An infiltration gradient testing machine and experimental method for fine-grained soil

Abstract

The present invention discloses a seepage gradient testing machine and an experimental method for fine-grained soil, belonging to the technical field of detection technology; the key points of its technical solution include a water supply tank, a permeation container and a graduated cylinder, and the water supply tank, the permeation container and the graduated cylinder are connected together through rubber hoses; the permeation container includes a cylindrical barrel, a fixed ring fixedly connected to the lower end of the barrel and a cover plate arranged at the upper end of the barrel; a portal-shaped support frame is further arranged at the upper end of the barrel, the two columns of the support frame are connected to the side wall of the barrel, and a bolt threadedly engaged with the support frame is inserted into the cross beam of the support frame; the cover plate is rotatably connected to the lower end of the bolt, so that the cover plate can rotate along its own axis, and a ring plate is fixedly connected to the lower surface of the cover plate; the outer diameter of the ring plate is the same as the diameter of the cover plate, and the inner ring surface of the ring plate is an inclined surface, and the end of the inclined surface away from the cover plate extends towards the direction close to the outer ring of the ring plate. The present invention solves the problem that the conventional testing machine is prone to inaccurate experimental results.

Description

Technical Field

[0001] The present invention relates to the technical field of detection technology, and particularly relates to a seepage gradient testing machine for fine-grained soil and an experimental method. Background Art

[0002] The research on the permeability and seepage problems of soil has become an important and practical topic in the fields of soil mechanics and geotechnical engineering. It is closely related to human life and involves fields such as water conservancy, construction, transportation, mining, petroleum, agriculture, and environment. Seepage can cause seepage deformation of the soil mass, directly affecting the stability and safety of geotechnical structures and foundations; at the same time, seepage will cause water loss and reduce the engineering benefits. The evaluation of seepage deformation and seepage failure is a basic item in the structural design and stability analysis of actual projects, directly related to the safety, reliability, and economic rationality of engineering design. Indoor seepage tests are one of the important means to verify seepage deformation calculation methods and reveal the physical mechanism of the formation of seepage force. For water conservancy projects, rockfill dams are one of the widely used high dam types at present. Ensuring the seepage stability of each partition of the dam is one of the key topics in the design and construction of rockfill dams. Obtaining the failure gradient through seepage failure tests on various types of dam materials is an important means to study the seepage stability of dams.

[0003] Common general testing machines, because they also need to conduct experiments on coarse particles, and the diameter of coarse particles is large and the gaps between them are also large, so the capacity of the testing machine needs to be very large. Therefore, when conducting experiments on fine-grained soil, more fine-grained soil samples are loaded. Therefore, during the compaction process of fine-grained soil, it is easy to cause some fine-grained soil not to be compacted, and because there are more samples, it is also very time-consuming during the compaction process. So the common general seepage gradient test devices currently available are not suitable for conducting seepage experiments on fine-grained soil, which easily leads to low efficiency and inaccurate experimental results of seepage experiments on fine-grained soil. Summary of the Invention

[0004] An object of the present invention is to provide a seepage gradient testing machine for fine-grained soil and an experimental method, which have the characteristic of improving the accuracy of experimental results.

[0005] The above object of the present invention is achieved through the following technical solutions: A seepage gradient testing machine for fine-grained soil includes a water supply tank, a seepage container, and a measuring cylinder, and the water supply tank, the seepage container, and the measuring cylinder are connected together through rubber hoses;

[0006] The seepage container includes a cylindrical material barrel, a fixed ring fixedly connected to the lower end of the material barrel, and a cover plate provided at the upper end of the material barrel;

[0007] A portal-shaped support frame is further provided at the upper end of the material barrel. The two columns of the support frame are connected to the side wall of the material barrel, and a bolt threadedly engaged with the support frame is inserted into the cross beam of the support frame;

[0008] The lower ends of the cover plate and the bolt are rotatably connected, enabling the cover plate to rotate along its own axis, and a circular plate is fixedly connected to the lower surface of the cover plate;

[0009] The outer diameter of the circular plate is the same as the diameter of the cover plate, and the inner surface of the inner circle of the circular plate is an inclined surface, and the end of the inclined surface away from the cover plate extends towards the outer circle of the circular plate.

