Hydraulic conductivity testing equipment for loess structural attenuation monitoring and application method of hydraulic conductivity testing equipment

Abstract

The invention relates to the technical field of loess structural attenuation monitoring equipment in geotechnical engineering, in particular to hydraulic conductivity testing equipment for loess structural attenuation monitoring and an application method thereof, and the hydraulic conductivity testing equipment comprises a drill rod, a probe, a low water head adjusting unit, a time domain reflectometer sensor, a vibrating wire pressure gauge, a flow sensor, a data acquisition instrument and a power device; a filter screen assembly of a three-layer composite structure is installed in the probe, a low water head adjusting unit, a time domain reflectometer sensor and a vibrating wire pressure gauge are sequentially connected above the filter screen assembly, a drill rod is connected between the vibrating wire pressure gauge and a power device, and a flow sensor, a data acquisition instrument and a water source are arranged above the ground. Through multi-parameter collaborative analysis, the structural attenuation state of the loess can be monitored in real time, the problems that fine particles block a filter screen, unsaturated loess is not matched, and structural dynamic changes are difficult to capture are effectively solved, and the method has the advantages of being high in monitoring precision, resistant to alkaline corrosion, easy and convenient to operate and the like and is good in engineering application prospect.

Description

Technical Field

[0001] This invention relates to the technical field of loess structural attenuation monitoring equipment in geotechnical engineering, and particularly to hydraulic conductivity testing equipment and its application method for monitoring loess structural attenuation. Background Technology

[0002] Loess structural decay is the process by which the structure of loess deteriorates under the influence of external factors, ultimately leading to a decline in its mechanical properties such as strength and stability. Loess structural decay is prone to triggering geological disasters such as ground subsidence and landslides, and has always been a focal point of concern in geotechnical engineering. Because loess structural decay is affected by factors such as water content and environment, traditional monitoring methods rely on manual observation. However, manual observation has low accuracy and is difficult to meet long-term monitoring needs. With the development of remote sensing technology, time-series InSAR technology is now widely used, but it is affected by factors such as atmospheric errors and has high requirements for the quantity and quality of images. Existing ground-based in-situ monitoring equipment, which is designed for local monitoring, is unable to capture rapid dynamic decay.

[0003] In existing technologies, the Permeafor device is a commonly used hydraulic conductivity testing tool in geotechnical engineering. Its core components include a probe, a filter, and a data acquisition system. It is suitable for granular soils, but it has significant limitations in monitoring loess. Because the Permeafor device uses a single-layer stainless steel filter, it can only intercept coarse particles. However, the fine particle content in loess is usually greater than 80%, which easily leads to the formation of a filter cake on the filter surface, affecting the acquisition of hydraulic conductivity. Furthermore, this device uses the saturated soil formula to calculate hydraulic conductivity, and cannot test unsaturated loess.

[0004] Loess structural attenuation easily leads to geological disasters and ecological damage. Monitoring loess structural attenuation can identify risks and provide early warnings, offering a scientific basis for disaster prevention and control. This invention addresses the shortcomings of Permeafor devices in loess monitoring by proposing a hydraulic conductivity testing device and its application method for monitoring loess structural attenuation. This testing technology addresses issues such as fine loess particles clogging filters, incompatibility with unsaturated loess, and inability to capture dynamic changes in structural attenuation. It offers advantages such as high monitoring accuracy, resistance to alkaline corrosion, and ease of operation, demonstrating promising engineering application prospects. Therefore, this application proposes a hydraulic conductivity testing device and its application method for monitoring loess structural attenuation. Summary of the Invention

[0005] The purpose of this invention is to address the problems in the prior art, such as the clogging of filter screens by fine loess particles, incompatibility with unsaturated loess, and inability to capture dynamic changes in structural attenuation, by proposing a hydraulic conductivity testing device and its application method for monitoring the structural attenuation of loess.

