Dynamic soil triaxial experiment equipment

Abstract

The invention relates to the technical field of nuclear magnetic detection of soil samples, and discloses dynamic soil triaxial experimental equipment which comprises a base frame, a pressure chamber structure, a reciprocating pressurization structure and a nuclear magnetic tester, the pressure chamber structure is installed on the base frame, and a pressure chamber used for containing a to-be-detected soil sample is formed in the pressure chamber structure; the reciprocating pressurizing structure is mounted on the base frame, and the output end of the reciprocating pressurizing structure is inserted into the pressure chamber and is suitable for pulling and pressing a to-be-detected soil sample in a reciprocating manner; the pressure chamber structure is sleeved with the nuclear magnetic tester, and the detection end of the nuclear magnetic tester right faces the pressure chamber. The pressurizing mechanism in the structure adopts a hydraulic low-frequency controllable oil cylinder action mode, repeatedly pulls and presses a to-be-detected soil sample, intermittently applies axial pressure to the to-be-detected soil sample, detects the physical property change condition of the to-be-detected soil sample online in real time, and provides more-dimensional real-time online contrast experiment data for researching the soil sample.

Description

Technical Field

[0001] The present invention relates to the technical field of soil sample nuclear magnetic detection, in particular to a dynamic earth triaxial test device. Background Art

[0002] Nuclear magnetic resonance technology is an analytical testing technology widely used in materials science, chemistry, biomedicine and other fields. Its basic principle is to use an external magnetic field to make the hydrogen nuclei (protons) in the sample undergo energy level transitions, and then use radio frequency pulses to excite the hydrogen nuclei to generate magnetic resonance signals. The signals are received and processed by a computer to obtain the structure and composition information of the sample.

[0003] Dynamic triaxial testing is an important test method in geotechnical engineering used to study the mechanical properties of soils under dynamic loading. It is particularly widely used in analyzing soil dynamic response (such as its behavior under earthquake and traffic loads) and assessing its liquefaction potential. However, conventional dynamic triaxial testing cannot accurately assess the dynamic response and liquefaction potential of soils under dynamic axial loading. Summary of the Invention

[0004] In view of this, the present invention provides a dynamic triaxial test device to solve the problem that traditional dynamic triaxial tests in related technologies cannot realize the dynamic response and liquefaction potential evaluation of soil under dynamic axial load conditions.

[0005] In a first aspect, the present invention provides a triaxial earthmoving test apparatus, comprising:

[0006] scaffolding;

[0007] A pressure chamber structure, the pressure chamber structure being mounted on the base frame, and having a pressure chamber formed therein for accommodating a soil sample to be tested;

[0008] a reciprocating pressurizing structure, the reciprocating pressurizing structure being mounted on the base frame, the output end of the reciprocating pressurizing structure being inserted into the pressure chamber, the output end of the reciprocating pressurizing structure being adapted to reciprocately pull and press the soil sample to be tested;

[0009] A nuclear magnetic tester is arranged outside the pressure chamber structure, and the detection end of the nuclear magnetic tester faces the pressure chamber.

[0010] Beneficial effects: When dynamic soil triaxial testing is required, the soil sample to be tested is first placed in the pressure chamber structure. The pressurizing mechanism adopts a hydraulic low-frequency controllable oil cylinder action mode to repeatedly pull and press the soil sample to be tested, and intermittently applies axial pressure to the soil sample to be tested. At the same time, the detection structure built into the reciprocating pressurizing structure will use the measurement value detected by the sensor as feedback to achieve fully automatic servo control through a closed-loop control system, thereby realizing a stress path or strain path control experiment. In the above process, it is also necessary to start the nuclear magnetic tester at the same time. The nuclear magnetic tester performs real-time detection of the soil sample to be tested in the pressure chamber structure, and performs real-time non-destructive online detection of the changes in the physical properties of the soil sample to be tested, such as deformation, porosity, permeability, and saturation under dynamic loads and different temperature and pressure states, providing more dimensional real-time online comparative experimental data for soil sample research.

[0011] In an optional embodiment, the pressure chamber structure includes: a sample tube, a first base and a second base; a cavity is opened in the sample tube along the axial direction;

[0012] The first base and the second base are symmetrically arranged at two ends of the sample tube. The first base, the second base and the sample tube enclose the cavity to form a pressure chamber.

