A fissure soil sample consolidation and solute migration test device and test method

Abstract

The application discloses a kind of fissure soil sample consolidation and solute migration test device, including container, pressure loading module, solute injection module and monitoring module, the pressure loading module is applicable to the soil sample in container is applied pressure, the container includes several detachable connection column segment, the soil sample and artificial fissure module are filled into column segment in layer, artificial fissure is directly formed in the soil sample after the artificial fissure module is removed, the data of the soil sample deformation and artificial fissure evolution under the load of pressure loading module are collected by the monitoring module.The test device of the application, the pressure loading module is applied to the soil sample in container is applied pressure to simulate the large deformation consolidation and solute migration of soil under load, artificial fissure is directly formed in soil, when soil sample is subjected to longitudinal load, soil will produce deformation, resulting in corresponding changes of artificial fissure, the simulation of artificial fissure under load and the simulation of the influence of artificial fissure evolution on solute migration are realized, and the application also relates to the test method of the above test device.

Description

TECHNICAL FIELD

[0001] The present application relates to a fissure soil sample consolidation and solute migration test device, and also relates to a fissure soil sample consolidation and solute migration test device comprising the test device. BACKGROUND

[0002] There are a large number of fissures in clay liners, and the existence of fissures leads to a substantial reduction in the service life of the liner. The consolidation of a landfill can also have a non-negligible impact, especially when large deformations occur, and the consolidation has a long-term impact on pollutants. It is meaningful to study the migration of pollutants in fissure-containing clay liners under large deformation conditions.

[0003] Li Lei et al. (2016) designed a soil column test device for the migration of pollutants in a single artificial fissure compacted liner. The test used stainless steel mesh to simulate clay fissures, and sodium chloride (NaCl) solution and bright blue dye were used as tracers to study the effects of different seepage water heads and fissure widths on pollutant migration. However, the stainless steel mesh fissure cannot simulate deformable fissures under pressure conditions, and the stainless steel mesh fissure embedded in the soil sample has a reinforcing effect when considering soil deformation. Qiu Jinwei et al. (2018) independently developed a large deformation consolidation and pollutant migration coupling test device. The device is loaded by a pneumatic cylinder and can be sampled at any time, but the research object is sediment, and the device cannot provide the evolution characteristics of fissures. The method and device for testing the migration of pollutants in undisturbed soil under load are disclosed in CN106124366A. Under the condition of large deformation consolidation, the soil sample deforms while the fissures evolve in shape, and thus the pollutant migration path also changes. The existing artificial fissures embedded directly cannot simulate the effect of fissure shape evolution on pollutant migration, so further tests are needed to obtain test data to further understand the migration law of fissure clay under the action of large deformation consolidation. SUMMARY

[0004] In view of the above shortcomings, the present application aims to provide a pollutant migration test device that simulates fissure evolution under load, and also aims to provide a test method comprising the test device.

[0005] To this end, the present application provides a fissure soil sample consolidation and solute migration test device, which comprises a container, a pressure loading module, a solute injection module and a monitoring module. The pressure loading module is suitable for applying pressure to the soil sample in the container. The container comprises a plurality of detachably connected column segments. The soil sample and the artificial fissure module are filled into the column segments in layers. After the artificial fissure module is removed, an artificial fissure is directly formed in the soil sample. The monitoring module collects data on the deformation of the soil sample and the evolution of the artificial fissure under the load of the pressure loading module.

[0006] Further, the column segments include a top cover, an upper segment, a middle segment and a base, sealing washers are arranged between the column segments to be connected to form a closed test space, and the side wall of the container is provided with a through hole connected to the conductivity sensor.

[0007] Further, the pressure loading module includes an electronic universal testing machine, a force transmission rod and a stainless steel porous disc, the middle cross beam of the electronic universal testing machine is connected to the force transmission rod at the lower end, the stainless steel porous disc is provided with a plurality of through holes, the lower end of the force transmission rod is threadedly connected to the stainless steel porous disc, and the electronic universal testing machine is provided with a force value sensor and a displacement sensor.

