An experimental system and test method for simulating artificial freezing and impermeability.

Abstract

This invention provides an experimental system and method for simulating artificial freezing and impermeability, relating to the field of freezing tests. The experimental system includes a permeability testing device, a low-temperature cold bath device, and a frozen wall monitoring system. The permeability testing device includes a model container and a flow meter, with an outlet at the bottom of the model container. The interior of the model container is filled with a soil sample mixed with a thermochromic solution, the color-changing boundary temperature of which is 0°C. At least one ring of freezing tubes is wound around the side wall of the model container; the number of rings is adjustable, and an electromagnetic exciter is fixed on the freezing tubes. A cryogenic fluid pipeline connects the low-temperature cold bath device and the freezing tubes. The frozen wall monitoring system includes a data processing host, an acoustic emission sensor, and multiple temperature sensors, which are distributed throughout the model container. By combining multiple methods, the morphological characteristics of the artificially frozen wall can be accurately obtained, enabling effective evaluation of the permeability resistance of the frozen wall under different freezing parameters over time.

Description

Technical Field

[0001] This invention relates to the field of freezing test technology, and in particular to an experimental system and test method for simulating artificial freezing and impermeability. Background Technology

[0002] Artificial ground freezing is widely used in engineering projects involving water-rich soft soil strata due to the excellent impermeability, high strength, and strong resistance to deformation of the frozen soil curtain it creates. Understanding the development morphology of the frozen wall and its permeability coefficient under different seepage velocities allows for a systematic understanding of the freezing method.

[0003] For example, Chinese invention patent application CN105092578A, published on November 25, 2015, discloses a device for tracking the migration process of water in frozen soil and its experimental method. Specifically, the device includes a soil sample tank, an upper cooling bath plate, and a lower cooling bath tank. The soil sample tank consists of a wide acrylic plate, a narrow acrylic plate, and a lower cooling bath plate. The lower cooling bath plate can be connected to an external Mauritian water supply bottle to simulate groundwater replenishment. The upper cooling bath plate has an inlet and outlet for the cryogenic liquid. The lower cooling bath tank consists of an acrylic plate trough and a serpentine copper tube. First, a mixture of fluorescent agent, water, and soil is filled into the soil sample tank. Then, the soil sample tank is placed in the lower cooling bath tank, with the upper cooling bath plate placed on top of the soil. The lower cooling bath plate is connected to the Mauritian water supply bottle.

[0004] In existing frozen soil moisture migration tracking devices, the upper cold bath plate and lower cold bath tank are connected to external cooling devices to cool the soil in one direction. Fluorescent agents and ultraviolet lamps are used to track the moisture migration process during the freezing process of the soil.

[0005] However, existing devices and methods are difficult to flexibly control artificial freezing parameters and cannot accurately obtain the morphological characteristics of artificially frozen walls, thus failing to effectively evaluate the relationship between the permeability of frozen walls and the permeation time under different freezing parameters. Summary of the Invention

[0006] To address the aforementioned problems, the present invention aims to provide an experimental system and method for simulating artificial freezing and impermeability, thereby solving the problems of existing devices and methods that are difficult to flexibly control artificial freezing parameters, cannot accurately obtain the morphological characteristics of the artificially frozen wall, and cannot effectively evaluate the relationship between the impermeability of the frozen wall and the permeation duration under different freezing parameters.

[0007] The technical solution of the experimental system for simulating artificial freezing and impermeability of the present invention is as follows:

[0008] The experimental system for simulating artificial freezing and seepage prevention includes a permeability test device, a low-temperature cold bath device, and a freezing wall monitoring system. A cryogenic liquid pipeline connects the low-temperature cold bath device and the permeability test device.

[0009] The permeability test device includes a model container and a water outlet. The lower part of the model container is provided with a water outlet corresponding to the water outlet. The interior of the model container is filled with a soil sample mixed with a thermochromic solution. The color change boundary temperature of the thermochromic solution is 0°C.

[0010] The side wall of the model container is provided with at least one turn of a freezing tube, and the number of turns of the freezing tube is adjustable. An electromagnetic exciter is also fixed on the freezing tube. The freezing liquid pipeline is connected between the low-temperature cold bath device and the at least one turn of the freezing tube.