[0013] Beneficial Effects: The first base, second base, and pressure chamber are integrated into one unit, providing a more sealed pressure chamber, facilitating real-time online testing and minimizing the impact of pressure components on nuclear magnetic resonance (NMR) testing. Furthermore, the diameter of the pressure chamber is reduced, allowing it to be placed inside a nuclear magnetic resonance (NMR) instrument, meeting both NMR and triaxial testing requirements.

[0014] In an optional embodiment, the reciprocating pressurizing structure includes:

[0015] a reciprocating pressurizing member, the reciprocating pressurizing member being fixed to a base frame at the bottom end of the pressure chamber structure, with a pressurizing end of the reciprocating pressurizing member being adapted to face the pressure chamber;

[0016] a first piston push rod, one end of which is mounted on the pressurizing end of the reciprocating pressurizing member, the other end of which passes through the first base and extends into the pressure chamber, and a first sample plug is mounted on the end of the first piston push rod away from the reciprocating pressurizing member;

[0017] a pressure sensor, wherein the pressure sensor is mounted on the second base;

[0018] a second piston push rod, the second piston push rod being passed through the second base, one end of the second piston push rod being fixed to the pressure sensor, and the other end of the second piston push rod being located in the pressure chamber; a second sample plug being installed at one end of the second piston and the first piston push rod away from the pressure sensor;

[0019] a pressure sensor fixing rod, one end of which is connected to the pressure sensor and the other end of which is fixed to the upper end of the base frame;

[0020] The soil sample to be tested is suitable for being placed between the first sample plug and the second sample plug; the reciprocating pressure member is suitable for driving the first piston push rod to move back and forth in a direction close to or away from the second sample plug to repeatedly pull and press the sample.

[0021] In an optional embodiment, the pressure chamber structure further comprises: a frame, the frame being configured as a cylinder, the frame being sleeved on the sample cylinder, and the two ends of the frame being respectively abutted against the first base and the second base;

[0022] The inner diameter of the skeleton is larger than the outer diameter of the sample tube, so that an annular gap is formed between the skeleton and the sample tube; and the nuclear magnetic tester and the skeleton are mutually engaged.

[0023] In an optional embodiment, the reciprocating pressurizing structure further includes a displacement sensor, and the displacement sensor is connected to the first piston push rod.

[0024] In an optional embodiment, a confining pressure liquid inlet is provided on the first base, and a confining pressure liquid outlet is provided on the second base, and both the confining pressure liquid inlet and the confining pressure liquid outlet are communicated with the pressure chamber.

[0025] In an optional embodiment, a first back-pressure channel is formed through the first piston push rod and the first sample plug;

[0026] A second back-pressure channel is provided through the second sample plug, the outlet of the second back-pressure channel is arranged relative to the soil sample to be tested, and the inlet of the second back-pressure channel is provided on the side of the second sample plug;

[0027] A third back-pressure channel is provided on the first base, and an outlet of the third back-pressure channel is connected to an inlet of the second back-pressure channel via a delivery pipe.

[0028] In an optional embodiment, the pressure chamber, the first sample plug and the second sample plug are made of ceramic.

[0029] In an optional embodiment, the base frame includes:

[0030] Mobile unit;

[0031] A lower pressing plate, the lower pressing plate being mounted on the moving unit, and the reciprocating pressing member being mounted on the lower pressing plate;

[0032] A reaction frame pull rod, the reaction frame pull rod is vertically fixed to the lower pressure plate, and the outer surface of the nuclear magnetic tester is suitable for being fixed on the reaction frame pull rod;

[0033] An upper pressing plate is fixed on the top end of the reaction frame pull rod, and the top end of the pressure sensor fixing rod is suitable for being installed on the upper pressing plate.