[0006] In a first aspect, the present invention provides a hydraulic conductivity testing device for monitoring the structural attenuation of loess. The testing device includes: a drill rod, a probe, a low-head adjustment unit, a time-domain reflectometry sensor, a vibrating wire pressure gauge, a flow sensor, a data acquisition instrument, and a power unit. A three-layer composite filter assembly is installed in the probe. The low-head adjustment unit, the time-domain reflectometry sensor, and the vibrating wire pressure gauge are connected sequentially above the filter assembly. The drill rod is connected between the vibrating wire pressure gauge and the power unit. The flow sensor, the data acquisition instrument, and a water source are arranged above the ground. All components are connected by data cables and wires, which are laid along the drill rod. The water source is connected to the low-head adjustment unit through a pipeline. The data acquisition instrument reads data from the low-head adjustment unit, the time-domain reflectometry sensor, the vibrating wire pressure gauge, and the flow sensor.

[0007] Optionally, the filter assembly includes a protective layer, a main filter layer, and a support layer. The inner wall of the probe is made of 316L stainless steel. The support layer is made of 316L stainless steel woven mesh with a pore size of 1000μm and a thickness of 1mm, and is welded to the probe body. The main filter layer is made of industrial-grade needle-punched geotextile, which is made of polyethylene terephthalate with a pore size of 100-150μm and a thickness of 1mm, and is fixed by folding, flanging, and sealing adhesive. The protective layer is made of PTFE-coated nylon mesh with a pore size of 500μm and a thickness of 0.5mm, and is embedded into the probe slot by a snap-fit ​​connection.

[0008] Optionally, the low head adjustment unit consists of a pressure adjustment device and a control module, and is located within 5cm above the filter screen.

[0009] Optionally, the low head adjustment unit, time domain reflectometer sensor, vibrating wire pressure gauge and flow sensor synchronously collect data once per minute under basic conditions. During encrypted data collection, the concave plate synchronously collects data once per second for 5 minutes, and the data is synchronously read and recorded by the data acquisition instrument.

[0010] Optionally, a connecting frame is fixed to the outside of the drill rod, and a concave plate is arranged above the ground. A motor is installed on the outside of the concave plate, and a vibration mechanism is provided at the output end of the motor. The vibration mechanism is used to strike the connecting frame, so that the drill rod shakes to make it easier to pick up.

[0011] Optionally, the vibration mechanism includes a transmission rod, a swashplate, two sets of connecting rods, a square rod, and a vibration rod. The transmission rod is connected to the output end of the motor, and the end of the transmission rod away from the motor is rotatably connected to the inner wall of the concave plate. The swashplate is fixed to the outside of the transmission rod. The two sets of connecting rods are respectively arranged on both sides of the swashplate, and both sets of connecting rods are fixed to the bottom end of the square rod. The square rod slides through the concave plate, and the vibration rod is fixed to the square rod. The vibration rod is in contact with the connecting frame.

[0012] Optionally, two sets of limiting rods slide through the inside of the vibration rod, and both sets of limiting rods slide through the connecting frame. A horizontal plate is provided on the outside of the connecting frame, and the horizontal plate is fixedly connected to the two sets of limiting rods. Two sets of guide rods are fixedly connected to the outside of the connecting frame, and both sets of guide rods slide through the horizontal plate. A side plate is fixedly connected to the end of the two sets of guide rods away from the horizontal plate, and a spring is fixedly connected between the side plate and the horizontal plate.

[0013] Optionally, a pull plate is fixedly connected to one end of the horizontal plate away from the limiting rod, and two sets of pedals are fixedly connected to the outer side of the concave plate.

[0014] Secondly, the present invention provides an application method for hydraulic conductivity testing for monitoring the structural attenuation of loess, applied to the hydraulic conductivity testing equipment for monitoring the structural attenuation of loess described in the first aspect, the method comprising the following steps: Step 1, Preparation Stage: First, level the site and mark the monitoring points. Then, check the equipment: the time domain reflectometer sensor needs to be calibrated with the standard soil sample, and the vibrating wire pressure gauge is calibrated from 0 to 50 kPa using a pressure tank. After that, assemble the filter screen in the order from bottom to top, which is the support layer, the main filter layer and the protective layer, and connect the pipelines and wires. Step 2, the testing phase: the probe is pressed into the soil by the power unit, the low head adjustment unit is adjusted and the equipment is started. Water is supplied to the low head adjustment unit through the pipeline and injected into the probe. During this process, real-time data is collected from the low head adjustment unit, the time domain reflectometer sensor, the vibrating wire pressure gauge and the flow sensor. Step 3: Data processing. After the data collection is completed, the data is transmitted to the data processing center for collaborative analysis of the parameters. Based on the hydraulic conductivity k obtained from the collaborative analysis, the structural attenuation of loess is identified.