[0011] The frozen wall monitoring system includes a data processing host, an acoustic emission sensor, and multiple temperature sensors. The data processing host is electrically connected to the temperature sensors and the acoustic emission sensor, respectively, and the multiple temperature sensors are distributed in the model container.

[0012] Furthermore, the thermochromic solution is a mixture of colorless antifreeze and copper tetrachlorodiethylammonium salt solution, and the thermochromic solution is bright green below 0°C and pale yellow above 0°C.

[0013] Furthermore, each ring of the cryogenic tube is provided with at least three electromagnetic exciters, and the at least three electromagnetic exciters in each ring are circumferentially spaced. The amplitude of the electromagnetic exciters is 40μm to 70μm and the vibration frequency is 10kHz to 30kHz.

[0014] Furthermore, the permeability test device also includes an upper permeable plate and a lower permeable plate, which are arranged at intervals in the model container, forming a soil sample receiving cavity between the upper permeable plate and the lower permeable plate.

[0015] Furthermore, the upper part of the model container is provided with an overflow outlet, which is arranged above the surface of the upper permeable plate, and the outlet is at the same horizontal position as the lower permeable plate.

[0016] Furthermore, the upper permeable plate and the lower permeable plate are respectively fitted with the inner wall of the model container with a gap, and the upper permeable plate and the model container, as well as the lower permeable plate and the model container, are connected by snap-fit.

[0017] Furthermore, the model container is cylindrical in shape, and a plurality of first temperature measuring holes are provided on one side of the model container, the plurality of first temperature measuring holes being distributed at intervals parallel to the axis of the cylindrical tube; a plurality of second temperature measuring holes are provided on the other side of the model container, the plurality of second temperature measuring holes being distributed at intervals parallel to the axis of the cylindrical tube.

[0018] Temperature sensors are installed in both the first and second temperature measuring holes. The temperature sensor in the first temperature measuring hole is located at the center of the cylindrical tube, and the temperature sensor in the second temperature measuring hole is located at half the radius of the cylindrical tube.

[0019] Furthermore, at least one acoustic emission sensor is provided, and at least one acoustic emission sensor is installed on the outside of the model container. An acoustic emission signal amplifier is electrically connected between the acoustic emission sensor and the data processing host. A temperature acquisition instrument is also electrically connected between the temperature sensor and the data processing host.

[0020] Furthermore, the frozen wall monitoring system also includes at least two industrial cameras, which are respectively set on the outside of the model container, and the industrial cameras are electrically connected to the data processing host.

[0021] The technical solution of the experimental method for simulating artificial freezing and impermeability of the present invention is as follows:

[0022] The experimental method using the above-described simulated artificial freezing seepage barrier system includes the following steps:

[0023] S1. First, dry and sieve the soil of the test stratum. Mix the sieved soil particles with the thermochromic solution and stir evenly. Seal and let stand for 24 hours to obtain the soil sample.

[0024] S2. Place the lower permeable plate in the model container and fix its position. Fill the model container with soil samples in layers. When the soil samples are filled to the position of each temperature measuring hole, bury the two rows of temperature sensors at the center depth and 1 / 2 radius depth of the model container, respectively. After the soil samples are filled to the set height, cover the soil samples with the upper permeable plate and fix its position.

[0025] S3. At least one loop of freezing tube is wound around the model container. The freezing tube is connected to the low-temperature cold bath device through the freezing liquid pipeline, and an electromagnetic exciter is fixed on each loop of freezing tube.

[0026] S4. Fix acoustic emission sensors on the outer wall of the model container, and electrically connect the acoustic emission sensors and multiple temperature sensors to the data processing host respectively; and set an industrial camera on the outside of the model container, with the industrial camera electrically connected to the data processing host to construct a frozen wall monitoring system.

[0027] S5. Open the inlet valve and set different flow rates. When the liquid flow rate discharged from the outlet is stable, start the low temperature cold bath device and electromagnetic exciter, and at the same time turn on the freezing wall monitoring system to start the test.

