Tunnel vault distributed optical fiber monitoring device

Abstract

The embodiment of the utility model provides a tunnel vault distributed optical fiber monitoring device, and the device comprises an optical fiber sensor which is used for monitoring the internal strain change of a tunnel vault; the curved surface adaptive supporting frame is used for supporting the optical fiber sensor; one end of the telescopic positioning rod is connected with the curved surface adaptive support frame, and the other end of the telescopic positioning rod is provided with a positioning hole and fixes the optical fiber sensor on the surface of the tunnel vault through a fastener; the angle adjusting assembly is arranged between the telescopic positioning rod and the curved surface adaptive supporting frame and can adjust the inclination angle of the telescopic positioning rod; one end of the flexible fixing belt is fixedly connected with the curved-surface adaptive support frame, and the other end of the flexible fixing belt is fixed on the tunnel vault. Through the scheme of the embodiment of the invention, the problem that a traditional fixing mode is difficult to adapt due to the curved surface form in the tunnel vault can be solved.

Description

Technical Field

[0001] The present application relates to the technical field of civil engineering monitoring, and in particular to a distributed optical fiber monitoring device for a tunnel vault. Background Art

[0002] The distributed fiber optic monitoring device for tunnel vaults is a technical device that uses the sensitive properties of optical fibers to monitor the health status of tunnel vault structures in real time. By capturing tiny deformations or stress changes, it can achieve a comprehensive assessment of tunnel safety and stability. However, in practical applications, there are challenges caused by the internal curved surface of the tunnel vault. Traditional fixing methods are not well adapted to such complex geometries, which can easily lead to problems such as damage to the optical fiber during installation or unstable signals during monitoring, thereby affecting the overall monitoring effect. Summary of the Invention

[0003] In view of this, an embodiment of the present disclosure provides a tunnel vault distributed optical fiber monitoring device, which at least partially solves the problems existing in the prior art.

[0004] The present application provides a tunnel vault distributed optical fiber monitoring device, comprising:

[0005] Fiber optic sensors are used to monitor strain changes inside the tunnel vault;

[0006] A curved surface adaptable support frame supports the optical fiber sensor;

[0007] A telescopic positioning rod, one end of which is connected to the curved surface adapting support frame, and the other end of which is provided with a positioning hole and fixed to the tunnel vault surface by a fastener;

[0008] An angle adjustment component is provided between the telescopic positioning rod and the curved surface adapting support frame, and is capable of adjusting the inclination angle of the telescopic positioning rod;

[0009] A flexible fixing belt, one end of which is fixedly connected to the curved surface adapting support frame and the other end is fixed to the tunnel vault, wherein

[0010] The telescopic positioning rod is composed of two sections, an inner section and an outer section, which are connected together, and a spiral pattern is provided on the outer section to facilitate tightening and adjustment using an inner hexagonal wrench;

[0011] The angle adjustment component adopts a spherical hinge structure, and the angle of the support frame can be freely adjusted by rotating the ball head, and

[0012] A plurality of adhesive pads are added on the contact surface between the flexible fixing belt and the curved surface adaptation support frame.

[0013] Preferably, the optical fiber sensor is installed in a groove pre-arranged inside the tunnel vault, and the groove is filled with an expandable sealing material.

[0014] Preferably, the curved surface adaptation support frame adopts a multi-segment split structure design and is provided with multiple folding joints.

[0015] Preferably, the gap between the positioning hole and the fixing member is sealed by an elastic filling ring.

[0016] Preferably, the angle adjustment assembly has a built-in precision screw as an actuator.

[0017] Preferably, one end of the flexible fixing belt is provided with a hook and loop buckle.

[0018] Preferably, the hook and loop fastener is in the form of Velcro.

[0019] Preferably, the area of the curved surface adaptation support frame with a larger curvature includes more adhesive pads than the area with a smaller curvature.

