Freezing simulation system based on coupling effect of temperature field and seepage field

Abstract

The invention discloses a freezing simulation system based on a coupling effect of a temperature field and a seepage field, which is applied to the field of testing and comprises the following steps: enabling clear water to flow through sand at different flow rates by virtue of a clear water circulation system to simulate seepage fields at different flow rates; refrigerants at different temperatures flow through the freezing pipe by using a refrigerant circulating system, and temperature fields at different temperatures are simulated, so that the influence of coupling of the two parts on the development of the freezing wall in the freezing process is explored; in addition, the system can adjust the installation depth of the infrared temperature sensor through a first installation rod and a first sliding frame, thereby facilitating the disassembly and replacement of the infrared temperature sensor. Through a second mounting rod and a second sliding frame, the mounting depth of the pressure sensor can be adjusted, and the pressure sensor is convenient to disassemble and assemble; in addition, a drill bit is arranged at the lower end of the cylinder, a cylinder cover is arranged at the upper end of the cylinder, the overall sinking depth of the detection pipe can be adjusted, the requirement for rapidly arranging and adjusting a temperature and pressure sensor is met, a traditional layered pre-embedding mode is replaced, and the experiment efficiency is effectively improved.

Description

Technical Field

[0001] This invention relates to the field of testing, and in particular to a freezing simulation system based on the coupling effect of temperature field and seepage field. Background Technology

[0002] With the accelerating pace of urbanization in my country, urban subway tunnel projects are increasing, and subway connecting passages constructed using the freezing method are becoming more common. However, the increasingly complex distribution of underground structures and pipelines places higher demands on construction. Among these challenges, excessively high groundwater flow velocity is one of the main difficulties faced by artificial ground freezing methods—groundwater continuously carries away cold energy, leading to slow development and difficulty in closing the frozen wall, and even failing to achieve the designed thickness and strength, seriously affecting construction safety and effectiveness. Given the limitations of traditional brine freezing technology in handling high-velocity groundwater, it is necessary to design and build an indoor experimental device to systematically study the coupling mechanism of the seepage field and temperature field. This device will simulate and verify the influence of key parameters such as different groundwater seepage velocities and different refrigerant temperatures on the formation and development of the frozen wall, especially the development of the frozen wall under the combined action of the seepage field and temperature field. This will provide theoretical basis and data support for optimizing freezing schemes and ensuring project safety.

[0003] Existing simulation experimental devices cannot effectively simulate the impact of the coupled effects of seepage field and temperature field on the development of frozen walls. Summary of the Invention

[0004] The core of this invention lies in solving the problem that existing technologies cannot effectively simulate the coupling effect of seepage field and temperature field through an experimental chamber, a clean water circulation system, and a refrigerant circulation system. At the same time, by integrating an infrared temperature sensor and a pressure sensor into the detection tube, the difficulty of sensor placement and adjustment is reduced.

[0005] To solve the above problems, the present invention adopts the following technical solution.

[0006] A freezing simulation system based on the coupling effect of temperature field and seepage field includes an experimental chamber, a clean water circulation system, a refrigerant circulation system, and a monitoring system. The experimental chamber has a central cavity for filling with sand. A left water storage cavity and a right water storage cavity are respectively opened on both sides of the central cavity. The left and right water storage cavities are connected to the central cavity through seepage holes evenly distributed on the inner wall of the central cavity. Geotextile is fixedly connected to the inner wall of the central cavity to cover the seepage holes and prevent sand from flowing out. The clean water circulation system includes a water pipe connecting the left and right water storage cavities. A water circulation pump, a clean water tank, a temperature sensor, and a flow sensor are connected in series on the water pipe. The refrigerant circulation system includes multiple evenly distributed freezing pipes inserted into the sand. The freezing pipes adopt a double-layer sleeve structure. The freezing pipes are connected in series with the refrigerant circulation pump and the refrigerant tank through the refrigerant pipeline. Temperature sensor 2 and flow sensor 2 are also connected in series on the refrigerant pipeline. The monitoring system includes multiple evenly distributed probes set on the outside of the freezing pipe. Multiple vertically equidistant infrared temperature sensors and multiple vertically equidistant pressure sensors are fixedly connected to the probes. The multiple infrared temperature sensors are used to monitor the temperature of sand layers at different depths, and the multiple pressure sensors are used to monitor the frost heave pressure of sand layers at different depths. A multi-point displacement meter is set on the outside of the probe, which is used to monitor the amount of frost heave deformation of the sand.

