High-water-content flow-state muddy water head penetration test device and use method thereof

Abstract

The invention discloses a high-water-content flow-state muddy water head penetration test device, and belongs to the technical field of penetration tests, the high-water-content flow-state muddy water head penetration test device comprises a base, a penetration container, a variable water head pipe and a water tank are respectively fixed on the base through supports, and a first water inlet pipe is connected between the water tank and the penetration container; a second water inlet pipe is connected between the variable water head pipe and the first water inlet pipe, a micro booster pump and a first electromagnetic valve are mounted on the first water inlet pipe, a second electromagnetic valve is mounted on the second water inlet pipe, a bottom layer water permeable structure is arranged at the bottom of the permeation container, and a pressurization fixing mechanism is placed on the base. The permeation container is provided with a layered exhaust mechanism; a reverse seepage water supply mode is adopted, a lifting effect on high-flowability mud particles can be formed, meanwhile, a variable head measurement system is matched, it can be ensured that the structure of a soil sample is complete in the whole test period, and a foundation is laid for accurate measurement of the permeability coefficient.

Description

Technical Field

[0001] This invention relates to the field of permeability testing technology, specifically to a high water content fluid slurry head permeability testing device and its usage method. Background Technology

[0002] In fields such as geotechnical engineering investigation and soft soil foundation treatment, the permeability coefficient of high water content fluid mud (such as soft soil, silt, and fluid clay) is a core parameter for assessing soil permeability, predicting the distribution of groundwater seepage fields, and formulating engineering seepage prevention schemes.

[0003] The sample loading stage is a fundamental prerequisite for permeability testing of high-moisture-content fluidized mud, directly determining the authenticity and homogeneity of the initial state of the soil sample, and thus decisively affecting the accuracy of the permeability coefficient measurement results. According to the test specifications and technical requirements, the loading of high-moisture-content fluidized mud samples must strictly follow the operating principle of "layered light laying and natural leveling": that is, the fluidized mud should be laid in multiple layers (each layer thickness is usually controlled at 2-3 cm) in the test tube. After each layer is laid, it should be gently leveled with a leveling tool. Compaction, patting, or other disturbance operations are prohibited throughout the process to ensure that the soil sample maintains its natural pore structure and moisture content state, avoiding distortion of the permeability path due to structural damage, which would lead to inaccurate permeability coefficient measurements.

[0004] However, existing high-moisture-content fluid sludge head permeability test devices and their associated sample loading methods all rely on manual operation. They lack a dedicated sample loading mechanism designed for the unique physical characteristics of fluid sludge, resulting in extremely poor sample loading accuracy. This has become a key technical bottleneck restricting the improvement of test precision. Specific defects are as follows:

[0005] 1. Insufficient precision in controlling layer thickness: During manual sample preparation, operators rely on experience to judge the thickness of each layer of fluid mud. Due to the high fluidity of fluid mud, local accumulation, flow, and diffusion are prone to occur during pouring, making it difficult to ensure uniform thickness of each layer. This uneven thickness leads to uneven distribution of pores within the soil sample, resulting in localized flow deviation during seepage, making the measured permeability coefficient unable to reflect the true permeability characteristics of the soil.

[0006] 2. Scraping operations can easily cause soil sample disturbance: During manual scraping, it is difficult to precisely control the contact force between the scraper and the soil sample surface. If the force is too great, it will compress the surface fluid mud, destroy its natural pore structure, and even cause the soil particles to rearrange and compact. If the force is too small, it will not be able to achieve effective leveling, and the soil sample surface will be uneven. During subsequent pressure fixing and seepage processes, stress concentration is likely to occur, causing local collapse or seepage damage to the soil sample.

