Multifunctional water-soil interaction experiment device and method based on image intelligent feedback

Abstract

The application discloses a multifunctional water and soil interaction experiment device and method based on image intelligent feedback, which comprises a device body, an air pressure device, a water supply device, an image acquisition system and a computer processing system; a soil sample is placed in the device body, the bottom of the device body is communicated with the air pressure device, the top of the device body is communicated with the water supply device, and the image acquisition system is opposite to the device body; the computer processing system is connected with the image acquisition system, the air pressure device and the water supply device respectively; by adjusting different pressure differences of the soil sample in the device body, the flow and the flow rate of water flowing into the device body are controlled, and the wetting and drying, leaching test and permeation of the soil sample under a negative pressure state are acquired in real time through the image acquisition system. The application realizes the functions of simulating the water movement in a rock-soil body, the migration law of a pollutant, the preparation of a contaminated soil sample, the wetting and drying of a rock-soil and the like in a laboratory through various water and soil interaction tests, and the real movement law of a water chemical solution in a rock-soil body is directly judged and obtained through image feedback.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of geotechnical property research equipment, and particularly relates to a multifunctional water-soil interaction experimental device and method based on image intelligent feedback. BACKGROUND

[0002] Geotechnical body has always been the key research object in the fields of water conservancy, environment, geotechnology, agriculture, forestry and the like, and the water-soil interaction test is a common test method for researching various hydrological properties of geotechnical body. Specifically, various types of geotechnical samples are collected and prepared, fluid motion conditions in geotechnical body, pollution migration rules, soil hydraulic properties and the like are simulated in the laboratory, and various parameters of the geotechnical sample are measured.

[0003] The water-soil interaction test device in the prior art has a single function, low efficiency and certain difficulties in studying some problems, cannot meet various experimental requirements, and cannot accurately simulate the state of geotechnical body in a real environment, resulting in deviation of test results.

[0004] For geotechnical sample wetting and drying test, the remolded soil sample currently adopts the artificial interference soil preparation method, and the undisturbed soil sample is mostly wetted according to the capillary action principle. The stress release effect of the undisturbed soil is ignored under the test conditions, and a long time is required to achieve uniform moisture of the soil sample, which is low in test efficiency.

[0005] At present, the tests for water-chemical pollution geotechnical body mainly include static leaching test and dynamic column test, and it is difficult to ensure steady-state seepage in these tests; and the leaching device of the above test destroys the structural property of the soil column body, so that the soil column body is only suitable for the current water head height, and the water head height cannot be adjusted according to different experimental requirements.

[0006] At present, the research on undisturbed soil polluted by water chemistry mostly adopts soaking method, permeation method, sprinkling method and air pressure method for pollution simulation. Among them, the soaking method and the permeation method can only simulate the dissolution of soil particles and their cementing materials, ignoring the structural property of the soil sample; the sprinkling method is difficult to ensure that the pollution liquid fully contacts the soil particles to occur chemical reaction in the sprinkling process; the existing air pressure method uses the wetting front as the termination condition for soil sample preparation, and it is difficult to effectively ensure the uniformity and sufficiency of the contact with the water chemical solution in the vertical direction. When the relative content of the water chemical solution concentration is not large, the soil sample at the bottom may not be polluted by using the method.

[0007] For the permeation test, some water chemical solutions have toxicity or corrosivity, and cannot be tested in conventional permeation instruments, so the test research on the permeation characteristics of the polluted soil is restricted. SUMMARY

[0008] In order to solve the above-mentioned defects existing in the prior art, the purpose of the present application is to provide an experimental device and method for water chemical contaminated soil based on image intelligent feedback, which can simulate the chemical pollution in actual engineering as much as possible, accelerate the test speed through the axial gas pressure while reducing the damage to the soil sample structure, realize automation and visualization through the computer processing system, and effectively improve the test effect and preparation rate.

[0009] The present application is realized by the following technical solutions.

[0010] In one aspect of the present application, a multifunctional water-soil interaction experimental device based on image intelligent feedback is provided, which comprises a device body, a gas supply device, a water supply device, an image acquisition system and a computer processing system.

