Consolidation test device for unidirectional freezing and thawing of coarse-grained soil

Abstract

The utility model discloses a consolidation test device for unidirectional freezing and thawing of coarse-grained soil, and relates to the technical field of mechanical tests for measuring soil under freezing and thawing cycles. The problems that indexes such as the compression coefficient and the consolidation coefficient of coarse-grained soil under different loads under the unidirectional freezing and thawing cycle cannot be tested, and the test condition cannot simulate the actual engineering boundary requirement, so that the credibility and the accuracy of a measurement result are low are solved. A constant-temperature water supplementing bottom plate is arranged at the top end of the base, the upper surface of the constant-temperature water supplementing bottom plate is fixedly connected with the opening end of the sample cylinder, a water permeable plate is arranged in the center of the upper surface of the constant-temperature water supplementing bottom plate, the outer surface of the sample cylinder is sleeved with a heat preservation cylinder, and the bottom surface of the heat preservation cylinder is fixedly connected with the upper surface of the constant-temperature water supplementing bottom plate; a through hole is machined in the center of the upper surface of the temperature control top plate, a pressure rod is arranged in the through hole, a displacement sensor is arranged at one end of the upper surface of the temperature control top plate, and a plurality of temperature sensors are arranged on the outer wall of the sample cylinder. The device is suitable for the technical field of mechanics experiments.

Description

Technical Field

[0001] This utility model relates to the field of mechanical testing technology for soil under freeze-thaw cycles, and specifically to a consolidation test device for coarse-grained soil under unidirectional freeze-thaw cycles. Background Technology

[0002] In seasonally frozen soil regions, freeze-thaw damage to foundation soils for projects such as dams, embankments, and roads is a prominent issue. These foundation soils are primarily composed of coarse-grained soils with varying particle sizes and a certain gradation. Seasonal temperature variations significantly impact the temperature and moisture fields of the foundation soil. Influenced by summer rainfall and groundwater recharge, the foundation soil is often saturated or even supersaturated, especially in foundations with poor drainage, where the soil has high water content and pore water pressure before freezing. When temperatures drop below freezing, the water in the soil freezes and expands, causing significant frost heave deformation. Spring temperatures fluctuate between positive and negative, causing the foundation soil to undergo freeze-thaw cycles, altering its pore structure and exhibiting higher compressibility and reduced shear strength. Under load, this results in varying degrees of settlement and damage, significantly impacting the normal operation of the project. To accurately assess the settlement deformation of coarse-grained soils, it is necessary to accurately and objectively test the changes in consolidation characteristics under freeze-thaw conditions.

[0003] Currently, there are relevant technical standards in China that can guide the testing of the consolidation performance of coarse-grained soil under normal conditions. However, there are no unified technical standards for testing the consolidation performance of coarse-grained soil under freeze-thaw cycles, and research on test devices for simulating unidirectional freezing and thawing of coarse-grained soil in seasonally frozen soil regions has not been reported. Testing the consolidation characteristics of coarse-grained soil under freeze-thaw cycles and loads in engineering projects in seasonally frozen soil regions requires special treatment of the test device; current testing methods cannot meet the requirements.

[0004] In summary, existing technologies cannot test the compression coefficient, consolidation coefficient, and other indicators of coarse-grained soil under different loads during unidirectional freeze-thaw cycles, and the test conditions cannot simulate the requirements of actual engineering boundaries, resulting in low reliability and accuracy of the measurement results. Utility Model Content

[0005] This invention addresses the problem that existing technologies cannot test the compression coefficient, consolidation coefficient, and other indicators of coarse-grained soil under different loads during unidirectional freeze-thaw cycles, and that the test conditions cannot simulate the requirements of actual engineering boundaries, resulting in low reliability and accuracy of measurement results. Therefore, this invention proposes a consolidation test device for coarse-grained soil under unidirectional freeze-thaw cycles.

