A method for zonal deployment of optical fibers for monitoring roof deformation in roadways

Abstract

This invention discloses a method for zonal deployment of optical fibers for monitoring roadway roof deformation, relating to the field of roadway surrounding rock safety monitoring technology. The method includes the following steps: (1) Zoning: Roadways with faults and folds are classified as geological structure zones, while roadways without faults and folds are classified as conventional condition zones; (2) Fiber deployment: In the conventional condition zone, a fiber is deployed in a sawtooth pattern on a row of anchor bolts or anchor cables along the roadway direction; in the geological structure zone, a fiber is deployed in a sawtooth pattern on at least three rows of anchor bolts or anchor cables along the roadway direction. Beneficial effects: This invention discloses a method for zonal deployment of optical fibers for monitoring roadway roof deformation, improving the accuracy of roadway roof deformation monitoring under complex conditions, solving the problems of existing technologies not considering differentiated deformation and insufficient applicability to key areas, overcoming the insufficient monitoring accuracy caused by inconsistent exposed lengths, and enhancing data stability.

Description

Technical Field

[0001] This invention patent relates to the field of tunnel surrounding rock safety monitoring technology, specifically to a fiber optic partitioning method for monitoring tunnel roof deformation. Background Technology

[0002] Monitoring roof deformation in underground coal mine roadways is a crucial aspect of monitoring the manifestation of mine pressure and is a mandatory requirement of the national coal mine safety regulations. The conventional method for on-site testing of roadway roof deformation is the "cross-shaped method," which involves setting fixed points on the roof, floor, and both sides of the roadway to form a cross-shaped measurement cross section. The distance from the fixed points on the roof to the lines connecting the two sides is then measured using a ruler or laser rangefinder. However, the "cross-shaped method" is a point-based approach with relatively large spacing, making continuous monitoring impossible. This inevitably leads to blind spots along the roadway's direction, failing to accurately reflect the characteristics of roof deformation and thus hindering its effective role in early warning of surrounding rock deformation.

[0003] In recent years, the development of distributed optical fiber sensing technology has provided a technical means to solve the above problems. The patent "A Real-time Monitoring Device and Construction Process for Full-Space Deformation of Roadway Surrounding Rock" (application number: 202210521708.6) discloses a method for monitoring roadway surrounding rock deformation using optical fibers. This method uses a concrete sprayed grout layer to place the optical fiber within the surrounding rock. This artificially increases the deformation transmission medium (sprayed grout layer) between the surrounding rock and the optical fiber, leading not only to deformation signal attenuation and decreased monitoring accuracy, but also to the risk of optical fiber breakage due to cracking or detachment of the sprayed grout layer, resulting in poor reliability. The paper "Feasibility Study of Distributed Optical Fiber Monitoring of Coal Roadway Roof" and the patent "A Monitoring Device for Settlement of Mining Roadway Roof" (application number: 202122037223.3) respectively propose horizontally arranging optical fibers along a row of anchor bolts (cables) on the roadway roof and setting fixing devices at the ends of the anchor bolts (cables). However, the strain transmission efficiency of the optical fiber is low under linear arrangement, resulting in poor monitoring sensitivity and measurement accuracy, and timeliness. The limitations include: Firstly, the lack of sufficient support trays at the bottom of the anchor rods in the fixing device makes the fiber optic cable prone to loosening due to anchor rod swaying, further affecting data stability. Secondly, while the paper "Fiber Optic Sawtooth Layout Technology and Principle for Roadway Settlement and Deformation Monitoring" discloses a method of laying fiber optic cables in a sawtooth shape along the longitudinal vertical plane of the roadway roof, significantly improving monitoring sensitivity, it is still limited to arranging fiber optic cables along a row of anchor rods along the roadway direction. It does not consider the differentiated deformation characteristics of the roadway roof under different engineering geological conditions (such as the difference in deformation patterns between geological structural areas and conventional areas), resulting in insufficient applicability to key monitoring areas. Furthermore, due to the influence of construction precision on the exposed length of anchor rods (cables) during roadway construction, existing technologies lack an effective height adjustment mechanism, leading to inconsistent sawtooth height differences between adjacent anchor rods (cables) during fiber optic sawtooth laying, directly affecting the accuracy and comparability of monitoring results.

