is in a relaxed state, and the measurement value is only affected by the temperature; the wavelengths of the two fiber gratings are obtained in the monitoring process, and the temperature compensation can be naturally performed by subtracting the wavelength values of the two fiber gratings), the wavelength of the first fiber grating 100 is obtained, the temperature influence on the strain is eliminated through the double grating method, and then the displacement settlement deformation amount at each measuring unit can be obtained by using the strain coefficient calibrated in the laboratory, and the deflection angle of each fiber grating can be calculated, a two-dimensional plane deformation coordinate graph is constructed, the initial rotation angle of the first measuring unit 300 is θ0, and the deflection angle θ1 of the second measuring unit 400 is obtained.

[0046] The length of the first fiber grating 100 is L, the vertical displacement of the second measuring unit 400 relative to the first measuring unit 300 is Δy, and then the displacement settlement deformation amount at each position (i=1, 2...n) of the second measuring unit 400 is obtained through the following formula

[0047]

[0048] The deformation detection method using the deformation monitoring device converts the strain of the fiber grating into the relative rotation angle of the first measuring unit 300 and the second measuring unit 400 at both ends of the rotating shaft 600, converts the rotation angle into the relative displacement at both ends of the first measuring unit 300 and the second measuring unit 400, the length of the measuring line can be increased or decreased according to the measurement requirement, the number of the first measuring unit 300 and the second measuring unit 400, the range of the first measuring unit 300 and the second measuring unit 400 is proportional to the length, and the range is not limited by the limit tensile strain of the fiber grating.

[0049] It can be understood that according to the laying form of the deformation monitoring device, not only horizontal displacement can be measured, but also vertical displacement can be measured, foundation settlement monitoring can be carried out, and slope deformation monitoring can be carried out, and the application scenarios are wide.

[0050] In the description of the present specification, the description referring to the terms “example”, “embodiment” or “some embodiments” or the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0051] Of course, the present application is not limited to the above-mentioned embodiments, and those skilled in the art can make equivalent modifications or replacements without departing from the spirit of the present application, and these equivalent modifications or replacements are included in the scope defined by the claims of the present application.

Claims

1. A deformation monitoring device, characterized by, The first fiber grating, the second fiber grating, the first measuring unit and the second measuring unit, the distal end of the first measuring unit is hinged with the proximal end of the second measuring unit, the second measuring unit can rotate relative to the first measuring unit in the settlement direction, the proximal end of the first fiber grating is close to and fixed on the top of the first measuring unit, the distal end of the first fiber grating is close to and fixed on the top of the second measuring unit, the proximal end of the second measuring unit is close to and fixed on the bottom of the first measuring unit, and the distal end of the second fiber grating is close to and fixed on the bottom of the second measuring unit.

2. The deformation monitoring apparatus according to claim 1, characterized by The first measuring unit comprises a first rod body and a first support part, the distal end of the first rod body is connected with the first support part, the second measuring unit comprises a second rod body and a second support part, the proximal end of the second support part is connected with the second rod body, the first support part is provided with a rotating shaft, and the second support part is provided with a shaft hole matched with the rotating shaft.

3. The deformation monitoring apparatus according to claim 2, characterized by The top of the first rod body is provided with a first clamping groove along the length direction thereof, the bottom of the first rod body is provided with a second clamping groove along the length direction thereof, the top of the second rod body is provided with a third clamping groove along the length direction thereof, the bottom of the second rod body is provided with a fourth clamping groove along the length direction thereof, the first clamping groove and the second clamping groove are used for clamping the first fiber grating, and the third clamping groove and the fourth clamping groove are used for clamping the second fiber grating.

4. The deformation monitoring apparatus according to claim 3, characterized by Glue is arranged in the first clamping groove, the second clamping groove, the third clamping groove and the fourth clamping groove.

5. The deformation monitoring apparatus according to claim 2, characterized by The second support part comprises a sleeve and a support plate, two support plates are arranged on the two sides of the sleeve, and the sleeve and the support plate are provided with the shaft hole.

6. The deformation monitoring apparatus according to claim 5, wherein An angle limiting assembly is arranged between the first support part and the second support part, the angle limiting assembly comprises a first sector-shaped block fixed on the first support part and a second sector-shaped block arranged on the support plate, and when the first measuring unit and the second measuring unit rotate by a certain angle, the first sector-shaped block and the second sector-shaped block are limited to abut.

7. The deformation monitoring apparatus according to claim 5, characterized by The first rod body and the first support part are connected through bolts, and the second rod body and the sleeve are connected through bolts.

8. The deformation monitoring apparatus according to claim 2, characterized by The lengths of the first rod body and the second rod body are equal.

9. The deformation monitoring apparatus of claim 1, wherein A buffer layer is arranged on the outer periphery of the first fiber grating, the second fiber grating, the first measuring unit and the second measuring unit.

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