Device and method for rapidly detecting lining defects of hydraulic tunnel

Abstract

The invention belongs to the technical field of tunnel quality detection, and particularly relates to a hydraulic tunnel lining defect rapid detection device and method.The hydraulic tunnel lining defect rapid detection device comprises an upper steel plate, a vertical steel plate is welded to the surface of the lower end of the upper steel plate along the center line position, and a lower steel plate is welded to the lower end of the vertical steel plate; a 120-degree large-viewing-angle rotatable probe is arranged in a hydraulic tunnel lining detection device, the problem that a traditional fixed device has multiple scanning blind areas is solved, the inner wall of a tunnel is often provided with a bent section or a local concave-convex surface, a large-angle rotating structure can synchronously scan a vault, a side wall and a joint part, the number of times of movement of the device is reduced, and in an inverted tunnel, the large-viewing-angle rotatable probe can be used for synchronously scanning the vault, the side wall and the joint part. The probe keeps the lens to be perpendicular to the lining surface all the time through active deflection, image distortion is avoided, the device adapts to lining cambered surfaces with different curvatures, no-dead-corner defect detection is achieved for tiny cracks or peeling areas, and the detection efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel quality detection, and in particular to a device and method for quickly detecting defects in a hydraulic tunnel lining. Background Art

[0002] In tunnel construction, tunnel lining construction is required after excavation to prevent weathering of the surrounding rock and groundwater infiltration. However, during lining construction, defects such as excessive or insufficient lining thickness and lining voids are prone to occur, seriously affecting the lining's bearing capacity, durability, and structural strength. Therefore, effective lining quality inspections are necessary to repair defective sections, thereby extending the tunnel's service life, reducing financial losses caused by reconstruction, and preventing accidents. Summary of the Invention

[0003] In view of the technical problem that the existing detection structure is too large and the installation is complicated, the present invention proposes a rapid detection device and method for hydraulic tunnel lining defects.

[0004] The present invention proposes a rapid detection device and method for hydraulic tunnel lining defects, comprising an upper steel plate, a vertical steel plate welded to the lower end surface of the upper steel plate along the center line, a lower steel plate welded to the lower end of the vertical steel plate, a wheel rotatably provided on the side surface of the vertical steel plate, a rotating shaft block rotatably mounted at the center of the outer surface of the wheel, and a bracket fixedly connected to the center of the outer circumferential surface of the rotating shaft block;

[0005] A mounting block is welded inside the circumferential surface of the bracket, an upper block is welded on the upper surface of the mounting block, curved blocks are installed at the left and right edges of the upper surface of the upper block, a fixing ring is provided on the upper curved surface of the curved block, a rotating bin is rotatably installed inside the fixing ring, a detection device is installed on the upper end of the circumferential surface of the rotating bin, a lower fixed bin is fixedly connected to the lower end of the circumferential surface of the rotating bin, a rotating groove is opened on the lower surface of the lower fixed bin, and a roller is rotatably provided inside the rotating groove.

[0006] Preferably, a fixing plate is welded at the midline position of the lower surface of the lower steel plate, and vacuum suction cups are installed on the lower surface of the fixing plate near the left and right edges.

[0007] Through the above technical solution, a vacuum suction cup is used to fix the lower end of the hydraulic tunnel detection track, which can be quickly adsorbed to the lining surface without drilling or welding, avoiding damage to the structure and greatly shortening the installation time. The suction cup adaptively fits the curved or inclined surface through negative pressure, and can maintain a stable grip especially in humid environments, preventing equipment slippage, improving the safety of inverted tunnel operations, and ensuring the data collection accuracy of the detection probe.

[0008] Preferably, lower limit rails are welded at the left and right edges of the upper surface of the lower steel plate, and upper limit rails are welded at the left and right edges of the lower surface of the upper steel plate.

[0009] Through the above technical solution, upper and lower limit rails are installed on the hydraulic tunnel detection track to constrain the travel trajectory of the detection equipment, prevent the wheels from derailing due to tunnel inclination, slippery surface or local deformation, reduce mechanical losses caused by derailment, and extend the service life of the device.

