A large-scale test equipment for frozen soil under multi-field coupling

Abstract

The application discloses a large-scale test equipment for permafrost multi-field coupling, and relates to the technical field of test equipment for cold region engineering geological environment, which comprises a loading test box, a bottom plate assembly arranged at the bottom of the loading test box and a normal loading device arranged above the loading test box. The bottom plate assembly comprises a water permeable plate, a double-sided groove plate and a blocking plate arranged in sequence from top to bottom. The top surface of the double-sided groove plate is provided with a top circulating groove in communication with the permeable holes of the water permeable plate, and the bottom surface is provided with a closed bottom circulating groove. The side walls of the double-sided groove plate are respectively provided with liquid inlet and outlet ports in communication with the top circulating groove and the bottom circulating groove. The normal loading device comprises a temperature control loading plate bottom plate provided with a circulating groove and a normal loading plate for transmitting the normal load. The two are provided with liquid inlet and outlet channels in communication. The application can simultaneously realize the normal loading, temperature control and bottom water replenishment and salt discharge functions of the test body.

Description

Technical Field

[0001] This invention relates to the field of engineering geological environment testing equipment in cold regions, and in particular to a large-scale testing equipment for multi-field coupling effects in frozen soil. Background Technology

[0002] In engineering construction in cold regions, the coupling and feedback effects of multiple fields such as temperature, moisture, salinity, stress, and strain in permafrost sites have always been a core problem that has plagued the academic community. Current experimental equipment and technologies for studying this problem have significant shortcomings: on the one hand, although existing true triaxial testing devices can achieve independent control of the three principal stresses during loading, their specimen size is relatively small, making it difficult to eliminate the influence of size effects on the test results; on the other hand, existing freeze-thaw testing equipment cannot simultaneously meet the needs of precise temperature control, water replenishment and desalination, and dynamic monitoring of multiple physical fields during the loading process, especially in simulating the top-down cooling and freezing heave process and the heating and thawing process in a three-dimensional open system under cold engineering geological conditions.

[0003] Therefore, there is an urgent need for a large-scale testing equipment that can simultaneously perform functions such as loading of large-size specimens, normal temperature control, bottom water replenishment and salt drainage, and horizontal baffle sliding guidance, in order to solve the equipment and technical bottlenecks faced by the current testing equipment in studying the multi-field coupling effects of cold-region engineering environments. Summary of the Invention

[0004] This invention provides a large-scale experimental apparatus for multi-field coupling in frozen soil to solve the technical problem of the inability to coordinate the control of loading, temperature control and water-salt exchange in multi-field coupling tests. It achieves the integration of normal loading and temperature control, bottom water replenishment and salt drainage and temperature gradient simulation, and significantly improves the accuracy and reliability of the test.

[0005] To achieve the above objectives, the present invention provides the following solution: This invention provides a large-scale experimental apparatus for multi-field coupling effects in frozen soil, comprising: Loading the test chamber; The base plate assembly, which is located at the bottom of the loading test chamber, includes a permeable plate, a double-sided groove plate and a blocking plate arranged sequentially from top to bottom; The permeable plate has multiple permeable holes. The top surface of the double-sided trough plate is provided with a top circulation trough, and the bottom surface is provided with a bottom circulation trough; the permeable plate is sealed to the top surface of the double-sided trough plate, and the permeation hole is connected to the top circulation trough; the blocking plate is sealed to the bottom surface of the double-sided trough plate and closes the bottom circulation trough. The side wall of the double-sided trough plate is provided with a bottom liquid inlet and a bottom liquid outlet communicating with the bottom circulation trough, and a water bath liquid inlet and a water bath liquid outlet communicating with the top circulation trough. A normal loading device, located above the loading test chamber, includes: The temperature control loading plate base plate has at least one circulation groove inside, and the circulation groove forms a circulation pipeline inside the temperature control loading plate base plate. A normal loading plate is disposed above the bottom plate of the temperature-controlled loading plate and is used to transfer normal loads. The temperature-controlled loading plate base plate and the normal loading plate are respectively provided with interconnected liquid inlet channels and liquid outlet channels, which are respectively connected to the liquid inlet and liquid outlet of the circulation tank.