[0007] 3. Interlayer interface defects are prone to occur during the sample loading process: When manually loading samples in layers, the spacing and overlap of adjacent layers of fluid mud are entirely controlled by experience, which easily leads to loose interlayer bonding and the formation of hidden interface gaps. During the test, water tends to preferentially seep along these interface gaps (i.e., "short-circuit seepage"), resulting in an overestimation of the measured seepage flow rate and a calculated permeability coefficient that is much larger than the true value of the soil, seriously affecting the reliability of the test data.

[0008] 4. Poor consistency of manual operation and poor test repeatability: Different operators have different sample loading techniques, force control, and thickness judgment standards. Even for the same batch of high water content fluid mud with the same characteristics, the sample loading test completed by different personnel will show significant data dispersion. The operation stability of the same operator in different test batches is also difficult to guarantee, resulting in poor repeatability of test results and failing to meet the data consistency requirements of parallel tests. Summary of the Invention

[0009] The purpose of this invention is to provide a high water content fluid slurry head permeability test device and its usage method, solving the following technical problems: In existing high water content fluid slurry head permeability tests, the manual sample loading method has many problems such as low layering accuracy, easy disturbance of soil samples, interlayer interface defects, poor operational consistency, and soil sample loss and pollution, which makes it difficult to guarantee the accuracy of sample loading, resulting in distorted permeability coefficient measurement results and poor test repeatability, which cannot meet the engineering needs for accurate evaluation of the permeability characteristics of high water content fluid slurry.

[0010] The objective of this invention can be achieved through the following technical solutions: A high water content fluid slurry head permeability test device includes a base, on which a permeation container, a variable head pipe and a water tank are fixed by a bracket. A first inlet pipe is connected between the water tank and the permeation container, and a second inlet pipe is connected between the variable head pipe and the first inlet pipe. A micro booster pump and a first solenoid valve are installed on the first inlet pipe, and a second solenoid valve is installed on the second inlet pipe. The bottom of the permeation container is provided with a bottom permeable structure. A pressure fixing mechanism is placed on the base, and the permeation container is provided with a layered venting mechanism. It also includes two lifting rods, the top ends of which are connected to an external drive source, and a cylinder is fixed to the bottom of the two lifting rods. A rotating shaft is movably installed at the bottom of the cylinder, and a sample loading cylinder is fixed on the rotating shaft. The top of the sample loading cylinder is funnel-shaped. An adjustment mechanism is provided between the rotating shaft and the cylinder to automatically adjust the height of the rotating shaft. A scraper is provided at the bottom of the rotating shaft.

[0011] As a further aspect of the present invention: the permeation container is a cylindrical structure made of transparent plexiglass, with graduations marked on the side wall and a polytetrafluoroethylene coating on the inner wall.

[0012] As a further embodiment of the present invention: the pressure fixing mechanism consists of a pressure tray, a water-permeable plate and a flexible silicone pad, the pressure tray, the water-permeable plate and the flexible silicone pad are connected in sequence from top to bottom, and the flexible silicone pad is provided with multiple water-permeable holes. The pressure tray is equipped with a handle and is used to place weights.

[0013] As a further aspect of the present invention: the permeable plate has the same structure as the bottom permeable structure, consisting of a coarse filter screen, permeable stones and a fine filter screen, which are distributed from top to bottom and are fixed by a stainless steel ring.

[0014] As a further aspect of the present invention: the layered exhaust mechanism includes a lower exhaust pipe, a middle exhaust pipe and an upper exhaust pipe connected to the side wall of the permeation container, and exhaust valves are installed on the lower exhaust pipe, the middle exhaust pipe and the upper exhaust pipe.

[0015] As a further aspect of the present invention: the adjusting mechanism includes a piston plate located inside the cylinder, a motor mounted on the upper surface of the piston plate, the output shaft of the motor connected to a rotating shaft, a spring connected between the piston plate and the top wall of the cylinder, support plates symmetrically mounted on the rotating shaft, sleeve rods fixed on the support plates, movable rods movably disposed inside the sleeve rods, a rotating ring fixed at the top of the two movable rods, a first through hole opened on the rotating ring, a second through hole with the same height as the first through hole opened on the cylinder, and limit blocks symmetrically fixed on the top wall of the cylinder.