[0007] As a further embodiment of the present invention, the experimental chamber is made of steel plate material, and the central cavity is a rectangular box structure with an opening at the top. A heat exchange coil is installed in the refrigerant tank and is connected to an external refrigeration device. The refrigerant tank is filled with alcohol, and the heat exchange coil is filled with liquid nitrogen. A heating rod and a thermocouple are fixedly connected in the clean water tank, and the clean water tank is filled with clean water. The heating rod and the thermocouple are used to adjust the temperature of the clean water to simulate groundwater at different temperatures.

[0008] As a further embodiment of the present invention, the detection tube includes a cylinder, and a temperature detection assembly is installed inside the cylinder. The temperature detection assembly includes a mounting rod that is inserted and fixed to the cylinder. Multiple sliding frames are slidably connected to the mounting rod. The sliding frames are threadedly connected to the mounting rod by positioning bolts. Multiple linearly equidistant bolt holes are opened on the sliding frames. An infrared temperature sensor is fixedly connected to the side wall of the sliding frame facing the inner wall of the cylinder. Detection holes corresponding to the bolt holes are opened on the side wall of the cylinder. A glass plate is fixedly connected inside the detection hole. The emitting end of the infrared temperature sensor is positioned opposite to the glass plate.

[0009] As a further embodiment of the present invention, a pressure detection assembly is also installed inside the cylinder. The pressure detection assembly includes a mounting rod 2 that is rotatably connected to the inner wall of the cylinder. Multiple sliding frames 2 are slidably connected to the mounting rod 2. The sliding frames 2 are threadedly connected to the mounting rod 2 through a threaded rod. Multiple linearly equidistant bolt holes 2 are opened on the mounting rod 2. A sliding groove is opened on the outer wall of the cylinder. A pressing block is slidably connected in the sliding groove. A pressure sensor is abutted against the inner wall of the pressing block. The pressure sensor is fixedly connected to the sliding frame 2.

[0010] As a further embodiment of the present invention, the extrusion block includes an arc-shaped block that is slidably connected to the inner wall of the sliding groove, a connecting rod that slides through the shell wall of the cylinder is fixedly connected to the inner wall of the arc-shaped block, a fan-shaped block is fixedly connected to the inner wall of the connecting rod, and the detection end of the pressure sensor has a hemispherical structure.

[0011] As a further embodiment of the present invention, the outer end of the arc-shaped block is provided with an arc-shaped surface, the arc-shaped surface being equal to the curvature of the outer wall of the cylinder, the connecting rod being a round rod structure, the curvature of the sector block being equal to the curvature of the inner cavity of the cylinder, the threaded rod and the pressure sensor being located at opposite positions on both sides of the sliding frame two, the end of the threaded rod away from the sliding frame two being a hemispherical structure, the threaded rod being configured to cooperate with the sector block, and when the mounting rod two is rotated so that the end of the threaded rod abuts against the inner wall of the sector block, the outer end arc-shaped surface of the arc-shaped block and the outer wall of the cylinder are in the same curved surface.

[0012] As a further embodiment of the present invention, a drill bit is fixedly connected to the lower end of the cylinder, and a cylinder cover is threadedly connected to the upper end of the cylinder. The first mounting rod is a square rod that passes through the cylinder cover and is slidably connected to it. The second mounting rod passes through the cylinder cover and is rotatably connected to it. A rotating shaft is fixedly connected to the lower end of the second mounting rod. A rotating groove for the rotating shaft to rotate is provided on the bottom wall of the cylinder, and a snap-fit ​​groove for the first mounting rod to be inserted is provided on the bottom wall of the cylinder.