[0006] Furthermore, it also includes: A heat-insulating fixing plate is disposed below the base plate assembly and located at the bottom of the blocking plate; The base plate assembly is mounted on the heat insulation fixing plate.

[0007] Furthermore, it also includes: A guide slide is arranged around the base plate assembly and is adapted to the thickness of the base plate assembly; The upper surface of the guide slide is used to support the horizontal loading plate and provide sliding guidance for the horizontal loading plate; The side wall of the guide slide has channels corresponding to the positions of the bottom liquid inlet, bottom liquid outlet, water bath liquid inlet, and water bath liquid outlet.

[0008] Furthermore, both the guide slide and the base plate assembly are mounted on the heat insulation fixing plate.

[0009] Furthermore, the normal loading device also includes a normal anti-overflow plate, which is disposed on the top surface of the loading test chamber and arranged around the periphery of the temperature control loading plate bottom plate; the normal anti-overflow plate is connected to a lifting cylinder, which can be raised and lowered under the drive of the lifting cylinder and make sealed contact with the top surface of the loading test chamber.

[0010] Furthermore, the temperature control loading plate base plate is provided with four independent circulation grooves, which are respectively distributed in four different areas of the temperature control loading plate base plate.

[0011] Furthermore, the top circulation groove and the bottom circulation groove are respectively U-shaped grooves.

[0012] Furthermore, the top circulation groove and the bottom circulation groove provided on the double-sided groove plate at least partially overlap in horizontal projection.

[0013] The present invention achieves the following technical effects compared to the prior art: First, the present invention combines the temperature-controlled loading plate base plate and the normal loading plate by setting a normal loading device above the loading test chamber. The circulation tank inside the temperature-controlled loading plate base plate can be circulated with circulating liquid to control the temperature of the test body. At the same time, the normal loading plate can apply a normal load to the test body, realizing the integration of loading and temperature control functions, and solving the problem that the loading device in the prior art cannot accurately control the temperature of the test body at the same time.

[0014] Secondly, the present invention uses a combination structure of a permeable plate, a double-sided groove plate and a blocking plate set at the bottom of the loading test chamber. The top circulation groove set on the top surface of the double-sided groove plate is connected to the permeable holes of the permeable plate, which can freely replenish water and salt to the test body. At the same time, the test body can also freely drain water and remove salt, which truly simulates the water and salt exchange conditions of an open system in a cold engineering geological environment.

[0015] Third, the invention uses a bottom circulation tank set on the bottom surface of the double-sided trough plate to allow circulating liquid to be introduced to maintain a constant temperature at the bottom of the test body. Combined with the normal loading device, it achieves a temperature gradient from top to bottom, realistically simulating the cooling and freezing heave process and the heating and thawing process of the earth's surface under natural working conditions. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the overall structure of the large-scale experimental equipment for multi-field coupling of frozen soil in an embodiment of the present invention.

[0018] Figure 2 This is a schematic diagram of the internal circulation groove of the temperature control loading plate bottom plate in an embodiment of the present invention.

[0019] Figure 3 This is a top view of the loading test chamber in an embodiment of the present invention.

[0020] Figure 4 This is a structural schematic diagram of the loading test chamber from another angle in an embodiment of the present invention.

[0021] Figure 5 This is a schematic diagram of the top circulation groove of the double-sided groove plate in an embodiment of the present invention.

[0022] Figure 6 This is a schematic diagram of the side structure of the double-sided groove plate in an embodiment of the present invention.

[0023] Figure 7This is a schematic diagram of the bottom circulation groove of the double-sided groove plate in an embodiment of the present invention.

[0024] Figure 8 This is a schematic diagram of the permeable plate in an embodiment of the present invention.

[0025] Figure 9 This is a schematic diagram of the blockage plate in an embodiment of the present invention.

