A self-feeding high-temperature unsaturated frozen soil interface shear test device and method

Abstract

The present invention provides a self-fed high-temperature unsaturated frozen soil interface shear test device and method thereof, relating to the field of civil engineering test technology. The test device includes a shell component, a torque loading component, a gas phase insertion component, a liquid phase insertion component, a soil sample holding component, and a self-fed component. The torque loading component includes a torque control box arranged on the inner side of a bottom box, wherein the torque control box is provided with a torque controller, a digital acquisition master controller, and a torque device. The output end of the torque device is fixedly connected to a hollow cylinder via a torque transmission shaft, and a plurality of shear plates are detachably connected to the hollow cylinder. By providing the gas phase insertion component, the liquid phase insertion component, and the self-fed component, and utilizing the self-regulation and feedback of the self-fed component, the shear characteristics of the interface between unsaturated high-temperature frozen soil and piles can be studied under different matrix suction, different overburden loads, and different freezing temperature conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of civil engineering tests, in particular to a self-feeding high-temperature unsaturated frozen soil interface shear test device and a method thereof. Background Art

[0002] Unsaturated frozen soil is a porous, multiphase medium composed of solid soil particles, unfrozen water, ice crystals, and pore gas. The gas and liquid phase content affects the matric suction of unsaturated frozen soil, which in turn affects the shear force at the unsaturated frozen soil interface. The presence of unsaturated frozen soil significantly impacts the stability and safety of engineering structures. Therefore, studying the mechanical properties of unsaturated frozen soil and its relationship to the pile-soil interface has important theoretical and practical applications.

[0003] In the related technology, there is a frozen soil tension-shear integrated testing instrument with the announcement number CN112611638B, which includes a horizontal loading device, a vertical loading device, a pulling clamp and a shearing clamp. This patent uses the application of horizontal and vertical forces to measure the shear force.

[0004] Another example is a creep test method for a pile-frozen soil shear specimen with the announcement number CN115876579A, which includes a material testing machine, a constant temperature chamber, and a pile-frozen soil shear specimen mold with controllable normal stress placed in the constant temperature chamber. This patent uses the application of vertical force to conduct creep tests.

[0005] Another example is the patent number CN113640213B, which describes an intelligent self-rotating hollow cylinder interface shear tester and its testing method. This patent can test the friction between different rock and soil interfaces under complex stress conditions, but it is still not suitable for testing unsaturated frozen soil interfaces.

[0006] Most existing frozen soil test devices lack self-regulation and feedback capabilities, and are difficult to adapt to the wide distribution range and complex environment of unsaturated frozen soil. They are unable to accurately understand the characteristics of the pile-soil interface shear properties at the interface between unsaturated frozen soil and thawed soil. Therefore, a self-fed high-temperature unsaturated frozen soil interface shear test device is urgently needed to be developed. Summary of the Invention

[0007] In response to the shortcomings of the existing technology, the present invention provides a self-fed high-temperature unsaturated frozen soil interface shear test device and method, which solves the problem that the existing frozen soil test device lacks self-adjustment and feedback capabilities; and cannot accurately understand the characteristics of the pile-soil interface shear characteristics at the interface between unsaturated frozen soil and thawed soil.

[0008] To achieve the above objectives, the present invention is implemented through the following technical solutions: a self-fed high-temperature unsaturated frozen soil interface shear test device, comprising:

[0009] The housing assembly includes, from bottom to top, a bottom box, a reaction support wall, and a detachable upper cover;

[0010] A torque loading assembly is provided on the inner side of the housing assembly and is used to apply torque to the soil sample; the torque loading assembly includes a torque control box provided on the inner side of the bottom box, the torque control box is provided with a torque controller, a digital acquisition master controller, and a torque device, the output end of the torque device is fixedly connected to a hollow cylinder via a torque transmission shaft, a plurality of shear plates are detachably connected to the hollow cylinder, a torque application fixing buckle is detachably connected to the upper portion of the hollow cylinder, and a plurality of temperature sensors are installed on the circumferential surface of the hollow cylinder;

[0011] A matrix suction control system, comprising a gas phase insertion component and a liquid phase insertion component, wherein the gas phase insertion component is disposed on the top of the reaction support wall and is used to introduce gas into the soil sample;