[0004] Therefore, it is necessary to improve the existing fiber optic monitoring technology and laying method for roadway roof deformation in order to achieve large-scale and high-precision monitoring of roadway roof deformation under different engineering geological conditions, thereby providing an effective means for monitoring and early warning of mine pressure and effective control of surrounding rock in coal mine roadways. Summary of the Invention

[0005] In view of this, the purpose of this invention is to provide a fiber optic partitioning method for monitoring roadway roof deformation. The method provided by this invention improves the accuracy of roadway roof deformation monitoring under complex conditions, solves the problems of existing technologies not considering differentiated deformation and insufficient applicability to key areas, overcomes the insufficient monitoring accuracy caused by inconsistent exposed lengths, and enhances data stability.

[0006] The present invention discloses a method for zonal deployment of optical fibers for monitoring roof deformation in roadways, comprising the following steps:

[0007] (1) Zoning: The monitoring area is divided according to whether there are faults or folds in the tunnel. The tunnel with faults and folds is the geological structure area, and the tunnel without faults and folds is the normal condition area.

[0008] (2) Fiber optic deployment: Based on the zoning results of step (1), a differentiated fiber optic deployment scheme is formulated: In the conventional condition zone, a fiber optic cable is deployed in a sawtooth pattern on a row of anchor rods or anchor cables along the tunnel direction; in the geological structure zone, a fiber optic cable is deployed in a sawtooth pattern on at least three rows of anchor rods or anchor cables along the tunnel direction; an adaptation scheme is formulated for different engineering geological conditions. In the geological structure zone, multiple deployments are used to strengthen the monitoring of key areas, avoid the problem of insufficient adaptation of single deployment to differentiated deformation characteristics, reduce monitoring blind spots, and accurately capture the deformation patterns of different areas.

[0009] (3) Fixing optical fibers: Use an anchor bolt optical fiber fixing device with position adjustment and anti-slip function, or an anchor cable optical fiber fixing device with space for anchor cable lock, and fix the optical fibers to the anchor bolts or anchor cables on the roof of the roadway according to the optical fiber layout scheme in step (2).

[0010] The anchor bolt fiber fixing device includes an anchor bolt fixing mechanism, a fiber fixing mechanism, and a fixing stud. The anchor bolt fixing mechanism and the fiber fixing mechanism are threadedly connected by the fixing stud. The anchor bolt fixing mechanism is provided with an anchor bolt position adjustment hole, an anchor bolt fixing hole, and an anti-slip hole in sequence from top to bottom. The thread in the anti-slip hole is screwed into the external thread of the anti-slip stud, and the internal thread of the anti-slip stud is screwed into the anchor bolt.

[0011] The anchor cable fiber fixing device includes an anchor cable fixing mechanism, a fiber fixing mechanism, and a fixing stud. The anchor cable fixing mechanism and the fiber fixing mechanism are threadedly connected by the fixing stud. The anchor cable fixing mechanism is provided with an upper anchor cable position adjustment hole, an anchor cable fixing hole, and a lower anchor cable position adjustment hole in sequence from top to bottom.

[0012] Furthermore, in step (2), in the geological structure area, the spacing between adjacent optical fibers is 80-120cm, and the distance between the optical fibers located on both sides of the tunnel and the tunnel sidewall is 50-100cm.

[0013] Furthermore, in step (2), the spacing between the high and low points of the optical fiber sawtooth pattern is 16-24 cm.

[0014] Furthermore, in step (3), the center lines of the anchor position adjustment hole, the anchor fixing hole and the anti-slip hole are the same straight line, the diameter of the anchor position adjustment hole is larger than the outer diameter of the anchor nut, and the wall of the anchor fixing hole is provided with threads to connect with the anchor.

[0015] Furthermore, in step (3), the center lines of the upper adjustment hole, the fixed hole, and the lower adjustment hole of the anchor cable are the same straight line, wherein the diameters of the upper adjustment hole and the lower adjustment hole of the anchor cable are the same.