[0026] The components include: 1. Loading test chamber; 2. Permeable plate; 3. Double-sided groove plate; 4. Blocking plate; 5. Top circulation groove; 6. Bottom circulation groove; 7. Permeation hole; 8. Water bath inlet; 9. Water bath outlet; 10. Bottom inlet; 11. Bottom outlet; 12. Temperature-controlled loading plate base plate; 13. Circulation groove; 14. Normal loading plate; 15. Heat insulation fixing plate; 16. Guide slide; 17. Horizontal loading enclosure plate; 18. Normal overflow prevention plate. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] The purpose of this invention is to provide a large-scale experimental equipment for multi-field coupling in frozen soil, so as to solve the technical problem that loading, temperature control and water-salt exchange cannot be controlled in a coordinated manner in multi-field coupling tests, and to achieve the effects of integrating normal loading and temperature control, bottom water replenishment and salt drainage and temperature gradient simulation, and significantly improving the accuracy and reliability of the test.

[0029] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] This invention provides a large-scale experimental apparatus for multi-field coupling effects in frozen soil, such as... Figures 1 to 9 As shown, the large-scale experimental equipment for multi-field coupling effects in frozen soil includes a loading test chamber 1. The loading test chamber 1 is used to accommodate the frozen soil test specimen and is the main space where multi-field coupling effects occur during the experiment. The dimensions of the loading test chamber 1 can be set according to experimental requirements. In this embodiment, the dimensions of the loading test chamber 1 are set to accommodate large-sized specimens to eliminate the influence of size effects on the experimental results.

[0031] like Figure 1 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 , Figure 9 As shown, the bottom of the loading test chamber 1 is provided with a bottom plate assembly. The bottom plate assembly includes a permeable plate 2, a double-sided groove plate 3, and a blocking plate 4 arranged sequentially from top to bottom. The permeable plate 2 is located at the top layer and is in direct contact with the test object; the double-sided groove plate 3 is located in the middle layer and plays a role in temperature control and water-salt exchange; the blocking plate 4 is located at the bottom layer and seals the bottom surface of the double-sided groove plate 3.

[0032] Specifically, such as Figure 8 As shown, the permeable plate 2 has multiple permeation holes 7 distributed on it. The permeation holes 7 penetrate the upper and lower surfaces of the permeable plate 2, connecting the test specimen above to the top circulation tank 5 below, allowing the test specimen to be replenished with water and salt, or drained and desalted, through the permeation holes 7. The number and distribution density of the permeation holes 7 can be designed according to the required permeation rate for the experiment. In this embodiment, the permeation holes 7 are evenly distributed across the entire surface of the permeable plate 2 to ensure the uniformity of water-salt exchange.

[0033] like Figure 5 and Figure 7 As shown, the top surface of the double-sided trough plate 3 is provided with a top circulation trough 5, and the bottom surface is provided with a bottom circulation trough 6. The top circulation trough 5 is used to receive water or salt solution that permeates from the permeable plate 2, and is also used to supply water or salt solution to the test body; the bottom circulation trough 6 is used to introduce circulating liquid to control the temperature at the bottom of the test body.

[0034] like Figure 5 , Figure 7 and Figure 8 As shown, the permeable plate 2 is sealed to the top surface of the double-sided groove plate 3, and the permeation hole 7 is connected to the top circulation groove 5. The lower opening of the permeation hole 7 faces the cavity of the top circulation groove 5, so that water or salt solution seeping from the test body can enter the top circulation groove 5 through the permeation hole 7. Conversely, water or salt solution supplied from the outside can also enter the test body through the top circulation groove 5 and the permeation hole 7.

[0035] The blocking plate 4 is sealed to the bottom surface of the double-sided groove plate 3, thus sealing the bottom circulation groove 6. The upper surface of the blocking plate 4 is sealed and fixed to the lower surface of the double-sided groove plate 3, so that the bottom circulation groove 6 forms a closed circulation chamber, in which the circulating fluid can flow without leakage.