[0020] The disclosed embodiment provides a distributed optical fiber monitoring device for a tunnel vault, comprising: an optical fiber sensor for monitoring strain changes inside the tunnel vault; a curved surface adapting support frame for supporting the optical fiber sensor; a telescopic positioning rod, one end of which is connected to the curved surface adapting support frame, the other end of which is provided with a positioning hole and fasteners for fixing the optical fiber sensor to the surface of the tunnel vault; an angle adjustment component, which is arranged between the telescopic positioning rod and the curved surface adapting support frame and can adjust the inclination angle of the telescopic positioning rod; and a flexible fixing belt, one end of which is fixedly connected to the curved surface adapting support frame and the other end of which is fixed to the tunnel vault. The solution of the disclosed embodiment can solve the problem that the traditional fixing method is difficult to adapt to the curved surface shape inside the tunnel vault. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the exemplary implementation methods of the embodiments of the present disclosure, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the embodiments of the present disclosure and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 This is a schematic diagram of the optical fiber sensor installed in a tunnel in the present utility model;

[0023] Figure 2 This is a schematic diagram of the telescopic positioning rod structure in the utility model;

[0024] Figure 3 This is a schematic diagram of the angle adjustment component structure of the utility model;

[0025] Figure 4 This is a schematic diagram of the structure of the flexible fixing belt in the utility model;

[0026] Figure 5 This is a schematic diagram of the curved surface adaptable support frame structure in the present invention.

[0027] Figure: 1. Fiber optic sensor; 2. Curved surface adaptor support; 3. Telescopic positioning rod; 4. Angle adjustment assembly; 5. Flexible fixing belt; 6. Expandable sealing material; 7. Folding joint; 8. Elastic filling ring; 9. Spherical hinge; 10. Precision screw; 11. Hook and loop fastener; 12. Adhesive pad DETAILED DESCRIPTION

[0028] In order to make the objectives, technical solutions and advantages of the embodiments of the present disclosure more clear, the embodiments of the present disclosure are further described in detail below in combination with the embodiments and drawings. The schematic implementation methods of the embodiments of the present disclosure and their descriptions are only used to explain the embodiments of the present disclosure and are not intended to limit the embodiments of the present disclosure.

[0029] like Figure 1 As shown, the distributed fiber optic monitoring device for tunnel vaults of the present application includes a fiber optic sensor 1, a curved surface adaptor support frame 2, a telescopic positioning rod 3, an angle adjustment assembly 4, and a flexible fixing belt 5. These components work together to enable the device to be accurately installed on tunnel vault surfaces with different curved shapes and effectively monitor internal strain changes, thereby ensuring safe and stable operation of the tunnel.

[0030] The fiber optic sensor 1, a key component of the entire device, is responsible for detecting and measuring minute deformation signals from the tunnel vault. Specifically, the sensor utilizes fiber Bragg grating (FBG) technology. When the tunnel deforms due to factors such as geological activity or the weight of the structure, it alters the propagation pattern of light within the optical fiber. This change is captured and converted into actual strain or displacement through an algorithm, reflecting the real-time condition of the vault. FBGs are not only highly sensitive but also resistant to corrosion and electromagnetic interference, demonstrating excellent performance even in the harsh environment of the tunnel.

[0031] The curved surface adaptable support frame 2 is used to support the fiber optic sensor 1, ensuring that it can be accurately positioned and maintain appropriate proximity to the varying curvatures of the tunnel. The support frame is typically made of a flexible material, such as a polymer composite or a lightweight metal that has undergone precise calculations. This material allows the frame to automatically adjust its shape as the tunnel contours change, maintaining a close fit for the sensor, thereby enhancing the accuracy and reliability of the collected data. Furthermore, the support frame may also include an internal fine-tuning system, allowing technicians to manually optimize its adaptability based on specific circumstances.