[0013] As a further embodiment of the present invention, the second mounting rod is a square rod, and a chuck that abuts against the cylinder cover is sleeved on the second mounting rod. The chuck is fixedly connected to the cylinder cover by a locking bolt.

[0014] As a further embodiment of the present invention, a perforated plate is fixedly connected to the upper end of the experimental box. The perforated plate has evenly distributed mounting holes. Mounting rings are fixedly connected to the outer walls of the freezing tube, the probe tube, and the multi-point displacement meter. The diameter of the mounting rings is larger than the diameter of the mounting holes. The mounting rings are fixedly connected to the perforated plate by bolts.

[0015] Compared with the prior art, the advantages of this invention are: (1) The present invention uses a water circulation system and an experimental chamber to allow water to flow through sand at different flow rates, thereby simulating the seepage field at different flow rates. The invention also uses a refrigerant circulation system to allow refrigerant at different temperatures to flow through the freezing pipe, thereby simulating the temperature field at different temperatures. This facilitates the investigation of the influence of the coupling effect of the seepage field and temperature field on the development of the frozen wall during the freezing process.

[0016] (2) The present invention achieves the adjustment of the installation depth of the infrared temperature sensor through the first mounting rod and the first sliding frame, and facilitates the disassembly and replacement of the infrared temperature sensor; it achieves the adjustment of the installation depth of the pressure sensor through the second mounting rod and the second sliding frame, and facilitates the disassembly and replacement of the pressure sensor; and it facilitates the adjustment of the overall immersion depth of the detection tube through the drill bit installed at the lower end of the cylinder and the cylinder cover installed at the upper end of the cylinder, thereby meeting the needs of rapid arrangement and adjustment of temperature and pressure sensors, replacing the traditional layered pre-embedded sensor installation method, and improving experimental efficiency. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the system piping connection of the present invention; Figure 2 This is a three-dimensional structural diagram of the detector tube from the left side view in this invention; Figure 3 This is a three-dimensional structural diagram of the detector tube from the right side view in this invention; Figure 4 This is a schematic diagram of the internal cross-sectional structure of the probe tube in this invention; Figure 5 This is a schematic diagram of the assembly structure of the infrared temperature sensor and mounting rod one in this invention; Figure 6 for Figure 4 Enlarged structural diagram at point A; Figure 7 This is a schematic diagram of the assembly structure of the pressure sensor and mounting rod 2 in this invention; Figure 8 This is a three-dimensional structural diagram of the extrusion block in this invention.

[0018] Explanation of the numbers in the diagram: 1. Experimental chamber; 101. Central cavity; 102. Left water storage chamber; 103. Right water storage chamber; 104. Seepage hole; 2. Geotextile; 3. Sand; 4. Water pipe; 5. Water circulation pump; 6. Clear water tank; 7. Temperature sensor one; 8. Flow sensor one; 9. Freezing pipe; 10. Refrigerant pipe; 11. Refrigerant circulation pump; 12. Refrigerant tank; 13. Temperature sensor two; 14. Flow sensor two; 15. Perforated plate; 16. Detector tube; 17. Multi-point displacement gauge; 18. Cylinder Body; 1801, Detection hole; 1802, Snap-fit ​​groove; 1803, Sliding groove; 1804, Rotating groove; 19, Drill bit; 20, Glass plate; 21, Mounting rod one; 22, Sliding frame one; 23, Positioning bolt; 24, Infrared temperature sensor; 25, Mounting rod two; 2501, Rotating shaft; 26, Sliding frame two; 27, Threaded rod; 28, Pressure sensor; 29, Extrusion block; 30, Arc-shaped block; 31, Connecting rod; 32, Fan-shaped block; 33, Cylinder cover; 34, Chuck; 35, Locking bolt. Detailed Implementation

