Segmented full-automatic soil column temperature control system and method based on soil body temperature control

Abstract

The invention relates to the technical field of soil body tests, in particular to a sectional type full-automatic soil column temperature control system and method based on soil body temperature control. The system comprises a temperature control module, a model cavity, a rainfall simulation module and a measurement module, the model cavity comprises a container, a blocking net and a soil column, drainage holes are formed in the bottom of the container, the blocking net is laid on the inner side of the bottom of the container, the container is filled with soil, the soil column is evenly divided into multiple layers of soil layer structures with the same thickness, and the contact faces between soil layers are stricken off. The container is provided with an overflow port at a position higher than a specified height of the surface of the soil column, the rainfall simulation module provides rainfall to the surface of the soil column, the measurement module is butted with the soil column and the overflow port to collect soil column data, and the temperature control module controls the temperature of the soil column. According to the device and the method, the aim of accurately controlling the temperature at different depths of the soil column is fulfilled, so that the requirement of researching the seepage characteristics of the plant-green soil covering layer under different temperature conditions is met.

Description

Technical Field

[0001] The present invention relates to the technical field of soil testing, and in particular to a segmented fully automatic soil column temperature control system and method based on soil temperature control. Background Art

[0002] During the operation of municipal solid waste landfills, the heat released by waste decomposition causes the temperature of the vegetated soil cover to rise. This temperature change can alter the cover's ability to regulate rainwater infiltration, affecting its water storage, permeability, and air permeability, thereby degrading or even destroying its anti-seepage and air-tightening properties. Currently, research on how temperature affects the seepage behavior of vegetated soil cover is insufficient, especially at the structural level, and lacks in-depth exploration of the impact of solid waste thermal effects.

[0003] Existing research on soil column temperature control systems often relies on circulating water systems with controllable water temperature. Some studies have achieved automated heating, but these systems still have several drawbacks. First, temperature control is based on the temperature of a heat source (e.g., water) rather than directly on soil temperature. The temperature difference between the heat source and the soil requires calibration of the soil and heat source temperatures, which can introduce errors and makes it difficult for others to verify the calibration relationship. Second, existing soil temperature control equipment is mostly integrated and cannot implement segmented heating (applying different temperatures at different depths in the soil). This limitation is inconsistent with reality. In solid waste landfills, the temperature of the waste layer is relatively high, while the temperature of the overburden layer above it typically decreases with depth. Therefore, traditional soil column temperature control methods cannot accurately simulate actual operating conditions, affecting the accuracy and reliability of test results. Furthermore, traditional methods based on single-point temperature control have significant shortcomings: soil is not an ideally uniform material. If the same heat energy is applied to the entire soil column based on a single point temperature, the resulting temperature effect will inevitably vary from location to location. Summary of the Invention

[0004] The present invention provides a segmented fully automatic soil column temperature control system and method based on soil temperature control, aiming to solve the defects of the traditional single-point temperature control method.

[0005] The present invention provides a segmented fully automatic soil column temperature control system based on soil temperature control, comprising a temperature control module, a model cavity, a rainfall simulation module, and a measurement module. The model cavity comprises a container, a barrier, and a soil column. A drainage hole is provided at the bottom of the container, the barrier is laid on the inner side of the bottom of the container, the soil is filled in the container, the soil column is evenly divided into multiple layers of soil layer structures with equal thickness, the contact surfaces between each layer of the soil layer are scraped flat, the container is provided with an overflow port at a position higher than a specified height of the soil column surface, the rainfall simulation module provides precipitation to the soil column surface, the measurement module connects the soil column and the overflow port to collect soil column data, and the temperature control module controls the temperature of the soil column.

[0006] As a further improvement of the present invention, the temperature control module includes a heating belt, a temperature probe, and a temperature control digital display module. Multiple temperature probes are buried at different depths in the soil column, and multiple independent heating belts are evenly wrapped around the outside of the soil column in sections from top to bottom. The temperature control digital display module is installed on the heating belt. The temperature control digital display module receives the signal from the temperature probe and controls the heating belt.