[0012] The liquid phase insertion assembly is arranged on the hollow cylinder and is used to introduce liquid into the soil sample; the liquid phase insertion assembly includes a water inlet device and a water distribution assembly, the water distribution assembly is arranged on the hollow cylinder, the water distribution assembly includes a flushing pipe, the water outlet end of the water inlet device is connected to the flushing pipe, and the flushing pipe is alternately provided with a control valve and a clay plate, and an S-shaped cavity is provided in the clay plate;

[0013] The gas phase insertion assembly includes an air inlet device, and the air outlet end of the air inlet device is connected to the flushing pipe through a pipe;

[0014] A soil sample accommodating assembly is provided on the inner side of the reaction support wall for containing soil samples; the soil sample accommodating assembly includes a soil sample loading base plate fixedly mounted on the bottom box, a rubber membrane is concentrically fixedly connected to the soil sample loading base plate, the torque transmission shaft passes through the soil sample loading base plate and is rotatably engaged with each other, a soil sample cavity is formed between the rubber membrane and the hollow cylinder, and a pressure cavity is formed between the rubber membrane and the reaction support wall;

[0015] A self-feeding assembly automatically controls the amount of antifreeze fluid injected into the pressure chamber based on the difference between the chamber's volumetric pressure and the reference pressure. By utilizing the self-regulation and feedback of the gas-phase and liquid-phase injection assemblies and self-feeding assemblies, the shear properties of the interface between unsaturated high-temperature frozen soil and piles can be studied under varying matrix suction, overburden loads, and freezing temperatures.

[0016] Preferably, the bottom box is fixedly connected to the reaction force support wall, the reaction force support wall is tubular, an upper load portion is provided at the center of the upper cover, and the upper load portion is in contact with the torque applying fixing buckle.

[0017] Preferably, a needle and / or a blade for embedding in a soil sample is fixedly connected to the lower surface of the torque applying fixing buckle, and a clamping portion is provided on the shear plate, and the clamping portion is clamped with the hollow cylinder.

[0018] Preferably, the self-fed component includes a liquid pumping device, a standard pressure feedback device, a pressure controller, a water level balancer, and a volume change test sensor. The volume change test sensor, pressure controller, liquid pumping device and standard pressure feedback device are all arranged in the bottom box, and the water level balancer is arranged on the outside of the reaction force support wall; the volume change test sensor is used to monitor the pressure value in the pressure chamber, the liquid pumping device is used to extract or pump antifreeze liquid of the target temperature into the pressure chamber, the standard pressure feedback device is used to calculate the difference between the pressure value of the pressure chamber and the standard value, and the pressure controller is used to control the operation of the liquid pumping device according to the difference.

[0019] Preferably, it also includes a computer, which is electrically connected to the standard pressure feedback device, pressure controller, water level balancer, temperature sensor, volume change test sensor, torque device and torque controller and digital acquisition master controller, and is used for test plan setting and test data collection and analysis.

[0020] The present invention also provides a self-fed high-temperature unsaturated frozen soil interface shear test method, which uses the above-mentioned self-fed high-temperature unsaturated frozen soil interface shear test device and includes the following steps:

[0021] Step 1: Test preparation: comprehensively inspect the entire device to ensure the overall airtightness of the device and the good condition of the sensors, and exhaust the air in all pipes of the device. Select a shear plate with an appropriate friction coefficient according to the properties of the soil sample;

[0022] Step 2: placing the soil sample; placing the soil sample into the soil sample cavity;

[0023] Step 3: Saturation and consolidation of soil samples: Start the gas phase insertion component and the liquid phase insertion component, and use the back pressure saturation combined with the relevant saturation method to saturate the soil sample so that the soil sample meets the saturation requirements of the test;

[0024] Step 4: Shear test: start the self-feeding component and the torque loading component, pump the antifreeze liquid of the target temperature into the pressure chamber, so that the soil sample is driven by torque under the action of the preset hydraulic pressure and temperature, and record the test data.

