A transparent soil rotary pressure sounding test device and deformation measurement method

Abstract

The application provides a transparent soil rotary pressure sounding test device and a deformation measurement method. The device comprises a rotary pressure sounding head, a sounding rod, a loading system, a transparent soil model box and a three-dimensional imaging system. The vertical loading assembly and the rotary drive assembly are used to cooperatively control the penetration speed and the rotation speed of the sounding head, and the axial penetration force, the torque and the penetration depth and other parameters are synchronously collected. In the penetration process, multi-angle imaging is performed on the high-brightness speckle in the laser plane, and the three-dimensional displacement field and the strain field of each part of the soil around the rotary pressure sounding head are obtained by inversion. The method can realize the full-process visualization of the rotary pressure sounding penetration-rotation process, intuitively reveal the starting, expansion and penetration process of the local shear band near the front edge and the side wall of the probe, and reveal the spatial distribution of the disturbance zone, the compaction zone and the relaxation zone, which makes up for the limitation that the existing rotary pressure sounding test only relies on the penetration force-torque curve with depth and is difficult to obtain the internal deformation information of the soil.

Description

Technical Field

[0001] This invention relates to the field of geotechnical and geological engineering technology, and in particular to a transparent soil vortex penetration test device and deformation measurement method. Background Technology

[0002] Spinning penetration testing (SPPT) is a technique that involves continuously rotating a penetration probe into the ground under controlled rotational speed and penetration velocity. A cableless data acquisition system is used to measure parameters such as cone tip resistance, rotational torque, and displacement during continuous penetration, reflecting the changes in the physical and mechanical properties of the soil along the depth direction. In conventional engineering investigations, SPPT is often used for in-situ testing of natural soil and rock masses. By obtaining cone tip resistance, torque curves, and pore pressure curves, it allows for the estimation of soil strength indicators, deformation modulus, and stratification characteristics, making it an important experimental method in geotechnical engineering investigation and design.

[0003] However, the interaction mechanism between the probe and the soil is extremely complex. During gyratory penetration testing, highly non-uniform stress paths and significant strain localization zones often appear at the probe's leading edge and surrounding soil, forming local shear bands and strong deformation zones around the cone and sidewalls. These localized failure phenomena significantly impact the morphology and parameter interpretation of the penetration curve. Existing experimental testing methods primarily rely on sensors on the probe or penetration rod to acquire macroscopic mechanical data. Currently, related research focuses on improving probe geometry to adapt to penetration requirements under different geological conditions. Essentially, gyratory penetration testing is still viewed as a one-dimensional survey line test along the drilling direction, emphasizing the refinement of scalar or curve information varying with depth. This boundary measurement-based approach has the following limitations:

[0004] The measured mechanical curves are integral results of the overall resistance of the soil around the probe, belonging to macroscopic scalar information, and cannot analyze the complex localized deformation characteristics inside the soil. For the unique helical shear failure mechanism of cyclotron penetration testing, traditional soil and rock internal monitoring methods are contact-based discrete monitoring. Not only is the number of measuring points limited, but the embedding of the sensor itself disrupts the original stress field of the soil, making it impossible to capture the continuous, dynamic three-dimensional displacement and strain field evolution around the probe without disturbing the soil structure. This results in a lack of direct physical experimental evidence for defining the spatial distribution of the disturbed, compacted, and relaxed zones in the soil during cyclotron penetration testing, making it difficult to establish a precise quantitative relationship between penetration parameters and the microscopic failure mechanism of the soil.

[0005] Therefore, it is of great significance to develop a transparent soil vortex penetration test device and deformation measurement method. Summary of the Invention

[0006] The purpose of this invention is to provide a transparent soil vortex penetration test device and deformation measurement method to solve the problems existing in the prior art.

[0007] The technical solution adopted to achieve the purpose of this invention is as follows: a transparent soil spun cone penetration test device, comprising: a spun cone penetration probe, a loading system, a penetration rod, a transparent soil model box, and a three-dimensional imaging system.