[0011] The soil sample is placed in the device body, the bottom is connected to the gas pressure device, the top is connected to the water supply device, and the image acquisition system is opposite to the device body; the computer processing system is connected to the image acquisition system, the gas pressure device and the water supply device respectively.

[0012] By adjusting the different pressure differences of the soil sample in the device body, the flow and speed of the water flowing into the device body are controlled, and the wetting, leaching test and permeation of the soil sample under negative pressure are obtained in real time through the image acquisition system.

[0013] Preferably, the device body is internally provided with water-permeable stones placed at both ends of the soil sample, a filter layer is placed between the soil sample and the water-permeable stones, the soil sample is wrapped with a rubber film, and a suction nozzle is arranged at the bottom of the device body and connected to the gas pressure device.

[0014] Preferably, the suction nozzle comprises a tray and a communicating suction pipe, the tray has an upper turning edge, and the suction pipe is a hollow conical pipe.

[0015] Preferably, the outer diameters of the water-permeable stones and the filter layer are the same as the diameter of the soil sample.

[0016] Preferably, the filter layer is made of PTFE (polytetrafluoroethylene) material; the suction nozzle is made of polyolefin material; and the rubber film is a transparent latex rubber film.

[0017] Preferably, the gas pressure device comprises a gas pressure pump, a vacuum cylinder, a gas pressure controller and a gas pressure gauge, the vacuum cylinder is connected to the gas pressure pump and the suction nozzle at the bottom of the device body through a conduit, the gas pressure controller is arranged on the conduit, and the gas pressure gauge is arranged on the vacuum cylinder.

[0018] Preferably, the bottom of the vacuum cylinder is provided with a liquid outlet hole, and the liquid outlet hole is connected to a liquid storage bottle.

[0019] Preferably, the image acquisition system comprises an industrial camera connected to the computer processing system, and the device body is within the field of view of the industrial camera camera.

[0020] Another aspect of the present application provides a multifunctional water-soil interaction experiment method based on image intelligent feedback of the device, comprising:

[0021] Controlling the negative pressure air pressure value of the soil sample in the device body;

[0022] Injecting the water solution required by the experiment into the upper end of the soil sample in the device body, and controlling the water content of the soil sample as required;

[0023] Obtaining image data of the soil sample under the negative pressure state;

[0024] According to the gray value g tt and the gray value g tb of the upper end surface photo of the soil sample at any time, the real-time photo gray value deviation of the upper and lower end surfaces of the soil sample is calculated one by one in the order of photographing;

[0025] According to the condition met by the real-time photo gray value deviation of the upper and lower end surfaces of the soil sample, the computer processing system is fed back to the air pressure controller, and the air supply device is closed to stop air extraction, and the internal uniform humidification process of the soil sample is completed.

[0026] Another aspect of the present application provides a multifunctional water-soil interaction experiment method based on image intelligent feedback of the device, comprising:

[0027] Controlling the negative pressure air pressure value of the soil sample in the device body;

[0028] Injecting the water chemical solution into the upper end of the soil sample in the device body, controlling the water flow and flow rate, and simulating the seepage water head;

[0029] Obtaining the gray value g rr and the gray value g rb of the upper end surface photo of the soil sample at any time t, and calculating the real-time photo gray value deviation of the upper and lower end surfaces of the soil sample one by one in the order of photographing;

[0030] According to the condition met by the real-time photo gray value deviation of the upper and lower end surfaces of the soil sample, the computer processing system is fed back to the air pressure controller, and the air supply device is closed to stop air extraction;

[0031] Calculating the permeability coefficient of the soil sample when the water chemical solution seepage pollution reaches a steady state, collecting the soil sample seepage liquid, and obtaining the real motion rule of the water chemical solution in the rock-soil body.

[0032] The present application has the following beneficial effects due to the above technical solutions:

[0033] 1. The device is connected with the device body by the air pressure supply device, the image acquisition system acquires the humidification condition of the soil sample in the device body under the negative pressure state in real time and feeds back to the computer processing system, the soil sample chemical pollution is fed back through the image, the soil sample structure damage is reduced, the soil preparation speed is accelerated through the axial hydraulic pressure, and the soil sample humidification effect and efficiency are improved.

