Soil saturated hydraulic conductivity measuring device

Abstract

The utility model discloses a soil saturation hydraulic conductivity measuring device which is applied to an undisturbed soil sample, the soil saturation hydraulic conductivity measuring device comprises a base, a cutting ring, a pipe fitting and a connecting piece, the cutting ring is located on the base and used for containing the undisturbed soil sample, the pipe fitting is arranged at the top of the cutting ring and is of a transparent structure, and the connecting piece is connected with the cutting ring. The pipe fitting is used for limiting the first space, the first space is used for containing liquid, the connecting piece is located between the cutting ring and the pipe fitting, and the interior of the cutting ring is communicated with the first space through the connecting piece in the assembling state. According to the device, through mutual combination of the cutting ring, the pipe fitting and the connecting piece, the water guiding performance of an undisturbed soil sample can be accurately measured, the authenticity and reliability of a measurement result are ensured, meanwhile, through the transparent pipe fitting, the water flow condition can be observed in real time, the measurement precision is further improved, and the device is compact in structure, easy to operate, low in cost and suitable for popularization and application. And subsequent operation and research are facilitated.

Description

Technical Field

[0001] This utility model relates to the field of soil moisture and physical property measurement technology, and in particular to a soil saturated hydraulic conductivity measuring device. Background Technology

[0002] Soil saturated hydraulic conductivity is a parameter of soil's ability to conduct water under saturated conditions. It is an important parameter in soil physics, determining the rate at which water infiltrates the soil. Soil saturated hydraulic conductivity is usually measured when soil moisture reaches saturation. It has important reference value for farmland irrigation planning, groundwater recharge assessment, ecological restoration strategy formulation, and soil hydrological model parameterization.

[0003] In related technologies, the saturated hydraulic conductivity of soil is affected by various factors, including soil particle size, soil pore structure, soil organic matter content, and soil compaction degree. Therefore, a soil saturated hydraulic conductivity device is needed to measure it using relevant methods. Common methods include the constant head method and the precipitation head method. Among them, the precipitation head method is more commonly used and simpler for measuring the saturated hydraulic conductivity of medium- to low-permeability soils under laboratory conditions.

[0004] However, existing soil saturated hydraulic conductivity measuring devices are expensive (such as the four-point saturated hydraulic conductivity meter produced in Japan). In addition, during the measurement process, researchers need to make continuous and repeated manual readings and records, which is time-consuming and labor-intensive, and is easily affected by human negligence or reading deviations. Utility Model Content

[0005] To address the problems of high cost, the need for continuous and repeated manual readings and recordings during the measurement process, and susceptibility to human error or reading deviations in existing soil saturated hydraulic conductivity measuring devices, this invention provides a soil saturated hydraulic conductivity measuring device. The technical solution adopted is as follows:

[0006] This application provides a soil saturated hydraulic conductivity measuring device, applied to undisturbed soil samples, comprising:

[0007] A base, on the top of which is provided a support;

[0008] A ring cutter, located on the support, is used to hold the undisturbed soil sample;

[0009] A tubular fitting is disposed on the top of the ring cutter. The tubular fitting has a transparent structure and is used to restrict a first space for containing liquid.

[0010] The connector is located between the ring cutter and the pipe fitting;

[0011] In the assembled state, the interior of the ring cutter is connected to the first space through the connector.

[0012] In some embodiments, the connector is composed of an upper connecting portion and a lower connecting portion, wherein the length of the upper connecting portion is smaller than the length of the lower connecting portion in the width direction of the connector.

[0013] In some embodiments, both the upper connecting portion and the lower connecting portion are cylindrical structures;

[0014] One end of the pipe fitting is sleeved on the upper connecting part, and the lower connecting part is detachably connected to the ring cutter.

[0015] In some embodiments, the connector is provided with a sealing component located at the end of the upper connector; and / or, the sealing component is located at the end of the lower connector.

[0016] In some embodiments, a counterweight is also included, which is sleeved on the pipe fitting;

[0017] Along the height direction of the pipe fitting, the sidewall of the pipe fitting is provided with graduated lines at intervals.

[0018] In some embodiments, the counterweight has a circular structure, and the counterweight and the connector are attracted to each other.

[0019] In some embodiments, the edge of the base has a raised structure that extends toward a side away from the base, such that there is a predetermined angle between the base and the raised structure.