[0028] S6. During the test, the industrial camera periodically collects image information to analyze the development of the frozen wall; the water flow meter is replaced and the reading is recorded every set time, and the permeability coefficient k for each time period is calculated using the following formula.

[0029] ;

[0030] Where α is the permeability reduction factor of the thermochromic solution compared to pure water, V is the solution volume of the outlet meter, L is the filling height of the soil sample, A is the cross-sectional area of ​​the soil sample, Δh is the height difference between the overflow and the outlet, and t is the seepage time.

[0031] Beneficial effects: This experimental system for simulating artificial freezing and seepage prevention includes a permeability test device, a low-temperature cold bath device, and a frozen wall monitoring system. The permeability test device includes a model container and a flow meter. Soil samples mixed with a thermochromic solution are filled into the model container. The flow meter collects the seepage liquid discharged from the outlet, so as to form a stable seepage field inside the model container. The thermochromic solution has a color change boundary temperature of 0℃, which makes it easy to distinguish between the frozen and unfrozen parts of the soil sample and accurately display the range, morphology, and other characteristics of the frozen area.

[0032] The model container of the permeation test device is wound with at least one turn of a freezing tube. The winding of the freezing tube can freeze the cross section of the freezing area in a short time. Furthermore, the number of turns of the freezing tube can be adjusted by changing the interface position of the freezing liquid pipeline, thereby achieving the purpose of flexibly adjusting different freezing wall thicknesses. An electromagnetic exciter is also fixed on the freezing tube. The electromagnetic exciter accelerates the movement of water in the area, thereby ensuring that the cross section of the freezing area is completely frozen.

[0033] Temperature sensors are distributed throughout the model container to accurately determine the freezing status of the entire soil sample section; acoustic emission sensors can record acoustic emission information generated by the cracking of frozen soil due to ice crystal growth, and transmit the amplified acoustic emission signal to the data processing host to ultimately analyze the formation characteristics of the frozen wall and achieve a quantitative evaluation of the ice crystal development status of the entire cross-sectional area during the formation of the frozen wall.

[0034] This experimental system simulating artificial freezing and impermeability integrates three methods: temperature monitoring, acoustic emission technology, and thermochromic sensing. It can acquire morphological characteristics such as the thickness and distribution of the frozen wall after the formation of a stable seepage field, thereby clarifying the formation and development of the frozen wall under different formation and freezing parameters. It allows for flexible control of artificial freezing parameters and accurate acquisition of the morphological characteristics of the artificial frozen wall, effectively evaluating the relationship between the impermeability of the frozen wall and the seepage duration under different freezing parameters. Attached Figure Description

[0035] Figure 1This is a schematic diagram of the experimental system in a specific embodiment of the experimental system for simulating artificial freezing and impermeability of the present invention.

[0036] In the diagram: 1-Permeability test apparatus, 10-Model container, 11-Outlet meter, 12-Outlet, 13-Refrigeration pipe, 14-Electromagnetic exciter, 15-Upper permeable plate, 16-Lower permeable plate, 17-Overflow outlet, 18-Support, 19-Inlet valve;

[0037] 2-Low-temperature cold bath device, 20-Refrigeration fluid piping;

[0038] 3-Frozen wall monitoring system, 30-Data processing host, 31-Acoustic emission sensor, 32-Temperature sensor, 33-Acoustic emission signal amplifier, 34-Temperature acquisition instrument, 35-Industrial camera. Detailed Implementation

[0039] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0040] Specific embodiment 1 of the experimental system for simulating artificial freezing and impermeability of the present invention, as follows: Figure 1 As shown, the experimental system for simulating artificial freezing and seepage prevention includes a permeability test device 1, a low-temperature cold bath device 2, and a frozen wall monitoring system 3. A cryogenic liquid pipeline 20 connects the low-temperature cold bath device 2 and the permeability test device 1. The permeability test device 1 includes a model container 10 and a water outlet 11. The lower part of the model container 10 is provided with a water outlet 12 corresponding to the water outlet 11. The interior of the model container 10 is filled with a soil sample mixed with a thermochromic solution. The color change boundary temperature of the thermochromic solution is 0℃.