[0032] One end of the telescopic positioning rod 3 is firmly connected to the curved surface adapter support frame 2, and the other end is provided with a positioning hole. Fasteners are used to secure the fiber optic sensor 1 to the tunnel vault surface. This adjustable telescopic structure can freely change the length range as needed and is suitable for installation in tunnel environments of different types and sizes. At the same time, it can also assist in adjusting the position and posture of the entire device, so that it is more closely attached to the test point. To ensure the stability and reliability of the device, the material selection gives priority to options with good strength-to-weight ratio characteristics, and uses anti-rust treatment to improve service life and reliability.

[0033] The angle adjustment assembly 4, located between the telescopic positioning rod 3 and the curved surface adaptable support frame 2, allows the device to adjust its installation angle according to actual conditions. It typically consists of a small mechanism composed of interlocking and rotating joints, providing the necessary flexibility while maintaining structural integrity. For example, a fine-tuning mechanism based on a wedge structure or a multifunctional adjustment unit with a ball-and-socket joint might be designed. Regardless of the form, the goal is to ensure that the device maintains the optimal monitoring posture even in extremely curved and complex arched areas, while minimizing the impact of errors caused by external factors such as wind pressure differences.

[0034] To ensure the long-term effective operation of the equipment, the flexible fixing belt 5 is used as an additional safety measure. One end of the flexible fixing belt is combined with the support frame to provide additional stability, and the other end can be fixed to the tunnel vault by screws (refer to Figure 4 ) to provide relative positioning between the curved adaptor support frame 2 and the tunnel vault. It is typically a flat, wide strip made of high-strength nylon braid or specialized polymers, with buckles fitted at both ends for easy wraparound securement. Workers can quickly assemble and disassemble the device by simply adjusting the tightness of the buckles, improving on-site work efficiency while ensuring overall structural consistency and preventing accidental slippage or displacement. This strap is typically designed to be easily replaceable after prolonged use or in adverse working conditions, ensuring easy maintenance and long-term use of the device.

[0035] In one embodiment, the optical fiber sensor 1 of the distributed optical fiber monitoring device for the tunnel vault of the present application is installed in a groove pre-arranged inside the tunnel vault. This arrangement takes into account the geometric shape of the tunnel vault and possible deformation factors. Through careful design, the sensor can adapt to and be embedded in the complex structure, which not only enhances the integrity of the structure but also improves the stability of the sensor. The groove is filled with a special expandable sealing material 6. This material can adapt to the curvature of the tunnel vault and any slight deformation, thereby strengthening the bonding between the sensor and the surrounding environment at the physical level. The groove is filled by selecting a material with good elasticity and sealing properties, and its formula is adjusted so that it can remain stable under temperature changes or other mechanical environments.

[0036] For example, during implementation, polyurethane foam or specialized epoxy resin can be used as the expandable sealing material 6 within the trench. Once the fiber optic sensor 1 is placed in the trench and filled with the corresponding sealing material, it can expand during curing to form a sealed and robust interface with the surrounding rock surface, significantly reducing the risk of fiber displacement and signal transmission attenuation caused by temperature and humidity fluctuations or structural vibration within the tunnel. Furthermore, optimizing the balance between material hardness and viscosity can extend its reliable service life in harsh environments, ensuring long-term, stable operation.

[0037] In one embodiment, the tunnel vault distributed optical fiber monitoring device of the present application includes an improved structural design for improving overall adaptability. Specifically, the curved surface adaptation support frame 2 in the device adopts a multi-segment split structure. This multi-segment design allows for a folding joint 7 to be provided at each connection portion (refer to FIG. Figure 5 ), these joints can bend in different directions. Through this unique structural configuration, the entire curved surface adaptation support frame 2 can be more flexibly fitted to the inner surface of tunnel vaults of various curvatures and sizes. This design concept directly improves a major problem faced by traditional fixed installation methods: it is difficult to effectively cover and monitor spaces with irregular or complex curved surface features, thereby making the device more practical and versatile. In actual operating scenarios, this enhanced adaptive function will greatly facilitate the operating procedures of installers, while ensuring that the optical fiber sensor 1 can maintain a stable and reliable working state regardless of the environment, further enhancing the effective range of tunnel road safety monitoring.