[0025] The present invention provides a self-feeding high-temperature unsaturated frozen soil interface shear test device and method thereof. It has the following beneficial effects:

[0026] The present invention provides a gas phase insertion component, a liquid phase insertion component, and a self-feeding component, and utilizes the self-regulation and feedback of the self-feeding component to study the shear characteristics of the interface between unsaturated high-temperature frozen soil and piles under different matrix suctions, different overlying loads, and different freezing temperatures.

[0027] The present invention completes the test of the total volume change of the soil sample by arranging a torsion loading component and using a shear plate to simulate the friction force at the interface of different rock and soil bodies. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a structural schematic diagram of the present invention;

[0029] Figure 2 A perspective view of a hollow cylindrical portion of the present invention;

[0030] Figure 3 A perspective view of a hollow cylinder and a temperature sensor according to the present invention;

[0031] Figure 4 It is a three-dimensional diagram of the water inlet device and the water equalization component of the present invention;

[0032] Figure 5 is a three-dimensional diagram of the water distribution assembly of the present invention;

[0033] Figure 6 is a cross-sectional view of a clay plate of the present invention;

[0034] Figure 7 It is a three-dimensional view of the shear plate of the present invention.

[0035] Among them, 1. soil sample cavity; 2. hollow cylinder; 3. torque applying fixing buckle; 5. temperature sensor; 6. pressure cavity; 7. rubber membrane; 8. air intake device; 9. water intake device; 10. volume change test sensor; 11. torque transmission shaft; 12. torque controller and digital acquisition master controller; 13. shear plate; 1301. snap-fit part; 14. reaction support wall; 1401. bottom box; 1402. upper cover; 15. torque control box; 16. liquid pumping device; 17. soil sample loading bottom plate; 18. standard pressure feedback device; 19. pressure controller; 20. computer; 21. water level balancer; 22. water equalization component; 2201. flushing pipe; 2202. control valve; 2203. clay plate; 31. S-shaped cavity. DETAILED DESCRIPTION

[0036] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only 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 ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0037] like Figure 1-Figure 7 As shown, an embodiment of the present invention provides a self-fed high-temperature unsaturated frozen soil interface shear test device, comprising:

[0038] The housing assembly includes, from bottom to top, a bottom box 1401, a reaction support wall 14, and a detachable upper cover 1402;

[0039] refer to Figure 1 The bottom box 1401 is mainly used to provide protection for internal components, and the reaction support wall 14 is used to provide support for the antifreeze liquid in the pressure chamber 6.

[0040] The bottom box 1401 is fixedly connected to the reaction support wall 14, which is tubular. An upper load portion is provided at the center of the upper cover 1402, and the upper load portion is in contact with the torque applying fixing buckle 3.

[0041] refer to Figure 1 The tubular reaction support wall 14 is used to form a supporting force on the circumferential surface and adapt to the shape of the pressure chamber 6; the upper load part is used to provide an upper load force for the soil sample, which can be achieved by utilizing the gravity of the upper cover 1402 itself or by utilizing a load device that provides a load. You can choose whether to use the load device according to actual test requirements. The load device here can be a hydraulic device.

[0042] A torque loading assembly is provided on the inner side of the housing assembly and is used to apply torque to the soil sample. The torque loading assembly includes a torque control box 15 provided on the inner side of the bottom box 1401. The torque control box 15 is provided with a torque controller and a digital acquisition master controller 12, and a torque device. The output end of the torque device is fixedly connected to a hollow cylinder 2 via a torque transmission shaft 11. A plurality of shear plates 13 are detachably connected to the hollow cylinder 2. A torque application fixing buckle 3 is detachably connected to the upper part of the hollow cylinder 2. A plurality of temperature sensors 5 are installed on the circumferential surface of the hollow cylinder 2.