[0041] The sidewall of the model container 10 is provided with at least one ring of freezing tube 13, and the number of rings of freezing tube 13 is adjustable. An electromagnetic exciter 14 is also fixed on the freezing tube 13. The cryogenic liquid pipeline 20 is connected between the low-temperature cold bath device 2 and the at least one ring of freezing tube 13. The frozen wall monitoring system 3 includes a data processing host 30, an acoustic emission sensor 31 and multiple temperature sensors 32. The data processing host 30 is electrically connected to the acoustic emission sensor 31 and the temperature sensors 32 respectively. The multiple temperature sensors 32 are distributed in the model container 10.

[0042] The experimental system for simulating artificial freezing and seepage prevention includes a permeability test device 1, a low-temperature cold bath device 2, and a frozen wall monitoring system 3. The permeability test device 1 includes a model container 10 and a water outlet 11. A soil sample mixed with a thermochromic solution is filled into the model container 10. The water outlet 11 is used to collect the seepage water discharged from the outlet 12, so as to form a stable seepage field inside the model container 10. The thermochromic solution has a color change boundary temperature of 0℃, which makes it easy to distinguish between the frozen and unfrozen parts of the soil sample and accurately display the range, morphology, and other characteristics of the frozen ice area.

[0043] In this device, the model container 10 of the permeation test apparatus 1 is wound with at least one turn of the freezing tube 13. The freezing tube 13 can freeze the cross section of the freezing area in a short time. Furthermore, the number of turns of the freezing tube 13 can be adjusted by changing the interface position of the freezing liquid pipeline 20, thereby achieving the purpose of flexibly adjusting different freezing wall thicknesses. An electromagnetic exciter 14 is also fixed on the freezing tube 13. The electromagnetic exciter 14 accelerates the movement of water in the area, thereby ensuring that the cross section of the freezing area is completely frozen.

[0044] Temperature sensors 32 are distributed throughout the model container 10, which can accurately determine the freezing status of the entire soil sample section; acoustic emission sensors 31 can record the acoustic emission information generated by the cracking of frozen soil caused by ice crystal growth, and transmit the amplified acoustic emission signal to the data processing host 30 to ultimately analyze the formation characteristics of the frozen wall and realize the quantitative evaluation of the ice crystal development status of the entire section area during the formation of the frozen wall.

[0045] This experimental system simulating artificial freezing and impermeability integrates three methods: temperature monitoring, acoustic emission technology, and thermochromic sensing. It can acquire morphological characteristics such as the thickness and distribution of the frozen wall after the formation of a stable seepage field, thereby clarifying the formation and development of the frozen wall under different formation and freezing parameters. It allows for flexible control of artificial freezing parameters and accurate acquisition of the morphological characteristics of the artificial frozen wall, effectively evaluating the relationship between the impermeability of the frozen wall and the seepage duration under different freezing parameters.

[0046] In this embodiment, the thermochromic solution is a mixture of colorless antifreeze and copper tetrachlorodiethylammonium salt solution. The thermochromic solution is bright green below 0°C and pale yellow above 0°C. Specifically, the concentration of the copper tetrachlorodiethylammonium salt solution is 5 g / L. Adjusting the color-changing boundary temperature of the thermochromic solution to 0°C facilitates the differentiation between frozen and unfrozen portions of the soil sample and accurately displays the extent, morphology, and other characteristics of the frozen area.

[0047] Each ring of freezing tubes 13 is equipped with at least three electromagnetic exciters 14, which are circumferentially spaced. The amplitude of each electromagnetic exciter 14 is 40μm to 70μm, and the vibration frequency is 10kHz to 30kHz. Preferably, each ring of freezing tubes 13 is circumferentially spaced with four electromagnetic exciters 14 to accelerate the movement of water in the area, thereby ensuring that the cross-section of the freezing area is completely frozen.