[0008] Further, the solute injection module includes a marshall bottle and an adjustable height base.

[0009] Further, the artificial fissure module includes a metal sheet.

[0010] Further, the adjacent column segments of the cavity include an upper connecting end and a lower connecting end matched with each other, the upper connecting end includes a sleeve connected to the column segment, the upper wing plate of the sleeve is bolted to the fixing plate arranged on the column segment, the lower end of the sleeve is provided with a transverse insertion hole, the insertion plate passes through the insertion hole and is matched with the inner wall of the column segment to be used for filling the soil sample, and the moving module for driving the sleeve to move vertically along the outer wall of the column segment is further included.

[0011] Further, the bottom of the sleeve is provided with a lower wing plate, the moving module includes a screw rod matched with the threaded hole of the fixing plate, the lower end of the screw rod is matched with the lower wing plate, a knob matched with the screw rod and used for driving the screw rod to rotate is arranged on the screw rod, the lower connecting end is provided with a connecting plate matched with the lower wing plate to be bolted, and the connecting plate is arranged below the end face of the lower connecting end at a predetermined distance, so that the insertion hole of the sleeve is shielded by the outer wall of the lower connecting end.

[0012] The artificial fissure module can also be in a strip shape and form a cavity in the interior through elastic deformation, and the cavity is used for inserting the insertion strip.

[0013] The artificial fissure module can also include two flat wall plates, the wall plates are curved into an arc shape, and the two sides of the arc shape are connected to the two sides of the other wall plate at the middle to form a cavity, the wall plates are connected to the inwardly inclined guide assembly, the bottom of the guide assembly is connected to the sleeve connector, and the sleeve connector is suitable for being connected to the traction assembly, in such a way that when the traction assembly moves upward through the cavity and drags the sleeve connector, the sleeve connector drives the wall plates to deform to the central position.

[0014] The application also includes a fissure soil sample consolidation and solute migration test method of the test device.

[0015] (1) Assembling the base, the middle segment and the upper segment of the cavity in sequence, pre-pressing and sealing through the sealing rubber gasket and the fastening bolt, and fixing the base of the outer frame of the electronic universal testing machine;

[0016] (2) From bottom to top, fill quartz sand, nylon net, vertically bury artificial fracture module, and fill and compact soil sample layer by layer, and after reaching the thickness of the test soil sample, remove the artificial fracture in turn, and cover the nylon net;

[0017] (3) The lower end of the force transmission rod is a stainless steel porous disc, the height of the cross beam in the electronic universal testing machine is adjusted, the cross beam in the electronic universal testing machine is moved downward by the main machine, and the stainless steel porous disc is in contact with the upper contact surface of the sample;

[0018] (4) Connect the liquid injection port and the marshall bottle through the rubber hose, connect the pore water pressure gauge and the conductivity sensor, and seal with the water stop, and connect the pore water pressure gauge and the conductivity sensor to the main machine;

[0019] (5) Adjust the height of the marshall bottle to control the seepage liquid head, use the main machine to determine and control the test loading rate and loading load value according to the test scheme, and collect the soil deformation and the solute conductivity of each layer at each time point;

[0020] (6) After the test is completed, the container is disassembled, the soil sample after the test is cut, the data is collected and analyzed.