[0034] 2. The negative pressure air pressure value of the soil sample in the device body is controlled, distilled water is injected to the upper end of the soil sample in the device body, the humidification water content is controlled, the soil sample humidification intensity change under the negative pressure state is obtained by calculating the gray value variance of the soil sample in the humidification process according to the average value of the gray value of the soil sample photo at any time, so that the water movement in the rock-soil body, the pollution migration rule, the rock-soil humidification and the real movement rule of the water chemical solution in the rock-soil body under the water-soil action are reflected, and various test requirements are met.

[0035] 3. The negative pressure air pressure value of the soil sample in the device body is controlled, the water solution is injected to the upper end of the soil sample in the device body, the water flow and flow rate are controlled, the seepage water head is simulated, the permeability coefficient of the contaminated soil is calculated, the soil sample seepage liquid is collected, and the permeation rule in the contaminated soil is obtained.

[0036] 4. The device body bottom is connected with the air pressure supply device by the self-made suction nozzle, a collection and export channel is provided for the soil sample seepage fluid in the experiment, and the size of the self-made suction nozzle is adjusted during the manufacturing, so that the self-made suction nozzle is tightly matched with the soil sample and the pipe and is tightly connected.

[0037] 5. The device can design different test schemes according to the experimental purpose and requirement, and solves the problems of single function, low efficiency and interference with the soil sample structure of the traditional water-soil action test device. DETAILED DESCRIPTION

[0038] The drawings described herein are used to provide further understanding of the present application, constitute a part of the present application, and do not constitute improper limitation to the present application, and in the drawings:

[0039] Figure 1 It is a device structure schematic view of the present application;

[0040] Figure 2 It is a self-made suction nozzle structure schematic view of the present application;

[0041] Figure 3 It is a computer processing system connection block diagram of the present application;

[0042] Figure 4 The soil sample strength contrast column chart of the embodiment of the present application.

[0043] Figure 1Fig. 1 is a schematic diagram of the water chemical pollution soil sample experimental device based on image intelligent feedback according to the present application. 1: soil sample; 2: water-permeable stone; 3: filter layer; 4: rubber film; 5: suction nozzle; 6: air pressure pump; 7: air pressure gauge; 8: air pressure controller; 9: water flow monitor; 10: vacuum cylinder; 11: liquid storage bottle; 12: liquid outlet hole; 13: conduit; 14: solution bottle; 15: water flow controller; 16: computer processing system; 17: industrial camera; 18: wire.

[0044] 5-1: tray; 5-2: suction hole; 5-3: suction tube. DETAILED DESCRIPTION

[0045] The present application will be described in detail below with reference to the accompanying drawings and specific examples, which are used to explain the present application but not to limit the present application.

[0046] Reference Figure 1 The present application provides a water chemical pollution soil sample experimental device based on image intelligent feedback, which comprises a device body, an air supply device, a water supply device, an image acquisition system and a computer processing system 16. The soil sample is placed in the device body, the bottom is connected to the air supply device through the suction nozzle, the top is connected to the water supply device, the image acquisition system is opposite to the device body and is connected to the computer processing system, and the computer processing system is connected to the air supply device and the water supply device. The soil sample under negative pressure is obtained in real time by the image acquisition system.

[0047] The device body comprises a soil sample 1, water-permeable stones 2 placed at the upper and lower ends of the soil sample, and a filter layer 3 placed between the soil sample 1 and the water-permeable stones 2. The soil sample is wrapped with a rubber film 4, and a customized suction nozzle 5 is arranged at the bottom of the device body. The outer diameter of the water-permeable stones 2 and the filter layer 3 is the same as the diameter of the soil sample 1.

[0048] In this embodiment, the rubber film 4 is a transparent latex rubber film, which can provide lateral restraint for the soil sample. The filter layer 3 should be a filter paper material air-permeable and water-permeable layer or a PTFE polytetrafluoroethylene material air-permeable and water-impermeable film according to the needs of the use function of the device.