[0043] refer to Figure 1, the torque control box 15 is used to provide protection for the internal components; the torque controller and digital acquisition master controller 12 are used to control the torque output value of the torque device, and collect torque data, and transmit the data to the computer 20 to reflect the value of the shear force; this torque is transmitted to the soil sample through the torque transmission shaft 11 and the hollow cylinder 2 and the shear plate 13; wherein, the shear plate 13 can be removed from the hollow cylinder 2, therefore, shear plates 13 with different friction coefficients can be selected, and the shear plate 13 is used to simulate the friction force of the interface of different rock and soil bodies to complete the test of the total volume change of the soil sample; wherein, the temperature sensor 5 is used to monitor the temperature of various parts of the soil sample to determine whether the soil sample is tested at the preset temperature value;

[0044] In temperature control, the temperature sensor 5 provides real-time feedback on the temperature values at various locations of the soil sample. Based on the soil sample being tested, the basic parameters of the corresponding soil sample, such as density, moisture content, and specific gravity, are input into the liquid pumping system corresponding to the pressure controller 19. After setting, the system pumps the antifreeze liquid content suitable for the temperature of the soil sample into the pressure chamber 6 through the liquid pumping device 16, reaching the set temperature value within a predetermined time, and the entire temperature control accuracy reaches ±0.1 degrees Celsius. This temperature control standard is also achieved during the shearing process, which improves the temperature control standard in the test. Compared with the temperature control range of the existing temperature control system of ±1.0°C, the temperature control accuracy is higher. For specific data, see: Temperature Control Test Data Table;

[0045]

[0046] The lower surface of the torque applying fixing buckle 3 is fixedly connected with a needle and / or a blade for embedding into the soil sample. The shear plate 13 is provided with a clamping portion 1301, which is engaged with the hollow cylinder 2.

[0047] refer to Figure 1 The needle and / or blade on the torque applying fixing buckle 3 is used to be inserted into the soil sample to increase the contact area between the soil sample and the torque applying fixing buckle 3, and prevent the soil sample from sliding relative to the torque applying fixing buckle 3 when torque is applied.

[0048] A matrix suction control system, comprising a gas phase insertion component and a liquid phase insertion component. The gas phase insertion component is disposed on the top of the reaction support wall 14 and is used to introduce gas into the soil sample.

[0049] The gas phase insertion assembly includes an air inlet device 8, the air outlet end of the air inlet device 8 is connected to the flushing pipe 2201 through a pipe;

[0050] refer to Figure 1The air intake device 8 can be an air pump, which is used to generate gas and pass the gas into the flushing pipe 2201. In order to avoid gas leakage, it should be used in conjunction with a valve to fully mix the gas phase and liquid phase in the S-shaped cavity 31, and evenly enter the soil sample to increase the gas phase and liquid phase components in the soil sample.

[0051] The liquid phase insertion component is arranged on the hollow cylinder 2 and is used to introduce liquid into the soil sample;

[0052] For the control of matrix suction, the clay plate 2203, the air inlet device 8, the pipeline, and the liquid phase insertion assembly cooperate with each other to achieve segmented control of matrix suction, which greatly shortens the matrix suction stabilization time of the entire sample by more than 75%, saving test costs. Specific data can be found in the matrix suction stabilization time and stabilization effect table.

[0053]

[0054] Note: The stabilization time was calculated using the dehumidification method. The above data was obtained by comparing the results of pressure plate testing with real-time moisture content (volume moisture content) measured using a Teros12 model test. The stabilization time was determined by testing the water output of pressure plates after preparing specimens of equal thickness using the ring knife method. The post-stabilization fluctuation value was obtained using a tensiometer. Since the tensiometer has a range of 0–100 kPa, no data is available above 100 kPa. The inventors of this technology have conducted similar indoor tests. Existing equipment uses air intake at the top of the specimen and controls pore water pressure at the bottom. The matrix suction equilibrium time (minimum height for triaxial testing is 76 mm) is approximately 30–45 days. When the specimen thickness is reduced to 20 mm, the matrix suction equilibrium path is shortened by 75%, to approximately 7–10 days. This reduction is over 75%. This test was conducted on silty clay.

[0055] The liquid phase insertion assembly includes a water inlet device 9 and a water distribution assembly 22. The water distribution assembly 22 is provided on the hollow cylinder 2. The water distribution assembly 22 includes a flushing pipe 2201. The water outlet end of the water inlet device 9 is connected to the flushing pipe 2201. The flushing pipe 2201 is alternately provided with a control valve 2202 and a clay plate 2203. The clay plate 2203 is provided with an S-shaped cavity 31.