[0010] By adopting the above technical solutions, the voids between fine-grained soils are very small. Therefore, during the experiment, not too many samples of fine-grained soils need to be taken. And the volume of the cylinder of this device is small, which is convenient for loading samples, improving the working efficiency. Moreover, after the samples are loaded, the samples can be tamped better, making the samples in the cylinder more in line with the actual situation, and thus making the experimental results more accurate; the inner surface of the inner circle of the circular plate on the cover plate is an inclined surface. Therefore, during the process of tightening the cover plate and applying pressure to the samples in the cylinder by the cover plate, the circular plate can make the samples gather towards the center, preventing the samples from overflowing from the gap between the cover plate and the cylinder, so that the samples can be pressed tighter, further improving the accuracy of the experiment.

[0011] The present invention is further configured as: two symmetrically arranged horizontal axes are fixedly connected to the circumferential surface of the cylinder, and the two side columns of the support frame are rotatably connected to the horizontal axes, enabling the support frame to rotate along the axis of the horizontal axes;

[0012] An adjusting nut is threadedly connected to the end of the horizontal axis protruding from the circular hole, and the adjusting nut can be in contact with the side wall of the column away from the cylinder.

[0013] By adopting the above technical solutions, the cover plate can be rotated to one side of the cylinder, so that the upper end of the cylinder is completely exposed, facilitating the loading of samples into the cylinder and improving the working efficiency.

[0014] The present invention is further configured as: two symmetrically arranged limiting blocks are fixedly connected to the circumferential side wall of the cylinder, the limiting blocks are located on one side of the horizontal axis, and the limiting blocks can be in contact with the side walls of the columns of the support frame.

[0015] By adopting the above technical solutions, during the process of tightening the cover plate, the cover plate and the cylinder need to be aligned. Therefore, the support frame needs to be in a vertical state. The limiting blocks can limit the rotation of the support frame. When the columns of the support frame are in contact with the limiting blocks, the support frame is exactly in a vertical state. Therefore, through the cooperation of the limiting blocks and the columns of the support frame, the support frame can be quickly and accurately moved to a vertical state, improving the working efficiency.

[0016] The present invention is further configured as: a workbench is provided below the cylinder, a vertical plate is fixedly connected to one side of the workbench, a leveling device is provided on the lower surface of the workbench, the cylinder is installed on the workbench, and a measuring cylinder and a water supply tank are installed on the vertical plate.

[0017] By adopting the above technical solutions, the barrel, the measuring cylinder and the water supply tank can be installed together, thus facilitating the coordinated cooperation among the three. Moreover, the workbench can keep the vertical plate in a vertical state, reducing the influence of the uneven ground surface on the liquid level in the measuring cylinder.

[0018] The present invention is further configured as: a moving plate is provided on the inner bottom surface of the barrel, and the circumferential surface of the moving plate fits with the inner wall of the barrel;

[0019] The lower surface of the moving plate is rotatably connected to a vertical rod. The vertical rod can rotate along its own axis, and the lower end of the vertical rod protrudes from the lower surface of the barrel. The vertical rod is in threaded cooperation with the barrel.

[0020] By adopting the above technical solutions, the fine-grained soil is compacted in the barrel. Therefore, after the experiment is completed, it is not easy to clean the fine-grained soil. So, a moving plate is provided. The moving plate is located on the inner bottom surface of the barrel, and the fine-grained soil is compacted on the upper surface of the moving plate. When it is necessary to clean the fine-grained soil in the barrel, rotate the vertical rod, and then the moving plate can be lifted, and then the moving plate can push out the fine-grained soil, which is convenient and fast, improving the work efficiency.

[0021] The present invention is further configured as: a sealing rubber pad is fixedly connected to the lower surface of the moving plate.

[0022] By adopting the above technical solutions, the sealing rubber pad can seal the gap between the moving plate and the bottom surface of the barrel, avoiding the clear water flowing out along the gap between the moving plate and the barrel during the experiment, and ensuring that the accuracy of the experimental results will not be affected.

[0023] The present invention is further configured as: a plurality of support columns are provided on the lower surface of the fixed ring. The support columns are evenly distributed around the axis of the barrel, and the length of the support columns is greater than the length of the vertical rod;

[0024] The upper end of the support column fits with the lower surface of the fixed ring, and a fixed rod is also fixedly connected to the upper end of the support column. The diameter of the fixed rod is smaller than the diameter of the support column;

[0025] The upper end of the fixed rod passes through the through hole and protrudes from the upper surface of the fixed ring. The upper end of the fixed rod is threadedly connected with a fixing nut, and the fixing nut can fit with the surface of the fixed ring.