[0049] The top of the device body is connected to the water supply device through the conduit 13. The water supply device comprises a solution bottle 14 and a water flow controller 15. The water flow controller 15 is arranged in the conduit 13 and is connected to the computer processing system 16. The solution bottle 14 is provided with a scale, and whether the solution bottle is transparent is determined according to the properties of the water chemical solution.

[0050] The bottom of the device body is connected to the air supply device through the conduit 13. The air supply device comprises an air pressure pump 6, an air pressure gauge 7, an air pressure controller 8 and a vacuum cylinder 10. The vacuum cylinder 10 is connected to the air pressure pump 6 through the conduit 13. The air pressure gauge 7 is arranged at the top of the vacuum cylinder 10. The conduit 13 connected to the device body is provided with the air pressure controller 8.

[0051] The vacuum cylinder can adopt a transparent cylinder body with scales. The air pressure pump 6 can control the negative pressure applied at the bottom of the soil sample 1 through the air pressure controller 8, control the permeation speed of the liquid in the test soil sample, and control the test simulated seepage water head and atmospheric environment change.

[0052] The vacuum cylinder 10 is provided with a liquid outlet hole 12, the liquid outlet hole 12 is communicated with the liquid storage bottle 11, and the liquid outlet hole 12 is provided with a rotary switch. The liquid overflowed from the bottom of the soil sample 1 in the test is collected through the bottom of the vacuum cylinder 10 communicated with the liquid storage bottle 11.

[0053] The image acquisition system comprises an industrial camera 17 connected with the computer processing system 16 through a lead 18, the device body is in the field of view of the camera of the industrial camera 17, the industrial camera comprises a magnification lens and a zoom lens, and the industrial camera can track the color change of the soil sample in real time.

[0054] As shown in the drawings, Figure 2 The suction nozzle 5 adopted in the application comprises a tray 5-1, a suction hole 5-2 provided in the middle of the tray 5-1 and connected with a suction pipe 5-3 below, and the suction pipe 5-3 communicated with the suction hole 5-2; the tray 5-1 is provided with an upper turning rim, and the inner diameter of the rim is consistent with the outer diameter of the soil sample 1 and the water permeable stone 2; the suction pipe 5-3 is hollow, and the inner wall and the outer wall are both conical surfaces, and the inner diameter and the outer diameter linearly change along the longitudinal length: the inner diameter is the largest at the connection with the tray, and the outer diameter is slightly larger than the inner diameter of the connected pipe; the inner diameter is the smallest at the outer end, and the outer diameter is slightly smaller than the inner diameter of the connected pipe.

[0055] The wall thickness of each part of the suction nozzle is consistent. When connected, the suction pipe part of the customized suction nozzle is inserted into the pipe, and the radial size of the suction pipe is gradually changed to extrude the side wall of the pipe, so that the connection is sealed. The suction nozzle is made of polyolefin material and can be made by 3D printing. The material is consistent with the connected pipe 13.

[0056] When the air pressure controller 8 controls the gas in the vacuum cylinder 10 to enter the device body, the self-made suction nozzle can collect the fluid seeped from the bottom of the soil sample 1 and guide it into the pipe 13 at the lower end of the soil sample 1 under the premise of effectively ensuring the sealing of the device, so as to realize the collection and measurement of the expected discharged fluid.

[0057] As shown in the drawings, Figure 3As shown, in the present application, the industrial camera 17, the water flow monitor 9, the air pressure controller 8 and the water flow controller 15 are all connected to the computer processing system 16. The air pressure controller 8 is controlled by the computer processing system 16 to adjust the vacuum degree in the device body, to inject water chemical solution into the upper end of the device body for humidification treatment, to start the air pressure supply device to adjust the air pressure controller 8, and to realize humidification of the contaminated soil sample. The industrial camera of the image acquisition system takes a real-time picture of the color change of the side of the soil sample, feeds back the real-time acquisition of the humidification of the contaminated soil sample to the computer processing system, and adjusts the axial hydraulic pressure of the device body to reduce the structure of the soil sample as much as possible and to speed up the preparation of the soil sample through the axial hydraulic pressure. This method is suitable for soil samples with high initial suction and obvious color change after wetting.