[0036] like Figure 5 and Figure 6As shown, the sidewall of the double-sided trough plate 3 is provided with a bottom inlet 10 and a bottom outlet 11 communicating with the bottom circulation trough 6, and a water bath inlet 8 and a water bath outlet 9 communicating with the top circulation trough 5. The bottom inlet 10 and the bottom outlet 11 are used to input and output circulating fluid into the bottom circulation trough 6, respectively. The circulating fluid can be antifreeze or other liquids with good heat transfer properties. The flow of the circulating fluid heats or cools the double-sided trough plate 3, thereby indirectly controlling the temperature of the bottom of the test body through the permeable plate 2. The water bath inlet 8 and the water bath outlet 9 are used to input and output water or salt solution into the top circulation trough 5, respectively, to replenish water and salt to the test body, and also to drain water or salt solution that seeps out from the test body.

[0037] like Figure 1 and Figure 2 As shown, a normal loading device is provided above the loading test chamber 1. The normal loading device includes a temperature-controlled loading plate base 12 and a normal loading plate 14.

[0038] like Figure 2 As shown, the temperature-controlled loading plate base 12 has at least one circulation groove 13 inside, forming a circulation pipeline within the temperature-controlled loading plate base 12. The circulation groove 13 can be configured as a U-shaped groove, a spiral groove, or other groove-shaped structure that can uniformly distribute the circulating fluid. A circulating fluid, such as antifreeze, is circulated into the circulation groove 13. The flow of the circulating fluid heats or cools the temperature-controlled loading plate base 12, thereby controlling the temperature of the upper surface of the test object in contact with it. By controlling the temperature and flow rate of the circulating fluid, precise cooling or heating of the upper surface of the test object can be achieved.

[0039] The normal loading plate 14 is disposed above the temperature-controlled loading plate base plate 12 and is used to transfer the normal load. A loading drive device (such as a dynamic hydraulic cylinder) is connected above the normal loading plate 14. The normal load applied by the loading drive device is transferred through the normal loading plate 14 to the temperature-controlled loading plate base plate 12, and then to the test object, so as to realize the normal static loading or dynamic loading of the test object.

[0040] The temperature-controlled loading plate base plate 12 and the normal loading plate 14 are respectively provided with interconnected liquid inlet and liquid outlet channels, which are respectively connected to the liquid inlet and liquid outlet of the circulation tank 13. Specifically, the liquid inlet channel runs through the temperature-controlled loading plate base plate 12 and the normal loading plate 14, with one end connected to the external circulating liquid supply system and the other end connected to the liquid inlet of the circulation tank 13; similarly, the liquid outlet channel runs through both, with one end connected to the liquid outlet of the circulation tank 13 and the other end connected to the external circulating liquid recovery system. With this design, the circulating liquid can enter the circulation tank 13 from the external supply system through the liquid inlet channel, flow in the circulation tank 13 and complete heat exchange, and then return to the external recovery system through the liquid outlet channel, realizing recycling.

[0041] Using the above technical solution, the large-scale experimental equipment for multi-field coupling effects in frozen soil in this embodiment first places the prepared frozen soil test specimen in the loading test chamber 1, so that the bottom of the test specimen is in contact with the permeable plate 2. A normal load is applied to the test specimen through the normal loading device to simulate the pressure of the overlying soil layer or engineering load. Simultaneously, circulating fluid is introduced through the circulation tank 13 in the bottom plate 12 of the temperature-controlled loading plate to control the temperature of the upper surface of the test specimen; circulating fluid is introduced through the bottom circulation tank 6 to control the temperature of the bottom of the test specimen; and water and salt are replenished or drained through the permeation holes 7 of the top circulation tank 5 and the permeable plate 2. Thus, a comprehensive simulation of the normal loading, temperature gradient control, and water-salt exchange conditions of the test specimen is achieved, realistically reproducing the multi-field coupling process under cold-region engineering geological environments.