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0020] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0021] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "sleeved / connected," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0022] Please see Figure 1 In one embodiment of the present invention, a freezing simulation system based on the coupling effect of temperature field and seepage field includes an experimental chamber 1, a clean water circulation system, a refrigerant circulation system and a monitoring system. The experimental chamber 1 has a central cavity 101 for filling sand 3. The experimental chamber 1 has a left water storage cavity 102 and a right water storage cavity 103 on both sides of the central cavity 101. The left water storage cavity 102 and the right water storage cavity 103 are connected to the central cavity 101 through seepage holes 104 evenly distributed on the inner wall of the central cavity 101. Geotextile 2 is fixedly connected to the inner wall of the central cavity 101. Geotextile 2 is used to cover the seepage holes 104 to prevent sand 3 from flowing out. Please see Figure 1 The clean water circulation system includes a water pipe 4 connecting the left water storage chamber 102 and the right water storage chamber 103. A water circulation pump 5, a clean water tank 6, a temperature sensor 7 and a flow sensor 8 are connected in series on the water pipe 4. Specifically, the water circulation pump 5 injects the clean water in the clean water tank 6 into the left water storage chamber 102 through the water pipe 4. Then, the clean water enters the central chamber 101 through the seepage hole 104. After flowing through the sand material 3 in the central chamber 101, it is discharged from the right water storage chamber 103. The water discharged into the right water storage chamber 103 flows back to the clean water tank 6 through the water pipe 4, realizing the circulation of water flow to simulate the groundwater seepage condition. The temperature sensor 7 is used to monitor the temperature of the clean water, and the flow sensor 8 is used to monitor the flow rate of the clean water. Please see Figure 1The refrigerant circulation system includes multiple evenly distributed freezing pipes 9 inserted into the sand 3. The freezing pipes 9 adopt a double-layer sleeve structure. The freezing pipes 9 are connected in series with the refrigerant circulation pump 11 and the refrigerant tank 12 through the refrigerant pipe 10. Temperature sensor 2 13 and flow sensor 2 14 are also connected in series on the refrigerant pipe 10. Specifically, the refrigerant circulation pump 11 causes the refrigerant to circulate between the freezing pipe 9 and the refrigerant tank 12. The refrigerant circulation pump 11 is used to control the refrigerant flow rate, the refrigerant tank 12 is used to control the temperature of the refrigerant, the temperature sensor 13 is used to monitor the temperature of the flowing refrigerant, and the flow sensor 14 is used to monitor the flow rate of the flowing refrigerant. Please see Figure 1 The monitoring system includes multiple evenly distributed probe tubes 16 set on the outside of the freezing pipe 9. Multiple vertically equidistant infrared temperature sensors 24 and multiple vertically equidistant pressure sensors 28 are fixedly connected to the probe tubes 16. The multiple infrared temperature sensors 24 are used to monitor the temperature of sand layers at different depths, and the multiple pressure sensors 28 are used to monitor the frost heave pressure of sand layers at different depths. A multi-point displacement meter 17 is set on the outside of the probe tubes 16. The multi-point displacement meter 17 is used to monitor the amount of frost heave deformation of the sand.

[0023] Specifically, during the freezing simulation experiment, the flow rate of clean water through the sand 3 is adjusted using a water circulation pump 5 and a flow sensor 8. At the same time, the temperature and flow rate of the refrigerant in the freezing pipe 9 are adjusted by controlling the refrigerant circulation pump 11 and the refrigerant tank 12. This simulates the development of the frozen wall in the sand 3 under different groundwater flow rates, different refrigerant flow rates, and temperatures. The development of the frozen wall is monitored by a multi-point displacement meter 17, a uniformly distributed infrared temperature sensor 24, and a pressure sensor 28. The calculation of the frozen wall thickness by the temperature and frost heave pressure inside the frozen wall is existing technology and will not be described further in this application.