[0015] Optionally, the principle for identifying the structural attenuation of loess in step three is as follows: (1) (2) (3) Where v is the seepage velocity, k is the saturated hydraulic conductivity, i is the hydraulic gradient, Δh is the seepage path length, θ is the water content measured by the time-domain reflectometry sensor (3), and θ is the measured soil water content. saturated moisture content The residual water content is given, and n and m are characteristic parameters of loess. The final hydraulic conductivity is then calculated. The values ​​of k, water pressure P, and measured water content θ are analyzed in the data processor to determine the structural decay stage of loess: when the fluctuation range of k is less than 10%, the fluctuation of P is less than 1 kPa, and the change of θ is less than 1% / h, the structural decay of loess is in a stable period; when the rate of change of k is greater than 10% / h, the P value decreases by 2-5 kPa / h, and the θ value increases but is less than 3% / h, the structural decay of loess is in an accelerated period; when the k value increases by more than or equal to one order of magnitude within 30 minutes, and the P value drops sharply by more than 20 kPa, the structural decay of loess is in a sudden change period.

[0016] Compared with the prior art, this application includes at least one of the following beneficial technical effects: This invention, through multi-parameter collaborative analysis, can monitor the structural attenuation state of loess in real time, effectively solving problems such as fine particles clogging the filter screen, unsaturated loess being unsuitable for the soil, and difficulty in capturing dynamic changes in the structure. It has the advantages of high monitoring accuracy, resistance to alkali corrosion, and simple operation, and has good prospects for engineering applications. Attached Figure Description

[0017] Figure 1 A schematic diagram of the overall structure of a hydraulic conductivity testing device used for monitoring the structural attenuation of loess. Figure 2 This is a flowchart illustrating the application of hydraulic conductivity testing equipment for monitoring structural attenuation in loess. Figure 3 A partial structural schematic diagram of a hydraulic conductivity testing device used for monitoring the structural attenuation of loess. Figure 4 This is a schematic diagram of the motor and swashplate. Figure 5 for Figure 4 A magnified structural diagram at point A.

[0018] Reference numerals: 1. Filter assembly; 101. Protective layer; 102. Main filter layer; 103. Support layer; 2. Low head regulating unit; 3. Time domain reflectometer sensor; 4. Vibrating wire pressure gauge; 5. Flow sensor; 6. Data acquisition instrument; 7. Water source; 8. Power unit; 9. Connecting frame; 10. Concave plate; 11. Motor; 12. Transmission rod; 13. Swashplate; 14. Connecting rod; 15. Square rod; 16. Vibrating rod; 17. Limiting rod; 18. Horizontal plate; 19. Guide rod; 20. Side plate; 21. Spring; 22. Pull plate; 23. Pedal. Detailed Implementation

[0019] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0020] In the description of this invention, it should be understood that the terms "upper," "lower," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. It should be noted that when a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be a component positioned centrally in the connection.