[0020] In some embodiments, a camera device is also included, the optical axis of which is oriented toward the tube, and the camera device is used to capture the height of the liquid within the first space.

[0021] The technological advancements achieved by this invention compared to existing technologies are as follows:

[0022] This invention, through the combination of a ring cutter, tubing, and connectors, can accurately measure the hydraulic conductivity of undisturbed soil samples, ensuring the authenticity and reliability of the measurement results. Simultaneously, the transparent tubing allows for real-time observation of water flow, further improving measurement accuracy. The device is compact, easy to operate, and low in cost, facilitating subsequent operations and research. Attached Figure Description

[0023] The accompanying drawings are provided to further understand the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention and do not constitute a limitation thereof.

[0024] In the attached diagram:

[0025] Figure 1 This is a structural diagram of the soil saturated hydraulic conductivity measuring device of this utility model;

[0026] Figure 2 This is a schematic diagram of the connector in this utility model;

[0027] Figure 3 This is a schematic diagram of the ring cutter of this utility model;

[0028] Figure 4 This is a schematic diagram of the structure of the ring cutter in this utility model;

[0029] Figure 5 This is a schematic diagram of the structure of the soil saturated hydraulic conductivity measuring device of this utility model.

[0030] In the diagram: 1. Base; 10. Support; 11. Raised structure; 2. Ring cutter; 20. Filter assembly; 3. Pipe fitting; 31. First space; 32. Scale line; 4. Connector; 41. Upper connection part; 42. Lower connection part; 5. Original soil sample; 6. Sealing assembly; 7. Counterweight; 8. Camera equipment. Detailed Implementation

[0031] The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this utility model will be described below with reference to the accompanying drawings.

[0032] like Figures 1 to 5 As shown, this utility model discloses a soil saturated hydraulic conductivity measuring device, applied to undisturbed soil samples. It includes a base 1, a ring cutter 2, a tube 3, and a connector 4. A support 10 is mounted on top of the base 1 to support the ring cutter 2 and ensure stability. Multiple perforated meshes are mounted on the support 10 for liquid permeation. The meshes can be square or circular. In one example, four circular perforated meshes are spaced apart on the support 10. The ring cutter 2 is located on the base 1, and its shape matches the perforated meshes. The ring cutter 2 holds the undisturbed soil sample 5. The ring cutter 2 can be made of stainless steel or other corrosion-resistant metal materials to ensure it is not affected by the external environment during operation and maintains the integrity of the undisturbed soil sample 5. The capacity of the ring cutter 2 can be adapted as needed; for example, a 100 cm³ ring cutter 2 can be used. 3Sampling is performed by size. In one example, the edge of the ring cutter 2 has a sharp structure, which can easily peel the undisturbed soil sample 5 from the soil layer, so that the undisturbed soil sample 5 is consistent with the shape and structure of the ring cutter 2, while reducing damage to the structure of the undisturbed soil sample 5. The inner wall of the ring cutter 2 has a rough surface, which ensures that the undisturbed soil sample 5 is not easy to slip out of the ring cutter 2, which is beneficial to the subsequent determination of the actual water conductivity of the undisturbed soil sample 5.

[0033] Continue to refer to Figures 1 to 5 The top of the ring cutter 2 is equipped with a tube 3, which restricts the first space 31 for containing liquid. The tube 3 is transparent, allowing the operator to directly observe the liquid flow during the measurement. The length and width of the tube 3 can be customized as needed; for example, the inner diameter of the tube 3 is 10 mm and the height is 350 mm. In one example, the liquid is water, and the tube 3 is cylindrical. The water flows in the first space 31 and is guided by the tube 3 into the undisturbed soil sample 5, ensuring the controllability of subsequent experiments and the accuracy of results. A connector 4 is located between the ring cutter 2 and the tube 3. The connector 4 is made of PVC. In the assembled state, the interior of the ring cutter 2 is connected to the first space 31 through the connector 4, ensuring the stability of the undisturbed soil sample 5 during the measurement process. In another example, such as... Figure 3 and Figure 4 As shown, a filter assembly 20 is provided at the bottom of the ring cutter 2. The filter assembly 20 is located between the ring cutter 2 and the support 10. The filter assembly 20 can be any one or more combinations of filter paper, porous bottom cover and screen. During the process of liquid permeating the undisturbed soil sample 5, the filter assembly 20 can filter the liquid onto the base 1 and prevent the undisturbed soil sample 5 from flowing out, so as to ensure the accuracy of the measurement.