[0026] By adopting the above technical solutions, the permeation container can be installed together with the workbench. When compacting the fine-grained soil, the barrel will not move, facilitating the loading of the fine-grained soil. Moreover, the permeation container can be disassembled, thus facilitating the replacement of the damaged permeation container.

[0027] Another object of the present invention is to provide a method for conducting a permeation gradient experiment on fine-grained soil. The advantage of this method is that it can more accurately simulate the actual environment and improve the accuracy of the experimental results.

[0028] The above object of the present invention is achieved by the following technical means: A method for conducting a seepage gradient experiment on fine-grained soil, comprising the following steps:

[0029] Filling the specimen: Load the sample for the experiment into the cylinder, and during the process of filling the specimen, compact it once every 3 cm of thickness is filled;

[0030] Saturating the specimen: The clear water in the water supply tank first enters the cylinder through a rubber hose to saturate the specimen by infiltration;

[0031] Storing water in the graduated cylinder: The clear water in the water supply tank enters the graduated cylinder through a rubber hose until it reaches the maximum measurement value of the graduated cylinder;

[0032] Starting the experiment: Lock the rubber hose connecting the water supply tank and the cylinder with an iron clamp, allowing the clear water in the graduated cylinder to enter the cylinder for the seepage test, and record the water level drop of the clear water in the graduated cylinder.

[0033] By adopting the above technical solution, the fine-grained soil can be more compacted in the cylinder, more in line with the actual situation, improving the accuracy of the experimental results. Moreover, the clear water first enters the graduated cylinder to reach the maximum range, and then enters the cylinder, which can more intuitively reflect the change in water volume, thereby measuring the seepage coefficient and reducing the error rate of reading.

[0034] In summary, the present invention has the following beneficial effects:

[0035] 1. Through the cooperation of a cylinder with a smaller volume, a cover plate, and an annular plate on the lower surface of the cover plate, the sample can be better compacted and measured, improving the speed when loading the sample and the accuracy of the experimental results;

[0036] 2. By the steps of filling the specimen, saturating the specimen, storing water in the graduated cylinder, and starting the experiment, the speed when loading the specimen can be increased, and the accuracy of the experimental results can also be improved. Description of the Drawings

[0037] Figure 1 is the overall structural diagram in the embodiment;

[0038] Figure 2 is the partial cross-sectional view highlighting the position of the movable plate in the embodiment;

[0039] Figure 3 is Figure 2 the enlarged view of part A in

[0040] In the figure, 1 is a workbench; 11 is a vertical plate; 12 is a leveling device; 13 is a support plate; 14 is an adjusting rod; 2 is a permeation container; 21 is a barrel; 211 is a horizontal axis; 212 is a limit block; 213 is a drain pipe; 214 is a permeable film; 22 is a cover plate; 221 is an annular plate; 222 is an inclined surface; 223 is an overflow pipe; 23 is a fixing ring; 24 is a support column; 25 is a fixing rod; 26 is a fixing nut; 27 is a moving plate; 271 is a vertical rod; 272 is a sealing gasket; 3 is a measuring cylinder; 4 is a water supply tank; 5 is a support frame; 51 is an adjusting bolt; 6 is a rubber hose; 61 is a tee; 62 is an iron clamp. Specific Embodiment

[0041] The present invention will be further described in detail below with reference to the accompanying drawings.

[0042] Example 1: A permeation gradient testing machine for fine-grained soil, as Figure 1 shown, includes a workbench 1, a permeation container 2, a measuring cylinder 3 and a water supply tank 4 arranged on the workbench 1; the water supply tank 4 stores clear water for use in the permeation experiment, the measuring cylinder 3 is used to display the change in water level for facilitating the observation of the water level change, and the permeation container 2 is used to load specimens for the permeation experiment.

[0043] As Figure 1 shown, a vertical plate 11 is fixedly connected to one side side wall of the workbench 1, the measuring cylinder 3 and the water supply tank 4 are installed on the vertical plate 11, and a leveling device 12 is further provided on the lower surface of the workbench 1; the leveling device 12 can keep the workbench 1 in a horizontal state on an uneven ground, so as to accurately read the water level in the measuring cylinder 3 and avoid inaccurate reading of the measuring cylinder 3 caused by the uneven ground.

[0044] As Figure 1 shown, the leveling device 12 includes a support plate 13 and an adjusting rod 14 rotatably connected to the upper surface of the support plate 13. The adjusting rod 14 can rotate along its own axis and is vertically arranged. The upper end of the adjusting rod 14 is threadedly connected to the lower surface of the workbench 1. Therefore, rotating the adjusting rod 14 can adjust the distance between the support plate 13 and the workbench 1, and thus the purpose of leveling the workbench 1 can be achieved.