[0016] Furthermore, a first anchor lock is screwed onto the anchor cable in the adjustment hole at the anchor cable position, and a second anchor lock is screwed onto the anchor cable in the adjustment hole at the anchor cable position below the anchor cable position. The diameter of the anchor cable fixing hole is larger than the diameter of the anchor cable, but smaller than the diameters of the first anchor lock and the second anchor lock.

[0017] Furthermore, in step (3), the optical fiber fixing mechanism includes an "L"-shaped optical fiber fixing frame, a clamping plate, and a clamping stud. The horizontal section of the optical fiber fixing frame is threadedly connected to the clamping plate through the clamping stud. An optical fiber hole is provided between the clamping plate and the horizontal section of the optical fiber fixing frame. The diameter of the optical fiber hole is smaller than the diameter of the optical fiber.

[0018] Furthermore, the vertical section of the fiber optic fixing frame is threadedly connected to the anchor bolt fixing mechanism via the fixing stud; the horizontal section of the fiber optic fixing frame connected to the anchor bolt fixing mechanism is located directly below the anchor bolt fixing mechanism.

[0019] Furthermore, the vertical section of the fiber optic fixing frame is threadedly connected to the anchor cable fixing mechanism via the fixing stud; the horizontal section of the fiber optic fixing frame connected to the anchor cable fixing mechanism is located on the side away from directly below the anchor cable fixing mechanism.

[0020] Furthermore, the method for fixing the optical fiber using the anchor bolt optical fiber fixing device or the anchor cable optical fiber fixing device specifically includes the following steps:

[0021] S1: When fixing optical fibers using anchor bolts on the roof of the tunnel, use the anchor bolt fixing holes to achieve threaded connection between the anchor bolt fixing mechanism and the exposed section of the anchor bolt. After adjusting the height, connect the inner and outer threads of the anti-slip stud to the anti-slip holes of the anchor bolt and the anchor bolt fixing mechanism respectively, and then tighten them.

[0022] When fixing optical fibers using anchor cables on the tunnel roof, first pass the exposed end of the anchor cable through the first anchor cable lock, the anchor cable fixing hole, and the second anchor cable lock in sequence. After adjusting the height, finally clamp the anchor cable fixing mechanism with the first anchor cable lock in the upper adjustment hole and the second anchor cable lock in the lower adjustment hole.

[0023] S2: Insert the optical fiber into the optical fiber hole of the optical fiber holder, and use the clamping plate to restrict the optical fiber within the optical fiber hole. Finally, tighten the clamping stud to realize the laying of the optical fiber between adjacent anchor rods or anchor cables.

[0024] Advantages of this invention:

[0025] 1. This invention discloses a method for optical fiber zoning for monitoring roof deformation in roadways. This method adopts a differentiated optical fiber deployment scheme for monitoring roof deformation in roadways based on engineering geological conditions. Specifically, the roadway is divided into a geological structure zone and a conventional condition zone according to whether there are faults or folds. In the conventional zone, a single zigzag optical fiber is deployed, while in the geological structure zone, at least three zigzag optical fibers are deployed. This method is specifically adapted to the roof deformation characteristics under different engineering geological conditions, improves the accuracy of roof deformation monitoring under complex conditions, and solves the problems of existing technologies not considering differentiated deformation and insufficient applicability to key areas.

[0026] 2. This invention discloses a fiber optic partitioning method for monitoring roof deformation in roadways. In this method, the anchor bolt fixing mechanism is provided with anchor bolt position adjustment holes and the anchor cable fixing mechanism is provided with vertical position adjustment holes, which have a height adjustment mechanism. This can flexibly adapt to the differences in exposed length of anchor bolts (cables), ensuring that the sawtooth height difference between adjacent anchor bolts (cables) is consistent when the sawtooth layout is used. This overcomes the defects of insufficient monitoring accuracy and comparability caused by inconsistent exposed lengths in the prior art.