[0010] Preferably, a protrusion is welded on the right side surface of the vertical steel plate and the lower steel plate, and a connection hole 1 is opened through the left and right surfaces of the protrusion. An installation groove is opened on the left side surface of the vertical steel plate and the lower steel plate, and a connection hole 2 is opened on the left and right surfaces of the inner upper end of the installation groove relative to the position of the connection hole 1.

[0011] Through the above technical solution, a special track structure for vertical and inverted tunnels is designed in the hydraulic tunnel lining defect detection device, which can significantly improve the detection efficiency and safety. The spliced track adopts modular connection, which can quickly complete the track laying of tunnels with different inclination angles and support inverted operations. At the same time, the lightweight material and rust-proof design reduce the installation difficulty of high-altitude operations and shorten the detection preparation time. It is suitable for water conservancy engineering environments with high drops and multiple bends, and provides reliable hardware guarantees for the accurate identification of hidden defects.

[0012] Preferably, a connecting column is fixedly connected to the center position of the lower surface of the mounting block, and a chassis is welded to the lower end of the connecting column.

[0013] Through the above technical solution, a connecting column is set at the lower end of the mounting block and connected to the chassis to ensure the stability of the entire mobile platform.

[0014] Preferably, a rotating rod is provided through the front and rear end edges of the chassis, and rotating wheels are rotatably installed on the left and right ends of the rotating rod.

[0015] Through the above technical solution, a rotating rod and a rotating wheel are arranged at the chassis position to ensure that the movable flat sleeve will not tilt left or right, and the lens is always in a state of being vertical to the lining surface.

[0016] Preferably, a roller groove is provided on the inner curved surface of the upper end of the upper block relative to the position of the roller.

[0017] Through the above technical solution, a roller groove is provided at the lower end of the roller, the purpose of which is to keep the roller rotating in the groove at all times and realize free rotation within 120 degrees.

[0018] Preferably, a battery pack is provided at the lower end of the circumferential surface of the rotating bin, which is located on the upper surface of the lower fixed bin.

[0019] Through the above technical solution, a dedicated battery pack is integrated inside the rotating chamber to provide an independent power supply for the rotating structure, freeing it from the site limitations of an external power supply and ensuring the continuous and stable operation of the equipment in humid and narrow tunnels.

[0020] Preferably, a cable is connected through the center of the lower surface of the battery pack, a front end of the cable is connected to a motor, and a front end of the motor is connected to a rotating shaft installed at the center of the rear surface of the roller.

[0021] Through the above technical solution, a small motor is used to drive the detection device to rotate. It has a compact size and stable power output, which is suitable for the narrow space of the tunnel. Its low power consumption characteristics match the built-in battery pack, which can extend the continuous operation time.

[0022] Preferably, a rapid detection device and method for hydraulic tunnel lining defects comprises the following steps:

[0023] Step 1: Weld the vertical steel plate along the center line of the lower end surface of the upper steel plate, weld the lower steel plate to the lower end of the vertical steel plate, and rotatably set the wheel on the side surface of the vertical steel plate, so that the wheel moves in the space formed by the upper steel plate, the vertical steel plate and the lower steel plate;

[0024] Step 2: The rotating shaft block is rotatably installed at the center position of the outer surface of the wheel, the center position of the outer circumferential surface of the rotating shaft block is fixedly connected to the bracket, the mounting block is welded inside the circumferential surface of the bracket, the upper block is welded on the upper surface of the mounting block, the curved blocks are installed at the left and right edges of the upper surface of the upper block, the fixing ring is provided on the upper curved surface of the curved block, the rotating bin is rotatably installed inside the fixing ring, the detection device is installed on the upper end of the circumferential surface of the rotating bin, the mobile platform constituted by the above structure moves on the track, and the inner wall of the tunnel is inspected for defects by the detection device;

[0025] Step 3: Then, the lower fixed bin is fixedly connected to the lower end of the circumferential surface of the rotating bin, the lower surface of the lower fixed bin is provided with the rotating groove, the roller is rotatably arranged inside the rotating groove, and the rotation of the roller drives the detection device to rotate synchronously within 120 degrees, and scans and detects the opposite side of the detection device;

[0026] Step 4: Then weld the protrusion on the right side surface of the vertical steel plate and the lower steel plate, and open the connecting hole 1 through the left and right surfaces of the protrusion. Open the installation groove on the left side surface of the vertical steel plate and the lower steel plate, and open the connecting hole 2 on the left and right surfaces of the upper inner end of the installation groove relative to the position of the connecting hole 1. Set the track into several modules for splicing, which can adapt to detection in tunnels of various geological environments and meet the needs of detection in vertical / inverted tunnels.