[0006] This utility model discloses a consolidation test device for unidirectional freeze-thaw of coarse-grained soil, which comprises a base 1, a constant temperature water supply base plate 3, a permeable plate 4, a sample cylinder 5, a heat insulation cylinder 7, a temperature control top plate 8, a displacement sensor 9, a pressure rod 10, and a temperature sensor 12.

[0007] The top of the base 1 is provided with a constant temperature water supply plate 3. The sample tube 5 and the heat preservation tube 7 are both cylindrical with openings at the top and bottom. The upper surface of the constant temperature water supply plate 3 is fixedly connected to one open end of the sample tube 5. A water permeable plate 4 is provided in the center of the upper surface of the constant temperature water supply plate 3, and the water permeable plate 4 is located inside the sample tube 5. The heat preservation tube 7 is fitted on the outer surface of the sample tube 5. The bottom surface of the heat preservation tube 7 is fixedly connected to the upper surface of the constant temperature water supply plate 3. A temperature control plate 8 is embedded in the other end of the sample tube 5. A through hole is machined in the center of the upper surface of the temperature control plate 8. A pressure rod 10 is provided inside the through hole. A displacement sensor 9 is provided at one end of the upper surface of the temperature control plate 8. n temperature sensors 12 are evenly provided along the length direction on the outer wall of the sample tube 5, where n is a positive integer.

[0008] Furthermore, the number n of temperature sensors 12 on the outer wall of the sample cylinder 5 is 4≤n≤10;

[0009] Furthermore, the constant temperature water supply base plate 3 includes an upper base plate 3-1 and a lower base plate 3-2. The upper base plate 3-1 and the lower base plate 3-2 are fixedly connected by bolts. The upper surface of the upper base plate 3-1 is evenly provided with an upper base plate drain port 3-1-1 and an upper base plate water supply port 3-1-2 along the circumferential direction. The lower surface of the upper base plate 3-1 is machined with a spiral groove. The first end of the spiral groove is machined with an upper base plate coolant inlet 3-1-4, and the end of the spiral groove is machined with an upper base plate coolant outlet 3-1-3.

[0010] Furthermore, the upper surface of the lower base plate 3-2 is uniformly provided with a lower base plate drain outlet 3-2-1 and a lower base plate water inlet 3-2-4 along the circumferential direction, and the lower surface of the lower base plate 3-2 is machined with a lower base plate coolant inlet 3-2-3 and a lower base plate coolant outlet 3-2-2.

[0011] Furthermore, the lower bottom plate refrigerant inlet 3-2-3 of the lower bottom plate 3-2 is connected to the upper bottom plate refrigerant inlet 3-1-4 of the upper bottom plate 3-1, and the lower bottom plate refrigerant outlet 3-2-2 of the lower bottom plate 3-2 is connected to the upper bottom plate refrigerant outlet 3-1-3 of the upper bottom plate 3-1.

[0012] Furthermore, the lower bottom plate 3-2 has a water pipe 2 for its lower bottom plate drain outlet 3-2-1 and lower bottom plate water inlet 3-2-4 respectively;

[0013] Furthermore, the lower base plate 3-2 is provided with a first-level refrigerant transport pipe 13 at the lower base plate refrigerant inlet 3-2-3 and the lower base plate refrigerant outlet 3-2-2 respectively;

[0014] Furthermore, the temperature control top plate 8 includes an upper temperature control top plate 8-1 and a lower temperature control top plate 8-2, which are fixedly connected by bolts.

[0015] Furthermore, the upper surface of the upper part 8-1 of the temperature control top plate is machined with an upper top plate refrigerant outlet 8-1-2 and an upper top plate refrigerant inlet 8-1-3, and four countersunk through holes 8-1-1 are uniformly machined along the circumferential direction on the upper surface of the upper part 8-1 of the temperature control top plate; the upper top plate refrigerant outlet 8-1-2 and the upper top plate refrigerant inlet 8-1-3 on the upper surface of the upper part 8-1 of the temperature control top plate are respectively provided with a second refrigerant transport pipe 11;

[0016] Furthermore, the upper surface of the lower part 8-2 of the temperature control top plate is machined with a spiral groove, the first end of the spiral groove is machined with a lower top plate coolant inlet 8-2-1, the end of the spiral groove is machined with a lower top plate coolant outlet 8-2-2, and the upper surface of the lower part 8-2 of the temperature control top plate is uniformly machined with four threaded holes along the circumferential direction.