[0048] In this embodiment, the permeability testing device 1 further includes an upper permeable plate 15 and a lower permeable plate 16, which are arranged vertically at intervals within the model container 10, forming a cavity for the soil sample. Specifically, both the upper and lower permeable plates 15 and 16 are permeable stone slabs, which allow for uniform fluid flow while preventing soil sample collapse and overflow. Furthermore, the upper part of the model container 10 is provided with an overflow outlet 17, which is positioned above the surface of the upper permeable plate 15. The outlet 12 is at the same horizontal level as the lower permeable plate 16, allowing excess fluid leached during the seepage process to be discharged through the overflow outlet 17 and the outlet 12.

[0049] The upper permeable plate 15 and the lower permeable plate 16 are respectively fitted with the inner wall of the model container 10 with clearance. The upper permeable plate 15 and the model container 10, as well as the lower permeable plate 16 and the model container 10, are connected by snap-fit. The upper permeable plate 15 and the lower permeable plate 16 are placed in the model container 10, and the snap-fit ​​is pushed and pulled to complete the fixation. Correspondingly, after the test, the snap-fit ​​is pushed and pulled to unlock, which facilitates quick disassembly and cleaning of the model container 10 and the permeable plate.

[0050] The model container 10 is cylindrical in shape. Multiple first temperature measuring holes are provided on one side of the model container 10, and the multiple first temperature measuring holes are distributed at intervals parallel to the axis of the cylindrical tube. Multiple second temperature measuring holes are provided on the other side of the model container 10, and the multiple second temperature measuring holes are distributed at intervals parallel to the axis of the cylindrical tube. Temperature sensors 32 are installed in both the first and second temperature measuring holes. The temperature sensor 32 in the first temperature measuring hole is located at the center of the cylindrical tube, and the temperature sensor 32 in the second temperature measuring hole is located at half the radius of the cylindrical tube.

[0051] Since the test results of temperature sensor 32 only reflect the local frozen soil temperature near the measuring point, the temperature at different heights on the central axis of the cylinder is tested by temperature sensor 32 in the first measuring hole, and the temperature at different heights on the axis of half radius of the cylinder is tested by temperature sensor 32 in the second measuring hole. By combining the test results of the two sets of temperature sensors, the errors and limitations of a single measuring point can be avoided, thereby accurately determining the freezing status of the entire soil sample section.

[0052] Furthermore, at least one acoustic emission sensor 31 is provided, and at least one acoustic emission sensor 31 is installed on the outside of the model container 10. An acoustic emission signal amplifier 33 is electrically connected between the acoustic emission sensor 31 and the data processing host 30. Specifically, two acoustic emission sensors 31 are provided to record the acoustic emission information generated by the cracking of permafrost due to ice crystal growth, and the acoustic emission signal is amplified and transmitted to the data processing host 30 for final analysis of the formation characteristics of the frozen wall. By using acoustic emission technology to obtain acoustic emission information of the ice formation process inside the permafrost, such as parameters such as events, impacts, ringing, amplitude, and energy, a quantitative evaluation of the ice crystal development status of the entire cross-sectional area during the formation of the frozen wall can be achieved.

[0053] In addition, a temperature acquisition instrument 34 is electrically connected between the temperature sensor 32 and the data processing host 30. The frozen wall monitoring system 3 also includes at least two industrial cameras 35, which are respectively set on the outside of the model container 10. The industrial cameras 35 are electrically connected to the data processing host 30. Specifically, by distributing three industrial cameras 35 on the outside of the model container 10, the shooting range can cover the entire outer wall of the model container 10. This is used to capture the thickness, distribution, and other morphological characteristics of the frozen wall after the formation of a stable seepage field. Combined with the thermochromic solution, the frozen and unfrozen areas are presented in the captured images, thereby clarifying the image information of the entire process of frozen wall formation and development under different formation parameters and freezing parameters.

[0054] The experimental method using the above-mentioned simulated artificial freezing seepage barrier system includes the following steps:

[0055] S1. First, the soil of the test stratum is dried and sieved. The sieved soil particles are mixed with the thermochromic solution and stirred evenly. The mixture is then sealed and left to stand for 24 hours to obtain a soil sample. In addition, the model container 10 is placed on the support 18 in advance. A water inlet valve 19 is provided directly above the model container 10. Seepage liquid can be introduced into the model container 10 through the water inlet valve 19.