[0038] In one embodiment, to achieve these characteristics, the connection points between each segment are designed as flexible joints that allow for a certain degree of bending and rotation. For example, this functionality can be achieved using hinged connectors or structures similar to adjustable joints. This design not only ensures that each segment can be precisely adjusted to the desired angle, but also physically ensures that the entire system is sufficiently rigid, preventing unnecessary deformation or misalignment due to gravity at the tunnel roof.

[0039] In one embodiment, reference Figure 2 The tunnel vault distributed fiber optic monitoring device of the present application adopts a specially designed telescopic positioning rod 3, which is composed of an inner and outer section that are connected together. This allows the positioning rod to be appropriately adjusted in length according to the specific shape of the tunnel vault. To ensure that the positioning rod can be stably fixed on the vault surface with different curvatures, a spiral pattern is provided on the outer section. The presence of the spiral pattern allows the operator to perform precise tightening adjustments using an Allen wrench. This mechanism not only greatly reduces the problem of sensor loosening caused by the complex terrain of the tunnel vault surface, but also improves the reliability and stability of the entire distributed fiber optic monitoring system, enabling it to more efficiently and accurately monitor various geological changes and potential safety risks.

[0040] Specifically, when faced with the challenge of installation on an irregular curved surface, the telescopic positioning rod 3 is initially deployed and the sensor is initially secured. The inner and outer segments are then adjusted according to the actual situation until they conform to the surface. A hexagonal wrench is then used to secure the sensor securely and precisely using the spiral grooves on the outer segment of the telescopic positioning rod 3. This ensures that the sensor is always in optimal condition for more accurate data. This technical implementation ensures that the device will not shift or experience poor contact even during long-term operation, adapting to a wide range of monitoring needs. For example, in urban subway projects with complex geological structures or underground tunnels on highways, the flexibility and reliability of this design are particularly prominent.

[0041] In one embodiment, the tunnel vault distributed fiber optic monitoring device of the present application seals the gap between the positioning hole and the fixing part by providing an elastic filling ring 8 between the two. This sealing structure effectively avoids the problem of corrosion of metal fixing parts caused by changes in environmental humidity, thereby improving the stability of the entire monitoring system and extending its service life. This design is particularly suitable for areas with high humidity, such as tunnel environments in rainy areas, and is more effective. Specifically, after the device is installed, the elastic filling ring 8 can automatically adapt to the space between the fixing part and the hole and form a tightly fitting sealing layer, ensuring that external moisture will not easily penetrate and cause corrosion or damage to the fixing parts.

[0042] For example, in practical applications, highly elastic and corrosion-resistant silicone can be used as the material for the elastic filling ring 8. This not only provides a reliable seal but also helps reduce wear caused by vibration in the tunnel environment. In this way, after the construction personnel complete the basic installation of the fixture, they only need to accurately position the prepared elastic sealing ring between the positioning hole and the metal fixture, and apply appropriate pressure to ensure that the sealing ring contacts the hole wall fully, leaving no gaps.

[0043] refer to Figure 3 In one embodiment, the tunnel vault distributed fiber optic monitoring device of the present application includes an angle adjustment component 4, wherein the angle adjustment component 4 adopts a spherical hinge 9 structure, which can freely adjust the angle of the support frame by rotating the ball head. Such a design is suitable for curved surfaces of any curvature, greatly enhancing the adaptability of the equipment to different tunnel forms, and effectively solving the problems of complex operation and difficult angle adjustment of traditional adjustment mechanisms. The design of the spherical hinge 9 makes angle adjustment more flexible and convenient, thereby improving the adjustability and application range of the overall equipment. Specifically, when encountering vaults with different radius curvatures, the present device can quickly and accurately position the monitoring equipment to the required position.