[0017] The lower top plate refrigerant inlet 8-2-1 of the lower part 8-2 of the temperature control top plate is connected to the upper top plate refrigerant inlet 8-1-3 of the upper part 8-1 of the temperature control top plate, and the lower top plate refrigerant outlet 8-2-2 of the lower part 8-2 of the temperature control top plate is connected to the upper top plate refrigerant outlet 8-1-2 of the upper part 8-1 of the temperature control top plate.

[0018] Furthermore, firstly, filter paper or non-woven fabric is placed on the upper surface of the permeable plate 4, and then the sample 6 is poured into the interior of the sample tube 5. A displacement sensor 9 is provided at one end of the upper surface of the temperature control top plate 8, and multiple temperature sensors 12 are uniformly arranged along the length direction on the outer wall of the sample tube 5, so as to monitor the deformation and temperature of the sample 6 inside the sample tube 5 in real time through the displacement sensor 9 and the temperature sensor 12. The sample 6 is compacted and formed inside the sample tube 5.

[0019] Then, the temperature control top plate 8 is placed on the sample 6, so that the two are in close contact. Then, a heat insulation cylinder 7 is fitted on the outer surface of the sample cylinder 5. The bottom surface of the heat insulation cylinder 7 is fixedly connected to the upper surface of the constant temperature water replenishment base plate 3, and there is a certain gap cavity between the heat insulation cylinder 7 and the sample cylinder 5, so that the sample 6 is insulated and heat-preserved. A one-way freeze-thaw cycle is performed from top to bottom. The displacement sensor 9 is installed on the temperature control top plate and connected to the data acquisition instrument to monitor the freeze-thaw deformation and compression deformation of the sample in real time. The temperature control top plate 8 is connected to the freeze-thaw testing machine. By setting different temperature control modes such as constant temperature, linear, and sinusoidal, the deformation performance of the sample 6 under different freeze-thaw modes can be tested.

[0020] Finally, the constant temperature water replenishment base plate 3 connects to the constant temperature testing machine and the water replenishment bottle to achieve constant temperature compensation and water replenishment at the bottom of the sample 6 during the unidirectional freeze-thaw process. The pressure rod 10 on the upper part of the temperature control top plate 8 contacts the pressure testing machine to apply pressure, enabling the sample 6 to be tested for indicators such as the compression coefficient and consolidation coefficient under different pressure conditions. During the test, the data acquisition instrument automatically records the readings and transmits the monitoring data to the computer terminal to monitor the temperature change, freeze-thaw deformation, and compression deformation of the sample 6 in real time.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] 1. This utility model connects a constant-temperature testing machine and a water supply bottle via a constant-temperature water supply base plate, achieving constant temperature compensation and water supply to the bottom of the sample during a unidirectional freeze-thaw cycle. The pressure rod on the upper part of the temperature-controlled top plate contacts the pressure testing machine to apply pressure, enabling the testing of the sample's compressibility coefficient, consolidation coefficient, and other indicators under different pressure conditions. This solves the experimental problem of testing the consolidation characteristics of coarse-grained soil under the influence of unidirectional freeze-thaw cycles, and can make up for the current lack of research on the consolidation characteristics of coarse-grained soil at the cyclic boundary. It is beneficial to the research on the freeze-thaw characteristics of coarse-grained soil in cold region engineering, and can conduct freeze-thaw tests at different freezing temperatures and different numbers of freeze-thaw cycles, as well as consolidation tests under different pressures after freeze-thaw cycles.

