Optical fiber embedding method for anchor rod slurry strain test

Abstract

The invention relates to the technical field of anchor rod slurry, and discloses an optical fiber embedding method for an anchor rod slurry strain test, which comprises the following construction steps: 1) enabling anchoring sections of a plurality of anchor bars to pass through a centering frame, and connecting guide caps to the end parts of the anchoring sections; (2) the middle of the optical fiber penetrates through the centering frame and the guide cap to form a continuously-arranged monitoring section, and the two ends of the optical fiber form connecting sections connected with acquisition equipment; (3) the multiple anchoring sections are arranged in the anchor holes, the monitoring sections are arranged in the anchor holes, and the connecting sections are located outside the anchor holes; (4) after the monitoring section is in a pre-tensioning state, the anchor hole is filled with grout, and the multiple anchoring sections, the guide cap and the monitoring section are wrapped in the grout; the monitoring section of the optical fiber deviates from the anchoring section, so that the optical fiber is prevented from being in direct contact with the anchoring section, the embedding position of the optical fiber is reasonable, interference to the optical fiber in the slurry solidification process is reduced, and the long-term stability and the measurement precision of the optical fiber are improved.

Description

Technical Field

[0001] The invention relates to the technical field of anchor slurry, and more specifically, to a method for burying optical fibers for anchor slurry strain testing. Background Art

[0002] As an important supporting structure, anchor rods are widely used in geotechnical engineering. Accurate monitoring of their performance is crucial to ensure engineering safety.

[0003] Anchor grout serves as the force transmission medium between the anchor and the rock and soil. Its strain state directly affects the overall mechanical properties of the anchor. Fiber optic sensing technology has been widely used in fields such as pile foundation testing due to its advantages such as high precision, strong anti-interference ability, high spatial resolution, and continuous data acquisition. However, its application in anchor grout strain testing is still relatively limited.

[0004] In the existing technology, optical fibers are usually directly attached to the surface of the anchor rod or anchor bar, resulting in direct contact between the optical fiber and the slurry. This causes interference with the optical fiber during the slurry solidification process, affecting measurement accuracy. In addition, when the slurry solidifies and shrinks unevenly, the bond between the optical fiber and the slurry will fail. The optical fiber will be damaged by local stress concentration and cannot accurately reflect the true strain of the slurry.

[0005] Since the optical fiber is directly exposed to the slurry and is affected by the chemical corrosion and physical wear of the slurry over a long period of time, its performance will gradually decline, affecting the reliability of monitoring.

[0006] In addition, traditional fiber optic burial methods usually place the optical fiber only in a local position of the anchor rod, which cannot fully capture the strain changes of the slurry in different areas. This makes the monitoring data insufficiently complete and makes it difficult to accurately evaluate the overall mechanical properties of the anchor rod. Summary of the Invention

[0007] The purpose of the present invention is to provide a method for burying optical fibers for anchor rod slurry strain testing, aiming to solve the problem of unreasonable burying of optical fibers for anchor rod slurry strain testing in the prior art.

[0008] The present invention is implemented as follows: a method for embedding an optical fiber for anchor slurry strain testing comprises the following construction steps:

[0009] 1) The anchor bar includes an anchoring section and a tensioning section. The anchoring sections of the plurality of anchor bars are passed through the centering frame. The plurality of anchor bars are arranged in a spaced and surrounding manner. The ends of the plurality of anchoring sections are connected with guide caps.

[0010] 2) Arrange an optical fiber in an integrated strip shape, wherein the middle portion of the optical fiber passes through the centering frame and the guide cap respectively, forming a monitoring section arranged continuously. The monitoring section is arranged away from the anchoring section, and the two ends of the optical fiber form a connection section connected to the collection equipment;

[0011] 3) placing the plurality of anchoring segments in the anchor hole, placing the monitoring segment in the anchor hole, and placing the connecting segment outside the anchor hole;

[0012] 4) After the monitoring section is in a pre-tensioned state, the anchor hole is filled with slurry, and the slurry solidifies to form a slurry. The slurry fills the anchor hole, and the plurality of anchoring sections, guide caps and monitoring sections are wrapped in the slurry.

[0013] Furthermore, in the construction step 1), multiple centering frames are arranged, and the anchoring section passes through the multiple centering frames in sequence. Along the length direction of the anchoring section, the multiple centering frames are arranged in sequence and at intervals; in the construction step 2), the monitoring section passes through the multiple centering frames in sequence.