[0044] In one embodiment, a specific method for achieving this feature is to integrate a spherical component with multiple degrees of freedom adjustment capabilities into the angle adjustment assembly 4, such as by using a ball head and its corresponding sleeve in combination to achieve adjustment freedom at multiple angles and in multiple directions. Specifically, the ball head is connected to one end of the support frame, and the ball head can rotate freely within a certain range, while a locking structure is provided in the other direction to fix the posture of the entire support frame after positioning, ensuring long-term stability and precision requirements. This mechanism not only improves the efficiency of installation and commissioning, but also ensures stability in the complex environment inside the tunnel, significantly improving the performance of the overall equipment.

[0045] In one embodiment, the distributed fiber optic monitoring device for tunnel vaults of the present application has made innovations in the design of the angle adjustment component 4. The component has a built-in precision screw 10 as an actuator, which can achieve high-precision angle adjustment function through rotation. This design enables the device to optimize the position point by point according to the actual geometry and curvature of the tunnel during installation, thereby ensuring that the monitoring element can always maintain the best working posture throughout the monitoring process. This not only greatly improves the problem of difficulty in angle adjustment in the past, but also effectively improves the overall detection accuracy and work efficiency of the device. Compared with traditional fixed structures or simple manual adjustment methods, mechanical adjustment using precision screws 10 provides higher accuracy and flexibility, and can adapt to tunnel vaults with different bending radii.

[0046] Specifically, the technical solution to achieve this feature is to install the precision screw 10 in the angle adjustment assembly 4 and connect it to the drive motor or other form of rotary power device. When the angle needs to be adjusted, the precision screw 10 is driven to rotate by controlling the drive system, and then converted into linear displacement through the thread, thereby realizing the change of the spatial position of the monitoring head relative to the bracket. In this process, in order to obtain the required high accuracy, a photoelectric encoder or other sensing equipment can be used to monitor the actual moving distance to form a closed-loop control system to ensure that each angle fine-tuning can achieve the desired effect. In addition, several common or standard curvature models can be preset for the operator to directly select and apply, simplifying the adjustment process while improving the convenience of on-site operation.

[0047] In one embodiment, Figure 4 As shown, the flexible fixing strap 5 mentioned in the tunnel vault distributed fiber optic monitoring device of the present application is provided with a hook and loop buckle 11 at one end, which is intended to provide a simple method for assembly and disassembly. This method allows the monitoring device to be quickly installed and disassembled under on-site conditions, greatly improving on-site operation efficiency. In addition, due to the flexible length adjustment design, the fixing strap can be adjusted to the appropriate tension according to the specific installation environment. This not only increases the applicability of the device on different curved surfaces, but also reduces the risk of the fixing device loosening over time, ensuring the reliability and durability of the overall system during long-term application.

[0048] Specifically, the hook-and-loop fastener 11 provided at one end of the flexible fixing strap 5 can be in the form of Velcro. This design is both simple and practical, allowing installation without the use of any tools. Simply adhere or secure the Velcro-attached side to another surface to achieve a stable installation. For example, when used on certain cave ceilings with significant curvature, by fine-tuning the contact points between different parts of the flexible fixing strap 5, appropriate tension can be easily achieved to ensure the secure fixation of the core components of the monitoring system. This effectively ensures the normal operation of the device and data accuracy, even in complex and ever-changing actual engineering scenarios.

[0049] In one embodiment, the distributed fiber optic monitoring device for tunnel vaults of the present application addresses the difficulty of securing conventional devices due to the tunnel's curved surface, as well as the problem of inaccurate monitoring data caused by minor vibrations. Several adhesive pads 12 are added to the contact surface between the flexible fixing band 5 and the curved surface adaption support frame 2. By enhancing adhesion, the adhesive pads 12 improve the overall stability of the monitoring device, effectively adapting to the complex and changing geometry of the tunnel. This significantly reduces the negative impact of external environmental influences and ensures data consistency and reliability under long-term monitoring conditions.

[0050] Specifically, to effectively implement the above solution, the adhesive pads 12 can be flexibly positioned based on the specific morphology of the tunnel's inner wall. For example, the number of carriers can be appropriately increased in areas with smaller radius of curvature or greater undulations, ensuring that each adhesive pad 12 is evenly stressed and firmly adhered to its designated location. Furthermore, adhesive pads 12 can be constructed from materials with high fatigue resistance and temperature compatibility, ensuring they maintain excellent physical and chemical properties, regardless of extreme weather conditions or long-term operation, thereby providing a stable and reliable mounting base for the fiber optic sensing network.