[0027] 3. This invention discloses a method for zonal deployment of optical fibers for monitoring roof deformation in roadways. The anchor fixing mechanism of this method has built-in anti-slip holes and anti-slip studs. The anchor is fixed by internal and external threads, which has an anti-slip structure design. This can effectively prevent the anchor from shaking and causing the optical fiber to loosen, thus enhancing data stability and solving the problem of data instability caused by loose anchor in existing fixing devices.

[0028] 4. This invention discloses a method for zonal fiber optic cable deployment for monitoring roof deformation in roadways. This method uses a sawtooth fiber optic cable deployment, which significantly improves strain transmission efficiency and monitoring sensitivity compared to a straight deployment. At the same time, the fiber optic cable fixing mechanism uses an "L"-shaped fiber optic cable fixing frame, clamping plate and other structures to firmly fix the fiber optic cable, avoiding signal attenuation caused by intermediate media such as sprayed grout layer. This achieves a combination of sawtooth deployment and adaptable fixing, improving monitoring sensitivity and timeliness.

[0029] 5. This invention discloses a method for zonal deployment of optical fibers for monitoring roof deformation in roadways. The horizontal section of the "L"-shaped optical fiber fixing frame of the anchor cable fixing mechanism is located on the side away from the direct below of the anchor cable fixing mechanism, providing an adaptation space for the anchor cable lock. It is used in conjunction with the upper and lower locking clamping fixing mechanism to have an anchor cable adaptability structure, which solves the installation interference problem between the anchor cable lock and the optical fiber fixing device and improves the installation reliability. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a top view of the fiber optic cable arrangement on the tunnel roof in this invention.

[0032] Figure 2 For the present invention Figure 1 A cross-sectional view of I in the diagram.

[0033] Figure 3 This is a schematic diagram of the anchor bolt fiber fixing device in Embodiment 1 of the present invention.

[0034] Figure 4 This is a schematic cross-sectional view of the anchor bolt fiber fixing device in Embodiment 1 of the present invention.

[0035] Figure 5 This is a schematic diagram of the connection structure between the anchor bolt fiber fixing device and the anchor bolt in Embodiment 1 of the present invention.

[0036] Figure 6 This is a schematic diagram of the anchor cable fiber fixing device in Embodiment 2 of the present invention.

[0037] Figure 7 This is a schematic cross-sectional view of the anchor cable fiber fixing device in Embodiment 2 of the present invention.

[0038] Figure 8This is a schematic diagram of the connection structure between the anchor cable fiber fixing device and the anchor cable in Embodiment 2 of the present invention.

[0039] 1. Tunnel 1, tunnel roof 1001, anchor bolt 2, anchor cable 3, optical fiber 4, anchor bolt fixing mechanism 5, anchor bolt position adjustment hole 51, anchor bolt fixing hole 52, anti-slip hole 53, optical fiber fixing mechanism 6, optical fiber fixing frame 61, clamping plate 62, clamping stud 63, optical fiber hole 64, anchor bolt nut 7, fixing stud 8, anti-slip stud 9, anchor cable fixing mechanism 10, upper anchor cable position adjustment hole 101, anchor cable fixing hole 102, lower anchor cable position adjustment hole 103, first anchor cable lock 11, second anchor cable lock 12. Detailed Implementation

[0040] The present invention will be further described in detail below through embodiments.

[0041] Example 1: As Figure 1-2 As shown, a method for zonal deployment of optical fibers for monitoring roof deformation in roadways includes the following steps:

[0042] (1) Zoning: The monitoring area is divided according to whether there are faults or folds in the tunnel 1. The tunnel 1 with faults and folds is the geological structure area, and the tunnel 1 without faults and folds is the normal condition area.

[0043] (2) Fiber 4: Based on the zoning results of step (1), a differentiated fiber 4 deployment scheme is formulated: In the normal condition zone, a fiber 4 is deployed in a sawtooth pattern on a row of anchor rods 2 along the direction of tunnel 1. In the geological structure zone, a fiber 4 is deployed in a sawtooth pattern on at least three rows of anchor rods 2 along the direction of tunnel 1. In the geological structure zone, the spacing between adjacent fiber 4 is 80-120cm, and the distance between the fiber 4 located on both sides of tunnel 1 and the side wall of tunnel 1 is 50-100cm.