[0014] Furthermore, in the construction step 1), a cable tie ring is provided between adjacent centering frames, and the plurality of anchoring segments respectively pass through the cable tie ring, and the cable tie ring radially gathers the plurality of anchoring segments.

[0015] Furthermore, in the construction step 2), the monitoring section includes two straight sections and a curved section, the curved section is formed between the two straight sections, and the straight sections extend outward to form the connecting section; the straight sections pass through multiple centering frames and extend along the length direction of the anchoring section, and the curved section passes through the guide cap.

[0016] Furthermore, in the construction step 2), after the curved section passes through the guide cap, the curved section is fixed to the guide cap.

[0017] Furthermore, in the construction step 4), before injecting slurry into the anchor hole, the connecting section is pulled outward and fixedly arranged so that the straight section is in a pre-tightened state.

[0018] Furthermore, in the construction step 4), after the straight section is in a pre-tightened state, the connecting section is fixed to the tensioning section to keep the anchoring section in a pre-tightened state.

[0019] Furthermore, in the construction step 2), the centering frame has a through hole, and the straight segment has a through section passing through the through hole; an elastic tube is sleeved on the outer periphery of the through section, the through section is fixedly connected to the elastic tube, and the elastic tube is placed in the through hole and fixedly connected to the centering frame;

[0020] In the construction step 4), when the straight section is in a pre-tightened state, the through section is pulled, causing the elastic tube to elastically deform, and the elastic tube is in an elastically stretched state.

[0021] Furthermore, in the construction step 2), the elastic tube has a straight and closed hollow cavity, the hollow cavity and the elastic tube extend coaxially, and both ends of the elastic tube have end blocks, and the end blocks are formed at the ends of the hollow cavity;

[0022] The through-section passes through the two end blocks and the hollow cavity respectively, and is fixedly connected to the two end blocks respectively; in the construction step 4), when the straight section is in a pre-tightened state, the through-section pulls the two end blocks to elastically stretch and deform.

[0023] Furthermore, in the construction step 2), a plurality of raised rings are formed on the outer circumference of the elastic tube, and the plurality of raised rings are arranged at intervals along the axial direction of the elastic tube; when the elastic tube is placed in the through hole, the plurality of raised rings abut against the inner side wall of the through hole, and an elastic gap is formed between the outer circumference of the elastic tube and the inner side wall of the through hole; the end block covers the end of the through hole and is fixedly connected to the centering frame, so that the elastic gap is in a sealed state;

[0024] In the construction step 4), when the straight section is in a pre-tightened state, the plurality of raised rings are fixedly arranged, and the elastic tube is elastically stretched and deformed along the axial direction of the through hole.

[0025] Compared with the prior art, the optical fiber embedding method for anchor slurry strain testing provided by the present invention avoids direct contact between the optical fiber and the anchoring section by arranging the monitoring section of the optical fiber away from the anchoring section, thereby rationalizing the optical fiber embedding position, reducing the interference to the optical fiber during the slurry solidification process, improving the long-term stability and measurement accuracy of the optical fiber, and ensuring that the optical fiber is not damaged during the slurry solidification process, thereby more accurately reflecting the actual strain of the slurry.

[0026] In addition, the optical fibers are arranged in a continuous manner, which can realize continuous monitoring of the entire range of the anchor slurry. Compared with local monitoring, it can more comprehensively capture the strain changes of the slurry in different areas, avoid the data deviation caused by local monitoring, and provide more complete and reliable data support for accurately evaluating the overall mechanical properties of the anchor. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of the process of the optical fiber embedding method for anchor slurry strain testing provided by the present invention;

[0028] Figure 2 is a cross-sectional schematic diagram of the anchor bar and the optical fiber in the anchor hole provided by the present invention;

[0029] Figure 3 It is a cross-sectional schematic diagram of the elastic tube and the through hole provided by the present invention;

[0030] Figure 4This is a schematic diagram of the main view of the centering frame provided by the present invention;

[0031] In the figure: anchoring section 100, tensioning section 101, guide cap 102, anchor hole 103, connecting section 104, straight section 105, curved section 106, adhesive tape 107;

[0032] Centering frame 200 , cable tie ring 201 , through hole 202 , through section 203 , elastic tube 204 , hollow cavity 205 , end block 206 , raised ring 207 , inner side wall 208 , elastic spacer 209 . DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0034] The implementation of the present invention is described in detail below with reference to specific embodiments.

[0035] The same or similar numbers in the drawings of this embodiment correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings. This is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0036] Reference Figure 1-4 The figure shows a preferred embodiment of the present invention.