[0023] 2. This utility model can achieve unidirectional freezing and thawing of coarse-grained soil under water replenishment conditions by setting up an insulation cylinder. After the sample freezes and thaws, the soil consolidation test can be carried out directly. That is, it realizes the integrated test of freeze-thaw cycle and consolidation test, which better simulates the engineering boundary conditions under natural environment, makes up for the defects of the current separate test of freeze-thaw cycle test and consolidation test, reduces human interference, and improves the accuracy and reliability of the test. Attached Figure Description

[0024] Figure 1 This is a main sectional view of a consolidation test device for unidirectional freeze-thaw of coarse-grained soil as described in this utility model.

[0025] Figure 2This is a top view of the upper base plate in a consolidation test device for unidirectional freeze-thaw of coarse-grained soil as described in this utility model.

[0026] Figure 3 yes Figure 2 A cross-sectional view (AA) of the upper base plate in a consolidation test apparatus for unidirectional freeze-thaw of coarse-grained soil.

[0027] Figure 4 This is a bottom view of the upper base plate in a consolidation test device for unidirectional freeze-thaw of coarse-grained soil as described in this utility model.

[0028] Figure 5 This is a top view of the lower base plate in a consolidation test device for unidirectional freeze-thaw testing of coarse-grained soil as described in this utility model.

[0029] Figure 6 yes Figure 5 A cross-sectional view of the lower base plate BB in a consolidation test apparatus for unidirectional freeze-thaw testing of coarse-grained soil.

[0030] Figure 7 This is a bottom view of the lower base plate in a consolidation test device for unidirectional freeze-thaw testing of coarse-grained soil as described in this utility model.

[0031] Figure 8 This is a top view of the upper part of the temperature control top plate in a consolidation test device for unidirectional freeze-thaw of coarse-grained soil as described in this utility model.

[0032] Figure 9 yes Figure 8 A CC cross-sectional view of the upper part of the temperature control top plate in a consolidation test device for unidirectional freeze-thaw of coarse-grained soil.

[0033] Figure 10 This is a bottom view of the upper part of the temperature control top plate in a consolidation test device for unidirectional freeze-thaw of coarse-grained soil as described in this utility model.

[0034] Figure 11 This is a bottom view of the lower part of the temperature control top plate in a consolidation test device for unidirectional freeze-thaw of coarse-grained soil as described in this utility model.

[0035] Figure 12 yes Figure 11 A DD cross-sectional view of the lower part of the temperature control top plate in a consolidation test device for unidirectional freeze-thaw of coarse-grained soil. Detailed Implementation

[0036] Specific implementation method one: Combining Figure 1This embodiment describes a consolidation test device for unidirectional freeze-thaw testing of coarse-grained soil, which comprises a base 1, a constant temperature water supply base plate 3, a permeable plate 4, a sample cylinder 5, a heat insulation cylinder 7, a temperature control top plate 8, a displacement sensor 9, a pressure rod 10, and a temperature sensor 12.

[0037] The top of the base 1 is provided with a constant temperature water supply plate 3. The sample tube 5 and the heat preservation tube 7 are both cylindrical with openings at the top and bottom. The upper surface of the constant temperature water supply plate 3 is fixedly connected to one open end of the sample tube 5. A water permeable plate 4 is provided in the center of the upper surface of the constant temperature water supply plate 3, and the water permeable plate 4 is located inside the sample tube 5. The heat preservation tube 7 is fitted on the outer surface of the sample tube 5. The bottom surface of the heat preservation tube 7 is fixedly connected to the upper surface of the constant temperature water supply plate 3. A temperature control plate 8 is embedded in the other end of the sample tube 5. A through hole is machined in the center of the upper surface of the temperature control plate 8. A pressure rod 10 is provided inside the through hole. A displacement sensor 9 is provided at one end of the upper surface of the temperature control plate 8. n temperature sensors 12 are evenly provided along the length direction on the outer wall of the sample tube 5, where n is a positive integer.