[0008] The transparent soil model box is used to hold transparent soil samples.

[0009] The spinning probe is positioned above the transparent soil model box. The spinning probe is connected to the lower end of the penetrometer rod. The loading system drives the penetrometer rod, thereby causing the spinning probe to advance vertically and rotate around its own axis.

[0010] The three-dimensional imaging system is positioned on the outside of the transparent soil model box.

[0011] Furthermore, the loading system includes a reaction frame, a rotary drive assembly, a vertical loading assembly, and an industrial control computer.

[0012] The vertical loading assembly is mounted on a reaction frame. The vertical loading assembly includes a second servo motor, a ball screw, a slider, and a force sensor, all arranged within a housing. The second servo motor drives the ball screw to rotate, causing the slider to move vertically. Parallel linear guides are arranged vertically inside the housing to provide rigid guidance for the slider. The force sensor is located between the output end of the vertical loading assembly and the upper surface of the rotary drive assembly, and is used to measure the axial penetration force.

[0013] The rotary drive assembly is located below the vertical loading assembly. The rotary drive assembly includes an L-shaped housing, a first servo motor, a transmission mechanism, a rotary shaft, and a torque sensor. The first servo motor is located in the horizontal section of the L-shaped housing, and the rotary shaft is located in the vertical section. The first servo motor is horizontally positioned and drives the vertically arranged rotary shaft to rotate via the transmission mechanism. The lower end of the rotary shaft has a concave helical structure. The upper end of the probe extends into the L-shaped housing and is threadedly connected to the rotary shaft. The torque sensor is coaxially connected in series with the rotary shaft and is used to detect the torque transmitted to the spinning probe.

[0014] Furthermore, the reaction frame includes a rigid panel with a central circular hole and four connecting rods. The rigid panel and the four connecting rods are connected by bolts. The reaction frame is fixed to the base platform by the four connecting rods and serves as the installation reference and reaction channel for the loading system.

[0015] Furthermore, the three-dimensional imaging system includes a rotatable frustum mounted on the outer periphery of the transparent soil model box, and a laser emitter and two cameras mounted on the rotatable frustum.

[0016] The laser emitter has a narrow slit at its front end for emitting a vertical laser plane passing through its central axis into the transparent soil model box. The two cameras are fixed to a rotatable frustum base via a telescopic bracket, and both cameras are on the same horizontal plane, with their focal points located at the center of the transparent soil model box. The central axis of the laser emitter is perpendicular to the axis of symmetry of the two cameras.

[0017] The rotatable frustum can rotate around the central axis of the transparent soil model box, driving the laser emitter and two cameras to perform circumferential scanning imaging of the transparent soil sample inside the transparent soil model box.

[0018] Furthermore, the rotatable frustum base includes a lower half and an upper half. The lower half is fixed to the base platform and has a frustum base driving assembly inside. The upper half is annular and fits around the outside of the transparent soil model box. The frustum base driving assembly drives the upper half to rotate relative to the lower half.

[0019] Furthermore, the spin-pressing probe includes a helical cone body and a connector. The surface of the helical cone body is machined with a helical tooth structure. The helical cone body is used to generate rotational shear disturbance on the transparent soil during vertical advancement and rotation. The first end of the connector is connected to the tail end of the helical cone body, and the tail end is threadedly connected to the probe rod.

[0020] Furthermore, the connector has a threaded hole along its axis for threaded connection with the probe rod. The connector also has a water outlet along its radial direction, connecting to the outside and the threaded hole. A water-blocking ring is fitted around the connector to seal the water outlet.

[0021] Furthermore, the transparent soil model box is a transparent acrylic cylinder. The transparent soil sample filled inside the transparent soil model box consists of framework particles and pore fluid. The refractive index of the framework particles, pore fluid, and the transparent soil model box material are matched.