[0037] The optical fiber embedding method for anchor slurry strain testing includes the following construction steps:

[0038] 1) The anchor bar includes an anchoring section 100 and a tensioning section 101. The anchoring sections 100 of multiple anchor bars are passed through the centering frame 200. The multiple anchor bars are arranged in a spaced and surrounding manner. The ends of the multiple anchoring sections 100 are connected to guide caps 102.

[0039] 2) Arrange the optical fiber in an integrated strip shape, with the middle portion of the optical fiber passing through the centering frame 200 and the guide cap 102, forming a continuous monitoring section. The monitoring section is arranged away from the anchoring section 100, and the two ends of the optical fiber form a connecting section 104 connected to the data acquisition equipment;

[0040] 3) Place multiple anchoring segments 100 in the anchor hole 103, place the monitoring segment in the anchor hole 103, and place the connecting segment 104 outside the anchor hole 103;

[0041] 4) After the monitoring section is in a pre-tensioned state, the anchor hole 103 is filled with slurry, which solidifies to form a slurry. The slurry fills the anchor hole 103, and the multiple anchoring sections 100, the guide cap 102 and the monitoring section are wrapped in the slurry.

[0042] The optical fiber embedding method for anchor slurry strain testing provided above avoids direct contact between the optical fiber and the anchoring section 100 by arranging the monitoring section of the optical fiber away from the anchoring section 100, thereby rationalizing the optical fiber embedding position, reducing the interference to the optical fiber during the slurry solidification process, improving the long-term stability and measurement accuracy of the optical fiber, and ensuring that the optical fiber is not damaged during the slurry solidification process, thereby more accurately reflecting the actual strain of the slurry.

[0043] In addition, the optical fibers are arranged in a continuous manner, which can realize continuous monitoring of the entire range of the anchor slurry. Compared with local monitoring, it can more comprehensively capture the strain changes of the slurry in different areas, avoid the data deviation caused by local monitoring, and provide more complete and reliable data support for accurately evaluating the overall mechanical properties of the anchor.

[0044] In this embodiment, in construction step 1), multiple centering frames 200 are arranged, and the anchoring section 100 passes through the multiple centering frames 200 in sequence. Along the length direction of the anchoring section 100, the multiple centering frames 200 are arranged in sequence and at intervals; in construction step 2), the monitoring section passes through the multiple centering frames 200 in sequence.

[0045] By arranging multiple centering frames 200 at intervals, it is possible to ensure that the positions of the anchoring section 100 and the monitoring section in the anchor hole 103 are accurate and stable, avoiding problems such as optical fiber damage or inaccurate monitoring data due to position offset, thereby improving construction accuracy and providing a reliable structural foundation for subsequent slurry strain monitoring.

[0046] In this embodiment, in construction step 1), a cable tie ring 201 is provided between adjacent centering frames 200, and multiple anchoring segments 100 pass through the cable tie ring 201 respectively, and the cable tie ring 201 radially gathers the multiple anchoring segments 100; in this way, the distribution of the anchoring segments 100 in the anchor hole 103 is more uniform, and mutual interference between the anchoring segments 100 is avoided, which not only improves the overall stability of the anchor rod, but also provides space for the reasonable arrangement of the optical fiber, further optimizing the construction process.

[0047] In this embodiment, in construction step 2), the monitoring section includes two straight sections 105 and a curved section 106. The curved section 106 is formed between the two straight sections 105. The straight sections 105 extend outward to form a connecting section 104. The straight sections 105 pass through multiple centering frames 200 and extend along the length direction of the anchoring section 100. The curved section 106 passes through the guide cap 102.

[0048] Through the extended arrangement of the straight section 105 and the reasonable design of the curved section 106, the stress concentration of the optical fiber during the construction process can be effectively reduced, thereby improving the service life and monitoring accuracy of the optical fiber. In addition, this design also solves the unreasonable burial of the optical fiber, avoids direct contact between the optical fiber and the anchoring section 100, and reduces the interference of the optical fiber during the slurry solidification process.

[0049] In this embodiment, in construction step 2), after the curved section 106 passes through the guide cap 102, the curved section 106 is fixed to the guide cap 102; in this way, the stability of the optical fiber in the anchor rod structure can be further enhanced, and the optical fiber can be prevented from being displaced during construction and use, which not only improves the anti-interference ability of the optical fiber, but also ensures the accuracy and reliability of the monitoring data.

[0050] In this embodiment, in construction step 4), before injecting slurry into the anchor hole 103, the connecting section 104 is pulled outward and fixedly arranged so that the straight section 105 is in a pre-tightened state; in this way, the relaxation of the optical fiber during the solidification process of the slurry can be effectively reduced. This pre-tightening measure can increase the initial tension of the optical fiber, thereby maintaining a more stable monitoring state after the slurry solidifies, further improving the monitoring accuracy.