[0056] S2. Place the lower permeable plate 16 in the model container 10 and fix its position. Fill the model container 10 with soil samples in layers. When the soil samples are filled to the position of each temperature measuring hole, bury the two rows of temperature sensors 32 at the center depth and the radius 1 / 2 depth of the model container 10, respectively. After the soil samples are filled to the set height, cover the soil samples with the upper permeable plate 15 and fix its position.

[0057] S3. At least one turn of freezing tube 13 is wound around the model container 10. The freezing tube 13 is connected to the low temperature cold bath device 2 through the freezing liquid pipeline 20, and an electromagnetic exciter 14 is fixed on each turn of the freezing tube 13. The number of turns of the freezing tube 13 can be adjusted according to the needs of the freezing test. Specifically, by changing the interface position of the freezing liquid pipeline 20, the purpose of flexibly adjusting different frozen wall thicknesses can be achieved.

[0058] S4. Fix an acoustic emission sensor 31 on the outer wall of the model container 10, and electrically connect the acoustic emission sensor 31 and multiple temperature sensors 32 to the data processing host 30 respectively; and set an industrial camera 35 on the outside of the model container 10, and electrically connect the industrial camera 35 to the data processing host 30 to form a frozen wall monitoring system 3.

[0059] S5. Open the inlet valve 19 and set different flow rates. When the liquid flow rate discharged from the outlet 12 is stable, start the low temperature cold bath device 2 and the electromagnetic exciter 14, and at the same time turn on the frozen wall monitoring system 3 to start the test.

[0060] S6. During the test, the industrial camera 35 periodically collects image information to analyze the development of the frozen wall; the water outlet 11 is replaced and the reading is recorded every set time, and the permeability coefficient k for each time period is calculated using the following formula.

[0061] ;

[0062] Where α is the permeability reduction coefficient of the thermochromic solution compared to pure water, V is the solution volume of the outlet meter 11, L is the filling height of the soil sample, A is the cross-sectional area of ​​the soil sample, Δh is the height difference between the overflow outlet 17 and the outlet 12, and t is the seepage time.

[0063] The specific embodiments of the experimental system for simulating artificial freezing and impermeability of the present invention are the same as the specific embodiments of the experimental method of the experimental system for simulating artificial freezing and impermeability of the present invention, and will not be repeated here.

[0064] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

Claims

1. An experimental system for simulating artificial frozen ground, characterized in that, The device comprises a permeation test device, a low-temperature cold bath device, and a frozen wall monitoring system, and a refrigerant pipeline is connected between the permeation test device and the low-temperature cold bath device. The permeation test device comprises a model container and a water outlet device, and the lower part of the model container is provided with a water outlet corresponding to the water outlet device; the inside of the model container is filled with soil samples mixed with soil and a temperature-sensitive color-changing solution, and the color-changing boundary temperature of the temperature-sensitive color-changing solution is 0℃. At least one circle of refrigeration pipes is arranged on the side wall of the model container, and the number of circles of the refrigeration pipes can be adjusted; an electromagnetic exciter is further fixed on the refrigeration pipes; and the refrigerant pipeline is connected between the low-temperature cold bath device and at least one circle of the refrigeration pipes. The frozen wall monitoring system comprises a data processing host, an acoustic emission sensor, and a plurality of temperature sensors, the data processing host is electrically connected with the temperature sensors and the acoustic emission sensor, and a plurality of temperature sensors are dispersedly arranged in the model container. The temperature-sensitive color-changing solution is a mixture of colorless antifreeze and a solution of diethylammonium tetrachlorocuprate, the concentration of the solution of diethylammonium tetrachlorocuprate is 5g / L, and the color-changing boundary temperature of the temperature-sensitive color-changing solution is adjusted to 0℃; the temperature-sensitive color-changing solution is bright green below 0℃ and light yellow above 0℃. At least three electromagnetic exciters are arranged on each circle of the refrigeration pipes, and the at least three electromagnetic exciters on each circle are distributed in a circumferential interval; the amplitude of the electromagnetic exciter is 40μm to 70μm, and the vibration frequency is 10kHz to 30kHz. The permeation test device further comprises an upper water-permeable plate and a lower water-permeable plate, the upper water-permeable plate and the lower water-permeable plate are arranged in an interval in the model container, and a soil sample accommodating cavity is formed between the upper water-permeable plate and the lower water-permeable plate. The model container is in the shape of a cylindrical barrel, a plurality of first temperature measuring holes are arranged on one side of the model container, and the first temperature measuring holes are distributed in an interval parallel to the axis of the cylindrical barrel; a plurality of second temperature measuring holes are arranged on the other side of the model container, and the second temperature measuring holes are distributed in an interval parallel to the axis of the cylindrical barrel. Temperature sensors are installed in the first temperature measuring holes and the second temperature measuring holes, the temperature sensor in the first temperature measuring hole is located at the center of the cylindrical barrel, and the temperature sensor in the second temperature measuring hole is located at a position of 1 / 2 of the radius of the cylindrical barrel.