[0007] As a further improvement of the present invention, the measurement module includes a volume moisture sensor, a soil water potential sensor, and a data acquisition instrument. A volume moisture sensor is buried in each soil layer, and soil water potential sensors are buried at multiple specified depths below the surface of the soil column. The data acquisition instrument is connected to multiple volume moisture sensors and multiple soil water potential sensors.

[0008] As a further improvement of the present invention, the measuring module further includes an electronic balance, a measuring water bucket, and a flow guide tube. The measuring water bucket is placed on the electronic balance, and both ends of the flow guide tube are respectively connected to the overflow port and the measuring water bucket.

[0009] As a further improvement of the present invention, the rainfall simulation module includes a water storage bottle, a pinhole rainfall dish, and a peristaltic pump. The pinhole rainfall dish is mounted above the container and aligned with the surface of the soil column. The water storage bottle is connected to the peristaltic pump through a pipe, and the peristaltic pump is connected to the pinhole rainfall dish through a pipe.

[0010] As a further improvement of the present invention, the rainfall simulation module also includes a heating device, which is arranged between the water storage bottle and the rainfall tray. The water storage bottle and the heating device are connected through a peristaltic pump and a pipeline, and the heating device and the rainfall tray are connected through a peristaltic pump and a pipeline.

[0011] As a further improvement of the present invention, the barrier net is a three-layer structure consisting of geotextile, wire mesh and geotextile in sequence.

[0012] As a further improvement of the present invention, the mold cavity further includes a heat insulation layer, and the heat insulation layer is connected to the outside of the bottom of the container.

[0013] As a further improvement of the present invention, the segmented fully automatic soil column temperature control system based on soil temperature control further includes a video recorder, and the two video recorders are respectively aimed at the sides of the soil column.

[0014] As a further improvement of the present invention, an anti-penetration agent is applied between the inner wall of the container and the soil column.

[0015] The present invention also provides a segmented fully automatic soil column temperature control method based on soil temperature control, comprising the following steps: S1. Place a cylindrical container on a flat, stable test surface. Create drainage holes at the bottom of the container. Evenly apply an anti-permeation agent to the inner wall of the container. Attach a thermal insulation layer to the outer bottom of the container. Lay a three-layer barrier net, followed by a geotextile, a wire mesh, and a geotextile, on the inner bottom of the container. S2. Mix the crushed and dried soil with air-free water to an initial volumetric moisture content of 15.0 ± 0.2%. After equilibration for 48 hours, fill the container with multiple layers to form soil columns. Compact each layer to a dry density of 1.40 ± 0.01 g / cm 3 , the contact surface between layers is scraped; S3. Temperature probes are embedded at different depths in the soil column and connected to a temperature control digital display module. Multiple independent heating tapes are wrapped around the outer wall of the soil column and connected to the temperature control digital display module. Temperature thresholds are set and automatic start / stop logic is configured: when the temperature detected by the temperature probe at a certain depth in the soil column falls below the set value, the corresponding heating tape starts heating and stops heating when the temperature returns to the set value. S4. Install a porous rainfall tray on top of the container, connecting a peristaltic pump and a water storage bottle via a pipe. Pre-calibrate the linear relationship between the peristaltic pump gear position and rainfall intensity. Adjust the peristaltic pump gear position to achieve the desired rainfall intensity. Ensure a constant height difference between the peristaltic pump, water storage bottle, and rainfall tray. Use gravity to maintain a raindrop morphology similar to natural rainfall. S5. Within the depth range of the soil column, volumetric moisture content sensors are buried at specified depths, and soil water potential sensors are buried at multiple specified depths of the soil column. The volumetric moisture content sensors and soil water potential sensors are connected to the data acquisition instrument through shielded cables. The sampling frequency is set, and a stabilized power supply is used to power the volumetric moisture content sensors and soil water potential sensors. A ruler is affixed to the outer wall of the container for manual recording of the depth of accumulated water. The overflow port is connected to a diversion tube connected to a measuring bucket on an electronic balance to monitor the overflow volume in real time. Two video recorders are aimed at the sides of the soil column, respectively, for recording the movement of the wetting front and monitoring the dynamics of accumulated water.