[0034] In an optional embodiment, the nuclear magnetic tester includes a nuclear magnetic tester frame and a nuclear magnetic tester body, the nuclear magnetic tester frame is installed on the reaction frame pull rod, and the nuclear magnetic tester frame is sleeved outside the pressure chamber structure; the detection end of the nuclear magnetic tester body faces the pressure chamber. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0036] Figure 1 This is a schematic diagram of the overall structure of a groundbreaking triaxial test device according to an embodiment of the present invention;

[0037] Figure 2 This is a front view of a triaxial test apparatus for breaking ground according to an embodiment of the present invention;

[0038] Figure 3 An internal cross-sectional view of a pressure chamber structure and a reciprocating pressurizing structure according to an embodiment of the present invention;

[0039] Figure 4 This is a structural schematic diagram of a pressure chamber structure and a reciprocating pressurizing structure placed in a nuclear magnetic resonance tester body according to an embodiment of the present invention;

[0040] Figure 5 This is a side view of the pressure chamber structure and the reciprocating pressurizing structure of the embodiment of the present invention placed in the nuclear magnetic tester body;

[0041] Description of reference numerals:

[0042] 1. Base frame; 11. Mobile unit; 12. Lower pressure plate; 13. Reaction frame pull rod; 14. Upper pressure plate;

[0043] 2. Pressure chamber structure; 21. Sample tube; 22. First base; 221. Confining pressure liquid inlet; 222. Third back pressure channel; 23. Second base; 231. Confining pressure liquid outlet; 24. Frame; 25. Pressure chamber;

[0044] 3. Reciprocating pressurizing structure; 31. Reciprocating pressurizing member; 32. Pressure sensor; 33. Displacement sensor; 34. First piston push rod; 35. First sample plug; 36. Second piston push rod; 37. Second sample plug; 38. First back-pressure channel; 39. Second back-pressure channel;

[0045] 4. Nuclear magnetic resonance tester; 41. Nuclear magnetic resonance tester frame; 42. Nuclear magnetic resonance tester body. DETAILED DESCRIPTION

[0046] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0047] Nuclear magnetic resonance technology is an analytical testing technology widely used in materials science, chemistry, biomedicine and other fields. Its basic principle is to use an external magnetic field to make the hydrogen nuclei (protons) in the sample undergo energy level transitions, and then use radio frequency pulses to excite the hydrogen nuclei to generate magnetic resonance signals. The signals are received and processed by a computer to obtain the structure and composition information of the sample.

[0048] Dynamic triaxial testing is an important test method in geotechnical engineering used to study the mechanical properties of soils under dynamic loading. It is particularly widely used in analyzing the dynamic response of soils and assessing their liquefaction potential. However, traditional dynamic triaxial testing cannot currently assess the dynamic response and liquefaction potential of soils under dynamic axial loading.

[0049] In order to solve the above technical problems, the following Figures 1 to 5 , describing embodiments of the present invention.

[0050] According to an embodiment of the present invention, on the one hand, a groundbreaking triaxial test device is provided, which specifically includes: a base frame 1, a pressure chamber structure 2, a reciprocating pressurizing structure 3 and a nuclear magnetic tester 4.

[0051] like Figure 1 and Figure 2 As shown, the pressure chamber structure 2 is installed on the base frame 1, and a pressure chamber 25 for accommodating the soil sample to be tested is formed in the pressure chamber structure 2; the reciprocating pressurizing structure 3 is installed on the base frame 1, and the output end of the reciprocating pressurizing structure 3 is inserted into the pressure chamber 25, and the output end of the reciprocating pressurizing structure 3 is suitable for reciprocating pulling and pressing the soil sample to be tested; the nuclear magnetic tester 4, the nuclear magnetic tester 4 is arranged outside the pressure chamber structure 2, and the detection end of the nuclear magnetic tester 4 is facing the pressure chamber 25.

[0052] When dynamic soil triaxial testing is required, the soil sample to be tested is first placed in the pressure chamber structure 2. The pressurizing mechanism adopts a hydraulic low-frequency controllable oil cylinder action mode to repeatedly pull and press the soil sample to be tested, and intermittently applies axial pressure to the soil sample to be tested. At the same time, the detection structure built into the reciprocating pressurizing structure 3 will use the measurement value detected by the sensor as feedback to achieve fully automatic servo control through a closed-loop control system, thereby realizing a stress path or strain path control experiment. In the above process, it is also necessary to start the nuclear magnetic tester 4 at the same time. The nuclear magnetic tester 4 performs real-time detection of the soil sample to be tested in the pressure chamber structure 2, and performs real-time non-destructive online detection of the changes in the physical properties of the soil sample to be tested, such as deformation, porosity, permeability, and saturation under dynamic loads and different temperature and pressure conditions, providing more dimensional real-time online comparative experimental data for soil sample research.