[0027] The beneficial effects of the present invention are:

[0028] 1. A 120-degree rotatable probe with a wide viewing angle is configured in the hydraulic tunnel lining inspection device to solve the problem of many blind spots in traditional fixed equipment. The inner wall of the tunnel often has curved sections or local concave and convex surfaces. The large-angle rotation structure can simultaneously scan the vault, side walls and joints, reducing the number of equipment movements. In inverted tunnels, the probe actively deflects to keep the lens perpendicular to the lining surface, avoiding image distortion and adapting to lining curved surfaces of different curvatures. It can achieve blind spot detection of subtle cracks or peeling areas, thereby improving inspection efficiency.

[0029] 2. Designing a dedicated track structure for vertical and inverted tunnels in the hydraulic tunnel lining defect detection device can significantly improve detection efficiency and safety. The spliced track adopts modular connection, which can quickly complete the track laying of tunnels with different inclination angles and support inverted operations. At the same time, the lightweight material and rust-proof design reduce the installation difficulty of high-altitude operations and shorten the detection preparation time. It is suitable for hydraulic engineering environments with high drop heights and multiple bends, providing reliable hardware support for the accurate identification of hidden defects.

[0030] 3. A vacuum suction cup is used to fix the lower end of the hydraulic tunnel inspection track. It can be quickly adsorbed to the lining surface without drilling or welding, avoiding structural damage and significantly shortening installation time. The suction cup adapts to curved or inclined surfaces through negative pressure, maintaining a stable grip especially in humid environments, preventing equipment slippage, improving the safety of inverted tunnel operations, and ensuring the data collection accuracy of the detection probe. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic diagram of the external structure of a rapid detection device and method for hydraulic tunnel lining defects proposed by the present invention;

[0032] Figure 2 This is a top view of the external structure of a rapid detection device and method for hydraulic tunnel lining defects proposed by the present invention;

[0033] Figure 3 This is a schematic diagram of the mobile platform structure of a hydraulic tunnel lining defect rapid detection device and detection method proposed by the present invention;

[0034] Figure 4 A top view of the mobile platform structure of a hydraulic tunnel lining defect rapid detection device and detection method proposed by the present invention;

[0035] Figure 5 This is a schematic diagram of the rotating chamber structure of a hydraulic tunnel lining defect rapid detection device and detection method proposed by the present invention;

[0036] Figure 6 This is a schematic diagram of the lower structure of the rotating chamber of a rapid detection device and method for hydraulic tunnel lining defects proposed by the present invention.

[0037] In the figure: 1. Upper steel plate; 2. Vertical steel plate; 3. Lower steel plate; 4. Wheel; 5. Vacuum suction cup; 6. Fixed plate; 7. Lower limit rail; 8. Connection hole 1; 9. Bump; 10. Upper limit rail; 11. Mounting slot; 12. Connection hole 2; 13. Rotating shaft block; 14. Chassis; 15. Mounting block; 16. Upper block; 17. Connecting column; 18. Rotating rod; 19. Rotating wheel; 20. Bracket; 21. Roller slot; 22. Rotating bin; 23. Curved block; 24. Fixed ring; 25. Detection device; 26. Battery pack; 27. Lower fixed bin; 28. Roller; 29. Rotating slot; 30. Cable; 31. Rotating shaft; 32. Motor. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0039] Reference Figure 1-6 A rapid detection device and method for hydraulic tunnel lining defects includes an upper steel plate 1, a vertical steel plate 2 welded to the lower end surface of the upper steel plate 1 along the center line, a lower steel plate 3 welded to the lower end of the vertical steel plate 2, a wheel 4 rotatably provided on the side surface of the vertical steel plate 2, a rotating shaft block 13 rotatably mounted at the center position of the outer surface of the wheel 4, and a bracket 20 fixedly connected to the center position of the outer circumferential surface of the rotating shaft block 13;