[0042] As an example of an implementable approach, such as Figure 4 As shown, this embodiment also includes a heat-insulating fixing plate 15. The heat-insulating fixing plate 15 is disposed below the base plate assembly and located at the bottom of the blocking plate 4. The base plate assembly is mounted on the heat-insulating fixing plate 15. The heat-insulating fixing plate 15 is made of a material with excellent heat insulation performance, such as a high and low temperature resistant heat insulation board, and its thickness can be selected according to the heat insulation requirements. The bottom of the heat-insulating fixing plate 15 is fixed to the worktable, serving to support the entire base plate assembly and provide heat insulation. During operation, when the circulating liquid in the bottom circulation tank 6 controls the temperature of the bottom of the test object, the heat-insulating fixing plate 15 can effectively block the downward transfer of heat, reduce heat loss, and improve temperature control accuracy and energy efficiency. At the same time, the heat-insulating fixing plate 15 can also firmly fix the base plate assembly to the worktable, ensuring the stability of the equipment during the test.

[0043] As an example of an implementable approach, such as Figure 3 and Figure 4As shown, this embodiment also includes a guide slide 16. The guide slide 16 is arranged around the base plate assembly and is adapted to the thickness of the base plate assembly. Specifically, the guide slide 16 is configured as a frame structure, with its inner contour matching the outer periphery of the base plate assembly. The height of the guide slide 16 is basically consistent with the overall thickness of the base plate assembly, so that the upper surface of the guide slide 16 is approximately flush with the upper surface of the permeable plate 2. The upper surface of the guide slide 16 is used to support the horizontal loading enclosure 17 and provide sliding guidance for the horizontal loading enclosure 17. There are four horizontal loading enclosures 17, corresponding to the four directions of positive X, negative X, positive Y, and negative Y, respectively. The lower edge of each horizontal loading enclosure 17 is in sliding contact with the upper surface of the guide slide 16. During horizontal loading, the horizontal loading hydraulic cylinder pushes the horizontal loading enclosure 17 to move along the upper surface of the guide slide 16 towards the test object, applying a horizontal load to the test object. The outer surface of the horizontal loading plate 17 can be provided with a friction-reducing structure (such as a linear friction-reducing guide rail) to reduce the friction between the horizontal loading plate 17 and the horizontal loading element when the horizontal loading plate 17 slides, and to provide sliding guidance, facilitating the adjustment of the position of the horizontal loading plate 17 during the experiment. The side wall of the guide slide 16 has channels corresponding to the positions of the bottom liquid inlet 10, the bottom liquid outlet 11, the water bath liquid inlet 8, and the water bath liquid outlet 9. These channels are used to avoid pipeline connections, allowing external pipelines to pass through the guide slide 16 and smoothly connect to the various liquid inlets and outlets on the side wall of the double-sided tank plate 3, avoiding pipeline interference.

[0044] As an example of an implementable approach, such as Figure 4 As shown, both the guide slide 16 and the base plate assembly are mounted on the heat-insulating fixing plate 15. Specifically, the upper surface of the heat-insulating fixing plate 15 simultaneously supports the base plate assembly and the guide slide 16. The base plate assembly is located in the central area of ​​the heat-insulating fixing plate 15, and the guide slide 16 is arranged around the outer periphery of the base plate assembly. The three can be connected by bolts or other detachable fixing methods for easy disassembly and maintenance. This integrated installation method ensures the relative positional accuracy between the base plate assembly and the guide slide 16, ensuring that the horizontal loading enclosure 17 can slide smoothly along the guide slide 16 without jamming. At the same time, the heat-insulating fixing plate 15 also provides heat insulation for the guide slide 16, preventing heat transfer between the base plate assembly and the guide slide 16 from affecting the test accuracy.