[0056] refer to Figure 1 、 Figure 2 、 Figure 4 、 Figure 5 、 Figure 6The water inlet device 9 can be a pump body, which is used to pass liquid into the soil sample, increase the liquid phase component in the soil sample, and finally obtain unsaturated frozen soil of a preset value. By controlling the amount of liquid and gas phase components, unsaturated frozen soil with different components can be formed; the liquid is pumped into the flushing pipe 2201 by the water inlet device 9, and whether the liquid enters each clay plate 2203 can be controlled by the control valve 2202. For example, the uppermost control valve 2202 is opened and the other control valves 2202 are closed, so that the liquid and gas can only enter the uppermost clay plate 2203, thereby being able to control the position of water inlet and air inlet;

[0057] In the initial state, the S-shaped cavity 31 can fully discharge the air in the flushing pipe 2201, preventing the air in the flushing pipe 2201 from affecting the gas phase component of the unsaturated frozen soil, and the water flow in the S-shaped cavity 31 will generate pressure at the bending part, making it easier for the water flow to enter the micropores in the clay plate 2203, thereby improving the efficiency of adding water to the soil sample; the bending part of the S-shaped cavity 31 can form a more complex microscopic pore network, promote the adsorption and penetration of water and gas phases, increase the rising height of the capillary effect, and disperse the water flow to a higher place on the clay plate 2203; the bending part of the S-shaped cavity 31 The water evaporation rate at the curved part is lower than that at the non-bent part. Therefore, in the process of temperature transfer, water evaporation is used to transfer heat, so that the heat is dispersed more evenly, reducing the test error of unsaturated frozen soil at different temperatures; since the test temperature variation range of unsaturated frozen soil is large, the low temperature state can be minus twenty degrees Celsius, and the high temperature state can be one degree Celsius, the structure of the S-shaped cavity 31 can reduce the cracking risk of the clay plate 2203 in the water absorption-loss cycle at different temperatures by dispersing stress, thereby maintaining the stability of the water absorption performance, and is more suitable for the test requirements of high-temperature unsaturated frozen soil.

[0058] The outer circumference of the clay plate 2203 is flush with the outer circumference of the hollow cylinder 2, ensuring that the clay plate 2203 can contact the soil sample, allow moisture to flow into the soil sample, and meet the conditions for applying torque.

[0059] A soil sample holding assembly is provided on the inner side of the reaction support wall 14 for holding soil samples. The soil sample holding assembly includes a soil sample loading base plate 17 fixedly mounted on the bottom box 1401. A rubber membrane 7 is concentrically fixedly connected to the soil sample loading base plate 17. The torque transmission shaft 11 passes through the soil sample loading base plate 17 and is rotationally engaged with each other. A soil sample cavity 1 is formed between the rubber membrane 7 and the hollow cylinder 2, and a pressure cavity 6 is formed between the rubber membrane 7 and the reaction support wall 14.

[0060] refer to Figure 1When adding soil samples, the upper cover 1402 and the torque-applying fixing buckle 3 can be removed to expose the upper part of the soil sample cavity 1, and the soil sample can be added to the soil sample cavity 1; the soil sample loading bottom plate 17 and the rubber membrane 7 can ensure the stability of the soil sample, and the rubber membrane 7 can isolate the soil sample cavity 1 and the pressure cavity 6, and meet the requirement of the pressure cavity 6 to apply circumferential pressure to the soil sample cavity 1, ensuring good pressure transmission and no pressure loss; the pressure cavity 6 is used to hold frozen liquid, and the temperature of the frozen liquid is used to simulate the experimental temperature of unsaturated frozen soil, and the test temperature of unsaturated frozen soil is changed by changing the temperature of the frozen liquid. The maximum temperature is 1°C, which is suitable for unsaturated frozen soil tests under high temperature conditions. The change of the frozen liquid temperature can be provided by the refrigeration equipment in the prior art.