[0058] The experimental method of the water chemical contaminated soil sample based on image intelligent feedback using the above device will be further described below through specific examples, which includes the following steps:

[0059] Example 1:

[0060] This example provides a use method of the device of the present application applied to the humidification device of the geotechnical sample. Based on the objective needs of the test method, this method is suitable for soil samples with high initial suction and obvious color change after wetting.

[0061] First step, select the undisturbed loess in the north suburb of Xi'an, and measure the undisturbed loess moisture content to be 18% in the indoor test. According to the soil test specification, a cylindrical soil sample (diameter 39.1 mm, height 80 mm) is made, a filter paper is placed between the soil sample 1 and the upper end of the water-permeable stone 2 as a gas permeable material filter layer 3, and a PTFE (polytetrafluoroethylene) gas permeable and water impermeable membrane is placed between the soil sample 1 and the lower end of the water-permeable stone 2 as a gas permeable material filter layer 3. The above soil sample is wrapped with a rubber film 4 to form a device body. A customized suction nozzle 5 is arranged at the bottom of the device body and connected to the vacuum cylinder 10 of the air pressure supply device through the conduit 13.

[0062] Second step, the computer processing system 16 is connected to the industrial camera 17, the air pressure controller 8, the water flow monitor 9 and the water flow controller 15 through the wire 18, and the air supply device, the water supply device and the device body are connected through the conduit 13.

[0063] Third step, open the air pressure pump 6 to vacuum the vacuum cylinder 10, adjust the air pressure controller 8 to control the air pressure to draw air from the soil sample 1 in the device body, and control the air pressure value to be 0.08 MPa through the air pressure controller.

[0064] At the same time, open the water flow controller 15 to inject water into the soil sample 1 through the conduit 13, and inject distilled water into the upper end of the soil sample to humidify to a moisture content of 29%.

[0065] Fourthly, take the photos of the soil sample 1 in real time by the industrial camera 17, and transmit them to the computer processing system 16 through the wire 18.

[0066] Fifthly, take the photos of the soil sample in real time during the humidification process by the industrial camera since the humidification starts, and transmit one photo per second to the computer processing system. The computer processing system extracts the gray scale values of the photos of the soil sample and carries out statistical analysis to obtain the gray scale value g tt of the upper end face of the soil sample at any time t (according to the continuous shooting order, the time when the first photo in which the minimum value of the gray scale value of the upper end face of the soil sample is obtained is taken is taken as the timing zero point t=0) and the gray scale value g tb of the lower end face of the soil sample.

[0067] According to the gray scale values g tt and g tb of the upper and lower end faces of the soil sample at any time, the real-time photo gray scale value deviation Δg t =|g tt -g tb | of the upper and lower end faces of the soil sample is calculated in sequence according to the shooting order, so that Δg t tends to the minimum value.

[0068] When Δg t =|g tt -g tb |≤γ·|g 0t -g 0b |, the computer processing system feeds back to the air pressure controller, and the air supply device is stopped.

[0069] In the formula, γ is an empirical coefficient related to the properties of the soil sample, which needs to be determined by statistical processing of the humidification test data, g ot and g ob are the gray scale values of the photos of the upper and lower end faces of the soil sample at the timing zero point t=0, respectively.

[0070] This step can make the internal uniform humidification of the soil sample as much as possible.

[0071] Sixthly, when the humidification is completed, the computer processing system 16 closes the air pressure controller 8 and the water flow controller 15, and at the same time, the air pressure pump 6 is closed.

[0072] Seventhly, the soil sample 1 is disassembled to complete the humidification test.

[0073] In order to better show the implementation effect of the scheme, please refer to Table 1 and Figure 4 . Table 1 shows the gray scale values of the photos of the original loess and the changes of the gray scale value variance when the loess is not humidified and humidified to the stable state. Figure 4The strength variation characteristics of the original soil sample and the remolded soil sample before and after humidification by the conventional method and the air pressure control method are shown.