[0040] A mounting block 15 is welded to the inside of the circumferential surface of the bracket 20, an upper block 16 is welded to the upper surface of the mounting block 15, curved blocks 23 are installed at the left and right edges of the upper surface of the upper block 16, a fixing ring 24 is provided on the upper curved surface of the curved block 23, a rotating bin 22 is rotatably installed inside the fixing ring 24, a detection device 25 is installed on the upper end of the circumferential surface of the rotating bin 22, a lower fixed bin 27 is fixedly connected to the lower end of the circumferential surface of the rotating bin 22, a rotating groove 29 is provided on the lower surface of the lower fixed bin 27, a roller 28 is rotatably provided inside the rotating groove 29.

[0041] Furthermore, a fixing plate 6 is welded at the midline position of the lower surface of the lower steel plate 3 , and vacuum suction cups 5 are installed on the lower surface of the fixing plate 6 near the left and right edges.

[0042] A vacuum suction cup is used to fix the lower end of the hydraulic tunnel inspection track, which can be quickly adsorbed to the lining surface without drilling or welding, avoiding damage to the structure and significantly shortening the installation time. The suction cup adaptively fits the curved or inclined surface through negative pressure, and can maintain a stable grip especially in humid environments, preventing equipment slippage, improving the safety of inverted tunnel operations, and ensuring the data collection accuracy of the detection probe.

[0043] Furthermore, lower limit rails 7 are welded to the left and right edges of the upper surface of the lower steel plate 3 , and upper limit rails 10 are welded to the left and right edges of the lower surface of the upper steel plate 1 .

[0044] Install upper and lower limit rails on the hydraulic tunnel inspection track to constrain the travel trajectory of the inspection equipment and prevent the wheels from derailing due to tunnel inclination, slippery surface or local deformation, thereby reducing mechanical losses caused by derailment and extending the service life of the device.

[0045] Furthermore, a protrusion 9 is welded to the right side surface of the vertical steel plate 2 and the lower steel plate 3, and a connection hole 8 is provided through the left and right surfaces of the protrusion 9. An installation groove 11 is provided on the left side surface of the vertical steel plate 2 and the lower steel plate 3, and a connection hole 2 12 is provided on the left and right surfaces of the upper end of the inner part of the installation groove 11 relative to the position of the connection hole 8.

[0046] Designing a dedicated track structure for vertical and inverted tunnels in the hydraulic tunnel lining defect detection device can significantly improve detection efficiency and safety. The spliced track adopts modular connection, which can quickly complete the track laying of tunnels with different inclination angles and support inverted operations. At the same time, the lightweight material and rust-proof design reduce the installation difficulty of high-altitude operations and shorten the detection preparation time. It is suitable for water conservancy engineering environments with high drops and multiple bends, and provides reliable hardware support for the accurate identification of hidden defects.

[0047] Furthermore, a connecting column 17 is fixedly connected to the center position of the lower surface of the mounting block 15 , and the lower end of the connecting column 17 is welded to the chassis 14 .

[0048] A connecting column is set at the lower end of the mounting block and connected to the chassis to ensure the stability of the entire mobile platform.

[0049] Furthermore, a rotating rod 18 is provided through the front and rear edges of the chassis 14 , and rotating wheels 19 are rotatably mounted on the left and right ends of the rotating rod 18 .

[0050] A rotating rod and a rotating wheel are arranged at the chassis position to ensure that the movable flat sleeve will not tilt left or right and the lens is always in a state of being vertical to the lining surface.

[0051] Furthermore, a roller groove 21 is formed on the inner curved surface of the upper end of the upper block 16 relative to the position of the roller 28 .

[0052] A roller groove is set at the lower end of the roller to keep the roller rotating in the groove at all times and achieve free rotation within 120 degrees.

[0053] Furthermore, a battery pack 26 is provided at the lower end of the circumferential surface of the rotating chamber 22 , located on the upper surface of the lower fixed chamber 27 .

[0054] A dedicated battery pack is integrated inside the rotating chamber to provide an independent power supply for the rotating structure, eliminating the site limitations of an external power supply and ensuring continuous and stable operation of the equipment in humid and narrow tunnels.