[0061] In terms of sealing, the rubber membrane 7, soil sample loading base plate 17, hollow cylinder 2, and torque application fixing buckle 3 cooperate with each other to reduce the resistance of the torque transmission shaft 11 to 0.1N~1.0N while ensuring the sealing performance, with an accuracy of 0.5kPa (50mm sample). Specific data can be found in the Axial Force Sealing System Friction Test Table;

[0062]

[0063] A self-feeding component is used to automatically control the amount of antifreeze liquid injected into the pressure chamber 6 according to the difference between the volumetric pressure value of the pressure chamber 6 and the standard pressure value;

[0064] The self-fed assembly includes a liquid pumping device 16, a standard pressure feedback device 18, a pressure controller 19, a water level balancer 21, and a volume change test sensor 10. The volume change test sensor 10, the pressure controller 19, the liquid pumping device 16, and the standard pressure feedback device 18 are all arranged in the bottom box 1401, and the water level balancer 21 is arranged on the outside of the reaction force support wall 14; the volume change test sensor 10 is used to monitor the pressure value in the pressure chamber 6, the liquid pumping device 16 is used to extract or pump antifreeze liquid of a target temperature into the pressure chamber 6, the standard pressure feedback device 18 is used to calculate the difference between the pressure value of the pressure chamber 6 and the standard value, and the pressure controller 19 is used to control the operation of the liquid pumping device 16 according to the difference;

[0065] refer to Figure 2 The liquid pumping device 16 can be a pump body, such as a centrifugal pump, which is used to extract or pump antifreeze liquid of the target temperature into the pressure chamber 6. The antifreeze liquid can be an ethylene glycol solution, which is combined with valves and pipes to control the temperature of the soil sample so that the soil sample meets the test temperature requirements; the water level balancer 21 is used to determine whether the entire device is in a horizontal position; the standard pressure feedback device 18, the water level balancer 21, the volume change test sensor 10, the pressure controller 19, the temperature sensor 5, and the computer 20 are all existing components and can be purchased directly from the market.

[0066] The apparatus further includes a computer 20, which is electrically connected to the standard pressure feedback device 18, the pressure controller 19, the water level balancer 21, the temperature sensor 5, the volume change test sensor 10, the torque device and the torque controller, and the digital acquisition master controller 12. The computer 20 is used for setting the test plan and collecting and analyzing the test data.

[0067] This embodiment also provides a self-fed high-temperature unsaturated frozen soil interface shear test method, which uses the above-mentioned self-fed high-temperature unsaturated frozen soil interface shear test device, including the following steps:

[0068] Step 1: Test preparation: comprehensively check the entire device to ensure the overall airtightness of the device and the good condition of the sensors, and exhaust the air in all pipes of the device. Select a shear plate 13 with a suitable friction coefficient according to the properties of the soil sample;

[0069] Step 2: placing the soil sample; placing the soil sample into the soil sample cavity 1;

[0070] Step 3: Saturation and consolidation of soil samples: Start the gas phase insertion component and the liquid phase insertion component, and use the back pressure saturation combined with the relevant saturation method to saturate the soil sample so that the soil sample meets the saturation requirements of the test;

[0071] Step 4: Shear test: start the self-feeding component and the torque loading component to drive the soil sample under the action of hydraulic pressure and record the test data.

[0072] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A self-fed high-temperature unsaturated frozen soil interface shear test device, characterized in that: include: A housing assembly, the housing assembly comprising, from bottom to top, a bottom box (1401), a reaction force support wall (14), and a detachable upper cover (1402); A torque loading assembly, the torque loading assembly being arranged on the inner side of the housing assembly and being used for applying torque to the soil sample; the torque loading assembly comprising a torque control box (15) arranged on the inner side of the bottom box (1401), the torque control box (15) being provided with a torque controller and a data acquisition master controller (12), and a torque device, the output end of the torque device being fixedly connected to a hollow cylinder (2) via a torque transmission shaft (11), the hollow cylinder (2) being detachably connected to a plurality of shear plates (13), the upper portion of the hollow cylinder (2) being detachably connected to a torque applying fixing buckle (3), and a plurality of temperature sensors (5) being installed on the circumferential surface of the hollow cylinder (2); A matrix suction control system, the matrix suction control system comprising a gas phase insertion component and a liquid phase insertion component, the gas phase insertion component being arranged on the top of the reaction force support wall (14) and being used for introducing gas into the soil sample; The liquid phase insertion component is arranged on the hollow cylinder (2) and is used to introduce liquid into the soil sample; the liquid phase insertion component comprises a water inlet device (9) and a water distribution component (22); the water distribution component (22) is arranged on the hollow cylinder (2); the water distribution component (22) comprises a flushing pipe (2201); the water outlet end of the water inlet device (9) is in communication with the flushing pipe (2201); the flushing pipe (2201) is alternately provided with a control valve (2202) and a clay plate (2203); an S-shaped cavity (31) is provided in the clay plate (2203); The gas phase insertion assembly comprises an air inlet device (8), the air outlet end of the air inlet device (8) being in communication with the flushing pipe (2201) via a pipe; A soil sample accommodating assembly is provided on the inner side of the reaction support wall (14) and is used to hold soil samples; the soil sample accommodating assembly comprises a soil sample loading base plate (17) fixedly mounted on the bottom box (1401); a rubber membrane (7) is coaxially fixedly connected to the soil sample loading base plate (17); the torque transmission shaft (11) passes through the soil sample loading base plate (17) and is rotationally engaged with each other; a soil sample cavity (1) is formed between the rubber membrane (7) and the hollow cylinder (2); and a pressure cavity (6) is formed between the rubber membrane (7) and the reaction support wall (14); A self-feeding component is used to automatically control the amount of antifreeze liquid injected into the pressure chamber (6) according to the difference between the volumetric pressure value of the pressure chamber (6) and the standard pressure value.