[0016] As a further aspect of the present invention: an air inlet pipe is connected to the top of the cylinder, an air inlet valve is installed on the air inlet pipe, and a protruding box is provided on the top wall of the cylinder.

[0017] As a further embodiment of the present invention: a rotating sleeve is rotatably mounted on the bottom of the rotating shaft, the scraper is fixed on the outer wall of the rotating sleeve, a first locking block is fixed on the bottom of the rotating shaft, a second locking block is fixed on the inner wall of the rotating sleeve, a compression spring is connected between the first locking block and the second locking block, a flexible silicone strip is provided on the bottom of the scraper, and a baffle is fixed on the scraper by a fixing rod.

[0018] A method for using a high-water-content fluid slurry head permeability test apparatus includes the following steps: S1. Fill the sample loading tube with the high water content fluid mud to be tested. With the help of the adjustment mechanism, spread the high water content fluid mud in layers in the permeation container. At the same time, scraper scrapes it flat. Then, place the pressure fixing mechanism in the permeation container to apply constant pressure to the high water content fluid mud. S2. Turn on the micro booster pump and the first solenoid valve, and in conjunction with the layered venting mechanism, perform graded saturation and venting of the soil sample to achieve full saturation of the soil sample. S3. Turn off the micro booster pump and the first solenoid valve, inject pure water into the variable head pipe to raise the water to the preset height, record the initial head height and the initial time, and open the second solenoid valve. The weak infiltration of the soil sample will cause the water level in the variable head pipe to drop slowly. S4. Stop the test after the infiltration reaches the predetermined time, record the termination time and termination head height, calculate the test results according to the formula, repeat three sets of parallel tests, and take the average value as the test result.

[0019] The beneficial effects of this invention are: (1) The present invention adopts the “reverse seepage” water supply mode, infiltrating from bottom to top. The seepage force is opposite to the direction of the soil sample’s own weight, which can form a “lifting” effect on highly fluid mud particles. At the same time, it is combined with a variable head measurement system, which is adapted to the characteristics of extremely low permeability of fluid mud. It can achieve seepage effect monitoring without long-term high head impact, further reducing the risk of seepage damage. It can ensure the structural integrity of the soil sample throughout the test cycle, laying the foundation for accurate measurement of permeability coefficient. (2) This invention enables automatic layered sample preparation, precisely controlling the thickness of each layer of fluid mud, thus avoiding problems such as uneven layer thickness and local accumulation caused by manual sample preparation relying on experience. Simultaneously, the automatic laying process employs a uniform and gentle material distribution method, coupled with scraper control, to achieve a smooth soil sample while avoiding compression and disturbance, ensuring that the natural pore structure and water content of the soil sample are not damaged. Furthermore, it ensures tight overlap between adjacent soil layers, eliminating interlayer interface gaps that are easily generated by manual sample preparation, and avoiding the problem of distorted test data caused by "short-circuit seepage." (3) The automatic layered sample loading of the present invention can realize the standardization and automation of the sample loading process, without the need for manual intervention in layering and leveling operations, ensuring that different test batches and different operators can obtain the same sample loading effect; combined with the standardized test process of the "variable head + reverse seepage" system, it can significantly improve the repeatability of test results, reduce the deviation of parallel test data, and meet the stringent requirements of engineering test for data reliability. Attached Figure Description

[0020] The invention will now be further described with reference to the accompanying drawings.

[0021] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the pressure fixing mechanism of the present invention; Figure 3 This is a schematic diagram of the internal structure of the permeation container of the present invention; Figure 4 This is a schematic diagram of the structure of the cylinder and the rotating shaft of the present invention; Figure 5 yes Figure 4 Enlarged view of point A in the middle; Figure 6 This is a schematic diagram of the internal structure of the cylinder of the present invention; Figure 7 This is a schematic diagram of the structure of the rotating shaft and rotating sleeve of the present invention.