[0045] As an example of an implementable approach, such as Figure 1As shown, the normal loading device also includes a normal overflow plate 18. The normal overflow plate 18 is disposed on the top surface of the loading test chamber 1 and arranged around the periphery of the temperature-controlled loading plate base plate 12. The normal overflow plate 18 has a frame-shaped structure, and its inner side maintains an appropriate gap with the outer periphery of the temperature-controlled loading plate base plate 12, allowing the temperature-controlled loading plate base plate 12 to move up and down within the frame of the normal overflow plate 18. The normal overflow plate 18 is connected to a lifting cylinder, which can be raised and lowered under the drive of the lifting cylinder, and makes sealed contact with the top surface of the loading test chamber 1. Specifically, the lifting cylinders are symmetrically arranged on both sides of the normal overflow plate 18. During the test preparation stage, the lifting cylinders drive the normal overflow plate 18 to rise, leaving space for the loading and movement of the test specimen; after the test specimen is in place, the lifting cylinders drive the normal overflow plate 18 to fall, so that its lower surface is tightly fitted with the top surface of the loading test chamber 1, forming a sealed structure. During normal loading, the temperature control loading plate bottom plate 12 moves downward through the hollow part of the normal overflow plate 18 to apply normal load to the test body. Since the normal overflow plate 18 is in sealed contact with the top surface of the loading test chamber 1, it can effectively prevent the test body from overflowing from the top during the pressure process, and also plays the role of heat preservation and preventing external interference.

[0046] As an example of an implementable approach, such as Figure 2 As shown, the temperature-controlled loading plate base 12 is equipped with four independent circulation tanks 13, which are distributed in four different areas of the temperature-controlled loading plate base 12. Each of the four circulation tanks 13 can be controlled independently, and each circulation tank 13 has an independent inlet and outlet, connected to the inlet and outlet channels respectively. By partitioning the circulation tanks 13, differentiated temperature control can be achieved for different areas of the temperature-controlled loading plate base 12. For example, when simulating a non-uniform temperature field, circulating liquids of different temperatures or flow rates can be introduced into the circulation tanks 13 in different areas, allowing different locations on the surface of the test specimen to obtain different temperatures, thus more realistically simulating complex temperature distribution conditions under natural working conditions. The four circulation tanks 13 can be symmetrically distributed, for example, divided according to four quadrants, for ease of control and analysis.

[0047] As an example of an implementable approach, such as Figure 5 and Figure 7As shown, the top circulation tank 5 and the bottom circulation tank 6 are both loop-shaped tanks. A loop-shaped tank refers to a structure in which the channels are distributed in a rectangular ring, that is, the channels are arranged along the four edges of the double-sided tank plate 3 to form a closed loop. The design of the loop-shaped tank can maximize the contact area between the circulating liquid and the double-sided tank plate 3, thereby improving the heat exchange efficiency. At the same time, the loop-shaped tank has a simple structure and is easy to process and seal. For the top circulation tank 5, the loop-shaped tank can make the water or salt solution evenly distributed throughout the entire plate surface, and uniformly replenish water and salt to the test body through the permeable holes 7 of the permeable plate 2; for the bottom circulation tank 6, the loop-shaped tank can make the circulating liquid flow evenly, thereby achieving uniform control of the temperature at the bottom of the test body.

[0048] As an implementable example, the top circulation groove 5 and the bottom circulation groove 6 provided on the double-sided groove plate 3 at least partially overlap in horizontal projection. Specifically, the top circulation groove 5 and the bottom circulation groove 6 can be configured as an overlapping structure, or as a staggered arrangement. The advantage of overlapping is that when rapid heating or cooling of the bottom of the test specimen is required, the liquid in the top circulation groove 5 and the bottom circulation groove 6 can synergistically heat or cool the same area of ​​the double-sided groove plate 3, improving the thermal response speed. At the same time, overlapping can also reduce the overall thickness of the double-sided groove plate 3, making the structure more compact. In this embodiment, both the top circulation groove 5 and the bottom circulation groove 6 adopt a U-shaped groove structure, and they completely overlap in horizontal projection, that is, the bottom circulation groove 6 is provided directly below the top circulation groove 5, and the two are separated only by the middle layer of the double-sided groove plate 3, which can achieve optimal temperature control efficiency.