[0053] In this embodiment, if Figure 3 As shown, the pressure chamber structure 2 includes: a sample tube 21, a first base 22, a second base 23, and a skeleton 24; the skeleton 24 is cylindrical, and the outer surface of the skeleton 24 is provided with protrusions in the radial direction. The inner wall of the nuclear magnetic analyzer 4 is provided with grooves that match the protrusions. The nuclear magnetic analyzer 4 and the skeleton 24 are mutually engaged, and the nuclear magnetic analyzer 4 can be fixed to the skeleton 24 using bolts or screws. The sample tube 21 is installed in the skeleton 24, and the skeleton 24 is sleeved outside the sample tube 21. A cavity is provided in the sample tube 21 along the axial direction, and the cavity is open to the top and bottom. The first base 22 is installed at the bottom end of the sample tube 21, and the second base 23 is installed at the top end of the sample tube 21. The end of the second base 23 away from the first base 22 is also covered with a base cover, and a cavity is also formed between the base cover and the second base 23. The central axis of the first base 22, the central axis of the second base 23 and the central axis of the sample tube 21 coincide with each other, and the first base 22, the second base 23 and the sample tube 21 enclose a pressure chamber 25. The two ends of the skeleton 24 are respectively abutted on the first base 22 and the second base 23. The inner diameter of the skeleton 24 is larger than the outer diameter of the sample tube 21, so that an annular gap is formed between the skeleton 24 and the sample. The annular gap ensures that the influence of the external temperature on the pressure chamber 25 is reduced, the sample temperature is isolated, and the data stability is improved. As needed, the annular gap can be filled with insulating material or vacuumed. The test end of the nuclear magnetic tester 4 is facing the pressure chamber 25 to obtain the best test results. The sample tube 21 is made of ceramic material to improve test performance and reduce data errors.

[0054] Through the above arrangement, the first base 22, the second base 23, and the pressure chamber 25 are integrated into one body. The pressure chamber 25 is more tightly sealed, facilitating real-time online testing and minimizing the impact of the pressure element on NMR testing. Furthermore, the diameter of the pressure chamber structure 2 is reduced, allowing it to be placed inside the NMR tester 4, thus meeting the requirements for both NMR testing and triaxial testing.

[0055] like Figures 1 to 3 As shown, the reciprocating pressurizing structure 3 includes a reciprocating pressurizing element 31, a pressure sensor 32, a displacement sensor 33, a first piston push rod 34, a first sample plug 35, a second piston push rod 36, a second sample plug 37, and a pressure sensor fixing rod. The reciprocating pressurizing element 31 is a small, low-frequency hydraulic cylinder made of titanium alloy or demagnetized metal. The cylinder can provide a load range of 0 to 10 kN at a frequency of 10 Hz, meeting the requirements of both nuclear magnetic resonance (NMR) testing and dynamic triaxial testing. A peripheral hydraulic pump system is also designed to control the movement and pressure of the reciprocating pressurizing element 31. A reciprocating pressure member 31 is fixed to the base frame 1, with its pressurizing end facing the pressure chamber 25. A first piston push rod 34 has one end fixed to the pressurizing end of the reciprocating pressure member 31 and its other end extending through the first base 22 and into the pressure chamber 25. A first sample plug 35 is attached to the end of the first piston push rod 34 facing away from the reciprocating pressure member 31. A pressure sensor 32 is mounted in the cavity between the base cover and the second base 23. The pressure sensor 32 is also made of aluminum alloy. A second piston push rod 36 is inserted through the second base 23. One end of the second piston push rod 36 is connected to the lower surface of the pressure sensor 32, and the other end extends downward into the pressure chamber 25. A second sample plug 37 is attached to the end of the first piston push rod 34 facing away from the pressure sensor 32. A pressure sensor fixing rod is attached to the upper end of the pressure sensor 32. One end of the pressure sensor fixing rod extends through the base cover and connects to the upper surface of the pressure sensor 32, while the other end is fixed to the top of the base frame 1. A displacement sensor 33 is mounted on the first piston rod 34 and is used to detect the travel distance of the first piston rod 34. The first and second sample plugs 35, 37 are made of ceramic, a non-metallic material that does not contain hydrogen atoms. These plugs lack a nuclear magnetic resonance (NMR) background signal to avoid interference with the NMR test results of unsaturated soil samples. The ceramic has a temperature resistance of -40°C to 100°C and a pressure resistance of 5 MPa, improving test performance and reducing data errors. The pressure sensor in this embodiment can accurately and in real time reflect the actual force applied to the sample, with an axial force accuracy of less than 0.1% FS and a range accuracy of less than 0.4 N.

