A two-dimensional flow test device and test method for simulating diving

Abstract

The present invention discloses a simulated two-dimensional subsurface flow test device and a test method. The simulated two-dimensional subsurface flow test device includes a soil tank body, a water spraying device, a heating device, and a liquid recovery pot. The soil tank body is used to hold test soil samples. A plurality of liquid level tubes and sampling tubes are provided on the soil tank body, and a first valve is respectively provided on each sampling tube. The water spraying device is arranged at the left end above the soil tank body and is used to add liquid into the soil tank body. The heating device is arranged at the right end above the soil tank body and is used to heat the test soil samples located below it in the soil tank body. An outlet pipe is provided at the lower right end of the soil tank body, and a second valve is provided at the outlet pipe. The liquid recovery pot is used to recover the liquid discharged from the outlet pipe. It has a simple structure but diverse functions, can simulate the two-dimensional subsurface flow process under different conditions, and simulate the migration and transformation process of different solutes in porous media.

Description

Technical Field

[0001] Indoor soil tank test is a commonly used research method for simulating two-dimensional groundwater flow. It is a common test method in hydrogeological work and is also widely used in research fields such as agriculture, forestry, water conservancy, and environment. For a long time, the design of traditional soil tank tests has been relatively simple, with single types and functions and inconsistent specifications. The overly square tank body has a poor simulation effect on two-dimensional groundwater flow. The water samples are collected by directly opening holes in the tank body, resulting in poor sampling effects. There is a lack of monitoring of water samples and soil samples under evaporation conditions, and a lack of monitoring of the water level in the tank. Due to the above defects, the effects of various types of soil tank tests are often not ideal.

[0002] At the same time, there are many unreasonable aspects in the existing soil tank tests, especially in the monitoring of test dynamic data and samples. Firstly, traditional soil tank tests generally only monitor two indicators of water volume and water quality, and cannot well monitor and analyze the temperature of the test soil samples, the composition of the test soil samples, the water evaporation volume, the water level in the soil tank, capillary phenomena, and the changes in the composition of the test soil samples under the influence of evaporation factors, which have great reference significance. Secondly, in traditional soil tank tests, the sampling pipe directly leads out the liquid outlet pipe after opening a hole in the tank body. This results in only obtaining the test soil sample solution close to the sampling port, and the test soil sample solution far from the sampling port cannot flow out smoothly, easily causing distortion of test data, and the obtained test solution is very limited, making it difficult to monitor various water quality factors. Thirdly, the monitoring of test soil samples in traditional soil tank tests is generally carried out by directly excavating from the upper part after the test until the position of the monitored test soil samples, which causes great disturbance to the test soil samples and is very inconvenient for sampling. Summary of the Invention

[0003] In order to solve the above technical problems, one of the purposes of the present invention is to provide a test device for simulating two-dimensional groundwater flow, which has diverse functions and can truly simulate the recharge conditions, runoff conditions, discharge conditions, evaporation conditions, and capillary phenomena in two-dimensional groundwater flow indoors. At the same time, it can conveniently measure the changes in the water volume, water quality, water level of the test water samples, as well as the changes in the composition and temperature of the test soil samples before and after.

[0004] In order to achieve the above purpose, the technical solution of the present invention is as follows: A test device for simulating two-dimensional groundwater flow includes a soil tank body, a water spraying device, a heating device, and a liquid recovery pot;

[0005] The soil tank body is a strip-shaped tank body horizontally arranged in the left-right direction with the tank opening facing upward horizontally. A plurality of vertical liquid level tubes are provided on the front side or the rear side of the soil tank body. The plurality of liquid level tubes are spaced apart in the left-right direction, and the lower end of each liquid level tube is communicated with the lower end inside the soil tank body. A plurality of sampling tubes penetrating through its interior are respectively provided at the middle and lower edge of the front side or the rear side side wall of the soil tank body, and a first valve is respectively provided on each sampling tube;

[0006] The watering device is arranged at the left end above the soil trough body, and is used to add liquid into the soil trough body. The heating device is arranged at the right end above the soil trough body, and is used to heat the test soil sample located below the soil trough body. A shielding member is provided at the notch at the upper end of the soil trough body, and is located between the watering device and the heating device.

[0007] A liquid outlet pipe is provided at the lower right end of the soil trough body, a second valve is provided at the liquid outlet pipe, and the liquid recovery pot is used to recover the liquid discharged from the liquid outlet pipe.