[0024] Compared to traditional freezing simulation experimental devices, this invention features a clean water circulation system and an experimental chamber 1, which allows clean water to flow through sand material 3 at different flow rates, thereby simulating seepage fields at different flow rates. Through a refrigerant circulation system, refrigerants at different temperatures flow through freezing pipes 9, thereby simulating temperature fields at different temperatures. This facilitates the investigation of the influence of the coupling effect of seepage field and temperature field on the development of the frozen wall during the freezing process.

[0025] In this embodiment, the experimental box 1 is made of steel plate material, the central cavity 101 is a rectangular box structure with an opening at the top, and the sand material 3 is coarse sand with a porosity of 30%.

[0026] Specifically, sand material 3 is used to simulate underground soil layers.

[0027] In this embodiment, a heat exchange coil is installed inside the refrigerant tank 12, and the heat exchange coil is connected to an external refrigeration device. The refrigerant tank 12 is filled with alcohol, and the heat exchange coil is filled with liquid nitrogen.

[0028] Specifically, the refrigerant box 12 adopts a secondary refrigeration temperature control method, which uses liquid nitrogen in the heat exchange coil to cool the alcohol in the refrigerant box 12, and then allows the cooled alcohol to flow into the freezing pipe 9 through the refrigerant pipe 10 for freezing. Through the secondary refrigeration temperature control method, the temperature of the refrigerant participating in the freezing is precisely controlled.

[0029] In this embodiment, a heating rod and a thermocouple are fixedly connected inside the clean water tank 6. The clean water tank 6 is filled with clean water. The heating rod and the thermocouple work together to regulate the temperature of the clean water, simulating groundwater at different temperatures.

[0030] In another embodiment of the invention, please refer to Figure 2-8 The detection tube 16 includes a cylinder 18, and a temperature detection assembly is installed inside the cylinder 18. The temperature detection assembly includes a mounting rod 21 that is inserted and fixed to the cylinder 18. Multiple sliding frames 22 are slidably connected to the mounting rod 21. The sliding frames 22 are threadedly connected to the mounting rod 21 by positioning bolts 23. Multiple linearly equidistant bolt holes are opened on the sliding frames 22. An infrared temperature sensor 24 is fixedly connected to the side wall of the sliding frame 22 facing the inner wall of the cylinder 18. A detection hole 1801 corresponding to each bolt hole is opened on the side wall of the cylinder 18. A glass plate 20 is fixedly connected inside the detection hole 1801. The emitting end of the infrared temperature sensor 24 is positioned opposite to the glass plate 20.

[0031] Specifically, by adjusting the position of the sliding frame 22 on the mounting rod 21, the installation height of the infrared temperature sensor 24 can be adjusted to meet the detection requirements of the temperature of sand layers at different depths. This replaces the traditional pre-embedded temperature sensor, improves the flexibility of the temperature detector layout, and allows for quick replacement when the infrared temperature sensor 24 is damaged.

[0032] Please see Figure 4 , Figure 6 , Figure 7 and Figure 8 The cylinder 18 is also equipped with a pressure detection assembly, which includes a mounting rod 25 that is rotatably connected to the inner wall of the cylinder 18. Multiple sliding frames 26 are slidably connected to the mounting rod 25. The sliding frames 26 are threadedly connected to the mounting rod 25 via a threaded rod 27. Multiple linearly equidistant bolt holes 2 are provided on the mounting rod 25. A sliding groove 1803 is provided on the outer wall of the cylinder 18. A pressing block 29 is slidably connected in the sliding groove 1803. A pressure sensor 28 is abutted against the inner wall of the pressing block 29. The pressure sensor 28 is fixedly connected to the sliding frame 26.

[0033] Specifically, by adjusting the height of the sliding frame 26, the installation depth of the pressure sensor 28 can be adjusted to meet the detection of frost heave pressure in sandy soil layers at different depths. At the same time, it is convenient to disassemble and replace the pressure sensor 28.