[0016] The beneficial effect of the present invention is that it uses multiple heating belts and embeds corresponding temperature probes at different depths in the soil column. By implementing a multi-point temperature control strategy in the soil column, it ensures that the set temperature is consistently reached at all depths. This achieves the goal of precise temperature control at different depths in the soil column, thus meeting the needs of studying the seepage characteristics of the green soil cover layer under different temperature conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the segmented fully automatic soil column temperature control system based on soil temperature control of the present invention. DETAILED DESCRIPTION

[0018] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0019] like Figure 1 As shown, the present invention is a segmented fully automatic soil column temperature control system based on soil temperature control, including a temperature control module, a model cavity, a rainfall simulation module, and a measurement module. The model cavity includes a container 1, a barrier 3, and a soil column 2. A drainage hole is provided at the bottom of the container 1, and the barrier 3 is laid on the inner side of the bottom of the container 1. The soil is filled in the container 1. The soil column 2 is evenly divided into multiple layers of soil layer structure with equal thickness. The contact surface between each soil layer is scraped flat. The container 1 is provided with an overflow port 4 at a position higher than a specified height from the surface of the soil column 2. The rainfall simulation module provides precipitation to the surface of the soil column 2. The measurement module connects the soil column 2 and the overflow port 4 to collect data of the soil column 2. The temperature control module controls the temperature of the soil column 2.

[0020] The container 1 of the model cavity is a cylindrical structure, 98 cm high and 28 cm in inner diameter. It has a drainage hole at the bottom and is used to fill a 70 cm high soil column 2. An overflow port 4 is opened on the barrel wall 5 cm above the surface of the soil column 2, allowing a maximum water depth of 5 cm. A scale is attached to the outer wall to record the water depth. The measurement module uses sensors embedded in the interior of the soil column 2 to measure parameters such as volumetric moisture content and soil water potential, and measures the moisture content of the soil column 2 by connecting to the overflow port 4. The temperature control module is used to monitor the temperature of the soil column 2 and heat the soil column 2 to maintain the temperature of the soil column 2. The rainfall simulation module is used to provide a rainfall effect on the surface of the soil column 2 to simulate the actual situation of soil being affected by rainfall.

[0021] The temperature control module includes a heating belt 5, a temperature probe, and a temperature control digital display module 6. Multiple temperature probes are buried at different depths in the soil column 2. Multiple independent heating belts 5 are evenly wrapped around the outside of the soil column 2 from top to bottom. The temperature control digital display module 6 is installed on the heating belt 5. The temperature control digital display module 6 receives the signal from the temperature probe and controls the heating belt 5.

[0022] The temperature control module includes four heating belts 5 (three 10cm wide and one 35cm wide) connected to a temperature control digital display module 6, as well as corresponding temperature probes embedded at different depths in soil column 2. The wide heating belt 5 covers the bottom area of ​​soil column 2, while the remaining narrow heating belts 5 are evenly distributed above soil column 2. Based on the principle of multi-point temperature control, the set temperature can be reached at different depths of soil column 2. After reaching the specified temperature, the system automatically stops heating and reheats the soil when it slowly cools down by 1°C, achieving precise control of the temperature of soil column 2. The four heating belts 5 are evenly wrapped around the outside of soil column 2, and the corresponding temperature probes are embedded at different depths in soil column 2. Ensure that the heating belts 5 are tightly connected to the temperature control digital display module 6 to achieve multi-point temperature control of soil column 2, ensuring that the set temperature is reached at all depths of soil column 2.