[0008] The beneficial effects of the above technical solution are: its structure is simple, but its functions are diverse, and it can control multiple environmental variables at the same time. By setting a water sprinkling device and a heating device, and locating them at the left and right ends of the upper end of the soil trough body respectively, it can simulate the two-dimensional submersible flow process under different conditions according to the actual situation, and simulate the migration and transformation process of different solutes in porous media; and the device is convenient for sampling, which is scientific and reasonable.

[0009] The bottom wall of the soil trough body in the above technical solution is an inclined surface that slopes downward from left to right.

[0010] The beneficial effect of the above technical solution is that the bottom plate at the lower end of the soil trough body is tilted from left to right, which can simulate the real aquifer bottom plate with a certain slope, and better create a certain submerged hydraulic slope to improve the simulation test effect.

[0011] In the above technical solution, a heat insulation plate is provided vertically along the front-to-back direction on one side of the middle part of the upper end of the soil trough body close to the heating device, the front and rear sides of the heat insulation plate extend close to the front and rear sides of the soil trough body, and the lower end of the heat insulation plate contacts the upper end of the test soil sample in the soil trough body.

[0012] The beneficial effect of the above technical solution is that it can avoid the heat from heating the rest of the slot of the soil trough body and affecting the evaporation effect of the water in the test soil sample.

[0013] In the above technical solution, a first filter is provided at the connection point between the liquid level pipe and the soil trough body.

[0014] The beneficial effect of the above technical solution is that it can prevent sand in the test soil sample from clogging the liquid level tube and affecting the test effect.

[0015] In the above technical solution, one end of the sampling tube communicating with the soil trough body extends into the soil trough body, and the tube wall inside the soil trough body is covered with through holes, and a layer of filter screen is provided outside the through holes.

[0016] The beneficial effects of the above technical solution are as follows: In this way, the sampling pipe penetrates through the middle of the test soil sample in the soil tank body, so that the aqueous solution at a certain position of the test soil sample can be uniformly obtained, and the sampling pipe can also be prevented from being blocked by sand in the test soil sample, thus affecting the test effect.

[0017] In the above technical solution, a second filter element is provided at the connection between the soil tank body and the liquid outlet pipe.

[0018] The beneficial effects of the above technical solution are as follows: In this way, the liquid outlet pipe can be prevented from being blocked by sand, thus affecting the test effect.

[0019] In the above technical solution, the watering device includes a sealing cover, a water supply kettle and a spray head. The sealing cover is in a trough shape with its trough opening facing downwards, and it covers the left end of the trough opening of the soil tank body. The spray head is placed inside the sealing cover with its spray holes facing downwards. The water supply kettle is placed above the soil tank body, and its lower end has a water outlet. The water outlet of the water supply kettle is communicated with the water inlet of the spray head, and a third valve is provided at the communication position.

[0020] The beneficial effects of the above technical solution are as follows: Its structure is simple. In this way, the effect of simulating rainfall or artificial irrigation on the test soil sample can be better, making the simulation of the test effect more realistic.

[0021] In the above technical solution, both the water supply kettle and the liquid recovery kettle are transparent kettles, and volume scales are provided on their side walls.

[0022] The beneficial effects of the above technical solution are as follows: In this way, the change in the liquid volume in the water supply kettle and the liquid recovery kettle can be conveniently known.

[0023] In the above technical solution, at least three groups of temperature measuring devices are provided at intervals up and down on the side wall of the front or rear side of the soil tank body below the heating device. Each group has at least two temperature measuring devices arranged horizontally and spaced apart in the front-rear direction. The temperature measuring part of each temperature measuring device extends into the soil tank body.

[0024] The beneficial effects of the above technical solution are as follows: In this way, the distribution state of the temperature of the test soil sample at the right end in the soil tank body changing with depth can be conveniently known.

[0025] The second object of the present invention is to provide a test method using the above-mentioned simulated two-dimensional flow of phreatic water test device.