[0038] In this specific embodiment, firstly, filter paper or non-woven fabric is arranged on the upper surface of the permeable plate 4, and then the sample 6 is poured into the interior of the sample tube 5. A displacement sensor 9 is provided at one end of the upper surface of the temperature control top plate 8, and multiple temperature sensors 12 are uniformly arranged along the length direction on the outer wall of the sample tube 5, so as to monitor the deformation and temperature of the sample 6 inside the sample tube 5 in real time through the displacement sensor 9 and the temperature sensor 12. The sample 6 is compacted and formed inside the sample tube 5.

[0039] Then, the temperature control top plate 8 is placed on the sample 6, so that the two are in close contact. Then, a heat insulation cylinder 7 is fitted on the outer surface of the sample cylinder 5. The bottom surface of the heat insulation cylinder 7 is fixedly connected to the upper surface of the constant temperature water replenishment base plate 3, and there is a certain gap cavity between the heat insulation cylinder 7 and the sample cylinder 5, so that the sample 6 is insulated and heat-preserved. A one-way freeze-thaw cycle is performed from top to bottom. The displacement sensor 9 is installed on the temperature control top plate and connected to the data acquisition instrument to monitor the freeze-thaw deformation and compression deformation of the sample in real time. The temperature control top plate 8 is connected to the freeze-thaw testing machine. By setting different temperature control modes such as constant temperature, linear, and sinusoidal, the deformation performance of the sample 6 under different freeze-thaw modes can be tested.

[0040] Finally, the constant temperature water replenishment base plate 3 connects to the constant temperature testing machine and the water replenishment bottle to achieve constant temperature compensation and water replenishment at the bottom of the sample 6 during the unidirectional freeze-thaw process. The pressure rod 10 on the upper part of the temperature control top plate 8 contacts the pressure testing machine to apply pressure, enabling the sample 6 to be tested for indicators such as the compression coefficient and consolidation coefficient under different pressure conditions. During the test, the data acquisition instrument automatically records the readings and transmits the monitoring data to the computer terminal to monitor the temperature change, freeze-thaw deformation, and compression deformation of the sample 6 in real time.

[0041] Specific Implementation Method Two: Combining Figure 1 This embodiment further defines the test apparatus described in Specific Embodiment 1. In this embodiment, a consolidation test apparatus for unidirectional freeze-thaw testing of coarse-grained soil is provided. The number n of temperature sensors 12 on the outer wall of the sample cylinder 5 is 4 ≤ n ≤ 10.

[0042] In this specific embodiment, the temperature at different heights inside the sample cylinder 5 can be effectively monitored, thereby providing more temperature data and improving the accuracy and reliability of the measurement.

[0043] Specific implementation method three: Combining Figures 2 to 4 This embodiment further defines the test apparatus described in Specific Embodiment 1. The consolidation test apparatus for unidirectional freeze-thaw testing of coarse-grained soil described in this embodiment includes an upper base plate 3-1 and a lower base plate 3-2, which are fixedly connected by bolts. The upper surface of the upper base plate 3-1 has a uniformly distributed upper base plate drainage port 3-1-1 and an upper base plate water inlet 3-1-2 along the circumferential direction. The lower surface of the upper base plate 3-1 is machined with a spiral groove, with an upper base plate cryogenic liquid inlet 3-1-4 at the beginning of the spiral groove and an upper base plate cryogenic liquid outlet 3-1-3 at the end of the spiral groove.

[0044] Specific implementation method four: Combination Figures 5 to 7 This embodiment further defines the test device described in Specific Embodiment 3. The consolidation test device for unidirectional freeze-thaw testing of coarse-grained soil described in this embodiment has a lower bottom plate 3-2 with a lower bottom plate drainage port 3-2-1 and a lower bottom plate water inlet 3-2-4 uniformly arranged along the circumferential direction on the upper surface of the lower bottom plate 3-2. The lower surface of the lower bottom plate 3-2 is machined with a lower bottom plate cryogenic liquid inlet 3-2-3 and a lower bottom plate cryogenic liquid outlet 3-2-2.