[0021] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0022] like Figure 1 and Figure 2As shown, the hydraulic conductivity testing device for monitoring the structural attenuation of loess proposed in this invention includes: a drill rod, a probe, a low-head adjustment unit 2, a time-domain reflectometry sensor 3, a vibrating wire pressure gauge 4, a flow sensor 5, a data acquisition unit 6, and a power unit 8. A three-layer composite filter assembly 1 is installed in the probe to effectively prevent clogging by fine loess particles and ensure durability. The low-head adjustment unit 2, the time-domain reflectometry sensor 3, and the vibrating wire pressure gauge 4 are sequentially connected above the filter assembly 1. The low-head adjustment unit 2 is used to achieve precise control and stable adjustment of the water head during the test. The time-domain reflectometry sensor 3 is used to monitor the dynamic changes in soil moisture content. The vibrating wire pressure gauge 4 is used to measure the pore water pressure or stress state in the strata. The drill rod is connected to the vibrating wire pressure gauge 4. The pressure gauge 4 and the power unit 8 serve to transmit mechanical power and support the probe. Above ground, a flow sensor 5, a data acquisition instrument 6, and a water source 7 are arranged. The flow sensor 5 is used to monitor the infiltration or pumping flow in real time. The data acquisition instrument 6 is responsible for automatically collecting and storing the signals from each sensor. The water source 7 provides a continuous and controllable water supply for the test. All components are connected by data cables and wires, which are laid along the drill rod to form a complete data transmission and power supply channel. The water source 7 is connected to the low head regulating unit 2 through a pipeline to achieve hydraulic connection. The data acquisition instrument 6 reads the data from the low head regulating unit 2, the time domain reflectometer sensor 3, the vibrating wire pressure gauge 4, and the flow sensor 5, thereby realizing the integrated and automated measurement of parameters such as loess permeability.

[0023] As one implementation method, such as Figure 1 and Figure 2 As shown, the filter assembly 1 includes a protective layer 101, a main filter layer 102, and a support layer 103. The inner wall of the probe is made of 316L stainless steel, which has excellent corrosion resistance and is suitable for groundwater or complex soil environments. The support layer 103 is made of 316L stainless steel woven mesh with a pore size of 1000μm and a thickness of 1mm. It is welded to the probe body and its function is to provide core structural support and ensure that the filter assembly 1 is firmly integrated with the probe. The main filter layer 102 is made of industrial-grade needle-punched geotextile, which is made of polyethylene terephthalate with a pore size of 100-150μm and a thickness of 1mm. It is fixed by folding and sealing with sealant. Its function is to finely filter fine particles in loess, effectively preventing clogging while ensuring water permeability. The protective layer 101 is made of PTFE-coated nylon mesh with a pore size of 500μm and a thickness of 0.5mm. It is embedded in the probe slot by a snap-fit ​​connection. Functionally, it provides mechanical protection and surface anti-adhesion. The detachable design facilitates maintenance and replacement.

[0024] Furthermore, such as Figure 1 and Figure 2As shown, the low head adjustment unit 2 consists of a pressure regulating device and a control module. The pressure regulating device and control module can accurately control the inlet water pressure during the test to simulate and maintain stable low head infiltration conditions. The unit is located within 5cm above the filter screen. The close-range installation minimizes the impact of pipeline losses on the head pressure and ensures the accuracy of the head applied to the sample.

[0025] Furthermore, such as Figure 1 and Figure 2 As shown, the low head adjustment unit 2, time domain reflectometer sensor 3, vibrating wire pressure gauge 4, and flow sensor 5 synchronously collect data once per minute under basic conditions. The function of this conventional mode is to continuously monitor the soil hydrological status at a low frequency, which is suitable for long-term and stable background data accumulation. During intensive collection, the concave plate synchronously collects data once every 10 seconds for 5 minutes. The data is synchronously read and recorded by the data acquisition instrument 6. This high-intensity sampling mode aims to accurately record the transient response of water, pressure, and flow during the initial infiltration stage or when conditions change abruptly.

[0026] As one implementation method, Figure 1 , Figure 2 and Figure 3 As shown, a connecting frame 9 is fixed to the outside of the drill rod, and a concave plate 10 is arranged above the ground. The concave plate 10 is used to support its inner and outer components. A motor 11 is installed on the outside of the concave plate 10. A vibration mechanism is provided at the output end of the motor 11. When the drill rod needs to be removed from the ground, the operator starts the motor 11. The operation of the motor 11 will drive the vibration mechanism to run synchronously. The vibration mechanism is used to strike the connecting frame 9, making the drill rod shake for easy removal. At this time, the vibration mechanism will drive the connecting frame 9 to shake, and the shaking of the connecting frame 9 will synchronously drive the drill rod to shake slightly. At this time, the drill rod will slightly loosen the surrounding soil, reducing the friction between the soil and the drill rod, thus making it easier for the operator to remove the drill rod.