[0021] The beneficial technical effects of the present application are:

[0022] The test device of the present application applies pressure to the soil sample in the container through the pressure loading module to simulate the large deformation consolidation of the soil body under the action of load, the artificial fracture is directly formed in the soil body, and the container is formed by a plurality of column segments which can be disassembled to realize the layered filling of the soil sample and the layered embedding of the artificial fracture module. After the artificial fracture module is removed, the artificial fracture is directly formed in the soil sample. This layered structure can avoid or reduce the disturbance to the soil sample when the artificial fracture module is removed. The artificial fracture of the present application deforms when the soil sample is subjected to longitudinal load, resulting in corresponding changes in the artificial fracture, thereby simulating the artificial fracture under the action of load and simulating the influence of artificial fracture evolution on solute migration. After the simulation test is completed, the present application also includes cutting the soil sample (along the artificial fracture), observing the final artificial fracture shape, and the path formed by the evolution of the artificial fracture under the action of load may be relatively complex. By layering, the column segments can be disassembled and cut, which simplifies the cutting difficulty, reduces the probability of soil sample collapse during cutting, and more accurately cuts along the artificial fracture. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 The schematic diagram of the specific embodiment 1 of the present application is shown in the figure;

[0024] Figure 2 The layered schematic diagram of the container is shown in the figure;

[0025] Figure 3 is a schematic view of a porous disc;

[0026] Figure 4 is a schematic view of an artificial fracture module in Example 2;

[0027] Figure 5 is a schematic view of an artificial fracture simulation in Example 3;

[0028] Figure 6 is a schematic view of a cross section of adjacent column segments in Example 4;

[0029] Figure 7 is a schematic view of Figure 4 from above.

[0030] BRIEF DESCRIPTION OF DRAWINGS 1, electronic universal testing machine; 101, outer frame; 102, middle beam; 103, force transmission rod; 2, porous disc; 3, sealing rubber gasket; 4, container; 401, top cover; 402, upper segment; 403, middle segment; 404, base; 405, injection port; 406, liquid outlet; 407, conductivity sensor; 408, artificial fracture; 409, upper connecting end; 410, lower connecting end; 411, sleeve; 412, upper wing plate; 413, fixed plate; 414, screw rod; 415, plug; 416, connecting plate; 5, quartz sand; 6, soil sample; 7, pore water pressure gauge; 8, Mariotte bottle; 9, measuring cup; 10, electronic scale; 11, main machine; 12, artificial fracture module; 121, plug; 122, guide assembly; 123, sleeve fitting. DETAILED DESCRIPTION

[0031] In order to further explain the technical means and effects adopted by the present application to achieve the predetermined purposes, the specific embodiments, structures, features and effects according to the present application are described in detail below in combination with the drawings and preferred embodiments.

[0032] Referring to Figures 1 to 3 , a crack soil sample consolidation and solute migration test device of the present application includes a container 4, a pressure loading module, a solute injection module and a monitoring module, the pressure loading module is suitable for applying pressure to the soil sample 6 in the container 4, the container 4 includes a plurality of detachably connected column segments, the soil sample 6 and the artificial fracture module 12 are filled into the column segments in layers, the artificial fracture 408 is directly formed in the soil sample 6 after the artificial fracture module 12 is removed, and the data of the deformation of the soil sample 6 and the evolution of the artificial fracture 408 under the load of the pressure loading module are collected by the monitoring module.

[0033] The present application mainly realizes the evolution simulation of the artificial fracture 408 under the load and the solute migration test, which is described in detail below in combination with Example 1.

[0034] Referring to Figure 1In the embodiment 1 of the present application, the container 4 has a cylindrical column segment structure with a height of 80 cm, a diameter of 25 cm and a thickness of 2 cm, and is made of high-strength organic glass. The container 4 includes a top cover 401, an upper segment 402, three middle segments 403 and a base 404. The three middle segments 403 are separately processed and formed, and are connected to each other by flanges. A sealing rubber gasket 3 is arranged between the middle segments 403 to form a closed test space. The sealing rubber gasket 3 is customized according to the size of the connecting part of the column segment. The side walls of the upper segment 402, the middle segments 403 and the base 404 of the container 4 are provided with through holes, which are respectively connected to a solute injection module, a monitoring module and used as a leachate outlet 406. The container 4 is fixed to the base of the outer frame 101 of the electronic universal testing machine 1. During the test, the quartz sand 5 is laid on the base 404 to a fixed height, the nylon net is placed on the top of the quartz sand 5, the artificial fissure module 12 is placed and the soil sample 6 is filled in layers and compacted, the artificial fissure module 12 is taken out in sequence when the required height is reached, the nylon net is laid on the top of the soil sample 6, the perforated disc 2 is placed above the nylon net, the perforated disc 2 is connected to the force transmission rod 103, and the top cover 401 is placed and fixed by bolts.