[0034] Please see Figure 6 , Figure 7 and Figure 8 The extrusion block 29 includes an arc-shaped block 30 that is slidably connected to the inner wall of the sliding groove 1803. A connecting rod 31 that slides through the shell wall of the cylinder 18 is fixedly connected to the inner wall of the arc-shaped block 30. A fan-shaped block 32 is fixedly connected to the inner wall of the connecting rod 31. The detection end of the pressure sensor 28 has a hemispherical structure.

[0035] Specifically, when localized frost heave occurs in the sand material 3, the arc-shaped block 30 is squeezed, and the arc-shaped block 30 squeezes the fan-shaped block 32 through the connecting rod 31. The fan-shaped block 32 squeezes the detection end of the pressure sensor 28 to realize the detection of frost heave pressure.

[0036] Please see Figure 6 and Figure 8 The outer end of the arc-shaped block 30 is provided with an arc-shaped surface, which is equal to the curvature of the outer wall of the cylinder 18. The connecting rod 31 is a round rod structure. The curvature of the fan-shaped block 32 is equal to the curvature of the inner cavity of the cylinder 18. The threaded rod 27 and the pressure sensor 28 are located on opposite sides of the sliding frame 26. The end of the threaded rod 27 away from the sliding frame 26 is a hemispherical structure. The threaded rod 27 is configured to cooperate with the fan-shaped block 32. When the mounting rod 25 is rotated so that the end of the threaded rod 27 abuts against the inner wall of the fan-shaped block 32, the outer arc-shaped surface of the arc-shaped block 30 and the outer wall of the cylinder 18 are in the same curved surface.

[0037] Specifically, during the installation of the cylinder 18, the threaded rod 27 abuts against the sector block 32, making the surface of the cylinder 18 flat and facilitating the installation of the probe tube 16.

[0038] Please see Figure 4 , Figure 6 and Figure 7 A drill bit 19 is fixedly connected to the lower end of the cylinder 18, and a cylinder cover 33 is threadedly connected to the upper end of the cylinder 18. Mounting rod 1 21 is a square rod that passes through the cylinder cover 33 and is slidably connected to it. Mounting rod 25 passes through the cylinder cover 33 and is rotatably connected to it. A rotating shaft 2501 is fixedly connected to the lower end of mounting rod 25. A rotating groove 1804 for rotating shaft 2501 is opened on the bottom wall of the cylinder 18, and a snap-fit ​​groove 1802 for mounting rod 1 21 to be inserted is opened on the bottom wall of the cylinder 18.

[0039] Specifically, when disassembling and assembling the temperature detection component and the pressure detection component, the cylinder cover 33 is screwed on to facilitate disassembly and installation. When installing the cylinder 18, a drilling machine is used to drive the cylinder 18 to rotate, and the drill bit 19 at the lower end of the cylinder 18 causes the cylinder 18 to drill vertically downward, improving the verticality of the cylinder 18 installation.

[0040] Please see Figure 3 , Figure 4 and Figure 7 Mounting rod 25 is a square rod, and mounting rod 25 is fitted with a chuck 34 that abuts against the cylinder cover 33. The chuck 34 is fixedly connected to the cylinder cover 33 by locking bolts 35.

[0041] Specifically, the mounting rod 25 is locked by the chuck 34 and the locking bolt 35 to improve the stability of the pressure sensor 28 installation.

[0042] Please see Figure 1 and Figure 2 The upper end of the experimental chamber 1 is fixedly connected to a perforated plate 15, which has evenly distributed mounting holes. Mounting rings are fixedly connected to the outer walls of the freezing tube 9, the probe tube 16, and the multi-point displacement meter 17. The diameter of the mounting rings is larger than the diameter of the mounting holes. The mounting rings are fixedly connected to the perforated plate 15 by bolts.

[0043] Specifically, the perforated plate 15 is used to position and fix the freezing tube 9, the detection tube 16 and the multi-point displacement meter 17, which facilitates the assembly and construction of the simulation system.