2. The experimental system for simulating artificial frozen ground according to claim 1, characterized in that, An overflow port is further arranged on the upper part of the model container, the overflow port is arranged higher than the surface of the upper water-permeable plate, and the water outlet and the lower water-permeable plate are located at the same horizontal position.

3. The experimental system for simulating artificial frozen ground according to claim 2, characterized in that, The upper water-permeable plate and the lower water-permeable plate are respectively gap-fitted with the inner wall of the model container, and the upper water-permeable plate and the model container and the lower water-permeable plate and the model container are buckle-connected.

4. The experimental system for simulating artificial frozen ground according to claim 1, characterized in that, At least one acoustic emission sensor is arranged on the outside of the model container, and an acoustic emission signal amplifier is electrically connected between the acoustic emission sensor and the data processing host; a temperature acquisition instrument is further electrically connected between the temperature sensor and the data processing host.

5. The experimental system for simulating artificially frozen ground barriers according to claim 1, characterized in that, The freezing wall monitoring system further comprises at least two industrial cameras, which are correspondingly arranged outside the model container and electrically connected to the data processing host.

6. A test method for applying the experimental system of artificial frozen ground simulating the permafrost of any one of claims 1 to 5, characterized in that, The method comprises the following steps: S1, the soil of the test stratum is dried and sieved, the sieved soil particles are mixed with the temperature-sensitive color-changing solution and stirred uniformly, and the soil sample is obtained by sealing and standing for 24 hours; S2, the lower water-permeable plate is placed in the model container and fixed in position, the soil sample is layered and filled into the model container, and when the soil sample is filled to the position of each temperature measuring hole, two rows of temperature sensors are buried at the center depth and the depth of 1 / 2 radius of the model container; when the soil sample is filled to the set height, the upper water-permeable plate is covered on the soil sample and fixed in position; S3, at least one circle of freezing pipes is wound on the model container, the freezing pipes are communicated with the low-temperature cold bath device through the freezing liquid pipeline, and the electromagnetic exciter is fixed on each circle of freezing pipes; S4, the acoustic emission sensor is fixed on the outer wall of the model container, the acoustic emission sensor and the multiple temperature sensors are electrically connected to the data processing host respectively, and the industrial camera is arranged outside the model container and electrically connected to the data processing host, so as to construct the freezing wall monitoring system; S5, open the water inlet valve and set different flow rates, when the liquid flow discharged from the water outlet is stable, start the low-temperature cold bath device and the electromagnetic exciter, and open the freezing wall monitoring system to start the test; S6, during the test, the industrial camera collects image information at regular time intervals to analyze the development of the freezing wall; the water discharge meter is replaced and the reading is recorded every set time interval, and the permeability coefficient k of each time interval is calculated by the following formula: ； Wherein, α is the permeability reduction coefficient of the temperature-sensitive color-changing solution relative to pure water, V is the solution volume of the water discharge meter, L is the filling height of the soil sample, A is the cross-sectional area of the soil sample, Δh is the height difference between the overflow outlet and the water outlet, and t is the seepage time.

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