[0022] Furthermore, the transparent soil sample contains tracer particles at a mass fraction of 0.01% to 0.1%. These tracer particles are pearlescent mica powder or fluorescent microspheres with a particle size of 10 to 80 μm, used to generate speckle patterns under laser planar irradiation.

[0023] This invention also discloses a method for measuring three-dimensional deformation of transparent soil using a vortex cone penetration test based on the above-mentioned device, comprising the following steps:

[0024] 1) Prepare transparent soil samples incorporating tracer particles in a transparent soil model box.

[0025] 2) Turn on the three-dimensional imaging system, adjust the laser emitter to generate a laser plane that illuminates the central surface inside the transparent soil sample, and adjust the focus of the two cameras.

[0026] 3) Control the loading system to drive the spinning probe to set the vertical forward speed and rotation speed to penetrate the transparent soil sample.

[0027] 4) Control the rotatable truncated cone to drive the laser emitter and two cameras to rotate synchronously around the transparent soil model box, and continuously acquire speckle images in the laser plane during the penetration process.

[0028] 5) Set the vertical displacement of the spin-type probe to not exceed the preset depth resolution within the time it takes for the rotatable frustum to rotate one revolution. The speckle image obtained by scanning this revolution is regarded as the image at the same penetration depth.

[0029] 6) Based on the acquired speckle images and camera calibration parameters, reconstruct the three-dimensional displacement and strain fields inside the transparent soil.

[0030] The technical effects of this invention are beyond doubt:

[0031] A. This invention is the first to organically combine spun cone penetration testing (SCP) technology with three-dimensional visualization of transparent soil. It can realistically reproduce the penetration-rotation process of SCP under laboratory conditions and obtain the penetration force-torque-penetration depth response, providing a reliable physical model platform for the mechanistic interpretation of SCP results. By mapping the penetration force-torque-penetration depth curves one-to-one with the three-dimensional displacement and strain field inside the transparent soil surrounding the probe, the initiation, expansion, and penetration process of local shear zones in the soil, as well as the spatial distribution characteristics of the penetration disturbance zone, compaction zone, and relaxation zone, can be intuitively revealed during the SCP process.

[0032] B. Employing an axial-torque composite servo loading structure, the vertical loading component and the rotary drive component are arranged coaxially, allowing for independent and precise control of the vertical forward speed and rotational speed, thus achieving continuous adjustment of the penetration ratio. This facilitates various loading paths, such as constant penetration ratio and variable penetration ratio, significantly improving the controllability and repeatability of the working conditions.

[0033] C. During a single penetration loading phase, speckle images of transparent soil samples around the probe can be acquired at multiple circumferential angles. Combined with camera calibration parameters and displacement inversion algorithms, the complete three-dimensional displacement and strain fields inside the soil around the spun cone probe can be reconstructed, fundamentally breaking through the limitation of traditional spun cone penetration testing, which can only obtain one-dimensional test scalar or curve information along the drilling direction.

[0034] D. The structure adopts a modular design. The spinning probe, probe rod, loading system and three-dimensional imaging system are all connected through standard interfaces. It is easy to replace spinning probes with different helical leads, diameters or head shapes. The size of the model box, penetration speed, rotation speed and scanning angle range can be adjusted according to research needs. It has good expandability and applicability. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the overall structure of the transparent soil rotary penetration test device.

[0036] Figure 2 A schematic diagram of a laser emitter illuminating a transparent soil model box;

[0037] Figure 3 The images show a cross-sectional view and a top view of the spin-forming contact probe.

[0038] Figure 4 This is a schematic diagram of the internal structure of the rotary drive component;

[0039] Figure 5 This is a schematic diagram of the internal structure of the vertically loaded component;

[0040] Figure 6 This is a front view of a transparent soil rotary penetration test device.

[0041] Figure 7 This is a schematic diagram of the components of the imaging system.