[0045] As Figure 2 and Figure 3As shown in the figure, the permeation container 2 includes a circular barrel 21, a cover plate 22 provided at the upper end of the barrel 21, and a circular fixing ring 23 fixedly connected to the lower end of the barrel 21; a circular ring plate 221 is fixedly connected to the lower surface of the cover plate 22. The inner circle of the ring plate 221 is an inclined surface 222. One end of the inclined surface 222 away from the cover plate 22 extends towards the outer circle of the ring plate 221. The outer circle diameter of the ring plate 221 is the same as the diameter of the cover plate 22. During the experiment, the sample of fine-grained soil needs to be loaded into the barrel 21, and at the same time, the sample needs to be tamped to better simulate the actual situation and achieve the purpose of improving the accuracy of the experimental results. When the cover plate 22 is closed, the inclined surface 222 of the ring plate 221 can cause the fine-grained soil to gather towards the middle, preventing the fine-grained soil from flowing out through the gap between the cover plate 22 and the barrel 21 when the cover plate 22 is not tightly fastened to the barrel 21, ensuring that the quantity of the fine-grained soil does not decrease. Moreover, the closing of the cover plate 22 reduces the space inside the barrel 21, enabling better tamping of the fine-grained soil and improving the accuracy of the experimental results.

[0046] As Figure 3 shown in the figure, a portal-shaped support frame 5 is also provided at the upper end of the barrel 21. An adjusting bolt 51 that is in threaded cooperation with it is inserted into the cross beam of the support frame 5. The lower end of the adjusting bolt 51 is rotatably connected to the cover plate 22, enabling the adjusting bolt 51 to rotate along its own axis. Rotating the adjusting bolt 51 can tightly fasten the cover plate 22 to the upper end of the barrel 21, preventing the overflow of water and further compacting the fine-grained soil sample.

[0047] As Figure 3 shown in the figure, two symmetrically arranged horizontal axes 211 are fixedly connected to the outer wall of the barrel 21. The columns of the support frame 5 are sleeved on the horizontal axes 211, enabling the support frame 5 to rotate along the axis of the horizontal axes 211. During the process of loading the fine-grained soil sample, the support frame 5 can be rotated, causing the cover plate 22 to be located on one side of the barrel 21, completely exposing the upper end of the barrel 21, facilitating the loading of the fine-grained soil sample and improving the work efficiency.

[0048] As Figure 3 shown in the figure, a limiting block 212 is also fixedly connected to the surface of the barrel 21 on one side of the horizontal axis 211. When the support frame 5 is in the vertical state, the side wall of the column of the support frame 5 is in contact with the limiting block 212. Therefore, the limiting block 212 can limit the rotation of the support frame 5, enabling the support frame 5 to quickly rotate to the vertical state and improving the work efficiency.

[0049] As Figure 3As shown, the diameter of the fixed ring 23 is larger than that of the barrel 21. A plurality of support columns 24 fixed to the workbench 1 are provided on the lower surface of the fixed ring 23. The plurality of support columns 24 are evenly distributed around the axis of the barrel 21, and the upper ends of the support columns 24 are in contact with the lower surface of the fixed ring 23; the upper ends of the support columns 24 are fixedly connected with fixing rods 25. The upper ends of the fixing rods 25 pass through the fixed ring 23 and protrude from the upper surface of the fixed ring 23. The upper ends of the fixing rods 25 are threadedly connected with fixing nuts 26, and the fixing nuts 26 can be in contact with the upper surface of the fixed ring 23; thus, the permeation container 2 can be stably installed on the workbench 1, and the barrel 21 will not move during the process of loading the specimen.

[0050] As Figure 3 shown, a moving disk 27 is provided inside the barrel 21. A vertical rod 271 that can rotate along its own axis is rotatably connected to the lower surface of the moving disk 27. The lower end of the vertical rod 271 protrudes from the bottom surface of the barrel 21 and is in threaded cooperation with the barrel 21. A sealing gasket 272 is also fixedly connected to the lower surface of the moving disk 27, and the sealing gasket 272 is in contact with the inner bottom surface of the barrel 21; after the fine-grained soil specimen is loaded into the barrel 21, it will be tamped, and the barrel 21 is fixedly installed on the workbench 1. Therefore, after the experiment is completed, it is not convenient to pour out the fine-grained soil specimen. Thus, the moving disk 27 is provided. After the experiment is completed, by rotating the vertical rod 271, the moving disk 27 can be moved upward, so that the moving disk 27 can push the fine-grained soil specimen out of the barrel 21, which is convenient for pouring out the fine-grained soil specimen and improves the work efficiency; the sealing gasket 272 can prevent clear water from entering between the moving disk 27 and the bottom surface of the barrel 21 during the experiment, thereby avoiding the clear water from flowing out through the gap between the vertical rod 271 and the barrel 21; avoiding affecting the accuracy of the experimental results.