[0044] Compared to traditional freezing simulation experimental systems, this invention uses mounting rod 21 and sliding frame 22 to adjust the installation depth of the infrared temperature sensor 24, facilitating its disassembly and replacement. Mounting rod 25 and sliding frame 26 are used to adjust the installation depth of the pressure sensor 28, also facilitating its disassembly and replacement. Furthermore, the drill bit 19 at the lower end of the cylinder 18 and the cylinder cover 33 at the upper end of the cylinder 18 allow for adjustment of the overall immersion depth of the probe tube 16, meeting the needs for rapid placement and adjustment of temperature and pressure sensors. This replaces the traditional layered pre-embedded sensor installation method, improving experimental efficiency.

[0045] The above description is merely a preferred embodiment of the present invention; however, the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and its improved concepts, should be covered within the scope of protection of the present invention.

Claims

1. A freezing simulation system based on the coupling effect of temperature field and seepage field, characterized in that, The system includes an experimental chamber (1), a clean water circulation system, a refrigerant circulation system, and a monitoring system. The experimental chamber (1) has a central cavity (101) for filling sand (3). The experimental chamber (1) has a left water storage cavity (102) and a right water storage cavity (103) on both sides of the central cavity (101). The left water storage cavity (102) and the right water storage cavity (103) are connected to the central cavity (101) through seepage holes (104) evenly distributed on the inner wall of the central cavity (101). Geotextile (2) is fixedly connected to the inner wall of the central cavity (101). The geotextile (2) is used to cover the seepage holes (104) to prevent the sand (3) from flowing out. The clean water circulation system includes a water pipe (4) connecting the left water storage cavity (102) and the right water storage cavity (103). A water circulation pump (5), a clean water tank (6), a temperature sensor (7), and a flow sensor (8) are connected in series on the water pipe (4). The refrigerant circulation system includes multiple evenly distributed freezing pipes (9) inserted into the sand (3). The freezing pipes (9) adopt a double-layer sleeve structure. The freezing pipes (9) are connected in series with the refrigerant circulation pump (11) and the refrigerant tank (12) through the refrigerant pipeline (10). Temperature sensor II (13) and flow sensor II (14) are also connected in series on the refrigerant pipeline (10). The monitoring system includes multiple evenly distributed probe tubes (16) set on the outside of the freezing tube (9). Multiple vertically equidistant infrared temperature sensors (24) and multiple vertically equidistant pressure sensors (28) are fixedly connected to the probe tubes (16). The multiple infrared temperature sensors (24) are used to monitor the temperature of sand layers at different depths, and the multiple pressure sensors (28) are used to monitor the frost heave pressure of sand layers at different depths. A multi-point displacement meter (17) is set on the outside of the probe tubes (16). The multi-point displacement meter (17) is used to monitor the amount of frost heave deformation of the sand.

2. The freezing simulation system based on the coupling effect of temperature field and seepage field according to claim 1, characterized in that, The experimental chamber (1) is made of steel plate material. The central cavity (101) is a rectangular box structure with an opening at the top. The refrigerant tank (12) is equipped with a heat exchange coil, which is connected to the external refrigeration equipment. The refrigerant tank (12) is filled with alcohol, and the heat exchange coil is filled with liquid nitrogen. The water tank (6) is fixedly connected with a heating rod and a thermocouple. The water tank (6) is filled with water. The heating rod and the thermocouple are used to adjust the temperature of the water to simulate groundwater at different temperatures.

3. The freezing simulation system based on the coupling effect of temperature field and seepage field according to claim 1, characterized in that, The detection tube (16) includes a cylinder (18), and a temperature detection assembly is installed inside the cylinder (18). The temperature detection assembly includes a mounting rod (21) that is inserted and fixed to the cylinder (18). Multiple sliding frames (22) are slidably connected to the mounting rod (21). The sliding frames (22) are threadedly connected to the mounting rod (21) by positioning bolts (23). Multiple linearly equidistant bolt holes are opened on the sliding frames (22). An infrared temperature sensor (24) is fixedly connected to the side wall of the sliding frame (22) facing the inner wall of the cylinder (18). A detection hole (1801) corresponding to the bolt hole is opened on the side wall of the cylinder (18). A glass plate (20) is fixedly connected inside the detection hole (1801). The emitting end of the infrared temperature sensor (24) is set opposite to the glass plate (20).