[0035] Referring to Figure 1 As shown in the figure, the pressure loading module includes the electronic universal testing machine 1, the force transmission rod 103 and the perforated disc 2 made of stainless steel. The electronic universal testing machine 1 includes a base, a middle cross beam 102 and a main machine 11. The middle cross beam 102 is connected to the force transmission rod 103 at the lower end. The perforated disc 2 is provided with a plurality of through holes to facilitate the passage of leachate. The middle part of the perforated disc 2 is provided with an internal thread, and the lower end of the force transmission rod 103 is provided with a matching external thread to be screwed into the perforated disc 2. The testing machine is provided with a force value sensor and a displacement sensor to collect the force value change and displacement change during the test.

[0036] The solute injection module includes a marshall bottle 8 and an adjustable height base. The marshall bottle 8 can control the stable water level of leachate and can inject at a constant speed. The adjustable height base can change the water head condition of the test. The marshall bottle 8 is connected to the inlet 405 of the container 4 by a rubber hose. In the embodiment 1, the inlet 405 is arranged on the side wall of the upper segment 402 of the container 4.

[0037] The monitoring module includes a pore water pressure gauge 7, an electrical conductivity sensor 407 and an electronic scale 10. The electrical conductivity sensor 407 is connected to the main machine 11 through the through hole arranged on the side wall of the container 4. A graduated cylinder is connected to the outlet 406 by a rubber hose. The graduated cylinder is placed on the electronic scale 10. The pore water pressure gauge 7 is connected to the main machine 11 through the through hole arranged on the side wall of the container 4.

[0038] Unlike the prior art in which the artificial fracture module 12 is directly buried in the soil sample 6, the key to the evolution simulation of the artificial fracture 408 under pressure load in the present application is to directly form the artificial fracture 408 in the soil sample 6. In Embodiment 1, the length of the artificial fracture 408 is 12 cm, and the width and depth are set according to specific requirements. The artificial fracture module 12 can use iron sheets of different sizes to form artificial fractures 408 of different widths. The artificial fracture 408 is segmented and buried in the soil sample 6 in the longitudinal direction, and the surface of the iron sheet is wrapped with a film to reduce disturbance to the soil sample 6 when it is removed. In this embodiment, the artificial fracture 408 is divided into 6 segments.

[0039] The specific test method is as follows:

[0040] (1) Assemble the base 404, the middle section 403, and the upper section 402 in order, pre-press seal with the sealing rubber gasket 3 and the fastening bolt, and fix on the base of the outer frame 101 of the electronic universal testing machine 1;

[0041] (2) From bottom to top, fill the quartz sand 5 and the nylon net, vertically bury the artificial fracture module 12, and then fill and compact the soil sample 6 layer by layer. After reaching the thickness of the test soil sample 6, remove the artificial fracture 408 in order, and cover the nylon net;

[0042] (3) Screw the lower end of the force transmission rod 103 with the stainless steel porous disc 2. After the upper end of the force transmission rod 103 passes through the through hole of the cavity top cover 401, pre-press seal the cavity top cover 401 with the upper section 402 through the sealing rubber gasket 3 and the fastening bolt. Adjust the height of the cross beam 102 in the electronic universal testing machine 1, screw the upper end of the force transmission rod 103 with the threaded groove of the cross beam 102 in the electronic universal testing machine 1, and control the cross beam 102 in the electronic universal testing machine 1 to move downward through the main machine 11, so that the stainless steel porous disc 2 contacts the upper contact surface of the soil sample;