[0026] In order to achieve the above object, another technical solution of the present invention is as follows: A test method using the simulated two-dimensional flow of phreatic water test device as described above includes the following steps:

[0027] Step 1: Assemble the simulated two-dimensional flow test device for diving, close the first valve, the second valve, and the third valve, and add the test soil sample that has been naturally air-dried into the soil tank body. During the addition process, compact the soil layer every 3 - 10 cm of height increase until the soil layer is raised to a level where its upper end surface is flush with the uppermost set of temperature measuring devices;

[0028] Step 2: Open the second valve, and spray water into the left end of the soil tank body through the water spraying device. Then, turn on the heating device to heat the test soil sample at the right end of the soil tank body. After the liquid has flowed into the liquid recovery pot for a period of time, monitor in real time the volume of the liquid sprayed by the water spraying device, the volume of the liquid recovered by the liquid recovery pot, the display value of the temperature measuring device, and the water level value in the liquid level tube. At the same time, take out the liquid sample from the sampling tube in real time and conduct a composition analysis of the liquid. After the test is completed, take the test soil samples at different positions in the soil tank body and conduct a composition analysis on them;

[0029] Step 3: Data processing: According to the dynamic measurement of the volume of the aqueous solution during the test process, draw a broken line graph of the recharge, discharge, and evaporation of the aqueous solution over time, and calculate the permeability coefficient of the test soil sample. Calculate the water capacity of the test soil sample based on the main water capacity of the soil tank body;

[0030] According to the temperature values measured during the test process, draw the temperature isopleth map of the upper right part of the soil tank body to understand the temperature change characteristics and the influence of different depths of the test soil sample on the evaporation intensity;

[0031] According to the water level values measured during the test process, draw the water level line and the flow field map of the soil tank body to distinguish the saturated zone and the vadose zone;

[0032] During the test process, according to the water quality test data obtained from each sampling tube at the same time period, draw an isopleth map of the concentration distribution of a certain component of the water quality; according to the water quality test data of a single sampling tube at different time periods, draw a broken line graph of the concentration change of a certain component of the water quality over time;

[0033] After the test is completed, according to the test results of the test soil sample, draw an isopleth map of the concentration distribution of a certain component in the test soil sample and a comparison graph of the test results before and after a certain component in the test soil sample.

[0034] The beneficial effects of the above technical solution are as follows: The method is simple, has many measurement indicators, can monitor in real time the indicators other than the component indicators of the test soil sample, and has high accuracy. Brief Description of the Drawings

[0035] Figure 1 It is a structural schematic diagram of the simulated two-dimensional flow test device for diving described in Embodiment 1 of the present invention;

[0036] Figure 2Another state diagram of the simulated diving two-dimensional flow test device described in Embodiment 1 of the present invention;

[0037] Figure 3 Partial view of the liquid level tube and the soil tank body described in Embodiment 1 of the present invention;

[0038] Figure 4 Partial view of the sampling tube and the soil tank body described in Embodiment 1 of the present invention;

[0039] Figure 5 Schematic diagram of the distribution of the test monitoring area in the soil tank body in Embodiment 2 of the present invention;

[0040] Figure 6 Schematic diagram of the principle of the simulated diving two-dimensional flow test device in Embodiment 2 of the present invention.

[0041] In the figure: 1 soil tank body, 11 liquid level tube, 111 first filter element, 12 sampling tube, 121 first valve, 122 filter screen, 13 shielding member, 14 liquid outlet pipe, 141 second valve, 15 heat insulation plate, 16 second filter element, 17 temperature measuring device, 18 cover plate, 2 watering device, 21 sealing cover, 22 water supply kettle, 23 spray head, 24 third valve, 3 heating device, 4 liquid recovery kettle. Detailed implementation manners

[0042] The principles and features of the present invention will be described below in conjunction with the accompanying drawings and embodiments. The examples given are only used to explain the present invention and are not intended to limit the scope of the present invention.

[0043] Embodiment 1

[0044] As Figure 1 and Figure 3 shown, this embodiment provides a simulated diving two-dimensional flow test device, including a soil tank body 1, a watering device 2, a heating device 3 and a liquid recovery kettle 4;

[0045] The soil tank body 1 is a strip-shaped tank body horizontally arranged in the left-right direction with the tank opening facing upwards horizontally. The soil tank body 1 is used to hold the test soil sample. A plurality of vertically arranged liquid level tubes 11 are provided on the front side or the rear side of the soil tank body 1. The plurality of liquid level tubes 11 are spaced apart in the left-right direction, and the lower end of each liquid level tube 11 communicates with the lower end inside the soil tank body 1. A plurality of sampling tubes 12 penetrating through its interior are respectively provided at the middle and the lower edge of the front side or the rear side side wall of the soil tank body 1 at intervals in the left-right direction, and a first valve 121 is respectively provided on each sampling tube 12;

