Riverway revetment deformation monitoring equipment based on optical fiber sensing

Abstract

The utility model relates to a river deformation monitoring equipment, especially a river revetment deformation monitoring equipment based on optical fiber sensing, including the concrete compression top that sets up in the dam top, the lateral wall of dam evenly is paved with a plurality of veneer, the longitudinal section of dam is provided with temperature monitoring subassembly, a plurality of veneer all inlay setting have deformation monitoring subassembly, through the distributed measurement of multiple point of stringing a plurality of optical fiber bragg grating sensors, and through the compensation to temperature to accurate identification structure deformation, be favorable to realize the simultaneous monitoring of local strain and overall strain.

Description

Technical Field

[0001] This utility model relates to a river deformation monitoring device, and more particularly to a riverbank deformation monitoring device based on fiber optic sensing. Background Technology

[0002] River engineering projects, such as dams and bridges, may deform due to various factors. If they are not monitored and addressed in a timely manner, they may lead to structural safety issues or even accidents such as collapses and dam failures. Therefore, early detection and resolution of river deformation problems are crucial to ensuring the safe operation of river engineering projects.

[0003] River channel structures are typically large in scale and wide in area, and the occurrence of damage is random. Therefore, traditional "point" strain gauges are not suitable for long-term monitoring of structures. On the one hand, "point" strain gauges often fail due to excessive local strain and the appearance of cracks. On the other hand, it is difficult to cover the entire structure with "point" strain gauges and it is very uneconomical. Utility Model Content

[0004] This invention proposes a riverbank deformation monitoring device based on fiber optic sensing. It connects multiple fiber Bragg grating sensors in series to achieve multi-point distributed measurement, and by compensating for temperature, it can accurately identify structural deformation, which is beneficial for simultaneous monitoring of local strain and overall strain.

[0005] A riverbank deformation monitoring device based on fiber optic sensing includes a concrete capping set on the top of the embankment, multiple facings evenly laid on the outer wall of the embankment, a temperature monitoring component set in the longitudinal section of the embankment, and a deformation monitoring component embedded in each of the multiple facings. The deformation monitoring component includes an upper strain sensing fiber and a lower strain sensing fiber embedded in the lining and arranged in parallel along the river channel direction. The upper strain sensing fiber and the lower strain sensing fiber have the same structure, each including multiple fiber Bragg grating sensors connected in sequence through anchoring sections. Each fiber Bragg grating sensor includes a fiber core, and multiple uniformly distributed fiber Bragg gratings are disposed in the fiber core. The outer wall of each fiber Bragg grating sensor is covered with a cladding layer and a protective layer from the inside to the outside. The temperature monitoring component includes a temperature sensing fiber disposed in the longitudinal section of the dam. A fiber optic processing terminal is installed on the top of the concrete capping structure. The fiber optic processing terminal is electrically connected to a fiber optic grating demodulator and a distributed fiber optic demodulator. The fiber optic grating demodulator is electrically connected to a coupler. The coupler is electrically connected to the upper strain sensing fiber and the lower strain sensing fiber. The upper strain sensing fiber and the lower strain sensing fiber are electrically connected to a data storage device. The distributed fiber optic demodulator is electrically connected to a temperature sensing fiber. The temperature sensing fiber is electrically connected to a data storage device. The data storage device is electrically connected to the fiber optic processing terminal.

[0006] Furthermore, the outer walls of both the upper strain sensing fiber and the lower strain sensing fiber are covered with fiber sleeves, and the fiber sleeves are basalt fiber sleeves.

[0007] Furthermore, the upper strain sensing fiber and the lower strain sensing fiber form a closed structure as a whole, and the two are electrically connected.

[0008] Furthermore, the fiber Bragg grating sensors in the upper strain sensing fiber and the lower strain sensing fiber are provided for each of the bonding surfaces, and the anchoring segment is provided for two adjacent bonding surfaces.

[0009] Furthermore, each of the fiber Bragg grating sensors is in a pre-tensioned state, and each of the anchoring sections is in a relaxed state.

[0010] Furthermore, the temperature sensing fiber is arranged in a meandering bend.