[0051] In this embodiment, in construction step 4), after the straight section 105 is in a pre-tightened state, the connecting section 104 is fixed on the tensioning section 101 to keep the anchoring section 100 in a pre-tightened state; the tension is transmitted through the tensioning section 101, thereby enhancing the overall stability of the anchor rod, so that the anchor rod can better exert its mechanical properties during the force-bearing process, and at the same time, it also provides a strong guarantee for the stable monitoring of the optical fiber.

[0052] In this embodiment, in construction step 2), the centering frame 200 has a through hole 202, and the straight segment 105 has a through section 203 that passes through the through hole 202; an elastic tube 204 is sleeved on the outer periphery of the through section 203, and the through section 203 is fixedly connected to the elastic tube 204. The elastic tube 204 is placed in the through hole 202 and is fixedly connected to the centering frame 200;

[0053] In construction step 4), when the straight section 105 is in a pre-tightened state, the through section 203 is pulled, causing the elastic tube 204 to elastically deform, and the elastic tube 204 is in an elastically stretched state.

[0054] By setting the elastic tube 204, the stress generated by the straight section 105 during the pre-tightening process can be effectively buffered, avoiding damage to the optical fiber due to stress concentration. At the same time, the elastic deformation of the elastic tube 204 can adapt to the volume change during the slurry solidification process, ensuring that the optical fiber maintains a stable monitoring state during the entire construction and use process, further improving the anti-interference ability and monitoring accuracy of the optical fiber.

[0055] In this embodiment, in construction step 2), the elastic tube 204 has a straight and closed hollow cavity 205, which extends coaxially with the elastic tube 204. The elastic tube 204 has end blocks 206 at both ends, and the end blocks 206 are formed at the ends of the hollow cavity 205.

[0056] The through-section 203 passes through the two end blocks 206 and the hollow cavity 205 respectively, and is fixedly connected to the two end blocks 206 respectively; in construction step 4), when the straight section 105 is in a pre-tightened state, the through-section 203 pulls the two end blocks 206 to elastically stretch and deform.

[0057] The structural design of the hollow cavity 205 and the end block 206 enables the elastic tube 204 to undergo more uniform elastic deformation when subjected to force, which not only improves the fatigue resistance of the elastic tube 204, but also better adapts to the volume changes during the slurry solidification process, ensuring that the optical fiber maintains a stable monitoring state throughout the construction and use process.

[0058] In this embodiment, in construction step 2), a plurality of raised rings 207 are formed on the outer circumference of the elastic tube 204. The plurality of raised rings 207 are spaced apart along the axial direction of the elastic tube 204. When the elastic tube 204 is placed in the through-hole 202, the plurality of raised rings 207 abut against the inner sidewall 208 of the through-hole 202. An elastic spacer 209 is defined between the outer circumference of the elastic tube 204 and the inner sidewall 208 of the through-hole 202. The end block 206 covers the end of the through-hole 202 and is fixedly connected to the centering frame 200, so that the elastic spacer 209 is in a sealed state.

[0059] In construction step 4), when the straight section 105 is in a pre-tightened state, the plurality of raised rings 207 are fixedly arranged, and the elastic tube 204 is elastically stretched and deformed along the axial direction of the through hole 202 .

[0060] The use of the raised ring 207 can effectively increase the friction between the elastic tube 204 and the inner wall 208 of the through-hole 202, thereby improving the fixing effect of the elastic tube 204 in the centering frame 200. At the same time, the sealed state of the elastic spacer 209 can prevent the slurry from entering the through-hole 202, further protecting the optical fiber from the erosion of the slurry. This not only improves the anti-interference ability of the optical fiber, but also ensures that the optical fiber maintains a stable monitoring state throughout the construction and use process, and also realizes the reasonable burial of the optical fiber, avoiding interference with the optical fiber during the slurry solidification process.

[0061] The optical fiber embedding method for anchor slurry strain testing provided in this embodiment also has the following advantages:

[0062] 1) By burying the optical fiber in the slurry, the slurry strain can be accurately tested instead of the anchor strain;

[0063] 2) Use the centering frame 200 and the adhesive tape 107 to fix the optical fiber. This installation process is simple and reliable.

[0064] 3) The optical fiber embedding method mentioned in the present invention is applicable to various types of anchor rods and has wide applicability.