[0042] In the diagram: 1. Spinning probe; 2. Loading system; 3. Probe rod; 4. Transparent soil model box; 5. 3D imaging system; 6. Spiral cone; 7. Water-retaining ring; 8. Water outlet; 9. Connector; 10. Reaction frame; 11. Rotary drive assembly; 12. Vertical loading assembly; 13. Industrial control computer; 14. Rigid panel; 15. Connecting rod; 16. Base platform; 17. First servo motor; 18. Transmission mechanism; 19. Rotary shaft; 20. Torque sensor; 21. Second servo motor; 22. Ball screw; 23. Slider; 24. Displacement sensor; 25. Force sensor; 26. Bearing seat; 27. Rotatable truncated cone; 28. Telescopic bracket; 29. ​​Camera; 30. Laser emitter; 31. Frustum drive assembly. Detailed Implementation

[0043] The present invention will be further described below with reference to embodiments, but it should not be construed that the scope of the present invention is limited to the following embodiments. Various substitutions and modifications made based on ordinary technical knowledge and common practices in the art without departing from the above-described technical concept of the present invention should be included within the scope of protection of the present invention.

[0044] Example 1:

[0045] This embodiment provides a transparent soil spun cone penetration test device, including: a spun cone probe 1, a loading system 2, a cone probe rod 3, a transparent soil model box 4, and a three-dimensional imaging system 5.

[0046] The transparent soil model box 4 is used to hold transparent soil samples.

[0047] The spinning probe 1 is positioned above the transparent soil model box 4. The spinning probe 1 is connected to the lower end of the probe rod 3. The loading system 2 is used to drive the probe rod 3, thereby causing the spinning probe 1 to advance vertically and rotate around its own axis.

[0048] The three-dimensional imaging system 5 is arranged on the outside of the transparent soil model box 4.

[0049] Example 2:

[0050] The main content of this embodiment is the same as that of embodiment 1. The loading system 2 includes a reaction frame 10, a rotation drive assembly 11, a vertical loading assembly 12, and an industrial control computer 13.

[0051] The vertical loading assembly 12 is mounted on the reaction frame 10. The vertical loading assembly 12 includes a second servo motor 21, a ball screw 22, a slider 23, and a force sensor 25, all arranged within the housing. The second servo motor 21 drives the ball screw 22 to rotate, causing the slider 23 to move vertically. Parallel linear guides are arranged vertically inside the housing to provide rigid guidance for the slider 23. The force sensor 25 is located between the output end of the vertical loading assembly 12 and the upper surface of the rotary drive assembly 11, and is used to measure the axial penetration force.

[0052] The rotary drive assembly 11 is located below the vertical loading assembly 12. The rotary drive assembly 11 includes an L-shaped housing, a first servo motor 17, a transmission mechanism 18, a rotary shaft 19, and a torque sensor 20. The first servo motor 17 is located in the horizontal section of the L-shaped housing, and the rotary shaft 19 is located in the vertical section. The first servo motor 17 is horizontally positioned and drives the vertically arranged rotary shaft 19 to rotate via the transmission mechanism 18. The lower end of the rotary shaft 19 has a concave helical structure. The upper end of the probe rod 3 extends into the L-shaped housing and is threadedly connected to the rotary shaft 19. The torque sensor 20 is coaxially connected in series with the rotary shaft 19 and is used to detect the torque transmitted to the spinning probe 1.

[0053] The industrial control computer 13 has a built-in motion control card. Its input end is electrically connected to the displacement sensor 24, force sensor 25, torque sensor 20, and the encoder built into the servo motor. Its output end is electrically connected to the drivers of the first servo motor 17 and the second servo motor 21, respectively. It is used to simultaneously collect data such as axial force, torque, and displacement during the penetration process according to the preset vertical forward speed, rotation speed, and target penetration depth.

[0054] Example 3:

[0055] The main content of this embodiment is the same as that of Embodiment 1 or 2, wherein the reaction frame 10 includes a rigid panel 14 with a central circular hole and four connecting rods 15. The rigid panel 14 and the four connecting rods 15 are connected by bolts. The reaction frame 10 is fixed on the base platform 16 by the four connecting rods 15, and serves as the installation reference and reaction channel for the loading system.