[0056] like Figure 1 and Figure 2As shown, the base frame 1 includes: a mobile unit 11, a lower pressure plate 12, a reaction frame rod 13 and an upper pressure plate 14. The mobile unit 11 is a mobile trolley, and a lower pressure plate 12 is horizontally fixed to the mobile unit 11. The lower pressure plate 12 is fixed to the side of the mobile unit 11. There is a certain distance between the lower pressure plate 12 and the bottom surface of the mobile unit 11 to facilitate the installation of the reaction frame rod 13. The end of the lower pressure plate 12 away from the side of the mobile unit 11 is fixed to the bottom surface of the mobile unit 11 by two brackets. There are four reaction frame pull rods 13, the lower ends of the four reaction frame pull rods 13 are fixed on the lower pressure plate 12, and the four reaction frame pull rods 13 are placed vertically. From a top-down perspective, the four reaction frame pull rods 13 are placed in a rectangular shape. The four reaction frame pull rods 13 have the same length, so that after installation, the top ends of the four reaction frame pull rods 13 are on the same horizontal plane. The upper pressure plate 14 is fixed to the upper ends of the four reaction frame pull rods 13, and the four reaction frame pull rods 13 are respectively fixed at the four corners of the upper pressure plate 14, and the upper pressure plate 14 is installed horizontally. The reaction frame pull rods 13 are made of titanium alloy to enhance the axial pressure stability provided by the reciprocating pressure structure 3 and avoid pressure errors. Four mounting brackets are fixed on the reaction frame pull rods 13, with two mounting brackets on each side, respectively fixing the four horizontal sides of the nuclear magnetic tester 4. The reciprocating pressure member 31 is fixed on the upper surface of the lower pressure plate 12 near the pressure chamber structure 2. The upper end of the pressure sensor fixing rod is fixed to the lower surface of the upper pressing plate 14 .

[0057] like Figure 4 and Figure 5 As shown, the nuclear magnetic tester 4 includes a nuclear magnetic tester frame 41 and a nuclear magnetic tester body 42. The nuclear magnetic tester frame 41 is in the shape of a rectangular parallelepiped, with four sides respectively fixed to four reaction frame tie rods 13. The nuclear magnetic tester frame 41 is installed in the installation space formed between the four reaction frame tie rods 13. The nuclear magnetic tester frame 41 is sleeved outside the pressure chamber structure 2. The nuclear magnetic tester frame 41 and the pressure chamber structure 2 are placed at the test end of the nuclear magnetic tester body 42, and the test end of the nuclear magnetic tester body 42 directly faces the pressure chamber 25.

[0058] In one embodiment, Figure 3 As shown, a confining pressure liquid inlet 221 is provided on the first base 22, and a confining pressure liquid outlet 231 is provided on the second base 23. One end of the confining pressure liquid inlet 221 communicates with the outside world and is connected to the confining pressure liquid input device, and the other end of the confining pressure liquid inlet 221 communicates with the pressure chamber 25. One end of the confining pressure liquid outlet 231 communicates with the outside world, and the other end of the confining pressure liquid outlet 231 communicates with the pressure chamber 25.

[0059] In one embodiment, Figure 3As shown, a first back-pressure channel 38 is provided through the first piston rod 34 and the first sample plug 35; the inlet of the first back-pressure channel 38 is provided on the lower side of the first piston rod 34, and the outlet of the first back-pressure channel 38 is provided on the top of the first sample plug 35. The middle first back-pressure channel 38 passes through the first piston rod 34 and the first sample plug 35. A second back-pressure channel 39 is provided through the second sample plug 37. The outlet of the second back-pressure channel 39 is arranged relative to the soil sample to be tested, and the inlet of the second back-pressure channel 39 is provided on the side of the second sample plug 37. A third back-pressure channel 222 is provided on the first base 22. The inlet of the third back-pressure channel 222 is provided on the side of the first piston rod 34. The outlet of the third back-pressure channel 222 is connected to the inlet of the second back-pressure channel 39 through a delivery pipe.