[0055] Furthermore, a cable 30 is connected through the center of the lower surface of the battery pack 26 , a front end of the cable 30 is connected to a motor 32 , and a front end of the motor 32 is connected to a rotating shaft 31 installed at the center of the rear surface of the roller 28 .

[0056] A small motor is used to drive the detection device to rotate. It has a compact size and stable power output, making it suitable for the narrow space of tunnels. Its low power consumption characteristics match the built-in battery pack to extend the continuous operation time.

[0057] Working principle:

[0058] Step 1: Weld a vertical steel plate 2 along the center line of the lower end surface of the upper steel plate 1, weld a lower steel plate 3 to the lower end of the vertical steel plate 2, and rotate and set wheels 4 on the side surface of the vertical steel plate 2. The wheels 4 move in the space formed by the upper steel plate 1, the vertical steel plate 2 and the lower steel plate 3;

[0059] Step 2: The rotating shaft block 13 is rotatably mounted on the center position of the outer surface of the wheel 4. The center position of the outer circumferential surface of the rotating shaft block 13 is fixedly connected to the bracket 20. The mounting block 15 is welded to the inner circumferential surface of the bracket 20. The upper block 16 is welded to the upper surface of the mounting block 15. Curved blocks 23 are mounted on the left and right edges of the upper surface of the upper block 16. A fixing ring 24 is provided on the upper curved surface of the curved block 23. The rotating chamber 22 is rotatably mounted inside the fixing ring 24. The upper end of the circumferential surface of the rotating chamber 22 is installed with a detection device 25. The mobile platform constituted by the above structure moves on the track, and the inner wall of the tunnel is inspected for defects by the detection device 25.

[0060] Step 3: The lower end of the circumferential surface of the rotating chamber 22 is fixedly connected to the lower fixed chamber 27. The lower surface of the lower fixed chamber 27 has a rotating groove 29. A roller 28 is provided inside the rotating groove 29. The rotation of the roller 28 drives the detection device 25 to rotate synchronously within 120 degrees, and scans and detects the opposite side of the detection device 25.

[0061] Step 4. Weld a protrusion 9 to the right side surface of the vertical steel plate 2 and the lower steel plate 3, and set a connection hole 8 through the left and right surfaces of the protrusion 9. Set an installation groove 11 on the left side surface of the vertical steel plate 2 and the lower steel plate 3. Set a connection hole 2 12 on the left and right surfaces of the upper end of the installation groove 11 relative to the position of the connection hole 8. Set the track into several modules for splicing, which can adapt to the detection in tunnels of various geological environments and meet the needs of detection in vertical / inverted tunnels.

[0062] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A rapid detection device for hydraulic tunnel lining defects, comprising an upper steel plate (1), characterized in that: A vertical steel plate (2) is welded to the lower end surface of the upper steel plate (1) along the center line, a lower steel plate (3) is welded to the lower end of the vertical steel plate (2), a wheel (4) is rotatably provided on the side surface of the vertical steel plate (2), a rotating shaft block (13) is rotatably installed at the center position of the outer surface of the wheel (4), and a bracket (20) is fixedly connected to the center position of the outer circumferential surface of the rotating shaft block (13); A mounting block (15) is welded inside the circumferential surface of the bracket (20), an upper block (16) is welded on the upper surface of the mounting block (15), curved blocks (23) are installed at the left and right edges of the upper surface of the upper block (16), a fixing ring (24) is provided on the upper curved surface of the curved block (23), a rotating bin (22) is rotatably installed inside the fixing ring (24), a detection device (25) is installed on the upper end of the circumferential surface of the rotating bin (22), a lower fixed bin (27) is fixedly connected to the lower end of the circumferential surface of the rotating bin (22), a rotating groove (29) is provided on the lower surface of the lower fixed bin (27), and a roller (28) is rotatably provided inside the rotating groove (29).

2. A rapid detection device for hydraulic tunnel lining defects according to claim 1, characterized in that: A fixing plate (6) is welded at the midline position of the lower surface of the lower steel plate (3), and vacuum suction cups (5) are installed on the lower surface of the fixing plate (6) near the left and right edges.