[0045] Specific Implementation Method Five: Combining Figures 2 to 7 This embodiment further defines the test apparatus described in Specific Embodiment Four. In this embodiment, a consolidation test apparatus for unidirectional freeze-thaw testing of coarse-grained soil is provided, wherein the lower bottom plate 3-2-3 of the lower bottom plate 3-2 is connected to the upper bottom plate 3-1-4 of the upper bottom plate 3-1, and the lower bottom plate 3-2-2 of the lower bottom plate 3-2 is connected to the upper bottom plate 3-1-3 of the upper bottom plate 3-1.

[0046] Specific Implementation Method Six: Combination Figures 1 to 7This embodiment further defines the test device described in Specific Embodiment Five. In this embodiment, a consolidation test device for unidirectional freeze-thaw testing of coarse-grained soil is provided, wherein the lower bottom plate 3-2 has a water pipe 2 at its lower bottom plate drainage port 3-2-1 and lower bottom plate water inlet 3-2-4 respectively.

[0047] Specific implementation method seven: Combination Figures 1 to 7 This embodiment further defines the test device described in Specific Embodiment Five. In this embodiment, a consolidation test device for unidirectional freeze-thaw testing of coarse-grained soil is provided, wherein the lower bottom plate 3-2 has a first-level cryogenic transport pipe 13 at the lower bottom plate cryogenic inlet 3-2-3 and the lower bottom plate cryogenic outlet 3-2-2.

[0048] Specific implementation method eight: Combination Figures 8 to 12 This embodiment further defines the test device described in Specific Embodiment 1. The consolidation test device for unidirectional freeze-thaw testing of coarse-grained soil described in this embodiment includes a temperature-controlled top plate 8 comprising an upper part 8-1 and a lower part 8-2, which are fixedly connected by bolts.

[0049] Specific Implementation Method Nine: Combining Figures 8 to 12 This embodiment further defines the test apparatus described in Specific Embodiment Eight. The consolidation test apparatus for unidirectional freeze-thaw testing of coarse-grained soil described in this embodiment has an upper surface of the temperature-controlled top plate 8-1 with an upper top plate cryogenic liquid outlet 8-1-2 and an upper top plate cryogenic liquid inlet 8-1-3. Four countersunk through holes 8-1-1 are uniformly machined along the circumferential direction on the upper surface of the temperature-controlled top plate 8-1. A second cryogenic liquid transport pipe 11 is respectively provided on the upper surface of the upper surface of the temperature-controlled top plate 8-1 with the upper top plate cryogenic liquid outlet 8-1-2 and the upper top plate cryogenic liquid inlet 8-1-3.

[0050] Specific Implementation Method Ten: Combining Figures 8 to 12 This embodiment further defines the test device described in Specific Embodiment Nine. The consolidation test device for unidirectional freeze-thaw testing of coarse-grained soil described in this embodiment has a spiral groove on the upper surface of the lower part 8-2 of the temperature-controlled top plate. The first end of the spiral groove has a lower top plate cryogenic liquid inlet 8-2-1, and the end of the spiral groove has a lower top plate cryogenic liquid outlet 8-2-2. The upper surface of the lower part 8-2 of the temperature-controlled top plate has four threaded holes uniformly machined along the circumferential direction.

[0051] The lower top plate refrigerant inlet 8-2-1 of the lower part 8-2 of the temperature control top plate is connected to the upper top plate refrigerant inlet 8-1-3 of the upper part 8-1 of the temperature control top plate, and the lower top plate refrigerant outlet 8-2-2 of the lower part 8-2 of the temperature control top plate is connected to the upper top plate refrigerant outlet 8-1-2 of the upper part 8-1 of the temperature control top plate.

[0052] Working principle

[0053] First, filter paper or non-woven fabric is placed on the upper surface of the permeable plate 4. Then, the sample 6 is poured into the interior of the sample tube 5. A displacement sensor 9 is provided at one end of the upper surface of the temperature control top plate 8. Multiple temperature sensors 12 are evenly arranged along the length direction on the outer wall of the sample tube 5 so as to monitor the deformation and temperature of the sample 6 inside the sample tube 5 in real time through the displacement sensor 9 and the temperature sensor 12. The sample 6 is compacted and formed inside the sample tube 5.