[0060] When a triaxial soil test is required, the soil sample to be tested is first placed in the pressure chamber 25, specifically between the first sample plug 35 and the second sample plug 37. The reciprocating pressure member 31 uses a small-sized low-frequency hydraulic cylinder to repeatedly push and pull the first piston push rod 34 in the direction close to or away from the second piston push rod 36, driving the first sample plug 35 to move upward to axially pressurize the soil sample to be tested, or to move downward to reduce the pressure applied to the soil sample to be tested. The force applied to the soil sample to be tested during this process will be transmitted to the pressure sensor 32 through the soil sample to be tested, the second sample plug 37 and the second piston push rod 36. The pressure sensor 32 measures the axial stress, and the displacement sensor 33 measures the repeated displacement distance of the first piston push rod 34 during the above process. The measured values ​​of the pressure sensor 32 and the displacement sensor 33 are used as feedback to realize fully automatic servo control through a closed-loop control system, thereby realizing a stress path or strain path control experiment.

[0061] During the repeated pressurization and decompression of the soil sample to be tested, the external confining pressure liquid input device is activated to inject confining pressure liquid. The confining pressure liquid enters the pressure chamber 25 through the confining pressure liquid inlet 221 and fills the pressure chamber 25, applying a compressive force around the soil sample to be tested, simulating the compressive effect of the surrounding soil on the test soil. The liquid is then discharged from the upper confining pressure liquid outlet 231, achieving confining pressure liquid circulation and ensuring the stability of the pressure applied to the soil sample to be tested. In addition, confining pressure liquid of a suitable temperature can be introduced to ensure the temperature stability of the soil sample to be tested. At the same time, the external water pump is activated to inject water from the bottom of the first back-pressure channel 38 and discharge it from the outlet above the first back-pressure channel 38; and water is injected from the inlet of the third back-pressure channel 222, discharged through the outlet of the third back-pressure channel 222, passed through the delivery pipe between the third back-pressure channel 222 and the second back-pressure channel 39, entered from the inlet of the second back-pressure channel 39, and discharged from the outlet at the lower end of the second back-pressure channel 39, respectively applying pore water pressure below and above the soil sample to be tested.

[0062] During the process of applying axial stress, radial stress and pore water pressure, the nuclear magnetic tester 4 is started to perform real-time detection on the soil sample to be tested in the pressure chamber 25, and the deformation, porosity, permeability, saturation and other physical property changes of the soil sample under different temperature and pressure conditions are detected online in real time and non-destructively, and the nuclear magnetic T spectrum is quantitatively obtained to characterize the changes in water migration, providing more dimensional real-time online comparative experimental data for soil sample research.

[0063] Through the above steps, the stress-strain relationship of soil under axial cyclic load is simulated, and the dynamic strength, dynamic modulus, damping ratio and liquefaction characteristics of the soil are measured.

[0064] In one embodiment, at the connection points of the various components of the soil triaxial nuclear magnetic resonance measurement device, such as the connection points between the first piston push rod 34 and the first base 22, a sealing ring and a sealing assembly are used, which has better sealing performance and can maintain a good sealing state during long-term use or frequent freezing and thawing.

[0065] Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention. Such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A triaxial earthmoving test device, characterized in that: include: Base frame (1); A pressure chamber structure (2), the pressure chamber structure (2) being mounted on the base frame (1), and a pressure chamber (25) for accommodating a soil sample to be tested being formed in the pressure chamber structure (2); a reciprocating pressurizing structure (3), the reciprocating pressurizing structure (3) being mounted on the base frame (1), the output end of the reciprocating pressurizing structure (3) being inserted into the pressure chamber (25), the output end of the reciprocating pressurizing structure (3) being suitable for reciprocatingly pulling and pressing the soil sample to be tested; A nuclear magnetic tester (4) is provided outside the pressure chamber structure (2), and a detection end of the nuclear magnetic tester (4) faces the pressure chamber (25).

2. The earth-moving triaxial test equipment according to claim 1, characterized in that: The pressure chamber structure (2) comprises: a sample cylinder (21), a first base (22) and a second base (23); a cavity is provided in the sample cylinder (21) along the axial direction; The first base (22) and the second base (23) are symmetrically arranged at both ends of the sample tube (21); the first base (22), the second base (23) and the sample tube (21) enclose the cavity to form a pressure chamber (25).