[0011] The beneficial effects of this utility model are as follows: 1. This utility model employs a combination of upper and lower strain sensing fibers arranged in parallel along the river channel, with multiple fiber Bragg grating sensors connected sequentially via anchoring sections inside, forming a long gauge-length closed structure. Compared to traditional "point" sensors, this structure facilitates the formation of a distributed sensor network. A fiber sheath serves as the outermost layer of the fiber Bragg grating sensor, ensuring free deformation within the gauge length. Each surface is used as a gauge length unit, with anchoring sections connected to both ends of the fiber Bragg grating sensor. Each fiber Bragg grating sensor is in a pre-tensioned state, while each anchoring section is in a relaxed state. This structural design ensures uniform deformation of the upper and lower strain sensing fibers within the gauge length, forming a uniform strain field. The change in the center wavelength represents the average strain within that gauge length. Damage within each gauge section is detected, reducing strain abrupt changes and preventing fiber Bragg grating sensor failure due to cracking or other issues.

[0012] 2. This utility model uses temperature-sensing optical fibers to monitor seepage in river embankments. The monitoring of seepage is mainly reflected by temperature changes. For embankment sections where only seepage is monitored, temperature-sensing optical fibers that do not require special fixing can be selected. For situations where piping is more likely to occur, a combination of upper strain-sensing optical fibers, lower strain-sensing optical fibers, and temperature-sensing optical fibers is selected to comprehensively determine the occurrence of large seepage by using temperature changes and abrupt changes in strain.

[0013] 3. The fiber Bragg grating sensor of this utility model includes a fiber core, a cladding, and a protective layer; wherein the cladding can reflect light of a specific wavelength emitted by the fiber core back into the fiber core to ensure that the light wave has the lowest transmission loss in the fiber core. The principle of this function is that the refractive index of the fiber core is higher than that of the cladding, so when the light wave propagates from the fiber core to the cladding, total internal reflection will occur. The outermost protective layer provides protection to prevent damage to the optical fiber caused by the external environment or external force. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a schematic diagram of the deformation monitoring component of this utility model; Figure 3 This is a schematic diagram of the structure of the fiber Bragg grating sensor of this utility model.

[0015] Reference numerals in the attached diagram: 1. Embankment; 2. Concrete capping; 3. Facing; 4. Temperature monitoring component; 41. Temperature sensing fiber optic cable; 5. Deformation monitoring component; 51. Upper strain sensing fiber optic cable; 52. Lower strain sensing fiber optic cable; 53. Anchoring section; 54. Fiber Bragg grating sensor; 55. Fiber core; 56. Fiber Bragg grating; 57. Cladding; 58. Protective layer; 59. Fiber sheath; 6. Fiber Bragg grating demodulator; 7. Distributed fiber optic demodulator. Detailed Implementation

[0016] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0017] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0018] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0019] like Figure 1 , 2 As shown, this embodiment provides a riverbank deformation monitoring device based on fiber optic sensing, including a concrete capping 2 set on the top of the embankment 1, multiple facings 3 evenly laid on the outer side wall of the embankment 1, a temperature monitoring component 4 set in the longitudinal section of the embankment 1, and a deformation monitoring component 5 embedded in each of the multiple facings 3. like Figure 2 , 3As shown, in this embodiment, the deformation monitoring component 5 includes an upper strain sensing fiber 51 and a lower strain sensing fiber 52 embedded in the surface 3 and arranged in parallel along the river channel direction. The upper strain sensing fiber 51 and the lower strain sensing fiber 52 have the same structure and form a closed structure as a whole, and are electrically connected. This utility model adopts a combination of upper strain sensing fiber 51 and lower strain sensing fiber 52 arranged in parallel along the river channel direction, and multiple fiber Bragg grating sensors 54 are connected sequentially through anchoring sections 53 to form a long gauge length closed structure, which is easier to form a distributed sensor network than traditional "point" sensors. The outer walls of the upper strain sensing fiber 51 and the lower strain sensing fiber 52 are covered with fiber sleeves 59, and the fiber sleeves 59 are basalt fiber sleeves, using fiber sleeves 59 as optical fibers. The outermost layer of the Bragg grating sensor 54 ensures free deformation of the fiber Bragg grating sensor 54 within the gauge length. The fiber Bragg grating sensors 54 in the upper strain sensing fiber 51 and the lower strain sensing fiber 52 are set for each of the mating surfaces 3, and the anchoring segments 53 are set for two adjacent mating surfaces 3. Taking each mating surface 3 as the gauge length unit, anchoring segments 53 are connected to both ends of the fiber Bragg grating sensor 54. Each fiber Bragg grating sensor 54 is in a pre-tensioned state, and each anchoring segment 53 is in a relaxed state. This structure ensures uniform deformation of the upper strain sensing fiber 51 and the lower strain sensing fiber 52 within the gauge length, forming a uniform strain field. The change in the center wavelength represents the average strain within the gauge length. Damage within each gauge segment is detected, strain abrupt changes are reduced, and the fiber Bragg grating sensor 54 will not fail due to cracking or other reasons.