[0023] The measurement module includes a volume moisture sensor, a soil water potential sensor, and a data acquisition device 7. A volume moisture sensor is buried in each soil layer, and soil water potential sensors are buried at multiple specified depths below the surface of the soil column 2. The data acquisition device 7 is connected to multiple volume moisture sensors and multiple soil water potential sensors.

[0024] The measurement system includes volumetric moisture sensors (Model EC-5) embedded in the soil column at depths of 25 to 65 cm (at 5 cm intervals), and soil water potential sensors (Model TEROS21) embedded at depths of 5 cm, 10 cm, and 15 cm below the surface of soil column 2. During installation, ensure full contact between the sensors and the soil to avoid gaps that could affect measurement accuracy. Care should also be taken to prevent interference between adjacent sensors (at intervals greater than 4 cm). A Meikong paperless data logger 7 was also used. Each sensor was connected to the data logger, and the data logger parameters were set. Data was collected and stored at a sampling rate of 1 minute. All connections were checked for tightness to ensure stable and reliable data transmission.

[0025] After completing the circuit wiring, place the voltage-stabilized power supply 8 (which serves as the sensor's excitation power supply) in an insulated plastic box and seal it. Only allow wires to enter and exit through the reserved holes to ensure electrical safety. After completing the assembly of the above components, conduct a comprehensive inspection of the entire device to ensure that all systems are tightly connected and operating properly.

[0026] The measurement module also includes an electronic balance 9, a measuring bucket 10, and a drainage pipe 11. The measuring bucket 10 is placed on the electronic balance 9, and the two ends of the drainage pipe 11 are connected to the overflow port 4 and the measuring bucket 10, respectively. The overflow port 4 is set at a height of 5 cm from the upper surface of the soil column 2. The drainage pipe 11 collects rainwater that overflows into the measuring bucket 10 through the overflow port and is weighed by the electronic balance 9 to calculate the moisture content of the soil column 2.

[0027] The rainfall simulation module includes a water storage bottle 12, a pinhole rainfall disc 13, and a peristaltic pump 14. The pinhole rainfall disc 13 is mounted above the container 1 and aligned with the surface of the soil column 2. The water storage bottle 12 is connected to the peristaltic pump 14 via a pipe, which in turn is connected to the pinhole rainfall disc 13 via a pipe. During the test, a water bucket is placed in an appropriate position, and the pinhole rainfall disc 13 and peristaltic pump 14 are connected via a pipe. The gear position of the peristaltic pump 14 is adjusted to achieve the desired rainfall intensity. The height difference between the peristaltic pump 14, water storage bottle 12, and pinhole rainfall disc 13 is maintained constant to ensure a linear relationship between rainfall intensity and the gear position of the peristaltic pump 14.

[0028] The rainfall simulation module also includes a heating device 15, which is located between the water bottle 12 and the pinhole rain tray 13. The water bottle 12 and the heating device 15 are connected by a peristaltic pump 14 and a pipe. The heating device 15 and the pinhole rain tray 13 are also connected by a peristaltic pump 14 and a pipe. The heating device 15 is used to control the temperature of the rainfall. Based on the structure of the water bottle 12, peristaltic pump 14, and pinhole rain tray 13, in order to simulate the different temperatures of rainwater in different weather conditions, the heating device 15 is added between the water bottle 12 and the pinhole rain tray 13. The liquid in the water bottle 12 is first pumped to the heating device 15 to be heated to the required temperature, and then pumped to the pinhole rain tray 13 to be poured onto the surface of the soil column 2, simulating rainfall conditions of different temperatures.

[0029] The barrier 3 is a three-layer structure consisting of geotextile, steel mesh, and geotextile. It is set between the drainage hole and the soil. The three-layer barrier 3 consisting of geotextile, steel mesh, and geotextile is laid out to reduce the loss of soil particles during rainfall infiltration.

[0030] The model cavity further includes a heat-insulating layer, which is connected to the outside of the bottom of the container 1 to reduce the influence of the ambient temperature on the bottom of the soil column 2 .