[0044] The spacing between the high and low points of the serrated fiber 4 is 16-24cm.

[0045] Adaptive solutions are developed for different engineering geological conditions. In geological structural areas, multiple arrays are deployed to strengthen monitoring of key areas, avoiding the problem of insufficient adaptation of single arrays to differentiated deformation characteristics, reducing monitoring blind spots, and accurately capturing deformation patterns in different areas.

[0046] (3) Fixing the optical fiber 4: Using an anchor bolt optical fiber fixing device with position adjustment and anti-slip function, the optical fiber 4 is fixed on the anchor bolt 2 of the roadway roof 1001 according to the optical fiber 4 layout scheme in step (2).

[0047] like Figure 3-4As shown, the anchor bolt fiber fixing device includes an anchor bolt fixing mechanism 5, a fiber optic fixing mechanism 6, and a fixing stud 8. The anchor bolt fixing mechanism 5 and the fiber optic fixing mechanism 6 are threadedly connected by the fixing stud 8. Within the anchor bolt fixing mechanism 5, from top to bottom, there are an anchor bolt position adjustment hole 51, an anchor bolt fixing hole 52, and an anti-slip hole 53. The thread in the anti-slip hole 53 is screwed into the external thread of the anti-slip stud 9, and the internal thread of the anti-slip stud 9 is screwed into the anchor bolt 2, forming a double-threaded locking structure of "anchor bolt-anti-slip stud-anchor bolt fixing mechanism." Its function is to prevent the anchor bolt nut 7 from sliding due to deformation or vibration of the surrounding rock of the tunnel 1, thereby causing the fiber optic fixing mechanism 6 to move downwards. This avoids additional strain on the fiber optic cable 4 due to positional displacement, ensuring that the monitored strain originates only from roof deformation, significantly improving the accuracy of the test results.

[0048] like Figure 5 As shown, the center lines of the anchor bolt position adjustment hole 51, the anchor bolt fixing hole 52, and the anti-slip hole 53 are on the same straight line, ensuring that the anchor bolt fixing mechanism 5 will not deviate during the adjustment of its height, avoiding loosening due to eccentric force, and indirectly improving the accuracy of monitoring data. The diameter of the anchor bolt position adjustment hole 51 is larger than the outer diameter of the anchor bolt nut 7, allowing the anchor bolt fixing mechanism 5 to slide up and down along the exposed section of the anchor bolt 2 to adjust its height, providing a basic condition for ensuring that the "sawtooth height difference is consistent" between adjacent anchor bolts 2 when the optical fiber 4 is laid in a sawtooth pattern. The hole wall of the anchor bolt fixing hole 52 is provided with threads to connect with the anchor bolt 2.

[0049] like Figure 3-5 As shown, the fiber optic fixing mechanism 6 includes an "L"-shaped fiber optic fixing frame 61, a clamping plate 62, and a clamping stud 63. The horizontal section of the fiber optic fixing frame 61 is threadedly connected to the clamping plate 62 via the clamping stud 63. A fiber optic hole 64 is provided between the clamping plate 62 and the horizontal section of the fiber optic fixing frame 61. The diameter of the fiber optic hole 64 is smaller than the diameter of the fiber optic cable 4. This interference fit design avoids the "empty path error" between the fiber optic cable 4 and the fixing mechanism, ensuring that even minor deformations of the top plate can be transmitted to the fiber optic cable 4 through the fiber optic hole 64, thus solving the defects of low strain transmission efficiency and insufficient timeliness when laid in a straight line. The vertical section of the fiber optic fixing frame 61 is threadedly connected to the anchor bolt fixing mechanism 5 via a fixing stud 8. The horizontal section of the fiber optic fixing frame 61 connected to the anchor bolt fixing mechanism 5 is located directly below the anchor bolt fixing mechanism 5. The rigidity of the "L"-shaped structure of the fiber optic fixing frame 61 can reduce the interference of its own deformation on the strain transmission of the fiber optic cable 4, avoiding monitoring errors caused by carrier deformation.