[0034] When using the device, the operator first uses the ring cutter 2 to obtain an undisturbed soil sample 5, and then fixes the pipe 3 to the top of the ring cutter 2 through the connector 4. After that, the required amount of water is poured into the first space 31 of the pipe 3. The water will seep into the undisturbed soil sample 5 over time. During this process, the operator observes the process of the water level dropping over time and calculates the saturated hydraulic conductivity of the soil.

[0035] In this application, the hydraulic conductivity of undisturbed soil samples can be accurately measured by combining the ring cutter, pipe fittings, and connectors, ensuring the authenticity and reliability of the measurement results. At the same time, the water flow can be observed in real time through the transparent pipe fittings, further improving the accuracy of the measurement. The device has a compact structure, is simple to operate, has low cost, and is convenient for subsequent operation and research.

[0036] In some embodiments, such as Figure 1 , Figure 2 and Figure 5As shown, the connector 4 is composed of an upper connecting part 41 and a lower connecting part 42, and in the width direction of the connector 4 (e.g., Figure 5 In the x-direction shown, the cross-section of the connector 4 is convex. The length of the upper connector 41 is smaller than that of the lower connector 42, so that the upper connector 41 is connected to the pipe 3 and reduces frictional resistance during liquid flow. The lower connector 42 is connected to the ring cutter 2, ensuring that the undisturbed soil sample 5 can be supported and fixed during the measurement process. This allows it to adapt to different pipes 3 and ring cutters 2, and provides sealing and operability for the device. In the assembled state, the lower connector 42 can provide a larger contact surface, thereby enabling the liquid to penetrate evenly into the undisturbed soil sample 5, thus ensuring the accuracy of subsequent measurements.

[0037] In some embodiments, the connector 4 may be cuboid or cylindrical, depending on the desired shape. In one example, continue to refer to... Figure 1 , Figure 2 and Figure 5 Both the upper connecting part 41 and the lower connecting part 42 are cylindrical structures. The connecting parts 4 are detachably connected to the pipe 3 and the ring cutter 2. One end of the pipe 3 is sleeved on the upper connecting part 41, and the lower connecting part 42 is snapped into the ring cutter 2. This allows the pipe 3 to be stably positioned on top of the ring cutter 2 through the connecting parts 4, providing stability to the entire device and ensuring that it will not loosen or shift during the measurement process. At the same time, the operator can install and disassemble it for timely replacement and inspection, and disassemble and store it after the measurement to avoid occupying a lot of space.

[0038] In some embodiments, such as Figure 1 and Figure 2 As shown, a sealing component 6 is provided on the connector 4. The sealing component 6 has a sealing function to prevent liquid leakage, which would affect the accuracy of subsequent measurements. The sealing component 6 can be a sealing ring, sealing strip, or adhesive, as long as it ensures a seamless connection. In one example, such as... Figure 2As shown, the sealing component 6 is a sealing ring located inside the end of the upper connecting part 41. During assembly, the pipe 3 can be tightly connected to the connecting part 4 through the sealing ring, ensuring stability and sealing, allowing liquid to flow into the undisturbed soil sample 5 along the extension direction of the pipe 3. In another example, the sealing ring is located inside the end of the lower connecting part 42, ensuring no gap between the lower connecting part 42 and the ring cutter 2. During measurement, the liquid can flow evenly into the undisturbed soil sample 5 inside the ring cutter 2, preventing liquid leakage outside the ring cutter 2 and affecting the accuracy of subsequent experiments. The sealing ring also has a rough surface for a firm connection, preventing loosening. In another example (not shown in the attached figure), the sealing component is a sealing strip. The sealing strip is adhesive to the pipe, connecting part, and ring cutter. The sealing strip is adhered to the connection between the pipe and the upper connecting part, and the connection between the lower connecting part and the ring cutter, ensuring no gaps at the connection points and guaranteeing sealing, thereby achieving the accuracy of the saturated hydraulic conductivity of the undisturbed soil sample.