[0074] Table 1 Change in gray value of the original loess before and after humidification

[0075]

[0076] Example 2:

[0077] The present embodiment provides a use method of the device of the present application for leaching and permeation tests of geotechnical samples:

[0078] In the first step, water-permeable stones 2 are placed at both ends of the soil sample 1, and filter paper is placed between the soil sample 1 and the water-permeable stones 2 as a filter layer 3 of air permeability material, and the soil sample is wrapped with a rubber film 4 to form a device body. The bottom of the device body is provided with a customized suction nozzle 5, which is connected to the vacuum cylinder 10 of the air supply device through the conduit 13.

[0079] In the second step, the computer processing system 16 is connected to the industrial camera 17, the air pressure controller 8, the water flow monitor 9, and the water flow controller 15 through the wire 18, and the air supply device, the water supply device, and the device body are connected through the conduit 13.

[0080] In the third step, the air pressure pump 6 is turned on to create a vacuum in the vacuum cylinder 10, and the water flow controller 15 is turned on to inject the required water chemical solution (simulated contaminated liquid) into the soil sample 1 through the conduit 13, and the water flow monitor 9 is turned on.

[0081] In the fourth step, the air pressure controller 8 is adjusted to control the air pressure to draw air from the soil sample 1, and the air pressure controller 8 is adjusted to increase the pressure difference between the upper and lower ends of the soil sample to simulate the seepage water head; the water flow monitor 9 monitors the flow rate and flow velocity of the solution, and the collected data is transmitted to the computer processing system 16 through the wire 18,

[0082] In the fifth step, starting from the air-drawing permeation, the industrial camera is used to take photos of the soil sample in real time during the permeation process, and the photos are taken continuously at a speed of 1 / s and transmitted to the computer processing system. The computer processing system extracts the gray values of the soil sample photos and performs statistical analysis to obtain the gray values of the upper end face of the soil sample at any time t (according to the continuous shooting order, the first photo taken at the time when the gray value of the upper end face of the soil sample in the photo reaches the minimum value is taken as the timing zero t = 0) g rr and the lower end face g rb .

[0083] According to the gray values of the upper end face of the soil sample at any time g tt and the lower end face g tb , the real-time photo gray value deviation Δg t = |gtt -g tb |。

[0084] When Δg t = |g tt -g tb |≤ γ· |g 0t -g 0b |, feedback to the air pressure controller by the computer processing system, and stop the air supply device to stop pumping (it can be considered that the soil sample is contaminated by water chemical solution penetration to reach steady state at this time).

[0085] The penetration coefficient of the soil sample contaminated by the water chemical solution penetration to reach steady state can be calculated, and the calculation formula is as follows:

[0086]

[0087] Wherein, k is the penetration coefficient of the soil sample, v is the flow rate collected by the water flow monitor, l is the axial length of the soil sample (the length of the seepage direction), ρ is the density of the seepage liquid, g is the acceleration of gravity, and p is the air pressure controlled by the air pressure controller (the pressure difference between the upper and lower ends of the soil sample).

[0088] In the fifth step, with the leaching, the seepage liquid is collected through the liquid outlet hole 12 at the lower end of the vacuum cylinder 10 into the liquid storage bottle 11 for later water quality analysis.

[0089] In the sixth step, the air pressure controller 8 and the water flow controller 15 are closed by the computer processing system 16, and at the same time, the air pressure pump 6 is closed, and the soil sample 1 is removed to complete the test.

[0090] As can be seen from the above embodiment, the method of the present application can realize the humidification of the rock-soil sample, and the true movement law of water in the rock-soil body can be obtained through the strength change characteristics of the soil sample before and after humidification under the control of air pressure. In addition, the method of the present application can realize the leaching and penetration test of the rock-soil sample, and the penetration law of the contaminated liquid in the soil can be obtained by simulating the process of the specified contaminated liquid penetrating in the soil sample and reaching steady state.

[0091] The present application is not limited to the above-mentioned embodiments, and based on the technical solutions disclosed in the present application, those skilled in the art can make some substitutions and modifications to some technical features without creative labor, and these substitutions and modifications are all within the protection scope of the present application.