[0027] Furthermore, such as Figure 3 and Figure 4 As shown, the vibration mechanism includes a transmission rod 12, a swashplate 13, two sets of connecting rods 14, a square rod 15, and a vibration rod 16. The vibration mechanism is described in detail below: The transmission rod 12 is connected to the output end of the motor 11. When the motor 11 runs, it drives the transmission rod 12 to rotate. The end of the transmission rod 12 away from the motor 11 is rotatably connected to the inner wall of the concave plate 10. The concave plate 10 supports the transmission rod 12 and the motor 11. The swashplate 13 is fixed to the outside of the transmission rod 12. When the transmission rod 12 rotates, it drives the swashplate 13 to rotate. Two sets of connecting rods 14 are respectively arranged on both sides of the swashplate 13. Since the swashplate 13 is inclined, when the swashplate 13 rotates, it will intermittently and sequentially press the two sets of connecting rods 14. When subjected to compressive force, the 14 rods will move in different directions, and both sets of connecting rods 14 are fixed to the bottom end of the square rod 15. When the connecting rod 14 moves towards the connecting frame 9, the connecting rod 14 drives the square rod 15 to move synchronously. The square rod 15 slides through the concave plate 10. The vibrating rod 16 is fixed to the square rod 15 and is in contact with the connecting frame 9. When the square rod 15 moves, it will drive the vibrating rod 16 to move. At this time, the vibrating rod 16 will hit the connecting frame 9. The connecting frame 9 is subjected to force and vibrates, which is transmitted to the drill rod. The drill rod shakes, causing the surrounding soil to loosen slightly.

[0028] Furthermore, such as Figure 4 and Figure 5 The vibrating rod 16 has two sets of limiting rods 17 slidingly passing through its interior. Initially, the two sets of limiting rods 17 are located inside the vibrating rod 16. Therefore, when the vibrating rod 16 moves, it synchronously drives the connecting frame 9 to move, causing the drill rod to shake. Both sets of limiting rods 17 slide through the connecting frame 9. A horizontal plate 18 is provided on the outer side of the connecting frame 9. When it is necessary to separate the vibrating rod 16 from the connecting frame 9, simply move the horizontal plate 18 away from the limiting rods 17. The horizontal plate 18 is fixedly connected to the two sets of limiting rods 17. When the horizontal plate 18 moves, it synchronously drives the limiting rods 17 to move. When the limiting rods 17 disengage from the horizontal plate 18 and the interior of the connecting frame 9, the vibrating rod 16 is stopped by the limiting rods 17, and the vibrating rod 16 can then be separated from the connecting frame 9. Two sets of guide rods 19 are fixed to the outside of the connecting frame 9. Both sets of guide rods 19 slide through the horizontal plate 18. A side plate 20 is fixed to the end of the two sets of guide rods 19 away from the horizontal plate 18. A spring 21 is fixed between the side plate 20 and the horizontal plate 18. When the horizontal plate 18 moves, the horizontal plate 18 will also press the spring 21 along the outside of the guide rods 19 in conjunction with the side plate 20, causing the spring 21 to deform under force and generate elastic potential energy. Therefore, when the vibrating rod 16 is inserted into the interior of the connecting frame 9 again, it is only necessary to release the horizontal plate 18. The spring 21 can then release its elastic potential energy, and the horizontal plate 18 pushes the limiting rod 17 to reset. The limiting rod 17 resets and slides through the vibrating rod 16 again, thus fixing the position of the vibrating rod 16 again and realizing the rapid connection between the vibrating rod 16 and the connecting frame 9.

[0029] As one implementation method, such as Figure 3 and Figure 5 As shown, a pull plate 22 is fixedly connected to one end of the horizontal plate 18 away from the limiting rod 17. The pull plate 22 makes it easier for the operator to move the horizontal plate 18, which is more in line with human mechanics. Two sets of pedals 23 are fixedly connected to the outer side of the concave plate 10. The two sets of pedals 23 make it easy for the operator to step on them, thereby fixing the concave plate 10.