[0022] In the diagram: 1. Base; 2. Permeation container; 201. Lower exhaust pipe; 202. Middle exhaust pipe; 203. Upper exhaust pipe; 3. Variable head pipe; 4. Water tank; 5. First inlet pipe; 6. Second inlet pipe; 7. First solenoid valve; 8. Second solenoid valve; 9. Pressurization fixing mechanism; 901. Pressurization tray; 902. Permeable plate; 903. Flexible silicone pad; 904. Handle; 10. Bottom permeable structure; 11. Lifting rod; 2. Cylinder body; 13. Piston plate; 14. Spring; 15. Motor; 16. Rotating shaft; 17. Sample loading cylinder; 18. Support plate; 19. Sleeve rod; 20. Movable rod; 21. Rotating ring; 22. First through hole; 23. Limiting block; 24. Second through hole; 25. Air inlet pipe; 26. Protruding box; 27. Rotating sleeve; 28. Scraper; 29. ​​Fixed rod; 30. Baffle; 31. First locking block; 32. Second locking block; 33. Compression spring.

[0023] The accompanying drawings are for illustrative purposes only and should not be construed as limiting the invention. To better illustrate this embodiment, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual size and shape of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] Please see Figures 1 to 7As shown, this invention is a high-water-content fluid slurry head permeability test device, comprising a base 1, on which a permeation container 2, a variable head pipe 3, and a water tank 4 are respectively fixed by a bracket. The permeation container 2 is a cylindrical structure made of transparent plexiglass, with graduations marked on the side wall and a polytetrafluoroethylene coating on the inner wall. A first inlet pipe 5 connects the water tank 4 to the permeation container 2, and a second inlet pipe 6 connects the variable head pipe 3 to the first inlet pipe 5. A micro booster pump and a first solenoid valve 7 are installed on the first inlet pipe 5, and a second solenoid valve 8 is installed on the second inlet pipe 6. A bottom permeable structure 10 is provided at the bottom of the permeation container 2, and a pressure fixing mechanism is placed on the base 1. 9. The pressure fixing mechanism 9 consists of a pressure tray 901, a permeable plate 902, and a flexible silicone pad 903. The pressure tray 901, permeable plate 902, and flexible silicone pad 903 are connected sequentially from top to bottom, and the flexible silicone pad 903 has multiple permeable holes. A handle 904 is installed on the pressure tray 901, which is used to place weights. The permeable plate 902 has the same structure as the bottom permeable structure 10, consisting of a coarse filter screen, permeable stones, and a fine filter screen. The coarse filter screen, permeable stones, and fine filter screen are distributed from top to bottom, and the three are fixed by a stainless steel ring. The permeation container 2 is equipped with a layered exhaust mechanism. It also includes two lifting rods 11, the tops of which are connected to the outer... The system is connected to a drive source. A cylinder 12 is fixed to the bottom of two lifting rods 11. A rotating shaft 16 is movably mounted on the bottom of the cylinder 12, and a sample loading cylinder 17 is fixed to the rotating shaft 16. The top of the sample loading cylinder 17 is funnel-shaped. An adjustment mechanism is provided between the rotating shaft 16 and the cylinder 12 to automatically adjust the height of the rotating shaft 16. A scraper 28 is provided at the bottom of the rotating shaft 16. An appropriate amount of high-water-content fluidized mud is filled into the sample loading cylinder 17. The cylinder 12 is fixed at a suitable height by the lifting rods 11, and the sample loading cylinder 17 is located inside the permeation container 2. Then, using the adjustment mechanism, the high-water-content fluidized mud is layered and spread inside the permeation container 2, while the scraper 28 flattens it. Finally, a pressure fixing mechanism 9 is applied. Place the sample in the infiltration container 2, add weights according to the soil sample stability requirements, apply constant pressure to the high water content fluid mud, turn on the micro booster pump and the first solenoid valve 7, and with the stratified venting mechanism, perform graded saturation and venting of the soil sample to achieve full saturation. Then turn off the micro booster pump and the first solenoid valve 7, inject pure water into the variable head pipe 3 to raise the water to the preset height, and record the initial head height and initial time. Turn on the second solenoid valve 8, and the weak infiltration of the soil sample will cause the water level in the variable head pipe 3 to drop slowly. Stop the test after the infiltration reaches the predetermined time, record the termination time and termination head height, calculate the test results according to the formula, repeat three sets of parallel tests, and take the average value as the test result.