[0043] (4) Connect the injection port 405 with the marini bottle 8 and the liquid outlet 406 with the measuring cup 9 through the rubber hose. Place the measuring cup 9 on the electronic scale 10. Connect the pore water pressure gauge 7 and the electrical conductivity sensor 407 at the through hole, and seal with a water stop. Connect the pore water pressure gauge 7 and the electrical conductivity sensor 407 with the main machine 11;

[0044] (5) Adjust the height of the marini bottle 8 to control the seepage water head. Use the main machine 11 to determine and control the test loading rate and loading load value according to the test scheme. Collect the soil deformation and the solute electrical conductivity at each time point through the main machine 11.

[0045] (6) After the solute migration test is completed, the valves of the inlet 405 and the outlet 406 are closed, the marshall bottle 8 and the measuring cup 9 are separated, the upper end of the transmission rod 103 and the cross beam 102 in the electronic universal testing machine 1 are separated, and then the cavity top cover 401, the lower end screw of the transmission rod 103 and the stainless steel porous disc 2 are separated, and then the upper section 402 of the container, the three middle sections 403 of the container are separated from top to bottom. When disassembling, the fastening bolts are removed first, then the steel wire is used to cut the soil, a digital camera is used to shoot the fracture morphology of each layer, and binary analysis is used for the fracture image; the test data is sorted out, and the test data is analyzed and processed. Through the settlement rate of the soil sample 6, the solute breakthrough curve, the solute concentration profile and the change of the fracture width, the large deformation consolidation, the fracture evolution and the migration rule and mechanism of the pollutants are studied.

[0046] Since the artificial fracture module 12 is directly buried in the soil sample 6, the soil sample 6 needs to be compacted, and after the artificial fracture module 12 is taken out, it is difficult to avoid extrusion and disturbance on the surface of the soil body, which will cause the size of the void to change and the soil sample 6 around the void to loosen to a certain extent, which will have a certain influence on the test results. Referring to Figure 4 When the width of the artificial fracture 408 required by the test is large, such as 3 mm or 4 mm, two strip-shaped thin metal sheets can be connected at both ends, and a predetermined thickness of the insertion bar 121 is inserted into the middle of the two metal sheets to make the metal sheets elastically deform. When taking out, the insertion bar 121 can be pulled out first, and the two metal sheets retract under the action of the elastic force and are separated from the contact with the soil body, thereby further reducing the disturbance to the pore. Referring to Figure 5 In another embodiment 3, the artificial fracture 408 includes two flat wall plates, the wall plates are curved into an arc shape, and the two sides of the arc shape are connected to the middle of the two sides of the other wall plate to form a cavity. The wall plate is connected with an inwardly inclined guide assembly 122, and the bottom of the guide assembly 122 is connected with a sleeve piece. The sleeve piece is suitable for being connected with a traction assembly. In this way, when the traction assembly moves upward through the cavity and pulls the sleeve piece, the sleeve piece drives the wall plate to deform to the center position and separates from the contact with the pore wall of the soil sample 6. The traction assembly can be a rope. When the traction assembly is deformed by traction, the artificial fracture module 12 can be fixed at the top by using a clamping device or other device first, and then the artificial fracture module 12 is taken out after the wall plate retracts. Of course, in the above-mentioned embodiment 2, the artificial fracture module 12 can also be fixed first when the insertion bar 121 is taken out, so as to avoid moving the artificial fracture module 12 in the longitudinal direction during the process of taking out the insertion bar 121.

