Underground pile foundation defect visualization detection device based on acoustic tomography

Abstract

The present application relates to pile foundation detection technical field, and disclose underground pile foundation defect visualization detection device based on acoustic tomography, including pile foundation column, fixing frame, data acquisition box, transducer, in the present application, through the positioning support mechanism added can be in the acoustic pipe inside the transducer forms multiple point balanced support, make the transducer always stable keep in the middle, vertical detection posture, effectively put an end to the detection process transducer radial swing, tilt, eccentric offset and other problems. The lead limiting mechanism configured can be transmitted to the whole process of lead limiting, guiding and regular, limit the lead in the process of retraction disorder swing, relaxation offset, lead uniform speed, orderly, stable retraction. Solve the traditional structure in the lead swing pull transducer, lead to transducer secondary offset swing chain problem, effectively avoid external disturbance on the probe detection posture interference, whole process maintains the stable working state of the transducer, provide stable hardware foundation for high-precision data acquisition.

Description

Technical Field

[0001] This invention relates to the field of pile foundation testing technology, specifically to a visual detection device for underground pile foundation defects based on acoustic tomography. Background Technology

[0002] Pile foundations are the core load-bearing foundation structures of civil engineering projects such as buildings, bridges, and rail transit. The integrity, internal density, and defect conditions of the piles directly determine the structural safety and service life of the entire project. Acoustic tomography (ATT) technology, with its advantages of non-destructive testing, full-domain imaging, precise defect location, and quantifiable analysis of defect morphology and size, has become the mainstream core technology for detecting defects in underground cast-in-place pile foundations. The core principle of ATT detection is as follows: Transmitting and receiving transducers are placed into pre-embedded acoustic logging tubes in the pile foundation. By vertically lifting and lowering the transducers, acoustic wave propagation parameters at different depths and along different propagation paths are collected. Combined with tomographic algorithms, the internal structure of the pile is reconstructed, ultimately generating a visualized image of the pile's interior, thereby determining the location, size, and type of pile foundation defects.

[0003] Most existing detection transducers lack any auxiliary support and positioning mechanisms, making it impossible for them to maintain a stable, centered posture within the acoustic logging tube. During vertical lifting and horizontal fine-tuning, the transducers are prone to radial swaying, tilting, and eccentric displacement. This swaying and displacement directly alters the actual propagation path of the sound waves, leading to distortions in the acquisition of core parameters such as sound wave propagation time, amplitude, and frequency, resulting in additional measurement errors. Furthermore, existing detection devices lack dedicated limiting and regulating mechanisms for their connecting wires. During manual or automated retraction, lifting, and movement, the transducer's signal transmission wires are susceptible to disordered swaying, tangling, and displacement due to tube wall friction, water flow disturbances, and equipment vibration. Since the wires are rigidly connected to the transducer, their swaying directly pulls and causes the transducer to sway and deviate synchronously within the acoustic logging tube, further exacerbating the transducer's instability. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a visual detection device for underground pile foundation defects based on acoustic tomography, which solves the problem of poor stability of existing pile foundation detection devices during the transducer detection process.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solution: a visual detection device for underground pile foundation defects based on acoustic tomography, comprising a pile foundation column, a fixing frame, a data acquisition box, and a transducer, wherein a limiting component is provided on the fixing frame to improve the stability of the transducer;

[0006] The limiting component includes a connecting frame fixedly connected to a fixed frame. An adjusting ring is fixedly connected to the side of the connecting frame away from the fixed frame. The adjusting ring has multiple telescopic grooves evenly distributed around its circumference. A telescopic block is slidably connected within the telescopic grooves. A circular ring is fixedly connected to the end of the adjusting ring away from the pile column. A rotating groove is formed on the end face of the circular ring. A rotating ring is rotatably connected within the rotating groove. Multiple arc-shaped grooves are evenly distributed on the rotating ring. A pull rod is fixedly connected to the end of the telescopic block near the rotating ring, and the pull rod is slidably connected to the arc-shaped groove. Two fixed rings are fixedly connected to the outer wall of the transducer. Multiple hinge seats are evenly installed around the fixed rings around its circumference. A rotating shaft is rotatably connected to the hinge seat. A spring is fixedly connected to both ends of the rotating shaft. The end of the spring away from the rotating shaft is fixedly connected to the hinge seat.

[0007] Preferably, the pile foundation column is evenly equipped with multiple sonic logging tubes along the circumference, the outer wall of the rotating shaft is fixedly connected to a support claw, and the end of the support claw away from the hinge seat is rotatably connected to a roller, the roller abutting against the inner wall of the sonic logging tube.