[0020] like Figure 3 As shown, in this embodiment, each fiber Bragg grating sensor 54 includes a fiber core 55, within which multiple uniformly distributed fiber Bragg gratings 56 are disposed. The outermost wall of each fiber Bragg grating sensor 54 is sequentially covered by a cladding layer 57 and a protective layer 58 from the inside out. When broadband light is incident on the fiber Bragg grating sensor 54, most stray light waves will pass through the fiber Bragg grating 56 unaffected, while only light of a specific wavelength (wavelength...) remains unaffected. (Determined by the effective refractive index of fiber core 55 and the period of fiber Bragg grating 56) After reflection at fiber Bragg grating 56, the light will return to its original direction. When external temperature or stress acts on fiber Bragg grating 56, it changes the effective refractive index and period of the fiber grating, causing a shift in the center wavelength of the reflected light. The relationship is as follows: In the formula The change in the center wavelength of the reflected light. For the change in strain, The change in temperature The effective elastic-optical coefficient of the optical fiber. and These are the thermal expansion coefficient and thermo-optic coefficient of the optical fiber, respectively; wherein the cladding 57 can transmit the wavelength emitted by the fiber core 55 to the optical fiber. The light is reflected back into the fiber core 55 to ensure that the light wave has the lowest transmission loss in the fiber core 55. The principle of this function is that the refractive index of the fiber core 55 is higher than that of the cladding 57. When the light wave propagates from the fiber core 55 to the cladding 57, total internal reflection will occur. The outermost protective layer 58 provides protection to prevent damage to the optical fiber caused by the external environment or external force.

[0021] like Figure 1 , 2 As shown, in this embodiment, the temperature monitoring component 4 includes a temperature sensing fiber 41 disposed in the longitudinal section of the dam 1. The temperature sensing fiber 41 is arranged in a meandering shape. It is used to monitor the seepage of the river dam 1. The monitoring of seepage is mainly reflected by the change in temperature. For the dam section that only monitors seepage, the temperature sensing fiber 41 that does not need to be specially fixed can be selected. For the case where piping is more likely to occur, a combination of upper strain sensing fiber 51, lower strain sensing fiber 52 and temperature sensing fiber 41 is selected to comprehensively determine the occurrence of large seepage by means of temperature change and strain abrupt change.

[0022] like Figure 1 , 2 As shown, in this embodiment, an optical fiber processing terminal is provided on the top of the concrete capping 2. The optical fiber processing terminal is electrically connected to a fiber Bragg grating demodulator 6 and a distributed optical fiber demodulator 7. The fiber Bragg grating demodulator 6 is electrically connected to a coupler. The coupler is electrically connected to the upper strain sensing fiber 51 and the lower strain sensing fiber 52. The upper strain sensing fiber 51 and the lower strain sensing fiber 52 are electrically connected to a data storage device. The distributed optical fiber demodulator 7 is electrically connected to the temperature sensing fiber 41. The temperature sensing fiber 41 is electrically connected to the data storage device. The data storage device is electrically connected to the optical fiber processing terminal. The optical fiber processing terminal is a MA5800-X17 model, the fiber Bragg grating demodulator 6 is a FS-2000 model, the distributed optical fiber demodulator 7 is a FS-3000 model, and the data storage device is an E5-2695V2 model.

[0023] The electrical components provided by this utility model are only used in accordance with the structural features of the product in this technical solution. The product will be adjusted and modified after purchase to better match and conform to the technical solution of this utility model. It is an optimal application of this technical solution. The product model can be replaced and modified according to the required technical parameters. It is well known to those skilled in the art. Therefore, those skilled in the art can clearly obtain the corresponding usage effect through the technical solution provided by this utility model.