[0051] As Figure 3 shown, rubber hoses 6 are fixedly connected to the barrel 21, the measuring cylinder 3, and the water supply tank 4. A tee 61 is provided at one end of the three rubber hoses 6 away from the barrel 21, the barrel 21, and the water supply tank 4. The tee 61 can connect the three rubber hoses 6 together; and a clamp 62 that can control the connection or closure of the rubber hose 6 is also provided on each rubber hose 6; during the experiment, the clear water inside the water supply tank 4 enters the measuring cylinder 3 and the barrel 21 to saturate the specimen in the barrel 21. After the saturation of the specimen is completed, the rubber hose 6 connecting the barrel 21 is clamped with the clamp 62. The water supply tank 4 continues to supply water to the measuring cylinder 3 until the measuring cylinder 3 is filled with clear water, and then the rubber hose 6 connecting the water supply tank 4 is clamped with the clamp 62; the clamp 62 on the rubber hose 6 connecting the barrel 21 is removed, so that the clear water inside the measuring cylinder 3 enters the barrel 21 through the rubber hose 6 for the permeation experiment. The experimental results can be displayed by the dropping water level in the measuring cylinder 3, which is more intuitive and convenient for reading, and improves the accuracy of reading.

[0052] As Figure 3As shown in the figure, a drain pipe 213 is fixedly connected to the side wall of the barrel 21. The drain pipe 213 is arranged near the lower end of the barrel 21. An overflow pipe 223 is connected to the cover plate 22. During the experiment, the water flow will first flow out from the drain pipe 213 and finally flow out from the overflow pipe 223. When the water flow flows out from the overflow pipe 223, it means that the experiment is completed, so that accurate experimental results can be obtained more conveniently and quickly.

[0053] As Figure 3 shown, water-permeable films 214 are fixedly connected to the joints of the drain pipe 213, the overflow pipe 223 with the barrel 21 and the cover plate 22. The water-permeable films 214 can prevent the fine-grained soil sample from entering the drain pipe 213 and the overflow pipe 223, avoid clogging the drain pipe 213 and the overflow pipe 223, and will not hinder the outflow of water.

[0054] Example 2: A method for conducting a seepage gradient experiment on fine-grained soil, comprising the following steps:

[0055] Filling the sample: Load the fine-grained soil sample for the experiment into the barrel 21. During the process of filling the sample, compact it once every 3 cm of filling thickness. After compaction, fill in a new sample and then compact it again. Repeating this work can make the fine-grained soil inside the barrel 21 more compact and more in line with the actual situation, improving the accuracy of the experimental results; after the sample is loaded, tighten the cover plate 22 to further compact the fine-grained soil sample, which can further improve the accuracy of the experimental results;

[0056] Saturating the sample: The clear water in the water supply tank first enters the barrel 21 through the rubber hose 6 to saturate the sample, simulating the actual seepage environment, so that the experiment can be more in line with the actual environment and improve the accuracy of the experimental results;

[0057] Storing water in the measuring cylinder 3: The clear water in the water supply tank enters the measuring cylinder 3 through the rubber hose 6 to reach the maximum measurement value of the measuring cylinder 3;

[0058] Starting the experiment: Lock the rubber hose 6 connecting the water supply tank and the barrel 21 with an iron clamp 62, so that the clear water in the measuring cylinder 3 enters the measuring cylinder 3 for the seepage test, and read and record the water level drop in the measuring cylinder 3;

[0059] During the experiment, the relationship curve between the seepage gradient and the seepage velocity should be plotted. Calculate the actual dry density and porosity of the sample according to the formula; calculate the seepage gradient and seepage velocity according to the formula; calculate the permeability coefficient of the fine-grained soil according to the formula.

[0060] This specific embodiment is only an interpretation of the present invention and not a limitation thereof. After reading this specification, those skilled in the art can make modifications to this embodiment without creative contributions as needed, but as long as it is within the scope of the claims of the present invention, it is protected by the patent law. This specific embodiment is only an interpretation of the present invention and not a limitation thereof. After reading this specification, those skilled in the art can make modifications to this embodiment without creative contributions as needed, but as long as it is within the scope of the claims of the present invention, it is protected by the patent law.