[0008] Preferably, a coil and a splined shaft are rotatably connected inside the fixed frame, and a wire is wound around the outer wall of the coil, with the end of the wire away from the coil being fixedly connected to the transducer.

[0009] Preferably, a toothed ring is fixedly connected to the end of the rotating ring away from the adjusting ring, and a drive motor is fixedly connected to the connecting frame.

[0010] Preferably, the output end of the drive motor is fixedly connected to a worm gear, and the teeth of the worm gear mesh with the teeth of the gear ring.

[0011] Preferably, a guide rail is fixedly connected inside the fixing frame, a guide shell is slidably connected to the outer wall of the spline shaft, and a guide seat is fixedly connected to the upper surface of the guide shell.

[0012] Preferably, a guide block is rotatably connected inside the guide housing, and the guide block is adapted to the spline shaft.

[0013] Preferably, a shaft is fixedly connected to the lower surface of the guide shell, and a guide wheel is rotatably connected to one end of the shaft near the guide rail.

[0014] Preferably, a second pulley is fixedly connected to one end of the spline shaft, and a first pulley is fixedly connected to one end of the spool near the second pulley. A transmission belt is fitted on the outer walls of the first pulley and the second pulley together.

[0015] Preferably, the data acquisition box and the transducer are connected by a wire, and a mounting frame is fixedly connected to one end of the telescopic block near the wire, with a limit wheel rotatably connected inside the mounting frame.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. In this invention, the added positioning support mechanism provides multi-point balanced support for the transducer inside the acoustic tube, ensuring the transducer remains stably centered and vertically upright during testing. This effectively prevents problems such as radial swaying, tilting, and eccentric offset of the transducer during testing. It guarantees a consistent and controllable propagation path for each sound wave transmission and reception, avoiding errors in sound wave timing and amplitude acquisition caused by abnormal probe posture, eliminating data dispersion issues, and ensuring the authenticity and stability of the test data.

[0018] 2. In this invention, the configured wire limiting mechanism can limit, guide, and regulate the transmission wire throughout its entire operation, restricting disorderly swaying, slack deviation, and entanglement during the wire's deployment and retraction, thus achieving uniform, orderly, and stable wire deployment and retraction. This solves the chain reaction problem in traditional structures where wire swaying pulls on the transducer, causing secondary deviation and swaying of the transducer. It effectively avoids external disturbances interfering with the probe's detection posture, maintaining the transducer's stable operating state throughout the entire process, and providing a stable hardware foundation for high-precision data acquisition. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of the visual detection device for underground pile foundation defects based on acoustic tomography according to the present invention.

[0020] Figure 2 This is a schematic diagram of the fixing frame structure of the underground pile foundation defect visualization detection device based on acoustic tomography according to the present invention.

[0021] Figure 3 This is a schematic diagram of the structure of the cable reel of the underground pile foundation defect visualization detection device based on acoustic tomography according to the present invention;

[0022] Figure 4 This invention relates to a visual detection device for underground pile foundation defects based on acoustic tomography. Figure 3 A magnified structural diagram at point A;

[0023] Figure 5 This is a schematic diagram of the connecting frame structure of the visual detection device for underground pile foundation defects based on acoustic tomography according to the present invention.

[0024] Figure 6 This is a schematic diagram of the cross-sectional structure of the adjustment ring of the underground pile foundation defect visualization detection device based on acoustic tomography according to the present invention;

[0025] Figure 7 This is a schematic diagram of the fixed ring structure of the underground pile foundation defect visualization detection device based on acoustic tomography according to the present invention.

[0026] In the diagram: 1. Pile foundation column; 2. Fixing frame; 3. Conductor; 4. Sonic logging tube; 5. Data acquisition box; 6. Cable reel; 7. First pulley; 8. Second pulley; 9. Splined shaft; 10. Guide shell; 11. Guide rail; 12. Adjusting ring; 13. Transducer; 14. Shaft; 15. Guide wheel; 16. Guide seat; 17. Transmission belt; 18. Guide block; 19. Telescopic block; 20. Mounting frame; 21. Rotating ring; 22. Gear ring; 23. Circular ring; 24. Rotating groove; 25. Arc groove; 26. Tie rod; 27. Telescopic groove; 28. Connecting frame; 29. ​​Drive motor; 30. Worm gear; 31. Fixing ring; 32. Rotating shaft; 33. Hinge seat; 34. Spring; 35. Limit wheel; 36. Support claw; 37. Roller. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] refer to Figures 1-7 The illustrated visual detection device for underground pile foundation defects based on acoustic tomography includes a pile column 1, a fixing frame 2, a data acquisition box 5, and a transducer 13. A limit component is installed on the fixing frame 2 to improve the stability of the transducer 13. A specific embodiment is shown below:

[0029] Example 1

[0030] Multiple sonic logging tubes 4 are evenly installed around the circumference of the pile column 1. A coil 6 and a spline shaft 9 are rotatably connected inside the fixing frame 2. A wire 3 is wound around the outer wall of the coil 6. The end of the wire 3 away from the coil 6 is fixedly connected to the transducer 13. A guide rail 11 is fixedly connected inside the fixing frame 2. A guide shell 10 is slidably connected to the outer wall of the spline shaft 9. A guide seat 16 is fixedly connected to the upper surface of the guide shell 10. A guide block 18 is rotatably connected inside the guide shell 10 and is adapted to the spline shaft 9. A shaft 14 is fixedly connected to the lower surface of the guide shell 10. A guide wheel 15 is rotatably connected to the end of the shaft 14 near the guide rail 11. A second pulley 8 is fixedly connected to one end of the spline shaft 9. A first pulley 7 is fixedly connected to the end of the coil 6 near the second pulley 8. A transmission belt 17 is sleeved on the outer wall of the first pulley 7 and the second pulley 8. The data acquisition box 5 is connected to the transducer 13 through the wire 3.

[0031] Before the concrete of the pile foundation column 1 is poured, multiple sonic logging tubes 4 are pre-embedded evenly along its circumference. The sonic logging tubes 4 penetrate vertically through the entire length of the pile foundation column 1, serving as the guide channel for the up-and-down movement of the transducer 13 and the channel for the sound wave propagation medium. When the device is working, the rotating motor matched with the coil 6 drives it to rotate, which can rotate in both forward and reverse directions to complete the winding and unwinding of the conductor 3, thereby pulling the transducer 13 to lower and rise inside the sonic logging tube 4. Relying on the synchronous transmission action of the first pulley 7, the transmission belt 17 and the second pulley 8, the rotation of the coil 6 can drive the spline shaft 9 to rotate synchronously, realizing the synchronous linkage of traction action and guidance action. The spline shaft 9 uses the meshing transmission characteristics of the spline groove and the guide block 18 to drive the guide shell 10 to slide synchronously along the axial direction of the spline shaft 9. With the rolling limit structure of the guide rail 11 and the guide wheel 15, the winding and stretching of the conductor 3 is directionally guided and the trajectory is constrained throughout the process, effectively preventing problems such as conductor 3 deviation, entanglement, jamming and wear. Through precise synchronous transmission, the transducer 13 is guaranteed to have a uniform lifting stroke and stable speed, providing a stable displacement foundation for continuous acoustic wave detection of the pile column 1.

[0032] Example 2

[0033] The limiting component includes a connecting frame 28 fixedly connected to the fixed frame 2. An adjusting ring 12 is fixedly connected to the side of the connecting frame 28 away from the fixed frame 2. The adjusting ring 12 has multiple telescopic grooves 27 evenly distributed circumferentially. Telescopic blocks 19 are slidably connected within the telescopic grooves 27. A circular ring 23 is fixedly connected to the end of the adjusting ring 12 away from the pile column 1. A rotating groove 24 is formed on the end face of the circular ring 23. A rotating ring 21 is rotatably connected within the rotating groove 24. Multiple arc-shaped grooves 25 are evenly distributed on the rotating ring 21. A pull rod 26 is fixedly connected to one end of the telescopic block 19 near the rotating ring 21, and the pull rod 26 is slidably connected to the arc groove 25. A toothed ring 22 is fixedly connected to one end of the rotating ring 21 away from the adjusting ring 12. A drive motor 29 is fixedly connected to the connecting frame 28. A worm gear 30 is fixedly connected to the output end of the drive motor 29. The teeth of the worm gear 30 mesh with the teeth of the toothed ring 22. A mounting frame 20 is fixedly connected to one end of the telescopic block 19 near the wire 3. A limit wheel 35 is rotatably connected inside the mounting frame 20.