[0024] The specific operating principle is as follows: The fiber optic processing terminal is electrically connected to a fiber Bragg grating demodulator 6 and a distributed fiber optic demodulator 7 to convert electrical signals into optical signals. The fiber Bragg grating demodulator 6 is electrically connected to a coupler to distribute optical signals. The coupler is electrically connected to the upper strain sensing fiber 51 and the lower strain sensing fiber 52. The upper strain sensing fiber 51 and the lower strain sensing fiber 52 are arranged in parallel along the river channel direction, and multiple fiber Bragg grating sensors 54 are sequentially connected internally through anchoring sections 53 to form a long gauge-length closed structure. The fiber sheath 59 serves as the outermost layer of the fiber Bragg grating sensors 54, ensuring the light within the gauge length... The fiber Bragg grating sensor 54 is freely deformable, with each cladding 3 serving as a gauge length unit. Each fiber Bragg grating sensor 54 is in a pre-tensioned state, while each anchoring section 53 is in a relaxed state. When the river embankment 1 deforms, this structural form ensures uniform deformation of the upper strain sensing fiber 51 and the lower strain sensing fiber 52 within the gauge length, forming a uniform strain field. The change in the center wavelength represents the average strain within that gauge length. Damage within each gauge section is detected, strain abrupt changes are reduced, and the fiber Bragg grating sensor 54 will not fail due to cracking or other issues. The cladding 57 can transmit the wavelength emitted by the fiber core 55 to the core. The light is reflected back into the fiber core 55 to ensure the lowest possible transmission loss. This function is achieved because the refractive index of the fiber core 55 is higher than that of the cladding 57. As a result, total internal reflection occurs when the light propagates from the fiber core 55 to the cladding 57. The outermost protective layer 58 provides protection to prevent damage to the optical fiber from the external environment or external forces. When external temperature or stress acts on the fiber Bragg grating 56, it changes the effective refractive index and period of the fiber Bragg grating, causing the center wavelength value of the reflected light to drift. The data will be transmitted to the optical fiber processing terminal through the data storage device, thereby accurately identifying the deformation of the river channel structure and realizing simultaneous monitoring of local and overall strain.

[0025] The distributed fiber optic demodulator 7 is electrically connected to a temperature sensing fiber 41, which is arranged in a meandering shape to monitor seepage in the river embankment 1. The monitoring of seepage is mainly reflected by temperature changes. For embankment sections where only seepage is monitored, the temperature sensing fiber 41, which does not require special fixing, can be selected. For situations where piping is more likely to occur, a combination of upper strain sensing fiber 51, lower strain sensing fiber 52, and temperature sensing fiber 41 is selected to comprehensively determine the occurrence of large seepage by using temperature changes and abrupt changes in strain.

[0026] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A riverbank deformation monitoring device based on fiber optic sensing, characterized in that: The dam includes a concrete capping at the top of the dam, multiple facings are evenly laid on the outer side wall of the dam, a temperature monitoring component is installed in the longitudinal section of the dam, and a deformation monitoring component is embedded in each of the multiple facings. The deformation monitoring component includes an upper strain sensing fiber and a lower strain sensing fiber embedded in the lining and arranged in parallel along the river channel direction. The upper strain sensing fiber and the lower strain sensing fiber have the same structure, each including multiple fiber Bragg grating sensors connected in sequence through anchoring sections. Each fiber Bragg grating sensor includes a fiber core, and multiple uniformly distributed fiber Bragg gratings are disposed in the fiber core. The outer wall of each fiber Bragg grating sensor is covered with a cladding layer and a protective layer from the inside to the outside. The temperature monitoring component includes a temperature sensing fiber disposed in the longitudinal section of the dam. A fiber optic processing terminal is installed on the top of the concrete capping structure. The fiber optic processing terminal is electrically connected to a fiber optic grating demodulator and a distributed fiber optic demodulator. The fiber optic grating demodulator is electrically connected to a coupler. The coupler is electrically connected to the upper strain sensing fiber and the lower strain sensing fiber. The upper strain sensing fiber and the lower strain sensing fiber are electrically connected to a data storage device. The distributed fiber optic demodulator is electrically connected to a temperature sensing fiber. The temperature sensing fiber is electrically connected to a data storage device. The data storage device is electrically connected to the fiber optic processing terminal.

2. The riverbank deformation monitoring device based on fiber optic sensing according to claim 1, characterized in that: The outer walls of both the upper strain sensing fiber and the lower strain sensing fiber are covered with fiber sleeves, and the fiber sleeves are basalt fiber sleeves.

3. The riverbank deformation monitoring device based on fiber optic sensing according to claim 1, characterized in that: The upper strain sensing fiber and the lower strain sensing fiber form a closed structure and are electrically connected.

4. The riverbank deformation monitoring device based on fiber optic sensing according to claim 1, characterized in that: The fiber Bragg grating sensors in the upper strain sensing fiber and the lower strain sensing fiber are provided for each of the bonding surfaces, and the anchoring segment is provided for two adjacent bonding surfaces.

5. The riverbank deformation monitoring device based on fiber optic sensing according to claim 1, characterized in that: Each of the fiber Bragg grating sensors is in a pre-tensioned state, and each of the anchoring sections is in a relaxed state.

6. The riverbank deformation monitoring device based on fiber optic sensing according to claim 1, characterized in that: The temperature sensing fiber is arranged in a meandering curve.

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