3. The earth-moving triaxial test equipment according to claim 2, characterized in that: The reciprocating pressurizing structure (3) comprises: a reciprocating pressurizing member (31), the reciprocating pressurizing member (31) being fixed on a base frame (1) at the bottom end of the pressure chamber structure (2), the pressurizing end of the reciprocating pressurizing member (31) being adapted to face the pressure chamber (25); a first piston push rod (34), one end of which is mounted on the pressurizing end of the reciprocating pressurizing member (31), the other end of which passes through the first base (22) and extends into the pressure chamber (25), and a first sample plug (35) is mounted on the end of the first piston push rod (34) away from the reciprocating pressurizing member (31); a pressure sensor (32), the pressure sensor (32) being mounted on the second base (23); a second piston push rod (36), the second piston push rod (36) is passed through the second base (23), one end of the second piston push rod (36) is fixed to the pressure sensor (32), and the other end of the second piston push rod (36) is located in the pressure chamber (25); a second sample plug (37) is installed at one end of the second piston and the first piston push rod (34) away from the pressure sensor (32); a pressure sensor fixing rod, one end of which is connected to the pressure sensor (32) and the other end of which is fixed to the upper end of the base frame (1); The soil sample to be tested is suitable for being placed between the first sample plug (35) and the second sample plug (37); the reciprocating pressure member (31) is suitable for driving the first piston push rod (34) to move back and forth in a direction close to or away from the second sample plug (37) to repeatedly pull and press the sample.

4. The earth-moving triaxial test equipment according to claim 3, characterized in that: The pressure chamber structure (2) further includes: a frame (24), the frame (24) being cylindrical, the frame (24) being sleeved on the sample cylinder (21), and the two ends of the frame (24) being respectively in contact with the first base (22) and the second base (23); The inner diameter of the skeleton (24) is larger than the outer diameter of the sample tube (21), so that an annular gap is formed between the skeleton (24) and the sample tube (21); and the nuclear magnetic tester (4) and the skeleton (24) are mutually engaged.

5. The earth-moving triaxial test equipment according to claim 4, characterized in that: The reciprocating pressurizing structure (3) further includes a displacement sensor (33), and the displacement sensor (33) is connected to the first piston push rod (34).

6. The earth-moving triaxial test equipment according to claim 4, characterized in that: A confining pressure liquid inlet (221) is provided on the first base (22), and a confining pressure liquid outlet (231) is provided on the second base (23); both the confining pressure liquid inlet (221) and the confining pressure liquid outlet (231) are in communication with the pressure chamber (25).

7. The earth-moving triaxial test equipment according to claim 4, characterized in that: A first back-pressure channel (38) is formed through the first piston push rod (34) and the first sample plug (35); A second back-pressure channel (39) is provided through the second sample plug (37), the outlet of the second back-pressure channel (39) is arranged relative to the soil sample to be tested, and the inlet of the second back-pressure channel (39) is provided on the side of the second sample plug (37); A third back-pressure channel (222) is provided on the first base (22), and the outlet of the third back-pressure channel (222) is connected to the inlet of the second back-pressure channel (39) via a delivery pipe.

8. The earth-moving triaxial test equipment according to claim 7, characterized in that: The pressure chamber (25), the first sample plug (35) and the second sample plug (37) are made of ceramics.

9. The earth-moving triaxial test equipment according to claim 4, characterized in that: The base frame (1) comprises: Mobile unit (11); A lower pressing plate (12), wherein the lower pressing plate (12) is mounted on the moving unit (11), and the reciprocating pressing member (31) is mounted on the lower pressing plate (12); A reaction frame pull rod (13), wherein the reaction frame pull rod (13) is vertically fixed on the lower pressure plate (12), and the outer surface of the nuclear magnetic tester (4) is suitable for being fixed on the reaction frame pull rod (13); An upper pressing plate (14) is fixed to the top end of the reaction frame pull rod (13), and the top end of the pressure sensor fixing rod is suitable for being installed on the upper pressing plate (14).

10. The earth-moving triaxial test equipment according to claim 9, characterized in that: The nuclear magnetic tester (4) comprises a nuclear magnetic tester frame (41) and a nuclear magnetic tester body (42); the nuclear magnetic tester frame (41) is mounted on the reaction frame pull rod (13); the nuclear magnetic tester frame (41) is sleeved outside the pressure chamber structure (2); and the detection end of the nuclear magnetic tester body (42) faces the pressure chamber (25).

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