[0039] In some embodiments, such as Figure 5 As shown, it also includes a counterweight 7, which is used to increase weight to maintain balance. Since adding water to the pipe fitting 3 will generate an upward pushing force, potentially dislodging the undisturbed soil sample 5 from the ring cutter 2, which would affect subsequent measurement results, the counterweight 7 is fitted onto the pipe fitting 3 to ensure that the ring cutter 2 and the undisturbed soil sample 5 are not pushed up and loosened. Along the height direction of the pipe fitting 3 (e.g., ... Figure 5 As shown in the z direction), the side wall of the pipe fitting 3 is provided with graduation lines 32 at intervals, which makes it convenient for operators to observe the changes in the water level of the liquid inside the pipe fitting 3 at all times.

[0040] In some embodiments, the shape of the counterweight 7 can be adapted as needed. In one example, the counterweight 7 has a ring structure, and the counterweight 7 and the connector 4 are attracted to each other. That is, a magnetic attraction element is provided on the contact surface between the connector 4 and the counterweight 7. The counterweight 7 is made of metal. In the assembled state, the counterweight 7 is attracted to the magnetic attraction element, which ensures the stability of the entire device and achieves the accuracy of the measurement.

[0041] In some embodiments, such as Figure 1 and Figure 5As shown, the edge of the base 1 has a raised structure 11, which is used to block the liquid from flowing out of the base. The raised structure 11 extends toward the side away from the base 1, so that there is a preset angle between the base 1 and the raised structure 11. The preset angle can be 40 degrees or 60 degrees, and can be adapted as needed. In this application, no restrictions are placed on this. During the measurement process, the liquid permeates from the first space 31 into the undisturbed soil sample 5 in the ring cutter 2. When the undisturbed soil sample 5 is completely permeated by the liquid, the excess liquid will flow from the ring cutter 2 into the base 1. The raised structure 11 can effectively restrict the flow position of the liquid, which is convenient for subsequent centralized processing.

[0042] In some embodiments, such as Figure 5 As shown, it also includes a camera device 8, the optical axis direction of the camera device 8 (e.g. Figure 5 (In the x direction shown) towards the pipe 3, the camera device 8 is used to capture the height change of the liquid in the first space 31. The camera device 8 can be a digital camera, a webcam, or a smartphone camera module, etc., as long as it can capture images. This application will not elaborate on this. During the measurement process, the operator sets the shooting interval of the camera device 8 through a timer controller or computer program. For example, it can take pictures once every minute, or at intervals of five minutes, ten minutes, etc., which can be adapted according to the permeability of the original soil sample.

[0043] The working principle of the soil saturated hydraulic conductivity measuring device in this application is as follows:

[0044] like Figures 1 to 5 As shown, firstly, the operator installs the pipe fitting 3 on the top of the ring cutter 2 via the connector 4, and seals the connection with the sealing component 6 to prevent subsequent leakage. The assembled component is then placed on the base 1. After that, the operator pours liquid (e.g., water) into the first space 31 of the pipe fitting 3, and uses the camera device 8 to film the change in liquid height. The data is then summarized, and finally the hydraulic conductivity of the undisturbed soil sample is calculated.

[0045] The specific steps for determining the saturated hydraulic conductivity of soil during use are as follows:

[0046] Step a. Insert a ring cutter into the soil layer in the preset area to obtain an undisturbed soil sample, and slowly deliver the first liquid from the bottom of the ring cutter to fully moisten the undisturbed soil sample until there is no residual air.

[0047] First, a suitable soil layer test area is selected, such as in the field, ensuring that the soil layer is in its natural state and unaffected by any external forces. The undisturbed soil sample 5 is then completely extracted by vertically inserting a ring cutter 2 into the soil layer, thus obtaining the undisturbed soil sample 5. Subsequently, a first liquid (e.g., water) is slowly introduced from the bottom of the ring cutter 2. The first liquid evenly seeps into the undisturbed soil sample 5 through the bottom of the ring cutter 2, ensuring that all pores of the undisturbed soil sample 5 are fully moistened until all air within the undisturbed soil sample 5 is completely expelled, ensuring no air residue remains. At this point, the undisturbed soil sample 5 reaches a saturated state, providing suitable preconditions for subsequent hydraulic conductivity measurements.