[0031] The segmented fully automatic soil column 2 temperature control system based on soil temperature control also includes a video recorder 16. Two video recorders 16 are respectively aimed at the sides of the soil column 2 to record the movement of the wetting front of the soil column 2 and monitor the dynamics of water accumulation.

[0032] An anti-penetration agent is applied between the inner wall of the container 1 and the soil column 2. The anti-penetration agent is preferably vaseline. During the test, vaseline is evenly applied to the inner wall of the container 1 to reduce the dominant flow caused by the gap between the soil column 2 and the side wall of the cavity.

[0033] The present invention provides a segmented, fully automatic soil column temperature control method based on soil temperature control, comprising the following steps: S1. Place a cylindrical plexiglass container 1 (98 cm high, 28 cm inner diameter) on a flat, stable test surface. Apply petroleum jelly evenly to the inner wall of container 1 to reduce the predominant flow between the soil column 2 and the cavity. Apply a polyurethane foam insulation layer to the outside of the bottom of container 1 to reduce the impact of ambient temperature on the bottom of soil column 2. Drain holes are provided at the bottom of container 1. A three-layer barrier 3, consisting of geotextile, steel mesh, and geotextile, is laid inside the bottom of container 1 in this order to prevent soil particle loss.

[0034] S2. Crush and dry approximately 200 kg of soil in advance. Use a spray bottle to spray the dry soil with air-free water until the initial volumetric moisture content reaches 15.0 ± 0.2%. Seal the soil in a plastic bag and equilibrate for 48 hours to ensure that the soil moisture reaches equilibrium. Transfer the equilibrated soil into container 1 and fill it into container 1 in 14 layers (5 cm per layer) to form soil column 2. Compact each layer to a dry density of 1.40 ± 0.01 g / cm. 3 , and the contact surface between each adjacent layer is scraped with a scraper to enhance the bonding and ensure close contact between the layers.

[0035] S3. Temperature probes are embedded at different depths in soil column 2 (e.g., 5 cm, 15 cm, 30 cm, and 50 cm) and connected to a temperature control digital display module 6. Four independent heating strips 5 (three 10 cm wide and one 35 cm wide) are wrapped around the outer wall of soil column 2. The wide heating strip 5 covers the bottom of soil column 2, with the remaining strips evenly distributed. Connect the temperature control digital display module 6 to the circuitry of the heating strips 5, set a temperature threshold (e.g., ±1°C), and configure automatic start-stop logic: when the temperature detected by the temperature probe at a certain depth in soil column 2 falls below the set value, the corresponding heating strip 5 starts heating and stops heating when the temperature returns to the set value.

[0036] S4. Install a pinhole rain disc 13 on top of container 1. Connect a peristaltic pump 14 to the water storage bottle 12 via silicone tubing. Pre-calibrate the linear relationship between the peristaltic pump 14 gear position and rainfall intensity (e.g., 90 mm / h corresponds to high gear, 30 mm / h corresponds to low gear) to ensure segmented rainfall simulation capabilities. Adjust the peristaltic pump 14 gear position to achieve the desired rainfall intensity. Ensure that the height difference between the peristaltic pump 14, water storage bottle 12, and pinhole rain disc 13 remains constant to ensure a linear relationship between rainfall intensity and peristaltic pump 14 gear position. The pinhole rain disc 13 is fixed at a fixed height, utilizing gravity to maintain a raindrop morphology similar to natural rainfall.

[0037] S5. Within the soil column 2, volumetric moisture content sensors were embedded every 5 cm from 5 cm to 65 cm deep. Soil water potential sensors were embedded at depths of 5 cm, 10 cm, and 15 cm in the soil column 2. The volumetric moisture content and soil water potential sensors were connected to a data acquisition device 7 via shielded cables, with a sampling frequency of 1 minute. A scale (with an accuracy of 1 mm) was attached to the outer wall of container 1 to manually record the depth of accumulated water. The overflow port 4 was connected to a diversion tube 11 connected to a measuring bucket 10 on an electronic balance 9 to monitor the overflow volume in real time. Two high-definition video recorders 16 were installed, each aimed at the side of soil column 2, to record the movement of the wetting front and monitor the dynamics of accumulated water, respectively. A regulated power supply 8 powered the volumetric moisture content and soil water potential sensors. The power supply circuits were sealed in an insulating plastic box for safety. All circuit interfaces and sensor connections were wrapped with waterproof tape to prevent moisture intrusion during the test.