[0046] The water spraying device 2 is arranged at the left end above the soil tank body 1 and is used to add liquid into the soil tank body 1. The heating device 3 is arranged at the right end above the soil tank body 1 and is used to heat the test soil sample located below it in the soil tank body 1. A shielding member 13 (preferably, the shielding member is a cover plate or a film) is covered between the water spraying device 2 and the heating device 3 at the upper end opening of the soil tank body 1;

[0047] A liquid outlet pipe 14 is provided at the lower right end of the soil tank body 1, and a second valve 141 is provided at the liquid outlet pipe 14. The liquid recovery pot 4 is used to recover the liquid discharged from the liquid outlet pipe 14. Its structure is simple but has diverse functions. It can control multiple environmental variables simultaneously. By setting the water spraying device and the heating device, which are respectively located at the left and right ends of the upper part of the soil tank body, different conditions of the two-dimensional groundwater flow process can be simulated according to the actual situation, and the migration and transformation processes of different solutes in porous media can be simulated. Moreover, the device is convenient for sampling, scientific and reasonable.

[0048] As Figure 2 shown, preferably, the liquid outlet pipe is a flexible pipe, so that the middle part of the liquid outlet pipe can be bent upward into an n shape, and its upper end is located in the middle of the right end of the soil tank body. Thus, when the liquid outlet pipe hangs down normally, the liquid in the soil tank body can flow out freely from the tail liquid discharge pipe under the action of gravity, and the test in the soil tank body is under the unsaturated state of the test soil sample; when the middle part of the liquid outlet pipe is bent upward to be higher than the inner bottom of the soil tank body, the lower part of the soil tank body is in a saturated state and the upper part of the test soil sample is in an unsaturated state. At this time, it is a test under the saturated-unsaturated state.

[0049] Preferably, the sampling pipes are all horizontally arranged in the front-rear direction.

[0050] In the above technical solution, the bottom wall of the soil tank body is an inclined surface that slopes downward from left to right. The bottom plate at the lower end of the soil tank body is in an inclined state from left to right, which can simulate the real aquifer bottom plate with a certain slope and better create a certain groundwater hydraulic gradient to improve the simulation test effect. Preferably, the bottom plate of the soil tank body is in a smooth downward arc structure from left to right, so that the bottom plate at the lower end of the soil tank body can simulate a more real aquifer bottom plate.

[0051] In the above technical solution, a heat insulation plate 15 vertically arranged in the front-rear direction is provided on one side of the middle part of the upper end of the soil tank body 1 close to the heating device 3. The front and rear sides of the heat insulation plate 15 extend to be close to the front and rear sides of the soil tank body 1, so as to avoid the heat from heating the remaining positions of the upper end opening of the soil tank body and affecting the evaporation effect of the moisture of the test soil sample.

[0052] Preferably, the size of the soil trough body may be 150-200 cm in length, 15-30 cm in width, 40-60 cm in height on the left side, and 80-120 cm in height on the right side.

[0053] like Figure 3 As shown, in the above technical solution, the connection between the liquid level pipe 11 and the soil tank body 1 is provided with a first filter 111, so as to prevent the sand in the test soil sample from clogging the liquid level pipe and affecting the test effect. Preferably, the first filter 111 is preferably composed of a cotton bag filled with medium-coarse particles of quartz sand, so that it has good filtration performance and does not affect the flow of the liquid.

[0054] like Figure 4 As shown, in the above technical solution, one end of the sampling tube 12 connected to the soil trough body 1 is extended into the soil trough body 1, and the tube wall located in the soil trough body 1 is covered with through holes and is wrapped with a layer of filter 122, so that the sampling tube passes through the test soil sample in the soil trough body, so that the aqueous solution at a certain position of the test soil sample can be evenly obtained, and the sampling tube can be prevented from being blocked by sand in the test soil sample and affecting the test effect.

[0055] In the above technical solution, a second filter 16 is provided in the soil trough body 1 at the connection point between the soil trough body 1 and the liquid outlet pipe 14, so as to prevent the liquid outlet pipe 14 from being blocked by sand and soil and affecting the test effect.

[0056] The water sprinkling device 2 in the above technical scheme includes a sealing cover 21, a water supply pot 22 and a nozzle 23. The sealing cover 21 is in the shape of a trough, and its notch faces downward. The cover is arranged at the left end of the notch of the soil trough body 1. The nozzle 23 is placed in the sealing cover 21, and its spray hole faces downward. The water supply pot 22 is placed above the soil trough body 1, and its lower end has a water outlet. The water outlet of the water supply pot 22 is connected with the water inlet of the nozzle 23, and a third valve 24 is provided at the connection point. The structure is simple, which can better simulate the effect of atmospheric precipitation or artificial irrigation on the watering of the test soil sample, so that the simulation of the test effect is better. Among them, the sealing cover is beneficial to reduce the evaporation of water, and the third valve 24 can adjust the flow rate of the water sprinkling device.