3. A rapid detection device for hydraulic tunnel lining defects according to claim 1, characterized in that: Lower limit rails (7) are welded to the left and right edges of the upper surface of the lower steel plate (3), and upper limit rails (10) are welded to the left and right edges of the lower surface of the upper steel plate (1).

4. A rapid detection device for hydraulic tunnel lining defects according to claim 1, characterized in that: A protrusion (9) is welded on the right side surface of the vertical steel plate (2) and the lower steel plate (3), and a connection hole (8) is provided through the left and right surfaces of the protrusion (9). A mounting groove (11) is provided on the left side surface of the vertical steel plate (2) and the lower steel plate (3), and a connection hole (12) is provided on the left and right surfaces of the upper end of the mounting groove (11) relative to the position of the connection hole (8).

5. A rapid detection device for hydraulic tunnel lining defects according to claim 4, characterized in that: A connecting column (17) is fixedly connected to the center position of the lower surface of the mounting block (15), and a chassis (14) is welded to the lower end of the connecting column (17).

6. A rapid detection device for hydraulic tunnel lining defects according to claim 5, characterized in that: A rotating rod (18) is provided through the edges of the front and rear ends of the chassis (14), and rotating wheels (19) are rotatably installed on the left and right ends of the rotating rod (18).

7. The rapid detection device for hydraulic tunnel lining defects according to claim 1, characterized in that: The inner curved surface of the upper end of the upper block (16) is provided with a roller groove (21) at a position relative to the roller (28).

8. The rapid detection device for hydraulic tunnel lining defects according to claim 1, characterized in that: A battery pack (26) is provided at the lower end of the circumferential surface of the rotating bin (22) and located on the upper surface of the lower fixed bin (27).

9. A rapid detection device for hydraulic tunnel lining defects according to claim 8, characterized in that: A cable (30) is connected through the center of the lower surface of the battery pack (26), a front end of the cable (30) is connected to a motor (32), and a front end of the motor (32) is connected to a rotating shaft (31) installed at the center of the rear surface of the roller (28).

10. A method for rapid detection of hydraulic tunnel lining defects according to any one of claims 1 to 9, characterized in that: The following steps are included: Step 1: Weld the vertical steel plate (2) along the centerline position on the lower end surface of the upper steel plate (1), weld the lower steel plate (3) at the lower end of the vertical steel plate (2), and rotate the side surface position of the vertical steel plate (2) to set the wheel (4), and the wheel (4) moves in the space formed by the upper steel plate (1), the vertical steel plate (2) and the lower steel plate (3); Step 2: The rotating shaft block (13) is rotatably mounted on the center position of the outer surface of the wheel (4); the center position of the outer circumferential surface of the rotating shaft block (13) is fixedly connected to the bracket (20); the mounting block (15) is welded inside the circumferential surface of the bracket (20); the upper block (16) is welded to the upper surface of the mounting block (15); the curved block (23) is mounted on the left and right edges of the upper surface of the upper block (16); the fixing ring (24) is provided on the upper curved surface of the curved block (23); the rotating chamber (22) is rotatably mounted inside the fixing ring (24); the detection device (25) is mounted on the upper end of the circumferential surface of the rotating chamber (22); the mobile platform composed of the above structure moves on the track, and the inner wall of the tunnel is inspected for defects by the detection device (25); Step 3: The lower end of the circumferential surface of the rotating bin (22) is fixedly connected to the lower fixed bin (27), and the lower surface of the lower fixed bin (27) is provided with the rotating groove (29). The roller (28) is arranged to rotate inside the rotating groove (29). The rotation of the roller (28) drives the detection device (25) to rotate synchronously within 120 degrees, and performs scanning detection on the opposite side of the detection device (25); Step 4: The protrusion (9) is welded to the right side surface of the vertical steel plate (2) and the lower steel plate (3), and the connecting hole (8) is opened through the left and right surfaces of the protrusion (9). The installation groove (11) is opened on the left side surface of the vertical steel plate (2) and the lower steel plate (3), and the connecting hole (12) is opened on the left and right surfaces of the upper end of the installation groove (11) relative to the position of the connecting hole (8). The track is set to several modules for splicing, which is suitable for detection in tunnels of various geological environments and meets the needs of detection in vertical / inverted tunnels.

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