[0051] In actual operation, when using this device, the optical fiber sensor 1 is first secured to the tunnel vault surface by inserting one end of the telescopic positioning rod 3 through its designated positioning hole using fasteners. The telescopic positioning rod 3 then provides basic support and can be adjusted in length to suit the specific application scenario, ensuring the initial stability of the entire device. The angle adjustment assembly 4 is then used to fine-tune the inclination of the telescopic positioning rod according to the actual curvature of the tunnel vault. This ensures that the optical fiber sensor device can adjust to the optimal position to follow the curvature, paving the way for high-precision measurements. Furthermore, the flexible fixing strap 5 forms a tight connection with the support structure and securely connects to the tunnel vault, ensuring that the support frame remains stable and stable, regardless of vibration or prolonged pressure. The coordinated operation of these components enables the monitoring device to accurately, continuously, and effectively perform monitoring operations, while also providing early warning of potential safety hazards. This ensures the stable operation of the entire system, playing a key role in engineering maintenance and technical support.

[0052] The above is a preferred embodiment of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles described in the present invention. These improvements and modifications should also be regarded as the scope of protection of this application.

Claims

1. A tunnel vault distributed optical fiber monitoring device, characterized in that: include: Optical fiber sensor (1) for monitoring strain changes inside the tunnel vault; A curved surface adaptable support frame (2) supports the optical fiber sensor (1); A telescopic positioning rod (3), one end of which is connected to the curved surface adapting support frame (2), and the other end of which is provided with a positioning hole and fixes the optical fiber sensor (1) to the surface of the tunnel vault via a fastener; An angle adjustment component (4) is arranged between the telescopic positioning rod (3) and the curved surface adaptation support frame (2), and is capable of adjusting the inclination angle of the telescopic positioning rod (3); A flexible fixing belt (5) is fixedly connected to the curved surface adapting support frame (2) at one end and fixed to the tunnel vault at the other end, wherein The telescopic positioning rod (3) is formed by sleeve-jointing two sections, inner and outer, and a spiral pattern is provided on the outer section to facilitate tightening and adjustment using an inner hexagonal wrench; The angle adjustment component (4) adopts a spherical hinge (9) structure, and the angle of the support frame (2) can be freely adjusted by rotating the ball head, and A plurality of adhesive pads (12) are added to the contact surface between the flexible fixing belt (5) and the curved surface adaptation support frame (2).

2. The tunnel vault distributed optical fiber monitoring device according to claim 1, characterized in that: The optical fiber sensor (1) is installed in a groove pre-arranged inside the tunnel vault, and the groove is filled with an expandable sealing material (6).

3. The tunnel vault distributed optical fiber monitoring device according to claim 1, characterized in that: The curved surface adaptation support frame (2) adopts a multi-segment split structure design and is provided with a plurality of folding joints (7).

4. The tunnel vault distributed optical fiber monitoring device according to claim 1, characterized in that: The gap between the positioning hole and the fixing piece is sealed by an elastic filling ring (8).

5. The tunnel vault distributed optical fiber monitoring device according to claim 1, characterized in that: The angle adjustment component (4) has a built-in precision lead screw (10) as an actuator.

6. The tunnel vault distributed optical fiber monitoring device according to claim 1, characterized in that: One end of the flexible fixing belt (5) is provided with a hook and loop buckle (11).

7. The tunnel vault distributed optical fiber monitoring device according to claim 6, characterized in that: The hook and loop fastener (11) is in the form of a Velcro.

8. The tunnel vault distributed optical fiber monitoring device according to claim 1, characterized in that: The area of the curved surface adaptation support frame (2) with a larger curvature comprises more adhesive pads (12) than the area with a smaller curvature.

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