[0047] When the width of the set artificial fracture 408 is very small, such as 0.4 mm, it is difficult to use the methods of the above-mentioned embodiments 2 and 3. Referring to Figure 6 and Figure 7As shown in embodiment 3, the adjacent column sections of the cavity include the upper connecting end 409 and the lower connecting end 410 which are matched with each other, the upper connecting end 409 includes the sleeve 411 sleeved on the column section, the upper wing plate 412 of the sleeve 411 is bolted with the fixing plate 413 arranged on the column section, the lower end of the sleeve 411 is provided with a transverse insertion hole, the insertion plate 415 passes through the insertion hole and is matched with the inner wall of the column section for filling the soil sample 6, and the moving module for driving the sleeve 411 to move vertically along the outer wall of the column section is further included, the moving module includes the screw rod 414 matched with the threaded hole on the fixing plate 413, the lower end of the screw rod 414 is matched with the lower wing plate, and the screw rod 414 is provided with the knob matched with the screw rod 414 for driving the screw rod 414 to rotate. In embodiment 3, the sleeve 411 is fixed with the column section, the insertion plate 415 forms the bottom plate of the column section, the soil sample 6 is arranged with the artificial fissure module 12, after the soil body is compacted, the artificial fissure module 12 is taken out, and each column section is assembled from bottom to top. First, the bolts on the upper wing plate 412 of the sleeve 411 and the fixing plate 413 are loosened, the knob is rotated to drive the screw rod 414 to slowly move downward to push the sleeve 411 downward, so that the bottom plate is separated from the bottom of the soil sample 6, and then the insertion plate is pulled out of the insertion hole. The position of the screw rod 414 can be used to clamp the insertion plate 415 together with the lower wing plate, after the insertion plate 415 is pulled out, the screw rod 414 is used to push the sleeve downward again. After the insertion plate is pulled out, the sleeve 411 is sleeved on the lower connecting end 410, the bolts between the sleeve 411 and the fixing plate 413 are tightened again, the bottom of the sleeve 411 can be provided with the lower wing plate, the lower connecting end 410 is provided with the connecting plate 416 matched with the lower wing plate for bolt connection, the connecting plate 416 is arranged at a predetermined distance below the end face of the lower connecting end 410, so that the end face of the lower connecting end 410 and the end face of the column section of the upper connecting end 409 are matched (the rubber gasket can be arranged in advance between the end faces, the filled soil sample 6 is flush with the gasket, so that the soil samples 6 between the layers are in contact), and the insertion hole of the sleeve 411 is shielded by the outer wall of the lower connecting end 410. Embodiment 3 is suitable for clay and other soil samples 6, and after the combination is completed, a period of time can be left for standing, so that the soil layers are combined together under the action of gravity.

[0048] The above is only the preferred embodiment of the present application, and does not limit the present application in any form. Although the present application has been disclosed as the above preferred embodiment, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to the above disclosed technical content to obtain equivalent embodiments with equivalent changes, without departing from the technical solution of the present application. Any modification, change, modification and equivalent change of the above embodiment based on the technical essence of the present application are still within the scope of the technical solution of the present application.