[0057] The water supply pot 22 and the liquid recovery pot 4 described in the above technical solution are both transparent pots, and volume scales are provided on their side walls, so that changes in the liquid volume in the water supply pot and the liquid recovery pot can be easily known.

[0058] In the above technical solution, at least three groups of temperature measuring devices 17 are provided on the side wall of the soil tank body 1 below the heating device 3 at the front or rear side, and each group has at least two temperature measuring devices 17 arranged horizontally and spaced in the front-rear direction. The temperature measuring part of each temperature measuring device 17 extends into the soil tank body 1, so that the distribution state of the temperature of the test soil sample at the right end in the soil tank body changing with depth can be conveniently known. Preferably, the temperature measuring device is preferably a digital display thermometer (temperature measuring range is between -55°C and 125°C), which is installed on the side wall of the soil tank body 1, and its sensing part extends into the soil tank body 1. Preferably, the heating device is suspended 10-20 cm above the soil tank body 1. The heating device can be a 1000w electric heating device, and the electric heating device can adopt an electric lamp. Further preferably, an adjustable resistance switch is provided on the conducting wire of the heating device to control the heating of the heating device at different powers to adjust the heating temperature, so as to simulate the influence of different evaporation intensities on the test.

[0059] Preferably, a plurality of sampling holes (preferably 20-40) penetrating through it are evenly distributed above the side wall of the front or rear side of the soil tank body, and a cover plate 18 is provided at the sampling hole. The cover plate 18 is installed at the sampling hole through a plurality of bolts and nuts. In this way, after the test is completed, the bolts can be unscrewed to remove the cover plate 18, and the test soil sample can be taken out from the soil tank body through the sampling hole. In this way, when taking the test soil sample after the test is completed, it is not necessary to turn over the inside of the tank body greatly, thus avoiding inaccurate sampling position or too large disturbance.

[0060] Preferably, the liquid level pipe and the sampling pipe are both installed on the soil tank body through a flange. The liquid level pipe and the sampling pipe respectively pass through the inner holes of the corresponding flanges and are fixedly connected and sealed with them. There are screw holes corresponding to the through holes of the flanges on the soil tank body. Each flange is respectively installed on the soil tank body through bolts threaded with the screw holes. In this way, the flange can be disassembled from the soil tank body after the test is completed to facilitate the discharge of the test soil sample in the soil tank body.

[0061] Embodiment 2

[0062] This embodiment provides a test method using the simulated phreatic two-dimensional flow test device as described in Embodiment 1, including the following steps:

[0063] Step 1: Assemble the simulated phreatic two-dimensional flow test device, close the first valve 121, the second valve 141 and the third valve 24, and add the naturally air-dried test soil sample into the soil tank body 1. During the adding process of the test soil sample, the soil layer is tamped every 3-10 cm of height increase until the soil layer is increased to the upper end surface flush with the uppermost group of temperature measuring devices 17.

[0064] Step 2: Open the second valve 141, and spray water into the left end of the soil tank body 1 through the water spraying device 2. Then, turn on the heating device 3 to heat the test soil sample at the right end of the soil tank body 1. After the liquid has flowed into the liquid recovery pot 4 for a period of time, monitor in real time the volume of the liquid sprayed by the water spraying device 2, the volume of the liquid recovered by the liquid recovery pot 4, the display value of the temperature measuring device 17, and the water level value in the water level tube 11. At the same time, take liquid samples from the sampling tube 12 in real time and analyze the composition of the liquid. After the test is completed, take test soil samples at different positions in the soil tank body 1 and analyze their composition;

[0065] Step 3: Data processing: According to the dynamic measurement of the volume of the aqueous solution during the test, draw a broken line graph of the recharge, discharge, and evaporation of the aqueous solution over time, and calculate the permeability coefficient of the test soil sample. Calculate the water capacity of the test soil sample based on the main water capacity of the soil tank body 1;

[0066] According to the temperature values measured during the test, draw the temperature isotherm of the upper right part of the soil tank body 1 to understand the temperature change characteristics and the influence of different depths of the test soil sample on the evaporation intensity;