[0034] During operation, the drive motor 29 outputs torque to rotate the worm gear 30. Through the meshing transmission between the worm gear 30 and the gear ring 22, the rotating ring 21 is driven to rotate circumferentially relative to the circular ring 23. Utilizing the self-locking characteristic of the worm gear 30 structure, the angle of the rotating ring 21 can be locked at any time to prevent the mechanism from loosening in the opposite direction or deflecting on its own. During the rotation of the rotating ring 21, its internal arc groove 25 presses against the pull rod 26, causing multiple sets of telescopic blocks 19 to synchronously converge or expand radially along the telescopic groove 27 of the adjusting ring 12, thereby realizing the synchronous adjustment of the spacing between multiple sets of limiting wheels 35. By having the limiting wheels 35 arranged in a ring-like manner hug and fit against the outer wall of the conductor 3, it can adapt to conductors 3 of different specifications, dynamically correct the offset of the conductor 3 in real time, and continuously lock the center position of the conductor 3 and the bottom transducer 13, so that the transducer 13 always remains coaxial with the acoustic tube 4.

[0035] Example 3

[0036] Two fixing rings 31 are fixedly connected to the outer wall of the transducer 13. Multiple hinge seats 33 are evenly installed on the fixing rings 31 along the circumference. A rotating shaft 32 is rotatably connected to the hinge seat 33. A spring spring 34 is fixedly connected to both ends of the rotating shaft 32. The end of the spring spring 34 away from the rotating shaft 32 is fixedly connected to the hinge seat 33. A support claw 36 is fixedly connected to the outer wall of the rotating shaft 32. A roller 37 is rotatably connected to the end of the support claw 36 away from the hinge seat 33. The roller 37 abuts against the inner wall of the acoustic tube 4.

[0037] Under normal conditions, the spring 34 remains slightly compressed, continuously providing a constant return torque to the shaft 32, driving the support claw 36 to expand outwards. This ensures that the end roller 37 remains tightly fitted against the inner wall of the acoustic logging tube 4. The spring 34 is made of austenitic stainless steel. The spring 34, hinge seat 33, shaft 32, support claw 36, and roller 37 are all made of non-magnetic, non-reflective materials, which do not interfere with radial ultrasonic wave propagation, generate noise or pseudo-waveforms, or affect the signal acquisition and tomographic imaging data of the transceiver module. During the lifting and lowering movement of the transducer 13, the roller 37 moves against the tube wall through rolling friction, reducing movement resistance and preventing jamming and scraping. For common on-site conditions such as slight deformation of the acoustic logging tube 4, diameter deviations, and uneven tube walls, the support claw 36 can adaptively retract inwards with changes in tube diameter, compressing the spring 34 to achieve elastic compensation. The spring force ensures that the roller 37 remains tightly fitted against the tube wall. By coordinating and limiting multiple sets of circumferential support structures, the transducer 13 achieves a stable posture without suspension, tilting, or shaking, ensuring that the transmission and reception directions of the transducer 13 remain constant and avoiding acoustic signal interference and data distortion caused by mechanical shaking.

[0038] The working principle of this invention is as follows: Before testing, the fixing frame 2 is erected on the top of the pile column 1, so that the adjusting ring 12, transducer 13 and sonic logging tube 4 are kept coaxial. The drive motor 29 is started, and the rotating ring 21 is driven to rotate through the meshing transmission of the worm gear 30 and the gear ring 22. The arc groove 25 and the pull rod 26 are used to drive multiple sets of telescopic blocks 19 to move radially synchronously. The limit wheel 35 hugs and clamps the wire 3, and the centering limit adjustment is completed according to the specifications of the wire 3 to lock the movement trajectory of the wire 3. At the same time, the support claw 36 on the outside of the transducer 13 automatically opens under the elastic force of the spring 34, and the roller 37 adaptively fits the inner wall of the sonic logging tube 4 to complete the centering support and anti-deviation positioning of the transducer 13. The equipment transmission system is started, and the wire spool 6 drives the spline shaft 9 to rotate synchronously through the synchronous transmission of the first pulley 7, the transmission belt 17 and the second pulley 8. During the rotation of the spline shaft 9, the drive guide housing 10 slides smoothly along the axial direction of the spline shaft 9. At the same time, the guide wheel 15 at the bottom of the shaft 14 rolls along the guide rail 11 to guide the conductor 3 precisely throughout the process. The reel 6 unwinds the conductor 3 at a uniform speed, and the traction transducer 13 descends vertically at a uniform speed along the sonic logging tube 4 to achieve full-depth scanning of the pile foundation. After the detection is completed, the reel 6 rotates in the opposite direction to wind up the conductor 3, driving the transducer 13 to return to its original position smoothly. During the uniform lifting and lowering process, the transducer 13 continuously emits ultrasonic waves and receives the reflected and transmitted sound wave signals after propagation through the pile foundation concrete medium. The real-time sound wave data is transmitted to the data acquisition box 5 through the conductor 3. The data acquisition box 5 filters, reduces noise, and processes parameters such as the propagation speed, amplitude, frequency, and attenuation of the sound waves.