Claims

1. A multifunctional experimental method for soil and water interaction based on image intelligent feedback, characterized in that, The apparatus used in the method includes: The device body, gas supply device, water supply device, image acquisition system, and computer processing system; Soil samples are placed inside the device body, with the bottom connected to the air pressure device and the top connected to the water supply device. The image acquisition system is directly facing the device body; the computer processing system is connected to the image acquisition system, the air pressure device, and the water supply device respectively. By adjusting the different pressure differences of the soil samples inside the device, the flow rate and velocity of the water flowing into the device are controlled, and the image acquisition system is used to acquire the soil sample's moisture increase / decrease, leaching test and seepage status in real time under negative pressure. The method includes: Control the negative pressure value of the soil sample inside the control device; An aqueous solution was injected into the upper part of the soil sample inside the device to control the moisture content of the soil sample; Acquire image data of soil samples under negative pressure conditions; Based on the grayscale value g of the upper surface photograph of the soil sample at any given time tt and the grayscale value g of the lower end face photo tb The real-time grayscale value deviation of the upper and lower surfaces of the soil samples was calculated one by one according to the order of taking the photos. Δg t =|g tt -g tb | Make Δg t It tends to the minimum value; When Δg t =|g tt -g tb |≤γ·|g 0t -g 0b At this point, stop pumping air to complete the process of uniformly humidifying the soil sample. Where γ is an empirical coefficient related to the properties of the soil sample, g 0t and g 0b These are the grayscale values ​​of the corresponding photos of the upper and lower surfaces of the soil sample at the zero point t=0.

2. A multifunctional water and soil interaction experimental method based on image intelligent feedback as described in claim 1, characterized in that, include: Control the negative pressure value of the soil sample inside the control device; A water-chemical solution was injected into the upper part of the soil sample inside the device to control the water flow rate and velocity, simulating the seepage head; Obtain the grayscale value g of the upper surface of the soil sample at any time t. tt and the grayscale value g of the lower end face photo tb The real-time grayscale value deviation of the upper and lower surfaces of the soil samples was calculated one by one according to the order of taking the photos. Δg t =|g tt -g tb | When Δg t =|g tt -g tb |≤γ·|g 0t -g 0b When | stop pumping air; Calculate the permeability coefficient of the soil sample when it reaches a steady state after being contaminated by the hydrochemical solution, collect the leachate from the soil sample, and obtain the true movement law of the hydrochemical solution in the soil sample.

3. The multifunctional water and soil interaction experimental method based on image intelligent feedback according to claim 1 or 2, characterized in that, The device body contains a soil sample with permeable stones placed at both ends. A filter layer is placed between the soil sample and the permeable stones. The soil sample is wrapped with a rubber membrane. A suction nozzle is installed at the bottom of the device body and connected to an air pressure device.

4. The multifunctional water and soil interaction experimental method based on image intelligent feedback according to claim 3, characterized in that, The suction nozzle includes a tray and a connected straw. The tray has an upturned rim, and the straw is a hollow conical tube.

5. The multifunctional water and soil interaction experimental method based on image intelligent feedback according to claim 3, characterized in that, The outer diameter of the permeable stone and filter layer is the same as the diameter of the soil sample.

6. The multifunctional water and soil interaction experimental method based on image intelligent feedback according to claim 3, characterized in that, The filter layer is made of PTFE (polytetrafluoroethylene); the nozzle is made of polyolefin material; and the rubber membrane is a transparent latex rubber membrane.

7. The multifunctional water and soil interaction experimental method based on image intelligent feedback according to claim 1 or 2, characterized in that, The pneumatic device includes a pneumatic pump, a vacuum cylinder, a pneumatic controller, and a pressure gauge. The vacuum cylinder is connected to the pneumatic pump and the suction nozzle at the bottom of the device body through a conduit. The pneumatic controller is located on the conduit, and the pressure gauge is located on the vacuum cylinder.

8. The multifunctional water and soil interaction experimental method based on image intelligent feedback according to claim 7, characterized in that, The vacuum cylinder has a liquid outlet at the bottom, which is connected to the liquid storage bottle.

9. The multifunctional water and soil interaction experimental method based on image intelligent feedback according to claim 1 or 2, characterized in that, The image acquisition system includes an industrial camera connected to a computer processing system, and the device body is within the field of view of the industrial camera.

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