[0048] Step b. Install the filter assembly at the bottom of the ring cutter, and install the connector and pipe fittings in sequence at the top of the ring cutter to form a soil saturated hydraulic conductivity measuring device;

[0049] A filter assembly is installed at the bottom of the ring cutter 2. The filter assembly includes qualitative filter paper, a porous bottom cover, and a highly permeable screen support to form a near-free drainage lower boundary. At the same time, the top of the ring cutter 2 is connected to the pipe 3 via a connector 4. All connections are sealed with a sealing component 6 to prevent liquid leakage. All components are placed on a base 1 for collecting seepage water. A counterweight 7 is also fitted on the pipe 3 to improve the stability of the device, thus forming a soil saturated hydraulic conductivity measuring device for easy subsequent measurement.

[0050] Step c. Aim the camera at the pipe fitting area and set the photo interval;

[0051] Set up the appropriate camera device 8 as required, and align the optical axis of the camera device 8 with the area of ​​the pipe fitting 3 to capture the liquid height change. At the same time, set the photo interval according to the liquid permeation situation.

[0052] Step d. The pipe contains a second liquid. When the second liquid is added into the pipe and reaches the initial height, time recording and shooting begin. When the second liquid drops to the final height, time recording and shooting stop, and relevant data is obtained through a computer.

[0053] The measurement begins by adding a second liquid (e.g., water) to the first space 31 of pipe 3 to an initial height of 200 mm. The camera is set to automatically take a picture every minute. When the permeability of the undisturbed soil sample 5 is low, the interval can be increased, such as to 10 minutes, to reduce storage space and post-processing pressure. After the required number of hours of experimental operation, the second liquid seeps down along the soil of the undisturbed soil sample 5. When the water level in pipe 3 gradually drops to 100 mm, it can be used as the termination height, and the shooting stops. The camera device 8 automatically takes pictures at predetermined intervals to obtain an image sequence of water level changes over time. After the experiment, the images in the camera device 8 are imported into a computer, and the water level scale is automatically identified by image recognition software (such as OpenCV) and matched with the corresponding time point to obtain a complete time data sequence.

[0054] Step e. Substitute the relevant data, namely the initial height, the final height, and the time interval, into the precipitation head method formula. ;

[0055] In the formula, It is the saturated hydraulic conductivity (cm / s or mm / s). This represents the cross-sectional area (cm²) of the water level measuring tube. The length of the soil sample is in cm. This represents the cross-sectional area (cm²) of the soil sample. The time interval is (s). This is the initial height (cm). The soil saturated hydraulic conductivity value is calculated based on the termination height (cm).

[0056] Finally, it should be noted that the above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of protection of the claims of this utility model.

Claims

1. A device for measuring the saturated hydraulic conductivity of soil, characterized in that, Applied to undisturbed soil samples, including: A base, on the top of which is provided a support; A ring cutter, located on the support, is used to hold the undisturbed soil sample; A tubular fitting is disposed on the top of the ring cutter. The tubular fitting has a transparent structure and is used to restrict a first space for containing liquid. The connector is located between the ring cutter and the pipe fitting; In the assembled state, the interior of the ring cutter is connected to the first space through the connector.

2. The soil saturated hydraulic conductivity measuring device according to claim 1, characterized in that, The connector consists of an upper connecting part and a lower connecting part. In the width direction of the connector, the length of the upper connecting part is smaller than the length of the lower connecting part.

3. The soil saturated hydraulic conductivity measuring device according to claim 2, characterized in that, Both the upper connecting part and the lower connecting part are cylindrical structures; One end of the pipe fitting is sleeved on the upper connecting part, and the lower connecting part is detachably connected to the ring cutter.

4. The soil saturated hydraulic conductivity measuring device according to claim 2, characterized in that, The connector is provided with a sealing component, which is located at the end of the upper connector; and / or, the sealing component is located at the end of the lower connector.

5. The soil saturated hydraulic conductivity measuring device according to claim 1, characterized in that, It also includes a counterweight, which is fitted onto the pipe fitting; Along the height direction of the pipe fitting, the sidewall of the pipe fitting is provided with graduated lines at intervals.

6. The soil saturated hydraulic conductivity measuring device according to claim 5, characterized in that, The counterweight has a circular ring structure, and the counterweight and the connector are attracted to each other.

7. The soil saturated hydraulic conductivity measuring device according to claim 1, characterized in that, The base has a raised structure on its edge, which extends toward the side away from the base, so that there is a preset angle between the base and the raised structure.

8. The soil saturated hydraulic conductivity measuring device according to claim 1, characterized in that, It also includes a camera device, the optical axis of which is oriented toward the pipe, and the camera device is used to capture the height of the liquid in the first space.

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