[0054] Then, the temperature control top plate 8 is placed on the sample 6, so that the two are in close contact. Then, a heat insulation cylinder 7 is fitted on the outer surface of the sample cylinder 5. The bottom surface of the heat insulation cylinder 7 is fixedly connected to the upper surface of the constant temperature water replenishment base plate 3, and there is a certain gap cavity between the heat insulation cylinder 7 and the sample cylinder 5, so that the sample 6 is insulated and heat-preserved. A one-way freeze-thaw cycle is performed from top to bottom. The displacement sensor 9 is installed on the temperature control top plate and connected to the data acquisition instrument to monitor the freeze-thaw deformation and compression deformation of the sample in real time. The temperature control top plate 8 is connected to the freeze-thaw testing machine. By setting different temperature control modes such as constant temperature, linear, and sinusoidal, the deformation performance of the sample 6 under different freeze-thaw modes can be tested.

[0055] Finally, the constant temperature water replenishment base plate 3 connects to the constant temperature testing machine and the water replenishment bottle to achieve constant temperature compensation and water replenishment at the bottom of the sample 6 during the unidirectional freeze-thaw process. The pressure rod 10 on the upper part of the temperature control top plate 8 contacts the pressure testing machine to apply pressure, enabling the sample 6 to be tested for indicators such as the compression coefficient and consolidation coefficient under different pressure conditions. During the test, the data acquisition instrument automatically records the readings and transmits the monitoring data to the computer terminal to monitor the temperature change, freeze-thaw deformation, and compression deformation of the sample 6 in real time.

Claims

1. An apparatus for consolidated testing of coarse-grained soils under unidirectional freeze-thaw, characterized in that: It includes base (1), constant temperature water replenishment bottom plate (3), water permeable plate (4), sample cylinder (5), heat preservation cylinder (7), temperature control top plate (8), displacement sensor (9), pressure rod (10) and temperature sensor (12); The top end of the base (1) is provided with the constant temperature water replenishment bottom plate (3), the sample cylinder (5) and the heat preservation cylinder (7) are both columnar bodies with upper and lower openings, the upper surface of the constant temperature water replenishment bottom plate (3) is fixedly connected with one open end of the sample cylinder (5), the central part of the upper surface of the constant temperature water replenishment bottom plate (3) is provided with the water permeable plate (4), and the water permeable plate (4) is arranged in the sample cylinder (5), the heat preservation cylinder (7) is sleeved on the outer surface of the sample cylinder (5), the bottom surface of the heat preservation cylinder (7) is fixedly connected with the upper surface of the constant temperature water replenishment bottom plate (3), the other end opening of the sample cylinder (5) is embedded with the temperature control top plate (8), the central part of the upper surface of the temperature control top plate (8) is processed with a through hole, the through hole is provided with the pressure rod (10), one end of the upper surface of the temperature control top plate (8) is provided with the displacement sensor (9), and the outer wall of the sample cylinder (5) is uniformly provided with n temperature sensors (12) along the length direction, wherein n is a positive integer.

2. The apparatus for unidirectional freeze-thaw consolidation test of coarse-grained soil according to claim 1, characterized in that: The number n of the temperature sensors (12) on the outer wall of the sample cylinder (5) is 4≤n≤10.

3. The apparatus for unidirectional freeze-thaw consolidation test of coarse-grained soil according to claim 1, characterized in that: The constant temperature water replenishment bottom plate (3) comprises an upper bottom plate (3-1) and a lower bottom plate (3-2), the upper bottom plate (3-1) and the lower bottom plate (3-2) are fixedly connected through bolts, the upper surface of the upper bottom plate (3-1) is uniformly provided with an upper bottom plate water outlet (3-1-1) and an upper bottom plate water replenishment opening (3-1-2) along the circumferential direction, the lower surface of the upper bottom plate (3-1) is processed with a spiral groove, and the first end of the spiral groove is processed with an upper bottom plate refrigerant inlet (3-1-4), and the last end of the spiral groove is processed with an upper bottom plate refrigerant outlet (3-1-3).