[0050] The method for fixing optical fiber 4 using an anchor bolt optical fiber fixing device specifically includes the following steps:

[0051] S1: When fixing the optical fiber 4 using the anchor bolt 2 of the roadway roof 1001, the anchor bolt fixing hole 52 is used to realize the threaded connection between the anchor bolt fixing mechanism and the exposed section of the anchor bolt 2. After adjusting the height, the internal and external threads of the anti-slip stud 9 are connected to the anti-slip hole 53 of the anchor bolt 2 and the anchor bolt fixing mechanism 5 respectively, and then tightened.

[0052] S2: Insert the optical fiber 4 into the optical fiber hole 64 of the optical fiber fixing bracket 61, and use the clamping plate 62 to restrict the optical fiber 4 within the optical fiber hole 64. Finally, tighten the clamping stud 63 to realize the laying of the optical fiber 4 between adjacent anchor rods 2.

[0053] Example 2: A method for zonal deployment of optical fibers for monitoring roof deformation in roadways, comprising the following steps:

[0054] (1) Zoning: The monitoring area is divided according to whether there are faults or folds in the tunnel 1. The tunnel 1 with faults and folds is the geological structure area, and the tunnel 1 without faults and folds is the normal condition area.

[0055] (2) Fiber 4: Based on the zoning results of step (1), a differentiated fiber 4 deployment scheme is formulated: In the normal condition zone, a fiber 4 is deployed in a sawtooth pattern on a row of anchor cables 3 along the direction of the tunnel 1. In the geological structure zone, a fiber 4 is deployed in a sawtooth pattern on at least three rows of anchor cables 3 along the direction of the tunnel 1. In the geological structure zone, the spacing between adjacent fiber 4 is 80-120cm, and the distance between the fiber 4 located on both sides of the tunnel 1 and the sidewall of the tunnel 1 is 50-100cm.

[0056] The spacing between the high and low points of the serrated fiber 4 is 16-24cm.

[0057] Adaptive solutions are developed for different engineering geological conditions. In geological structural areas, multiple arrays are deployed to strengthen monitoring of key areas, avoiding the problem of insufficient adaptation of single arrays to differentiated deformation characteristics, reducing monitoring blind spots, and accurately capturing deformation patterns in different areas.

[0058] (3) Fixing the optical fiber 4: Using an anchor cable optical fiber fixing device with space for the anchor cable 3 locking device, the optical fiber 4 is fixed on the anchor cable 3 of the roadway roof 1001 according to the optical fiber 4 layout scheme in step (2).

[0059] like Figure 6-7 As shown, the anchor cable fiber fixing device includes an anchor cable fixing mechanism 10, a fiber fixing mechanism 6, and a fixing stud 8. The anchor cable fixing mechanism 10 and the fiber fixing mechanism 6 are threadedly connected by the fixing stud 8. The anchor cable fixing mechanism 10 is provided with an upper anchor cable position adjustment hole 101, an anchor cable fixing hole 102, and a lower anchor cable position adjustment hole 103 arranged sequentially from top to bottom.

[0060] The centerlines of the upper anchor position adjustment hole 101, the lower anchor position adjustment hole 102, and the lower anchor position adjustment hole 103 are on the same straight line, with the diameters of the upper and lower anchor position adjustment holes 101 and 103 being identical. By placing the first anchor lock 11 and the second anchor lock 12 into the upper and lower anchor position adjustment holes 101 and 103 respectively, the locks can slide along the axial direction of the anchor cable 3, thereby adjusting the height of the anchor cable fixing mechanism 10. This ensures that the height difference of the optical fiber 4 sawtooth between adjacent anchor cables 3 is consistent, solving the problem of insufficient monitoring accuracy caused by inconsistent exposed lengths of the anchor cables 3 in the prior art. Simultaneously, the bidirectional adjustment design expands the height adaptation range and improves the compatibility of the device with different construction scenarios.