[0038] After assembling all the above components, conduct a comprehensive inspection of the entire system to ensure that all components are tightly connected and operating properly. Turn on the temperature control system and rainfall simulation system to observe changes in soil column 2's temperature, rainfall patterns, and the accuracy of sensor data collection. Perform necessary debugging and optimization until the device can stably and accurately conduct soil column 2 testing.

[0039] The advantages of this segmented fully automatic soil column temperature control system and method based on soil temperature control are: (1) Precise temperature control: The temperature probe is placed directly in the soil, rather than being controlled based on the temperature of the heat source, thereby achieving more precise and direct temperature control. This effectively avoids the temperature difference problem between the heat source and the soil, eliminates the need for tedious calibration steps, reduces the source of error, and makes the experimental results more reliable and repeatable.

[0040] (2) Segmented heating: Multiple independent heating belts 5 are used to perform segmented temperature control at different depths throughout the soil column 2. This allows for simulating the complex temperature distribution in actual scenarios, such as municipal solid waste landfills, where the temperature of the waste layer is high while the temperature of the overburden layer gradually decreases with depth. This makes the experimental conditions more realistic and helps to further explore the seepage patterns of the green soil overburden under the coupling of different depths and temperatures.

[0041] (3) Fully automatic operation: The system has a fully automatic temperature control function. Once the specified temperature (e.g., 44°C) is reached, heating will automatically stop. After the soil slowly cools down to the set threshold (e.g., 43°C), heating will automatically restart. This process does not require human intervention, which not only improves experimental efficiency but also ensures the stability and accuracy of temperature control, providing a strong guarantee for the smooth progress of long-term experiments.

[0042] The above is a further detailed description of the present invention in conjunction with specific preferred embodiments, and the specific implementation of the present invention should not be considered to be limited to these descriptions. For those skilled in the art to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, and all of these should be considered to fall within the scope of protection of the present invention.

Claims

1. The segmented fully automatic soil column temperature control system based on soil temperature control is characterized by: It includes a temperature control module, a model cavity, a rainfall simulation module, and a measurement module. The model cavity includes a container, a barrier, and a soil column. The bottom of the container is provided with a drainage hole. The barrier is laid on the inner side of the bottom of the container. The soil is filled in the container. The soil column is evenly divided into multiple layers of soil with equal thickness. The contact surface between each layer of the soil is scraped flat. The container is provided with an overflow port at a position higher than a specified height of the soil column surface. The rainfall simulation module provides precipitation to the surface of the soil column. The measurement module connects the soil column and the overflow port to collect soil column data. The temperature control module controls the temperature of the soil column.

2. The segmented fully automatic soil column temperature control system based on soil temperature control according to claim 1 is characterized in that: The temperature control module includes a heating belt, a temperature probe, and a temperature control digital display module. Multiple temperature probes are buried at different depths in the soil column. Multiple independent heating belts are evenly wrapped around the outside of the soil column in sections from top to bottom. The temperature control digital display module is installed on the heating belt. The temperature control digital display module receives signals from the temperature probe and controls the heating belt.

3. The segmented fully automatic soil column temperature control system based on soil temperature control according to claim 1 is characterized in that: The measurement module includes a volumetric moisture sensor, a soil water potential sensor, and a data acquisition instrument. A volumetric moisture sensor is buried in each soil layer, and soil water potential sensors are buried at multiple specified depths below the surface of the soil column. The data acquisition instrument is connected to multiple volumetric moisture sensors and multiple soil water potential sensors.