[0056] Example 4:

[0057] The main content of this embodiment is the same as any one of embodiments 1 to 3. The three-dimensional imaging system 5 includes a rotatable frustum 27 disposed on the outer periphery of the transparent soil model box 4, a laser emitter 30 and two cameras 29 mounted on the rotatable frustum 27.

[0058] The laser emitter 30 has a narrow slit emission port at its front end for emitting a vertical laser plane passing through its central axis into the transparent soil model box 4. The two cameras 29 are fixed to a rotatable frustum base 27 via a telescopic bracket 28, and both cameras 29 are on the same horizontal plane, with their focal points located at the center of the transparent soil model box 4. The central axis of the laser emitter 30 is perpendicular to the axis of symmetry of the two cameras 29.

[0059] The rotatable frustum 27 can rotate around the central axis of the transparent soil model box 4, driving the laser emitter 30 and two cameras 29 to perform circumferential scanning imaging of the transparent soil sample inside the transparent soil model box 4.

[0060] Example 5:

[0061] The main content of this embodiment is the same as any one of embodiments 1 to 4, wherein the rotatable frustum base 27 includes a lower half and an upper half. The lower half is fixed on the base platform 16 and has a frustum base driving assembly 31 inside. The upper half is annular and fits around the outside of the transparent soil model box 4. The frustum base driving assembly 31 drives the upper half to rotate relative to the lower half.

[0062] Example 6:

[0063] This embodiment is similar in main content to any one of embodiments 1 to 5, wherein the spinning probe 1 includes a spiral cone head 6 and a connector 9. The surface of the spiral cone head 6 is machined with a spiral tooth structure. The spiral cone head 6 is used to generate rotational shear disturbance on the transparent soil during vertical advancement and rotation. The first end of the connector 9 is connected to the tail end of the spiral cone head 6, and the tail end is threadedly connected to the probe rod 3.

[0064] Example 7:

[0065] This embodiment is similar in main content to any one of embodiments 1 to 6, wherein the connector 9 has a threaded hole along its axis for threaded connection with the probe rod 3. The connector 9 has a water outlet 8 in the radial direction that connects to the outside and the threaded hole. A water-blocking ring 7 is fitted around the connector 9. The water-blocking ring 7 blocks the water outlet 8.

[0066] Example 8:

[0067] The main content of this embodiment is the same as any one of embodiments 1 to 7, wherein the transparent soil model box 4 is a transparent acrylic cylindrical structure. The transparent soil sample filled inside the transparent soil model box 4 is composed of skeleton particles and pore fluid. The refractive index of the skeleton particles, pore fluid and the transparent soil model box 4 are matched, which can minimize the distortion of light refraction.

[0068] Example 9:

[0069] The main content of this embodiment is the same as any one of embodiments 1 to 8, wherein the transparent soil sample contains tracer particles with a mass fraction of 0.01% to 0.1%. The tracer particles are pearlescent mica powder or fluorescent microspheres with a particle size of 10 to 80 μm, used to generate speckle patterns under laser planar irradiation.

[0070] Example 10:

[0071] This embodiment provides a method for measuring three-dimensional deformation of transparent soil using a penetrometer based on the device described in any one of embodiments 1 to 9, including the following steps:

[0072] 1) After preparing transparent soil in transparent soil model box 4, evenly sprinkle tracer particles and stir to make the air bubbles disappear, then put it into a vacuum box for vacuum consolidation.

[0073] 2) After consolidation, turn on the laser emitter 30 and adjust the power so that a vertical laser plane appears in the transparent soil and the bright speckle can be clearly seen. Then turn on the two cameras 29 and focus on the bright speckle area.

[0074] 3) Set and match the vertical forward speed v of loading system 2. z The angular velocity ω of the rotatable frustum 27 causes the vertical displacement of the spin-forming probe 1 to be such that the spin-forming probe 1 changes direction during the time it takes for the rotatable frustum 27 to rotate one revolution. No more than the preset depth resolution δ z Thus, the speckle image obtained by the circle scan can be approximated as displacement and strain information at the same penetration depth, realizing a one-to-one correspondence between the three-dimensional displacement field, strain field and penetration depth.