[0065] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An optical fiber embedding method for anchor slurry strain testing, characterized in that: The construction steps include: 1) The anchor bar includes an anchoring section and a tensioning section. The anchoring sections of the plurality of anchor bars are passed through the centering frame. The plurality of anchor bars are arranged in a spaced and surrounding manner. The ends of the plurality of anchoring sections are connected with guide caps. 2) Arrange an optical fiber in an integrated strip shape, wherein the middle portion of the optical fiber passes through the centering frame and the guide cap respectively, forming a monitoring section arranged continuously. The monitoring section is arranged away from the anchoring section, and the two ends of the optical fiber form a connection section connected to the collection equipment; 3) placing the plurality of anchoring segments in the anchor hole, placing the monitoring segment in the anchor hole, and placing the connecting segment outside the anchor hole; 4) After the monitoring section is in a pre-tensioned state, the anchor hole is filled with slurry, and the slurry solidifies to form a slurry. The slurry fills the anchor hole, and the plurality of anchoring sections, guide caps and monitoring sections are wrapped in the slurry.

2. The optical fiber embedding method for anchor slurry strain testing according to claim 1, characterized in that: In the construction step 1), multiple centering frames are arranged, and the anchoring section passes through the multiple centering frames in sequence. Along the length direction of the anchoring section, the multiple centering frames are arranged in sequence and at intervals; in the construction step 2), the monitoring section passes through the multiple centering frames in sequence.

3. The optical fiber embedding method for anchor slurry strain testing according to claim 1, characterized in that: In the construction step 1), a cable tie ring is provided between adjacent centering frames, and the plurality of anchoring segments respectively pass through the cable tie ring, and the cable tie ring radially gathers the plurality of anchoring segments.

4. The optical fiber embedding method for anchor slurry strain testing according to any one of claims 1 to 3, characterized in that: In the construction step 2), the monitoring section includes two straight sections and a curved section, the curved section is formed between the two straight sections, and the straight sections extend outward to form the connecting section; the straight sections pass through multiple centering frames and extend along the length direction of the anchoring section, and the curved section passes through the guide cap.

5. The optical fiber embedding method for anchor slurry strain testing according to claim 4, characterized in that: In the construction step 2), after the curved section passes through the guide cap, the curved section is fixed to the guide cap.

6. The optical fiber embedding method for anchor slurry strain testing according to claim 4, characterized in that: In the construction step 4), before injecting slurry into the anchor hole, the connecting section is pulled outward and fixedly arranged so that the straight section is in a pre-tightened state.

7. The optical fiber embedding method for anchor slurry strain testing according to claim 4, characterized in that: In the construction step 4), after the straight section is in a pre-tightened state, the connecting section is fixed to the tensioning section to keep the anchoring section in a pre-tightened state.

8. The optical fiber embedding method for anchor slurry strain testing according to claim 4, characterized in that: In the construction step 2), the centering frame has a through hole, and the straight segment has a through section passing through the through hole; an elastic tube is sleeved on the outer periphery of the through section, the through section is fixedly connected to the elastic tube, and the elastic tube is placed in the through hole and fixedly connected to the centering frame; In the construction step 4), when the straight section is in a pre-tightened state, the through section is pulled, causing the elastic tube to elastically deform, and the elastic tube is in an elastically stretched state.

9. The optical fiber embedding method for anchor slurry strain testing according to claim 8, characterized in that: In the construction step 2), the elastic tube has a straight and closed hollow cavity, the hollow cavity and the elastic tube extend coaxially, and the elastic tube has end blocks at both ends, the end blocks being formed at the ends of the hollow cavity; The through-section passes through the two end blocks and the hollow cavity respectively, and is fixedly connected to the two end blocks respectively; in the construction step 4), when the straight section is in a pre-tightened state, the through-section pulls the two end blocks to elastically stretch and deform.

10. The optical fiber embedding method for anchor slurry strain testing according to claim 8, characterized in that: In the construction step 2), a plurality of raised rings are formed on the outer circumference of the elastic tube, and the plurality of raised rings are arranged at intervals along the axial direction of the elastic tube; when the elastic tube is placed in the through hole, the plurality of raised rings abut against the inner side wall of the through hole, and an elastic gap is formed between the outer circumference of the elastic tube and the inner side wall of the through hole; the end block covers the end of the through hole and is fixedly connected to the centering frame, so that the elastic gap is in a sealed state; In the construction step 4), when the straight section is in a pre-tightened state, the plurality of raised rings are fixedly arranged, and the elastic tube is elastically stretched and deformed along the axial direction of the through hole.

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