4. The segmented fully automatic soil column temperature control system based on soil temperature control according to claim 1 is characterized in that: The measuring module further comprises an electronic balance, a measuring water bucket, and a flow guide tube. The measuring water bucket is placed on the electronic balance, and two ends of the flow guide tube are respectively connected to the overflow port and the measuring water bucket.

5. The segmented fully automatic soil column temperature control system based on soil temperature control according to claim 1 is characterized in that: The rainfall simulation module includes a water storage bottle, a rainfall tray, and a peristaltic pump. The rainfall tray is mounted above the container and aligned with the surface of the soil column. The water storage bottle is connected to the peristaltic pump through a pipe, and the peristaltic pump is connected to the rainfall tray through a pipe.

6. The segmented fully automatic soil column temperature control system based on soil temperature control according to claim 5 is characterized in that: The rainfall simulation module also includes a heating device, which is arranged between the water storage bottle and the rainfall tray. The water storage bottle and the heating device are connected through a peristaltic pump and a pipeline, and the heating device and the rainfall tray are connected through a peristaltic pump and a pipeline.

7. The segmented fully automatic soil column temperature control system based on soil temperature control according to claim 1 is characterized in that: The barrier net is a three-layer structure consisting of geotextile, wire mesh and geotextile in sequence.

8. The segmented fully automatic soil column temperature control system based on soil temperature control according to claim 1 is characterized in that: The mold cavity further comprises a heat insulation layer, which is connected to the outside of the bottom of the container.

9. The segmented fully automatic soil column temperature control system based on soil temperature control according to claim 1 is characterized in that: It also includes a video camera, and two video cameras are respectively aimed at the sides of the soil column.

10. A segmented fully automatic soil column temperature control method based on soil temperature control, characterized in that: The following steps are involved: S1. Place a cylindrical container on a flat, stable test surface. Create drainage holes at the bottom of the container. Evenly apply an anti-permeation agent to the inner wall of the container. Attach a thermal insulation layer to the outer bottom of the container. Lay a three-layer barrier net, followed by a geotextile, a wire mesh, and a geotextile, on the inner bottom of the container. S2. Mix the crushed and dried soil with air-free water to an initial volumetric moisture content of 15.0 ± 0.2%. After equilibration for 48 hours, fill the container with multiple layers to form soil columns. Compact each layer to a dry density of 1.40 ± 0.01 g / cm 3 , the contact surface between layers is scraped; S3. Temperature probes are embedded at different depths in the soil column and connected to a temperature control digital display module. Multiple independent heating tapes are wrapped around the outer wall of the soil column and connected to the temperature control digital display module. Temperature thresholds are set and automatic start / stop logic is configured: when the temperature detected by the temperature probe at a certain depth in the soil column falls below the set value, the corresponding heating tape starts heating and stops heating when the temperature returns to the set value. S4. Install a porous rainfall tray on top of the container, connecting a peristaltic pump and a water storage bottle via a pipe. Pre-calibrate the linear relationship between the peristaltic pump gear position and rainfall intensity. Adjust the peristaltic pump gear position to achieve the desired rainfall intensity. Ensure a constant height difference between the peristaltic pump, water storage bottle, and rainfall tray. Use gravity to maintain a raindrop morphology similar to natural rainfall. S5. Within the depth range of the soil column, volumetric moisture content sensors are buried at specified depths, and soil water potential sensors are buried at multiple specified depths of the soil column. The volumetric moisture content sensors and soil water potential sensors are connected to the data acquisition instrument through shielded cables. The sampling frequency is set, and a stabilized power supply is used to power the volumetric moisture content sensors and soil water potential sensors. A ruler is affixed to the outer wall of the container for manual recording of the depth of accumulated water. The overflow port is connected to a diversion tube connected to a measuring bucket on an electronic balance to monitor the overflow volume in real time. Two video recorders are aimed at the sides of the soil column, respectively, for recording the movement of the wetting front and monitoring the dynamics of accumulated water.

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