[0067] According to the water level values measured during the test, draw the water level line and the flow field diagram of the soil tank body 1 to distinguish the saturated zone and the vadose zone;

[0068] During the test, according to the water quality test data obtained from each sampling tube at the same time period, draw an isoconcentration line diagram of a certain component of the water quality; according to the water quality test data of a single sampling tube at different time periods, draw a broken line graph of the concentration change of a certain component of the water quality over time;

[0069] After the test is completed, according to the test results of the test soil sample, draw an isoconcentration line diagram of a certain component in the test soil sample and a comparison graph of the test results before and after a certain component in the test soil sample. The method is simple, has many measurement indicators, can monitor other indicators in real time except for the component indicators of the test soil sample, and has high accuracy.

[0070] As Figure 5 and Figure 6 shown, during the test, the entire simulated two-dimensional groundwater flow test device is divided into seven regions, specifically: A1 - Recharge solution volume monitoring area; A2 - Discharge solution volume monitoring area; B - Evaporation temperature monitoring area; C - Water level monitoring area; D - Water sample and test soil sample monitoring area in the phreatic runoff zone (saturated zone); E1 - Test soil sample monitoring area for capillary phenomenon in the vadose zone; E2 - Test soil sample monitoring area for evaporation in the vadose zone.

[0071] A: Water volume monitoring.

[0072] During the experiment, the change amount of the solution in the water supply kettle, the change amount of the solution in the liquid recovery kettle, and the water sample collection amount (the amount of liquid collected by the sampling pipe) can be monitored in real time; by monitoring the above water volume changes, the evaporation amount of the aqueous solution at the upper right end of the soil tank body can be calculated, and the calculation formula is as follows:

[0073] Evaporation amount = total supply amount of the solution in the water supply kettle - water capacity of the soil tank body - total amount of the solution in the liquid recovery kettle - water sample collection amount.

[0074] Among them: The water capacity of the soil tank body includes the water capacity of the runoff zone (saturated zone) of the soil tank and the amount of capillary water rising in the vadose zone. The calculation method is that after 12 hours of the first drainage of the liquid outlet pipe, the total supply amount of the solution in the water supply kettle - the total amount of the solution in the liquid recovery kettle = the water capacity of the soil tank body.

[0075] The water volume monitoring positions on the two-dimensional groundwater flow test device can be divided into the replenishment solution volume monitoring area (A1) and the discharge solution volume monitoring area (A2).

[0076] B: Temperature monitoring.

[0077] During the experiment, 6 - 10 temperature measuring devices are buried on the surface and inside of the test soil sample under the heating device, and the surface and internal temperatures of the test soil sample in the evaporation area can be monitored in real time.

[0078] The temperature monitoring position on the two-dimensional groundwater flow test device is the evaporation temperature monitoring area (B).

[0079] C: Water level monitoring.

[0080] During the experiment, the change of the groundwater level in the soil tank body can be monitored in real time through 5 - 10 liquid level pipes led out from the lower end of the soil tank body.

[0081] The water level monitoring position on the two-dimensional groundwater flow test device is the water level monitoring area (C).

[0082] D: Monitoring of water samples and test soil samples in the saturated zone.

[0083] During the experiment, according to the need, the first valve on the soil tank body can be opened regularly to obtain the test water sample in the soil tank body, and then the water quality changes at different positions of the test soil sample can be obtained through detection means; after the experiment, the cover plate on the soil tank body can be opened to collect the test soil samples at different positions of the soil tank body, test their chemical compositions, and understand the changes of the test soil samples before and after.

[0084] The monitoring positions of water samples and test soil samples in the saturated zone on the two-dimensional groundwater flow test device are the water samples and test soil sample monitoring area (D) in the groundwater runoff zone (saturated zone).

[0085] E: Monitoring of test soil samples in the vadose zone.

[0086] After the test, the cover plate on the soil tank body can be opened to collect the test soil samples at the positions of the evaporation area and the capillary water rising area of the soil tank, test their chemical compositions, and understand the changes in the test soil samples before and after.

[0087] The monitoring positions of the test soil samples in the vadose zone are the capillary phenomenon test soil sample monitoring area (E1) and the evaporation test soil sample monitoring area (E2) of the vadose zone on the two-dimensional groundwater flow test device.