[0061] like Figure 8 As shown, a first anchor lock 11 is screwed onto the anchor 3 in the upper adjustment hole 101, and a second anchor lock 12 is screwed onto the anchor 3 in the lower adjustment hole 103. The diameter of the anchor fixing hole 102 is larger than the diameter of the anchor 3, but smaller than the diameter of the first anchor lock 11 and the second anchor lock 12.

[0062] like Figure 6-8 As shown, the fiber optic fixing mechanism 6 includes an "L"-shaped fiber optic fixing frame 61, a clamping plate 62, and a clamping stud 63. The horizontal section of the fiber optic fixing frame 61 is threadedly connected to the clamping plate 62 via the clamping stud 63. A fiber optic hole 64 is provided between the clamping plate 62 and the horizontal section of the fiber optic fixing frame 61, and the diameter of the fiber optic hole 64 is smaller than the diameter of the fiber optic 4. The vertical section of the fiber optic fixing frame 61 is threadedly connected to the anchor cable fixing mechanism 10 via a fixing stud 8. The horizontal section of the fiber optic fixing frame 61 connected to the anchor cable fixing mechanism 10 is located on the side away from the anchor cable fixing mechanism 10 directly below it. The core function of this special design is to provide sufficient installation and operation space for the anchor cable lock, avoid interference between the lock and the fiber optic fixing frame 61, solve the problem of poor compatibility between the anchor cable lock and the fiber optic fixing device, and ensure that in the scenario of anchor cable 3 deployment, the fixing of the fiber optic 4 and the installation of the lock can be operated independently without affecting each other.

[0063] The method for fixing optical fiber 4 using an anchor cable optical fiber fixing device specifically includes the following steps:

[0064] S1: When fixing the optical fiber 4 using the anchor cable 3 of the roadway roof 1001, first pass the exposed end of the anchor cable 3 through the first anchor cable lock 11, the anchor cable fixing hole 102 and the second anchor cable lock 12 in sequence. After adjusting the height, finally clamp the anchor cable fixing mechanism 10 with the first anchor cable lock 11 in the upper adjustment hole 101 and the second anchor cable lock 12 in the lower adjustment hole 103.

[0065] S2: Insert the optical fiber 4 into the optical fiber hole 64 of the optical fiber fixing bracket 61, and use the clamping plate 62 to restrict the optical fiber 4 within the optical fiber hole 64. Finally, tighten the clamping stud 63 to realize the laying of the optical fiber 4 between adjacent anchor cables 3.