[0039] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A visual detection device for underground pile foundation defects based on acoustic tomography, comprising a pile column (1), a fixing frame (2), a data acquisition box (5), and a transducer (13), characterized in that: The fixing frame (2) is provided with a limiting component, which is used to improve the stability of the transducer (13); The limiting component includes a connecting frame (28) fixedly connected to the fixed frame (2). An adjusting ring (12) is fixedly connected to the side of the connecting frame (28) away from the fixed frame (2). The adjusting ring (12) has a plurality of expansion grooves (27) evenly distributed around its circumference. An expansion block (19) is slidably connected in the expansion groove (27). A circular ring (23) is fixedly connected to the end of the adjusting ring (12) away from the pile column (1). A rotating groove (24) is opened on the end face of the circular ring (23). A rotating ring (21) is rotatably connected in the rotating groove (24). The rotating ring (21) has a plurality of expansion grooves (27) evenly distributed around its circumference. The transducer (13) has multiple arc-shaped grooves (25) evenly spaced. A pull rod (26) is fixedly connected to one end of the telescopic block (19) near the rotating ring (21), and the pull rod (26) is slidably connected to the arc-shaped groove (25). Two fixing rings (31) are fixedly connected to the outer wall of the transducer (13). Multiple hinge seats (33) are evenly installed on the fixing rings (31) along the circumference. A rotating shaft (32) is rotatably connected to the hinge seat (33). A spring spring (34) is fixedly connected to both ends of the rotating shaft (32). The end of the spring spring (34) away from the rotating shaft (32) is fixedly connected to the hinge seat (33).

2. The visual detection device for underground pile foundation defects based on acoustic tomography as described in claim 1, characterized in that: The pile foundation column (1) is uniformly equipped with multiple sonic logging tubes (4) along the circumference. The outer wall of the rotating shaft (32) is fixedly connected with a support claw (36). The end of the support claw (36) away from the hinge seat (33) is rotatably connected with a roller (37). The roller (37) abuts against the inner wall of the sonic logging tube (4).

3. The visual detection device for underground pile foundation defects based on acoustic tomography as described in claim 1, characterized in that: The fixed frame (2) is rotatably connected to a coil (6) and a spline shaft (9). A wire (3) is wound around the outer wall of the coil (6). The end of the wire (3) away from the coil (6) is fixedly connected to the transducer (13).

4. The visual detection device for underground pile foundation defects based on acoustic tomography as described in claim 1, characterized in that: A toothed ring (22) is fixedly connected to the end of the rotating ring (21) away from the adjusting ring (12), and a drive motor (29) is fixedly connected to the connecting frame (28).

5. The visual detection device for underground pile foundation defects based on acoustic tomography according to claim 4, characterized in that: The output end of the drive motor (29) is fixedly connected to a worm (30), and the teeth of the worm (30) mesh with the teeth of the toothed ring (22).

6. The visual detection device for underground pile foundation defects based on acoustic tomography according to claim 3, characterized in that: The fixed frame (2) is fixedly connected to the guide rail (11), the outer wall of the spline shaft (9) is slidably connected to the guide shell (10), and the upper surface of the guide shell (10) is fixedly connected to the guide seat (16).

7. The visual detection device for underground pile foundation defects based on acoustic tomography according to claim 6, characterized in that: The guide housing (10) is rotatably connected to a guide block (18), and the guide block (18) is adapted to the spline shaft (9).

8. The visual detection device for underground pile foundation defects based on acoustic tomography according to claim 7, characterized in that: A shaft (14) is fixedly connected to the lower surface of the guide shell (10), and a guide wheel (15) is rotatably connected to one end of the shaft (14) near the guide rail (11).

9. The visual detection device for underground pile foundation defects based on acoustic tomography according to claim 3, characterized in that: One end of the spline shaft (9) is fixedly connected to a second pulley (8), and the end of the spool (6) near the second pulley (8) is fixedly connected to a first pulley (7). The outer walls of the first pulley (7) and the second pulley (8) are together fitted with a transmission belt (17).

10. The visual detection device for underground pile foundation defects based on acoustic tomography according to claim 1, characterized in that: The data acquisition box (5) and the transducer (13) are connected by a wire (3). The telescopic block (19) is fixedly connected to a mounting bracket (20) at one end near the wire (3). A limit wheel (35) is rotatably connected inside the mounting bracket (20).

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