[0088] The characteristics of the above embodiments are as follows: This test method can simulate the process and changes of two-dimensional groundwater flow under natural infiltration-evaporation conditions or separate infiltration conditions, and can monitor multiple indicators such as water volume, temperature, water level, water quality, and changes in test soil samples in the soil tank test. Except for the change index of the test soil samples, other indicators can be monitored in real time;

[0089] Second, this test method considers the changes in the composition of the test soil samples under saturated conditions, the changes in the composition of the test soil samples in the vadose zone under evaporation conditions, and the changes in the composition of the test soil samples in the vadose zone under capillary action, and sets up monitoring zones to monitor the changes in the test soil samples before and after;

[0090] Third, this test method has made an innovative improvement to the water and soil sampling device, which can uniformly obtain the water samples in the soil tank body at each sampling tube. By opening the cover plate, the test soil samples in the soil tank body can be obtained without disturbance, making the test data more comprehensive, effective, and real;

[0091] Fourth, this method can monitor the migration and transformation process of different solutes under two-dimensional groundwater flow conditions. The solutes can be pollutants (such as heavy metals, organic pollutants), major ions in water (such as chloride ions, sulfate ions, fluoride ions), etc. When simulating the test, the solution can be artificially prepared or natural rainwater, river water, groundwater, etc.;

[0092] Fifth, this method can achieve the purpose of continuous sampling in layers and at points in the soil tank body. During the test process, according to needs, multiple groups of water samples can be collected in real time at multiple points at the same time, or multiple groups of water samples can be collected at the same monitoring point at different times, and then the change curves of different solute concentrations of the infiltration liquid can be drawn; After the simulation test, the test soil samples at the corresponding points can also be collected for testing and compared with the water quality results, or the water evaporation amount can be compared with the change amount of solute concentration and the change amount of the composition concentration of the test soil samples before and after, and various laws of the migration and transformation of solutes in the soil tank body can be comprehensively obtained, which brings great convenience and help to the research on the migration and transformation of solutes under two-dimensional groundwater flow conditions;

[0093] Sixth, this method is scientific and reasonable, and basically can meet the simulation and monitoring requirements of agricultural cultivated land, forest land, grassland soil samples or solid waste site soil samples such as gangue and fly ash.

[0094] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A two-dimensional flow test device for simulating diving, characterized in that, It includes a soil trough body (1), a water spraying device (2), a heating device (3) and a liquid recovery pot (4); The soil trough body (1) is a strip-shaped trough body horizontally arranged in the left-right direction with its trough opening facing upward horizontally. A plurality of vertically arranged liquid level tubes (11) are provided on the front side or the rear side of the soil trough body (1). The plurality of liquid level tubes (11) are spaced apart in the left-right direction, and the lower end of each liquid level tube (11) communicates with the lower end inside the soil trough body (1). At the middle part and the lower edge of the front side or the rear side side wall of the soil trough body (1), a plurality of sampling tubes (12) penetrating through its interior are respectively arranged at intervals in the left-right direction. A first valve (121) is provided on each sampling tube (12); The water spraying device (2) is arranged at the left end above the soil trough body (1) and is used to add liquid into the soil trough body (1). The heating device (3) is arranged at the right end above the soil trough body (1) and is used to heat the test soil sample located below it in the soil trough body (1). A shielding member (13) is covered between the water spraying device (2) and the heating device (3) at the upper end trough opening of the soil trough body (1); An outlet pipe (14) is provided at the lower right end of the soil trough body (1). A second valve (141) is provided on the outlet pipe (14). The liquid recovery pot (4) is used to recover the liquid discharged from the outlet pipe (14); The shielding member is a cover plate or a film; The bottom wall of the soil trough body (1) is an inclined surface inclined downward from left to right; The outlet pipe is a flexible pipe. The middle part of the outlet pipe can be bent upward into an "n" shape, and its upper end is located in the middle of the right end of the soil trough body; When the outlet pipe hangs downward normally, the liquid in the soil trough body can freely flow out from the tail drain pipe under the action of gravity, and the interior of the soil trough body is for the test under the unsaturated state of the test soil sample; Or the middle part of the outlet pipe is bent upward to be higher than the inner bottom of the soil trough body. The lower test soil sample in the soil trough body is in a saturated state, and the upper test soil sample is in an unsaturated state. At this time, it is for the test under the saturated-unsaturated state.