[0049] The structures, connections, or operation methods not described in detail in this invention can be superimposed on each other without interference, and these adaptive changes all fall within the protection scope of this invention. For those skilled in the art, based on the concept of this invention, there will be changes in specific implementation methods and application scope. Therefore, the content of this specification should not be construed as limiting the invention.

Claims

1. A large-scale experimental apparatus for multi-field coupling effects in frozen soil, characterized in that, include: Loading test chamber (1); The bottom plate assembly, which is located at the bottom of the loading test chamber (1), includes a permeable plate (2), a double-sided groove plate (3) and a blocking plate (4) arranged sequentially from top to bottom. The permeable plate (2) has multiple permeable holes (7) distributed on it. The top surface of the double-sided trough plate (3) is provided with a top circulation trough (5), and the bottom surface is provided with a bottom circulation trough (6); the permeable plate (2) is sealed to the top surface of the double-sided trough plate (3), and the permeation hole (7) is connected to the top circulation trough (5); the blocking plate (4) is sealed to the bottom surface of the double-sided trough plate (3) and closes the bottom circulation trough (6); The side wall of the double-sided trough plate (3) is provided with a bottom liquid inlet (10) and a bottom liquid outlet (11) communicating with the bottom circulation trough (6), and a water bath liquid inlet (8) and a water bath liquid outlet (9) communicating with the top circulation trough (5). A normal loading device, located above the loading test chamber (1), includes: The temperature control loading plate base plate (12) has at least one circulation groove (13) inside it, and the circulation groove (13) forms a circulation pipeline inside the temperature control loading plate base plate (12); A normal loading plate (14) is disposed above the temperature control loading plate base plate (12) for transmitting normal loads; The temperature-controlled loading plate base plate (12) and the normal loading plate (14) are respectively provided with interconnected liquid inlet channels and liquid outlet channels, which are respectively connected to the liquid inlet and liquid outlet of the circulation tank (13).

2. The large-scale experimental equipment for multi-field coupling effects in frozen soil according to claim 1, characterized in that, Also includes: A heat-insulating fixing plate (15) is disposed below the base plate assembly and at the bottom of the blocking plate (4); The base plate assembly is mounted on the heat insulation fixing plate (15).

3. The large-scale experimental equipment for multi-field coupling effects in frozen soil according to claim 2, characterized in that, Also includes: A guide slide (16) is arranged around the base plate assembly and is adapted to the thickness of the base plate assembly; The upper surface of the guide slide (16) is used to support the horizontal loading enclosure (17) and provide sliding guidance for the horizontal loading enclosure (17); The side wall of the guide slide (16) has channels corresponding to the positions of the bottom liquid inlet (10), the bottom liquid outlet (11), the water bath liquid inlet (8), and the water bath liquid outlet (9).

4. The large-scale experimental equipment for multi-field coupling effects in frozen soil according to claim 3, characterized in that, Both the guide slide (16) and the base plate assembly are mounted on the heat insulation fixing plate (15).

5. The large-scale experimental equipment for multi-field coupling effects in frozen soil according to claim 1, characterized in that, The normal loading device also includes a normal anti-overflow plate (18), which is disposed on the top surface of the loading test chamber (1) and arranged around the periphery of the temperature control loading plate bottom plate (12); the normal anti-overflow plate (18) is connected to a lifting cylinder, which can be lifted and lowered under the drive of the lifting cylinder and make sealed contact with the top surface of the loading test chamber (1).

6. The large-scale experimental equipment for multi-field coupling effects in frozen soil according to claim 1, characterized in that, The temperature control loading plate base plate (12) is provided with four independent circulation grooves (13), which are respectively distributed in four different areas of the temperature control loading plate base plate (12).

7. The large-scale experimental equipment for multi-field coupling effects in frozen soil according to claim 1, characterized in that, The top circulation groove (5) and the bottom circulation groove (6) are respectively spiral grooves.

8. The large-scale experimental equipment for multi-field coupling effects in frozen soil according to claim 1, characterized in that, The top circulation groove (5) and the bottom circulation groove (6) provided on the double-sided groove plate (3) overlap at least partially in the horizontal projection.

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