[0066] The above are preferred embodiments of the present invention. For those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for optical fiber zonal deployment for monitoring deformation of a roadway roof, characterized in that, It includes the following steps: (1) Zoning: The monitoring area is divided according to whether there are faults or folds in the tunnel. The tunnel with faults and folds is the geological structure area, and the tunnel without faults and folds is the normal condition area. (2) Fiber optic cable deployment: Based on the zoning results of step (1), a differentiated fiber optic cable deployment scheme is formulated: In the conventional condition zone, a fiber optic cable is deployed in a sawtooth pattern on a row of anchor bolts or anchor cables along the tunnel direction; in the geological structure zone, a fiber optic cable is deployed in a sawtooth pattern on at least three rows of anchor bolts or anchor cables along the tunnel direction. (3) Fixing optical fibers: Use an anchor bolt optical fiber fixing device with position adjustment and anti-slip function, or an anchor cable optical fiber fixing device with space for anchor cable lock, and fix the optical fibers to the anchor bolts or anchor cables on the roof of the roadway according to the optical fiber layout scheme in step (2). The anchor bolt fiber fixing device includes an anchor bolt fixing mechanism, a fiber fixing mechanism, and a fixing stud. The anchor bolt fixing mechanism and the fiber fixing mechanism are threadedly connected by the fixing stud. The anchor bolt fixing mechanism is provided with an anchor bolt position adjustment hole, an anchor bolt fixing hole, and an anti-slip hole in sequence from top to bottom. The thread in the anti-slip hole is screwed into the external thread of the anti-slip stud, and the internal thread of the anti-slip stud is screwed into the anchor bolt. The center lines of the anchor bolt position adjustment hole, the anchor bolt fixing hole and the anti-slip hole are the same straight line. The diameter of the anchor bolt position adjustment hole is larger than the outer diameter of the anchor bolt nut. The hole wall of the anchor bolt fixing hole is provided with threads to connect with the anchor bolt. The anchor cable fiber fixing device includes an anchor cable fixing mechanism, a fiber fixing mechanism, and a fixing stud. The anchor cable fixing mechanism and the fiber fixing mechanism are threadedly connected by the fixing stud. The anchor cable fixing mechanism is provided with an upper anchor cable position adjustment hole, an anchor cable fixing hole, and a lower anchor cable position adjustment hole arranged sequentially from top to bottom. The center lines of the upper anchor position adjustment hole, the lower anchor position adjustment hole, and the anchor position fixing hole are the same straight line, wherein the diameters of the upper anchor position adjustment hole and the lower anchor position adjustment hole are the same. The fiber optic fixing mechanism includes an "L"-shaped fiber optic fixing frame, a clamping plate, and clamping studs. The horizontal section of the fiber optic fixing frame is threadedly connected to the clamping plate via clamping studs. A fiber optic hole is provided between the clamping plate and the horizontal section of the fiber optic fixing frame, and the diameter of the fiber optic hole is smaller than the diameter of the fiber. The vertical section of the fiber optic fixing frame is threadedly connected to the anchor bolt fixing mechanism via the fixing stud; the horizontal section of the fiber optic fixing frame connected to the anchor bolt fixing mechanism is located directly below the anchor bolt fixing mechanism. The vertical section of the fiber optic fixing frame is threadedly connected to the anchor cable fixing mechanism via the fixing stud; the horizontal section of the fiber optic fixing frame connected to the anchor cable fixing mechanism is located on the side away from directly below the anchor cable fixing mechanism.

2. The method according to claim 1, wherein, In step (2), in the geological structure area, the spacing between adjacent optical fibers is 80-120cm, and the distance between the optical fibers located on both sides of the tunnel and the tunnel sidewall is 50-100cm.

3. The fiber optic zoning method for monitoring tunnel roof deformation according to claim 1, characterized in that, In step (2), the spacing between the high and low points of the optical fiber sawtooth pattern is 16-24 cm.

4. The fiber optic zoning method for monitoring tunnel roof deformation according to claim 1, characterized in that, A first anchor lock is screwed onto the anchor cable in the adjustment hole at the anchor cable position, and a second anchor lock is screwed onto the anchor cable in the adjustment hole at the anchor cable position below the anchor cable position. The diameter of the anchor cable fixing hole is larger than the diameter of the anchor cable, but smaller than the diameters of the first anchor lock and the second anchor lock.

5. The fiber optic zoning method for monitoring tunnel roof deformation according to claim 1, characterized in that, The method for fixing optical fibers using the anchor bolt optical fiber fixing device or the anchor cable optical fiber fixing device specifically includes the following steps: S1: When fixing optical fibers using anchor bolts on the roof of the tunnel, use the anchor bolt fixing holes to achieve threaded connection between the anchor bolt fixing mechanism and the exposed section of the anchor bolt. After adjusting the height, connect the inner and outer threads of the anti-slip stud to the anti-slip holes of the anchor bolt and the anchor bolt fixing mechanism respectively, and then tighten them. When fixing optical fibers using anchor cables on the roof of the tunnel, first pass the exposed end of the anchor cable through the first anchor cable lock, the anchor cable fixing hole and the second anchor cable lock in sequence. After adjusting the height, finally clamp the first anchor cable lock in the upper adjustment hole and the second anchor cable lock in the lower adjustment hole of the anchor cable to the anchor cable fixing mechanism. S2: Insert the optical fiber into the optical fiber hole of the optical fiber holder, and use the clamping plate to restrict the optical fiber within the optical fiber hole. Finally, tighten the clamping stud to realize the laying of the optical fiber between adjacent anchor rods or anchor cables.

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