4. The freezing simulation system based on the coupling effect of temperature field and seepage field according to claim 3, characterized in that, The cylinder (18) is also equipped with a pressure detection assembly. The pressure detection assembly includes a second mounting rod (25) that is rotatably connected to the inner wall of the cylinder (18). Multiple sliding frames (26) are slidably connected to the second mounting rod (25). The sliding frames (26) are threadedly connected to the second mounting rod (25) through a threaded rod (27). Multiple bolt holes (2) are linearly and equidistantly distributed on the second mounting rod (25). A sliding groove (1803) is provided on the outer wall of the cylinder (18). A pressing block (29) is slidably connected in the sliding groove (1803). A pressure sensor (28) is abutted against the inner wall of the pressing block (29). The pressure sensor (28) is fixedly connected to the sliding frame (26).

5. A freezing simulation system based on the coupling effect of temperature field and seepage field according to claim 4, characterized in that, The extrusion block (29) includes an arc-shaped block (30) that is slidably connected to the inner wall of the sliding groove (1803). The inner wall of the arc-shaped block (30) is fixedly connected to a connecting rod (31) that slides through the shell wall of the cylinder (18). The inner wall of the connecting rod (31) is fixedly connected to a fan-shaped block (32). The detection end of the pressure sensor (28) has a hemispherical structure.

6. A freezing simulation system based on the coupling effect of temperature field and seepage field according to claim 5, characterized in that, The outer end of the arc block (30) is provided with an arc surface, which is equal to the curvature of the outer wall of the cylinder (18). The connecting rod (31) is a round rod structure. The curvature of the fan block (32) is equal to the curvature of the inner cavity of the cylinder (18). The threaded rod (27) and the pressure sensor (28) are located at the relative positions on both sides of the sliding frame (26). The end of the threaded rod (27) away from the sliding frame (26) is a hemispherical structure. The threaded rod (27) and the fan block (32) are fitted together. When the mounting rod (25) is rotated so that the end of the threaded rod (27) abuts against the inner wall of the fan block (32), the outer end arc surface of the arc block (30) and the outer wall of the cylinder (18) are in the same curved surface.

7. A freezing simulation system based on the coupling effect of temperature field and seepage field according to claim 4, characterized in that, The lower end of the cylinder (18) is fixedly connected to a drill bit (19), and the upper end of the cylinder (18) is threadedly connected to a cylinder cover (33). Mounting rod one (21) is a square rod. Mounting rod one (21) passes through the cylinder cover (33) and is slidably connected to it. Mounting rod two (25) passes through the cylinder cover (33) and is rotatably connected to it. The lower end of mounting rod two (25) is fixedly connected to a rotating shaft (2501). The bottom wall of the cylinder (18) is provided with a rotating groove (1804) for the rotating shaft (2501) to rotate. The bottom wall of the cylinder (18) is provided with a snap-fit ​​groove (1802) for the mounting rod one (21) to be inserted.

8. A freezing simulation system based on the coupling effect of temperature field and seepage field according to claim 7, characterized in that, The second mounting rod (25) is a square rod, and the second mounting rod (25) is fitted with a chuck (34) that abuts against the cylinder cover (33). The chuck (34) is fixedly connected to the cylinder cover (33) by a locking bolt (35).

9. A freezing simulation system based on the coupling effect of temperature field and seepage field according to claim 1, characterized in that, The upper end of the experimental box (1) is fixedly connected to a perforated plate (15). The perforated plate (15) has evenly distributed mounting holes. The outer walls of the freezing tube (9), the probe tube (16) and the multi-point displacement meter (17) are all fixedly connected to mounting rings. The diameter of the mounting rings is larger than the diameter of the mounting holes. The mounting rings are fixedly connected to the perforated plate (15) by bolts.

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