2. The simulated diving two-dimensional flow test device according to claim 1, characterized in that On one side of the middle part of the upper end of the soil trough body (1) close to the heating device (3), a heat insulation plate (15) vertically arranged in the front-rear direction is provided. The front and rear sides of the heat insulation plate (15) extend to be close to the front and rear sides of the soil trough body (1), and the lower end of the heat insulation plate (15) contacts the upper end of the test soil sample in the soil trough body (1); 3. The simulated diving two-dimensional flow test device according to claim 1, characterized in that, A first filtering member (111) is provided at the connection between the liquid level tube (11) and the soil trough body (1); 4. The simulated diving two-dimensional flow test device according to claim 1, wherein, One end of the sampling tube (12) connected to the soil trough body (1) extends into the soil trough body (1) internally, and the pipe wall of it located inside the soil trough body (1) is covered with through holes and is wrapped with a layer of filter screen (122) outside the through holes; 5. The simulated diving two-dimensional flow test device according to claim 1, wherein, A second filtering member (16) is provided inside the soil trough body (1) at its connection with the outlet pipe (14).

6. The simulated diving two-dimensional flow test device according to any one of claims 1-5, characterized in that, The water spraying device (2) includes a sealing cover (21), a water supply kettle (22) and a spray head (23). The sealing cover (21) is in a trough shape with its trough opening facing downwards, and it covers the left end of the trough opening of the soil trough body (1). The spray head (23) is placed inside the sealing cover (21) with its spray holes facing downwards. The water supply kettle (22) is placed above the soil trough body (1), and its lower end has a water outlet. The water outlet of the water supply kettle (22) is communicated with the water inlet of the spray head (23), and a third valve (24) is provided at the communication position.

7. The simulated diving two-dimensional flow test device according to claim 6, wherein Both the water supply kettle (22) and the liquid recovery kettle (4) are transparent kettles, and volume scales are provided on their side walls.

8. The simulated diving two-dimensional flow test device according to claim 7, characterized in that, On the side wall of the front or rear side of the soil trough body (1) below the heating device (3), at least three groups of temperature measuring devices (17) are arranged at intervals in the vertical direction. Each group has at least two temperature measuring devices (17) arranged horizontally and at intervals in the front and rear directions. The temperature measuring part of each temperature measuring device (17) extends into the soil trough body (1).

9. A test method using the simulated diving two-dimensional flow test device as described in claim 8, characterized in that, It includes the following steps: Step 1: Assemble the simulated two-dimensional flow test device for diving, close the first valve (121), the second valve (141) and the third valve (24), and add the naturally air-dried test soil sample into the soil trough body (1). During the adding process of the test soil sample, when the soil layer is increased by 3 - 10 cm each time, the soil layer is tamped until the upper end surface of the soil layer is flush with the uppermost group of temperature measuring devices (17). Step 2: Open the second valve (141), and spray water into the left end of the soil trough body (1) through the water spraying device (2). Then, turn on the heating device (3) to heat the test soil sample at the right end of the soil trough body (1). After the liquid has flowed into the liquid recovery kettle (4) for a period of time, monitor the volume of the liquid sprayed out by the water spraying device (2), the volume of the liquid recovered by the liquid recovery kettle (4), the displayed value of the temperature measuring device (17) and the water level value in the water level tube (11) in real time. At the same time, take out the liquid sample from the sampling tube (12) in real time and conduct component analysis on the liquid. After the test is completed, take the test soil samples at different positions in the soil trough body (1) and conduct component analysis on them. Step 3: Data processing: According to the dynamic measurement of the volume of the aqueous solution during the test process, draw a broken line graph of the supply amount, excretion amount and evaporation amount of the aqueous solution changing with time, and calculate the permeability coefficient of the test soil sample. Calculate the water holding capacity of the test soil sample according to the main water holding capacity of the soil trough body (1). According to the temperature values measured during the test process, draw the temperature isotherm of the upper right part of the soil trough body (1) to understand the temperature change characteristics and the influence of different depths of the test soil sample on the evaporation intensity. According to the water level values measured during the test process, draw the water level line and flow field map of the soil trough body (1) to distinguish the saturated zone and the vadose zone. During the test process, according to the water quality test data of the same period obtained from each sampling tube, draw an isoconcentration map of the concentration distribution of a certain component of the water quality; according to the water quality test data of different periods of a single sampling tube, draw a broken line graph of the concentration change of a certain component of the water quality changing with time. After the test, according to the test results of the test soil samples, draw the contour map of the concentration distribution of a certain component in the test soil samples and the comparison chart of the test results before and after a certain component in the test soil samples.

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