[0075] 4) Depth resolution δ z Take 1 / 10 to 1 / 50 of the probe diameter, preferably 1 / 20;

[0076] 5) During the loading process, two cameras continuously took 29 pictures of each bright speckle area to obtain the displacement information of the bright speckles in each part of the transparent soil throughout the entire process.

[0077] The three-dimensional deformation measurement includes stereo calibration of two cameras to establish the correspondence between the camera imaging plane and the real coordinate system of the transparent soil model box; using speckle images acquired in the laser plane before and after penetration, the pixel displacement of tracer particles or speckles in the transparent soil sample is tracked, and the three-dimensional displacement vector and strain distribution of the transparent soil sample in the real coordinate system are calculated according to the correspondence.

Claims

1. A transparent soil rotary cone penetration test apparatus, characterized in that, include: The spinning contact probe (1), loading system (2), probe rod (3), transparent soil model box (4) and three-dimensional imaging system (5); The transparent soil model box (4) is used to hold transparent soil samples; The spinning probe (1) is arranged above the transparent soil model box (4); the spinning probe (1) is connected to the lower end of the probe rod (3); the loading system (2) is used to drive the probe rod (3), thereby driving the spinning probe (1) to feed in the vertical direction and rotate around its own axis; The three-dimensional imaging system (5) is arranged on the outside of the transparent soil model box (4).

2. The transparent soil vortex penetration test apparatus according to claim 1, characterized in that: The loading system (2) includes a reaction frame (10), a rotary drive assembly (11), a vertical loading assembly (12), and an industrial control computer (13). The vertical loading assembly (12) is mounted on the reaction frame (10); the vertical loading assembly (12) includes a second servo motor (21), a ball screw (22), a slider (23), and a force sensor (25) arranged inside the housing; the second servo motor (21) drives the ball screw (22) to rotate, thereby causing the slider (23) to move in the vertical direction; parallel linear guides are arranged inside the housing in the vertical direction to provide rigid guidance for the slider (23); the force sensor (25) is located between the output end of the vertical loading assembly (12) and the upper end face of the rotary drive assembly (11) to measure the axial penetration force; The rotary drive assembly (11) is located below the vertical loading assembly (12); the rotary drive assembly (11) includes an L-shaped housing, a first servo motor (17), a transmission mechanism (18), a rotary shaft (19), and a torque sensor (20); the first servo motor (17) is located in the horizontal section of the L-shaped housing, and the rotary shaft (19) is located in the vertical section; the first servo motor (17) is horizontally positioned and drives the vertically arranged rotary shaft (19) to rotate through the transmission mechanism (18); the lower end of the rotary shaft (19) is provided with a concave spiral structure; the upper end of the probe rod (3) extends into the L-shaped housing and is threadedly connected to the rotary shaft (19); the torque sensor (20) is coaxially connected in series with the rotary shaft (19) and is used to detect the torque transmitted to the spinning probe (1); The industrial control computer (13) has a built-in motion control card. Its input end is electrically connected to the displacement sensor (24), force sensor (25), torque sensor (20), and the encoder built into the servo motor. Its output end is electrically connected to the drivers of the first servo motor (17) and the second servo motor (21), respectively. It is used to simultaneously collect data such as axial force, torque, and displacement during the penetration process according to the preset vertical forward speed, rotation speed, and target penetration depth.

3. The transparent soil vortex penetration test apparatus according to claim 2, characterized in that: The reaction frame (10) includes a rigid panel (14) with a central circular hole and four connecting rods (15); the rigid panel (14) and the four connecting rods (15) are connected by bolts; the reaction frame (10) is fixed on the base platform (16) by the four connecting rods (15) and is the installation reference and reaction channel of the loading system.