Claims

1. A test apparatus for consolidation and solute migration of fractured soil samples, comprising a container, a pressure loading module, a solute injection module, and a monitoring module, wherein the pressure loading module is suitable for applying pressure to the soil sample in the container, characterized in that: The container includes several detachably connected column segments. The soil sample and the artificial fracture module are filled into the column segments in layers. After the artificial fracture module is removed, artificial fractures are directly formed in the soil sample. The monitoring module collects data on the deformation of the soil sample and the evolution of the artificial fractures under the load of the pressure loading module. The artificial fracture module includes a metal sheet. Adjacent column segments of the container include an upper connecting end and a lower connecting end that cooperate with each other. The upper connecting end includes a sleeve fitted onto the column segment. The upper flange of the sleeve is bolted to a fixing plate on the column segment. The lower end of the sleeve has a transverse insertion hole. An insertion plate passes through the insertion hole and cooperates with the inner wall of the column segment for filling with soil samples. The module also includes a moving module that drives the sleeve to move vertically along the outer wall of the column segment. The bottom of the sleeve has a lower flange. The moving module includes a screw that mates with a threaded hole on the fixing plate. The lower end of the screw mates with the lower flange. A knob is provided on the screw to drive its rotation. The lower connecting end has a connecting plate that mates with the lower flange for bolted connection. The connecting plate is positioned at a predetermined distance below the end face of the lower connecting end, so that the insertion hole of the sleeve is blocked by the outer wall of the lower connecting end. The artificial fissure module is strip-shaped and forms a cavity inside through elastic deformation. The cavity is used to insert the insert. When removing it, the insert is pulled out first, and the two metal plates retract under the action of elasticity, separating from the contact with the soil. Alternatively, the artificial fissure module may include two flat wall panels, one of which is bent into an arc shape and the two sides of the arc are connected to the two sides of the other wall panel to form a cavity in the middle. An inwardly inclined guide component is connected to the wall panel, and a sleeve is connected to the bottom of the guide component. The sleeve is connected to a traction component. When the traction component moves upward through the cavity to pull the sleeve, the sleeve causes the wall panel to deform towards the center position. Each column segment is filled with soil independently, and the artificial fissure module is buried in the soil sample. After the soil is compacted, the artificial fissure module is taken out. Each column segment is assembled from bottom to top. The insert plate is pulled out from the insertion hole, and the sleeve is put on the lower connecting end.

2. The experimental apparatus for consolidation and solute migration of fractured soil samples according to claim 1, characterized in that: The container includes a top cover, an upper section, a middle section, and a base. Sealing gaskets are installed between the sections to form a sealed test space. Through holes are opened on the side wall of the container to connect to conductivity sensors.

3. The test apparatus for consolidation and solute migration of fractured soil samples according to claim 2, characterized in that: The pressure loading module includes an electronic universal testing machine, a force transmission rod, and a stainless steel perforated plate; the lower end of the crossbeam of the electronic universal testing machine is connected to the force transmission rod, the stainless steel perforated plate has multiple through holes, the lower end of the force transmission rod is threaded to the stainless steel perforated plate, and the electronic universal testing machine is equipped with a force sensor and a displacement sensor.

4. The test apparatus for consolidation and solute migration of fractured soil samples according to claim 3, characterized in that: The solute injection module includes a Marshall flask and an adjustable height base.

5. A method for testing the consolidation and solute migration of fractured soil samples, comprising the test apparatus described in claim 4, characterized in that: Includes the following steps: (1) Assemble the base, middle section and upper section of the container in sequence, pre-seal it with sealing rubber gaskets and fastening bolts, and fix it on the base of the outer frame of the electronic universal testing machine; (2) Fill the artificial fracture module with quartz sand and nylon mesh from bottom to top, vertically bury the artificial fracture module, and fill and compact the soil sample in layers. After reaching the thickness of the test soil sample, take out the artificial fracture module in sequence and cover it with nylon mesh. (3) The lower end of the force transmission rod is connected to a stainless steel perforated plate. Adjust the height of the crossbeam in the electronic universal testing machine and control the crossbeam in the electronic universal testing machine to move downward through the host machine so that the stainless steel perforated plate contacts the contact surface on the sample. (4) Connect the injection port to the Marsh bottle through a rubber hose, connect the pore water pressure gauge and the conductivity sensor, and seal the connection with a waterstop. Connect the pore water pressure gauge and the conductivity sensor to the main unit. (5) Adjust the height of the Marsh bottle by controlling the leachate head, use the host to determine and control the test loading rate and load value according to the test plan, and collect the soil deformation and solute conductivity of each layer at each time by the host. (6) After the test, the container was disassembled, the soil sample after the test was cut, the data was collected and analyzed; the column section was disassembled first, the soil was cut with a steel wire, the crack morphology of each layer was photographed with a digital camera, and the crack image was analyzed by binarization.

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