Claims

1. A penetration slope tester for fine-grained soil, characterized in that: The invention comprises a water supply box (4), a permeation container (2) and a measuring cylinder (3), wherein the water supply box (4), the permeation container (2) and the measuring cylinder (3) are connected together via a rubber hose (6); the permeation container (2) comprises a cylindrical barrel (21), a fixing ring (23) fixedly connected to the lower end of the barrel (21), and a cover plate (22) arranged at the upper end of the barrel (21); a door-shaped support frame (5) is also arranged at the upper end of the barrel (21), and two upright posts of the support frame (5) are connected to the side wall of the barrel (21) to support the barrel (21). The crossbeam of the frame (5) is plugged with bolts that are threadedly matched with the crossbeam; the cover plate (22) and the lower end of the bolt are rotatably connected so that the cover plate (22) can rotate along its own axis, and a ring plate (221) is fixedly connected to the lower surface of the cover plate (22); the outer diameter of the ring plate (221) is the same as the diameter of the cover plate (22), and the inner surface of the ring plate (221) is an inclined surface (222), and the inclined surface (222) extends from one end of the cover plate (22) to the direction close to the outer circle of the ring plate (221); Two symmetrically arranged transverse axes (211) are fixedly connected to the circumferential surface of the barrel (21), and the two side columns of the support frame (5) are rotatably connected to the transverse axes (211), so that the support frame (5) can rotate along the axis of the transverse axes (211); The inner bottom surface of the barrel (21) is provided with a movable disk (27), and the circumferential surface of the movable disk (27) is in contact with the inner wall of the barrel (21); the lower surface of the movable disk (27) is rotatably connected to a vertical rod (271), the vertical rod (271) can rotate along its own axis, and the lower end of the vertical rod (271) protrudes from the lower surface of the barrel (21), and the vertical rod (271) and the barrel (21) are threadedly matched; The lower surface of the fixing ring (23) is provided with a plurality of support columns (24), the support columns (24) are evenly distributed around the axis of the barrel (21), and the length of the support columns (24) is greater than the length of the vertical rod (271); the upper ends of the support columns (24) fit the lower surface of the fixing ring (23), and the upper ends of the support columns (24) are also fixedly connected to fixing rods (25), and the diameter of the fixing rods (25) is smaller than the diameter of the support columns (24); the upper ends of the fixing rods (25) pass through the through holes and protrude from the upper surface of the fixing ring (23), and the upper ends of the fixing rods (25) are threadedly connected to fixing nuts (26), and the fixing nuts (26) can fit the surface of the fixing ring (23).

2. A penetration slope tester for fine-grained soil according to claim 1, characterized in that: Two symmetrically arranged limit blocks (212) are fixedly connected to the side wall of the circumferential surface of the barrel (21), the limit blocks (212) are located on one side of the transverse axis (211), and the limit blocks (212) can fit with the side wall of the column of the support frame (5).

3. A penetration slope tester for fine-grained soil according to claim 1, characterized in that: A workbench (1) is provided below the barrel (21), a vertical plate (11) is fixedly connected to one side of the workbench (1), a leveling device (12) is provided on the lower surface of the workbench (1), the barrel (21) is mounted on the workbench (1), and the measuring cylinder (3) and the water supply tank (4) are mounted on the vertical plate (11).

4. A penetration slope tester for fine-grained soil according to claim 1, characterized in that: A sealing rubber pad (272) is fixedly connected to the lower surface of the movable plate (27).

5. A permeability gradient test method based on the permeability gradient test machine according to claim 1, characterized in that: The following steps are involved: Filling the sample: The sample for the experiment is placed in the barrel (21), and during the filling process, the sample is compacted once every 3 cm of thickness; Saturated sample: The clean water in the water supply tank (4) first enters the barrel (21) through the rubber hose (6) to saturate the sample; the measuring cylinder (3) stores water: Clean water in the water supply tank (4) enters the measuring cylinder (3) through the rubber hose (6) and reaches the maximum measurement value of the measuring cylinder (3); The experiment begins: the rubber hose (6) connecting the water supply box (4) and the barrel (21) is locked by the iron clamp (62), so that the clean water in the measuring cylinder (3) enters the measuring cylinder (3) to perform a permeation test, and the falling water level of the clean water in the measuring cylinder (3) is recorded.

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