4. The transparent soil vortex penetration test apparatus according to claim 1, characterized in that: The three-dimensional imaging system (5) includes a rotatable frustum (27) set on the outer periphery of the transparent soil model box (4), a laser emitter (30) and two cameras (29) mounted on the rotatable frustum (27). The laser emitter (30) has a narrow slit emission port at its front end for emitting a vertical laser plane passing through its central axis into the transparent soil model box (4); the two cameras (29) are fixed on a rotatable frustum base (27) by a telescopic bracket (28), and the two cameras (29) are on the same horizontal plane, with their focal points located at the center of the transparent soil model box (4); the central axis of the laser emitter (30) is perpendicular to the axis of symmetry of the two cameras (29); The rotatable frustum (27) can rotate around the central axis of the transparent soil model box (4), driving the laser emitter (30) and two cameras (29) to perform circumferential scanning imaging of the transparent soil sample inside the transparent soil model box (4).

5. The transparent soil vortex penetration test apparatus according to claim 4, characterized in that: The rotatable frustum base (27) includes a lower half and an upper half; the lower half is fixed on the base platform (16) and has a frustum base driving assembly (31) inside; the upper half is annular and is fitted on the outside of the transparent soil model box (4); the frustum base driving assembly (31) drives the upper half to rotate relative to the lower half.

6. The transparent soil vortex penetration test apparatus according to claim 1, characterized in that: The spin-pressing probe (1) includes a spiral cone head (6) and a connector (9); the surface of the spiral cone head (6) is machined with a spiral tooth structure; the spiral cone head (6) is used to generate rotational shear disturbance to the transparent soil during vertical advance and rotation; the head end of the connector (9) is connected to the tail end of the spiral cone head (6), and the tail end is threadedly connected to the probe rod (3).

7. The transparent soil vortex penetration test apparatus according to claim 6, characterized in that: The connector (9) has a threaded hole along its axis for threaded connection with the probe rod (3); the connector (9) has a water outlet (8) in the radial direction that connects to the outside and the threaded hole; a water-blocking ring (7) is fitted around the connector (9); the water-blocking ring (7) blocks the water outlet (8).

8. The transparent soil vortex penetration test apparatus according to claim 1, characterized in that: The transparent soil model box (4) is a transparent acrylic cylinder; the transparent soil sample filled in the transparent soil model box (4) is composed of skeleton particles and pore liquid; the refractive index of the skeleton particles, pore liquid and the transparent soil model box (4) are matched.

9. The transparent soil vortex penetration test apparatus according to claim 8, characterized in that: The transparent soil sample contains tracer particles with a mass fraction of 0.01% to 0.1%; the tracer particles are pearlescent mica powder or fluorescent microspheres with a particle size of 10 to 80 μm, used to generate speckle patterns under laser planar irradiation.

10. A method for measuring three-dimensional deformation of transparent soil using a rotary cone penetration test based on the device described in any one of claims 1 to 9, characterized in that, Includes the following steps: S1) Prepare a transparent soil sample incorporating tracer particles in a transparent soil model box (4); S2) Turn on the three-dimensional imaging system (5), adjust the laser emitter (30) to generate a laser plane that illuminates the central plane inside the transparent soil sample, and adjust the two cameras (29) to focus; S3) Control the loading system (2) to drive the spinning probe (1) to penetrate the transparent soil sample at the set vertical forward speed and rotation speed; S4) Control the rotatable frustum (27) to drive the laser emitter (30) and two cameras (29) to rotate synchronously around the transparent soil model box (4) and continuously collect speckle images in the laser plane during the penetration process; S5) Set the vertical displacement of the spin-press probe (1) to not exceed the preset depth resolution within the time it takes for the rotatable frustum base (27) to rotate one revolution. The speckle image obtained by scanning this revolution is regarded as the image at the same penetration depth. S6) Based on the acquired speckle images and camera calibration parameters, reconstruct the three-dimensional displacement and strain fields inside the transparent soil.

Images