4. The apparatus for unidirectional freeze-thaw consolidation test of coarse-grained soil according to claim 3, characterized in that: The upper surface of the lower bottom plate (3-2) is uniformly provided with a lower bottom plate water outlet (3-2-1) and a lower bottom plate water replenishment opening (3-2-4) along the circumferential direction, and the lower surface of the lower bottom plate (3-2) is processed with a lower bottom plate refrigerant inlet (3-2-3) and a lower bottom plate refrigerant outlet (3-2-2).

5. The apparatus for unidirectional freeze-thaw consolidation test of coarse-grained soil according to claim 4, characterized in that: The lower bottom plate refrigerant inlet (3-2-3) of the lower bottom plate (3-2) is correspondingly and communicatively arranged with the upper bottom plate refrigerant inlet (3-1-4) of the upper bottom plate (3-1), and the lower bottom plate refrigerant outlet (3-2-2) of the lower bottom plate (3-2) is correspondingly and communicatively arranged with the upper bottom plate refrigerant outlet (3-1-3) of the upper bottom plate (3-1).

6. The apparatus for unidirectional freeze-thaw consolidation test of coarse-grained soil according to claim 5, characterized in that: The lower bottom plate water outlet (3-2-1) and the lower bottom plate water replenishment opening (3-2-4) of the lower bottom plate (3-2) are respectively provided with one water pipeline (2).

7. The apparatus for unidirectional freeze-thaw consolidation test of coarse-grained soil according to claim 5, characterized in that: The lower bottom plate refrigerant inlet (3-2-3) and the lower bottom plate refrigerant outlet (3-2-2) of the lower bottom plate (3-2) are respectively provided with one first refrigerant transportation pipeline (13).

8. The apparatus for unidirectional freeze-thaw consolidation test of coarse-grained soil according to claim 1, characterized in that: The temperature control top plate (8) comprises a temperature control top plate upper portion (8-1) and a temperature control top plate lower portion (8-2), and the temperature control top plate upper portion (8-1) and the temperature control top plate lower portion (8-2) are fixedly connected through bolts.

9. The apparatus for unidirectional freeze-thaw consolidation test of coarse-grained soil according to claim 8, characterized in that: The upper surface of the temperature control top plate upper portion (8-1) is processed with an upper top plate refrigerant outlet (8-1-2) and an upper top plate refrigerant inlet (8-1-3), and the upper surface of the temperature control top plate upper portion (8-1) is uniformly processed with four countersunk through holes (8-1-1) in the circumferential direction; the upper top plate refrigerant outlet (8-1-2) and the upper top plate refrigerant inlet (8-1-3) of the upper surface of the temperature control top plate upper portion (8-1) are respectively provided with a No. 2 refrigerant transportation pipeline (11).

10. The apparatus for unidirectional freeze-thaw consolidation test of coarse-grained soil according to claim 9, characterized in that: The upper surface of the temperature control top plate lower portion (8-2) is processed with a spiral groove, the first end of the spiral groove is processed with a lower top plate refrigerant inlet (8-2-1), the last end of the spiral groove is processed with a lower top plate refrigerant outlet (8-2-2), and the upper surface of the temperature control top plate lower portion (8-2) is uniformly processed with four threaded holes in the circumferential direction. The lower top plate refrigerant inlet (8-2-1) of the temperature control top plate lower portion (8-2) is correspondingly and communicatively arranged with the upper top plate refrigerant inlet (8-1-3) of the temperature control top plate upper portion (8-1), and the lower top plate refrigerant outlet (8-2-2) of the temperature control top plate lower portion (8-2) is correspondingly and communicatively arranged with the upper top plate refrigerant outlet (8-1-2) of the temperature control top plate upper portion (8-1).

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