2. A self-fed high-temperature unsaturated frozen soil interface shear test device according to claim 1, characterized in that: The bottom box (1401) is fixedly connected to the reaction force support wall (14), the reaction force support wall (14) is tubular, and an upper load portion is provided at the center of the upper cover (1402), and the upper load portion is in contact with the torsion applying fixing buckle (3).

3. The self-fed high-temperature unsaturated frozen soil interface shear test device according to claim 1, characterized in that: A needle and / or a blade for embedding in a soil sample is fixedly connected to the lower surface of the torque applying fixing buckle (3), and a clamping portion (1301) is provided on the shear plate (13), and the clamping portion (1301) is mutually clamped with the hollow cylinder (2).

4. The self-fed high-temperature unsaturated frozen soil interface shear test device according to claim 1, characterized in that: The self-feeding assembly includes a liquid pumping device (16), a standard pressure feedback device (18), a pressure controller (19), a water level balancer (21), and a volume change test sensor (10). The volume change test sensor (10), the pressure controller (19), the liquid pumping device (16), and the standard pressure feedback device (18) are all arranged in the bottom box (1401), and the water level balancer (21) is arranged on the outside of the reaction force support wall (14); the volume change test sensor (10) is used to monitor the pressure value in the pressure chamber (6), the liquid pumping device (16) is used to extract or pump antifreeze liquid of a target temperature into the pressure chamber (6), the standard pressure feedback device (18) is used to calculate the difference between the pressure value of the pressure chamber (6) and the standard value, and the pressure controller (19) is used to control the operation of the liquid pumping device (16) according to the difference.

5. The self-fed high-temperature unsaturated frozen soil interface shear test device according to claim 1, characterized in that: The invention also includes a computer (20), which is electrically connected to a standard pressure feedback device (18), a pressure controller (19), a water level balancer (21), a temperature sensor (5), a volume change test sensor (10), a torque device and a torque controller, and a digital acquisition master controller (12). The computer (20) is used for setting a test plan and collecting and analyzing test data.

6. A self-fed high-temperature unsaturated frozen soil interface shear test method, using a self-fed high-temperature unsaturated frozen soil interface shear test device according to any one of claims 1 to 5, characterized in that: The following steps are involved: Step 1: Test preparation: comprehensively check the entire device to ensure the overall airtightness of the device, the good condition of the sensor, and exhaust the air in all the pipes of the device. Select a shear plate with a suitable friction coefficient according to the properties of the soil sample (13); Step 2: placing the soil sample; placing the soil sample into the soil sample cavity (1); Step 3: Saturation and consolidation of soil samples: Start the gas phase insertion component and the liquid phase insertion component, and use the back pressure saturation combined with the relevant saturation method to saturate the soil sample so that the soil sample meets the saturation requirements of the test; Step 4: Shear test, start the self-feeding component and the torque loading component, pump the antifreeze liquid of the target temperature into the pressure chamber (6), so that the soil sample is driven by torque under the action of the preset hydraulic pressure and temperature, and record the test data.

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