[0030] In this embodiment, when the equipment is working, the probe is first pressed into the soil at the calibrated monitoring point. Under the condition of low water head and constant water supply, the time domain reflectometer sensor 3, vibrating wire pressure gauge 4 and flow sensor 5 respectively acquire water content (θ), water pressure (P) and seepage data. After the data acquisition instrument 6 records these parameters simultaneously, the actual hydraulic conductivity is obtained by inversion based on Darcy's law and unsaturated correction model. Finally, based on the coordinated change law of k value, P value and θ value (such as fluctuation amplitude, change rate and abrupt change characteristics), the loess structure is automatically judged to be in a stable period, an accelerated period or an abrupt change period, thereby providing a quantitative basis for early warning of soil and rock disasters.

[0031] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A hydraulic conductivity testing device for monitoring the structural attenuation of loess, characterized in that: The test equipment includes: a drill rod, a probe, a low head adjustment unit (2), a time domain reflectometer sensor (3), a vibrating wire pressure gauge (4), a flow sensor (5), a data acquisition unit (6), and a power unit (8); a three-layer composite filter assembly (1) is installed in the probe, and the low head adjustment unit (2), the time domain reflectometer sensor (3), and the vibrating wire pressure gauge (4) are connected in sequence above the filter assembly (1). The drill rod is connected between the vibrating wire pressure gauge (4) and the power unit (8). The flow sensor (5), the data acquisition unit (6), and the water source (7) are arranged above the ground. All components are connected by data lines and wires. The data lines and wires are laid along the drill rod. The water source (7) is connected to the low head adjustment unit (2) through a pipeline. The data acquisition unit (6) reads the data of the low head adjustment unit (2), the time domain reflectometer sensor (3), the vibrating wire pressure gauge (4), and the flow sensor (5).

2. The hydraulic conductivity testing device for monitoring the structural attenuation of loess according to claim 1, characterized in that, The filter assembly (1) includes a protective layer (101), a main filter layer (102), and a support layer (103). The inner wall of the probe is made of 316L stainless steel. The support layer (103) is made of 316L stainless steel woven mesh with a pore size of 1000μm and a thickness of 1mm, and is welded to the probe body. The main filter layer (102) is made of industrial-grade needle-punched geotextile, which is made of polyethylene terephthalate with a pore size of 100-150μm and a thickness of 1mm. It is fixed by folding and sealing. The protective layer (101) is made of PTFE-coated nylon mesh with a pore size of 500μm and a thickness of 0.5mm. It is embedded in the probe slot by a snap-fit ​​connection.

3. The hydraulic conductivity testing device for monitoring the structural attenuation of loess according to claim 1, characterized in that, The low head adjustment unit (2) consists of a pressure adjustment device and a control module, and is located within 5cm above the filter screen.

4. The hydraulic conductivity testing device for monitoring the structural attenuation of loess according to claim 1, characterized in that, The low head adjustment unit (2), time domain reflectometer sensor (3), vibrating wire pressure gauge (4) and flow sensor (5) collect data synchronously once per minute under basic conditions. When the data is collected in an encrypted manner, the concave plate (10) collects data synchronously once every 10 seconds for 5 minutes. The data is synchronously read and recorded by the data acquisition instrument (6).

5. The hydraulic conductivity testing device for monitoring the structural attenuation of loess according to claim 1, characterized in that, A connecting frame (9) is fixed to the outside of the drill rod, and a concave plate (10) is arranged above the ground. A motor (11) is installed on the outside of the concave plate (10), and a vibration mechanism is provided at the output end of the motor (11). The vibration mechanism is used to strike the connecting frame (9) to make the drill rod shake so that it can be easily picked up.

6. The hydraulic conductivity testing device for monitoring the structural attenuation of loess according to claim 5, characterized in that, The vibration mechanism includes a transmission rod (12), a swashplate (13), two sets of connecting rods (14), a square rod (15), and a vibration rod (16). The transmission rod (12) is connected to the output end of the motor (11). The end of the transmission rod (12) away from the motor (11) is rotatably connected to the inner wall of the concave plate (10). The swashplate (13) is fixed to the outside of the transmission rod (12). The two sets of connecting rods (14) are respectively arranged on both sides of the swashplate (13), and both sets of connecting rods (14) are fixed to the bottom end of the square rod (15). The square rod (15) slides through the concave plate (10). The vibration rod (16) is fixed to the square rod (15) and fits against the connecting frame (9).

7. The hydraulic conductivity testing device for monitoring the structural attenuation of loess according to claim 6, characterized in that, The vibrating rod (16) has two sets of limiting rods (17) slidingly passing through its interior. Both sets of limiting rods (17) slide through the connecting frame (9). A horizontal plate (18) is provided on the outside of the connecting frame (9). The horizontal plate (18) is fixedly connected to the two sets of limiting rods (17). Two sets of guide rods (19) are fixedly connected on the outside of the connecting frame (9). Both sets of guide rods (19) slide through the horizontal plate (18). A side plate (20) is fixedly connected to one end of the two sets of guide rods (19) away from the horizontal plate (18). A spring (21) is fixedly connected between the side plate (20) and the horizontal plate (18).

8. The hydraulic conductivity testing device for monitoring the structural attenuation of loess according to claim 7, characterized in that, A pull plate (22) is fixedly connected to one end of the horizontal plate (18) away from the limiting rod (17), and two sets of pedals (23) are fixedly connected to the outer side of the concave plate (10).

9. An application method for hydraulic conductivity testing for monitoring the structural attenuation of loess, applied to the hydraulic conductivity testing equipment for monitoring the structural attenuation of loess as described in any one of claims 1-4, characterized in that, Includes the following steps: Step 1, Preparation stage: First, level the site and mark the monitoring points. Then, check the equipment: the time domain reflectometer sensor (3) needs to be calibrated with the standard soil sample, and the vibrating wire pressure gauge (4) is calibrated from 0 to 50 kPa through the pressure tank. After that, assemble the filter screen (1) in the order from bottom to top, which is the support layer (103), the main filter layer (102) and the protective layer (101), and connect the pipeline and wires. Step 2, the testing phase, the probe is pressed into the soil by the power device (8), the low head adjustment unit (2) is adjusted and the equipment is started. The water source (7) supplies water to the low head adjustment unit (2) through the pipeline and injects it into the probe. During this process, real-time data is collected from the low head adjustment unit (2), the time domain reflectometer sensor (3), the vibrating wire pressure gauge (4) and the flow sensor (5). Step 3: Data processing. After the data collection is completed, the data is transmitted to the data processing center for collaborative analysis of the parameters. Based on the hydraulic conductivity k obtained from the collaborative analysis, the structural attenuation of loess is identified.

10. The application method for hydraulic conductivity testing for monitoring the structural attenuation of loess according to claim 9, characterized in that, The principle behind identifying the structural attenuation of loess in step three is as follows: (1) (2) (3) Where v is the seepage velocity, k is the saturated hydraulic conductivity, i is the hydraulic gradient, Δh is the seepage path length, θ is the water content measured by the time-domain reflectometry sensor (3), and θ is the measured soil water content. saturated moisture content, The residual water content is given, and n and m are characteristic parameters of loess. The final hydraulic conductivity is then calculated. The values ​​of k, water pressure P, and measured water content θ are analyzed in the data processor to determine the structural decay stage of loess: when the fluctuation range of k is less than 10%, the fluctuation of P is less than 1 kPa, and the change of θ is less than 1% / h, the structural decay of loess is in a stable period; when the rate of change of k is greater than 10% / h, the P value decreases by 2-5 kPa / h, and the θ value increases but is less than 3% / h, the structural decay of loess is in an accelerated period; when the k value increases by more than or equal to one order of magnitude within 30 minutes, and the P value drops sharply by more than 20 kPa, the structural decay of loess is in a sudden change period.

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