[0026] See Figure 1 and Figure 3The stratified venting mechanism includes a lower vent pipe 201, a middle vent pipe 202, and an upper vent pipe 203 connected to the side wall of the infiltration container 2. Each of the lower vent pipe 201, middle vent pipe 202, and upper vent pipe 203 is equipped with a venting valve. During the venting stage, the venting valves on the middle vent pipe 202 and upper vent pipe 203 are closed, and the venting valve of the lower vent pipe 201 and the micro booster pump are opened to introduce pure water into the infiltration container 2 at a low head. When water continuously flows out of the lower vent pipe 201 without any air bubbles, the venting valve is closed, and the venting valve of the middle vent pipe 202 is opened to gradually increase the head to 5 cm and maintain it for 2-4 hours to expel the air in the middle of the soil sample. Finally, the venting valve of the upper vent pipe 203 is opened to increase the head until no air bubbles overflow from any of the venting ports, thus completing the full saturation of the soil sample.

[0027] See Figure 1 , Figures 4 to 6 The adjusting mechanism includes a piston plate 13 located inside the cylinder 12. A motor 15 is mounted on the upper surface of the piston plate 13, and the output shaft of the motor 15 is connected to a rotating shaft 16. A spring 14 connects the piston plate 13 and the top wall of the cylinder 12. Support plates 18 are symmetrically mounted on the rotating shaft 16, and sleeve rods 19 are fixed on the support plates 18. Movable rods 20 are movably arranged inside the sleeve rods 19. A rotating ring 21 is fixed to the top of the two movable rods 20. A first through hole 22 is opened on the rotating ring 21, and a second through hole 24 with the same height as the first through hole 22 is opened on the cylinder 12. Limit blocks 23 are symmetrically fixed on the top wall of the cylinder 12. An air inlet pipe 25 is connected to the top of the cylinder 12, and an air inlet valve is installed on the air inlet pipe 25. A protruding box 26 is provided on the top wall of the cylinder 12. After the soil sample is loaded, the piston plate 13 is located at the bottom of the cylinder 12, the spring 14 is stretched, and air is injected into the cylinder 12 through the air inlet pipe 25. The piston plate 13 is placed under high pressure. Initially, there is a slight misalignment between the first through hole 22 and the second through hole 24, preventing the gas in the cylinder 12 from escaping. The motor 15 is started to drive the rotating shaft 16 to rotate, causing the soil in the sample loading cylinder 17 to fall into the infiltration container 2. When the motor 15 drives the rotating shaft 16 to rotate nearly one revolution, the first through hole 22 and the second through hole 24 are aligned. At this time, the air in the cylinder 12 is discharged through the first through hole 22 and the second through hole 24. The motor 15 is turned off, and the mass of the soil sample in the sample loading cylinder 17 is reduced. Under the action of the spring 14, the piston plate 13 rises. The time is calculated based on the amount of air discharged. When the piston plate 13 rises 3cm, the motor 15 is started again to perform the second sample loading operation. Subsequently, the above operation is repeated every time the rotating shaft 16 rotates normally one revolution, so as to achieve automatic layered sample loading. The scraper 28 levels the soil sample to ensure that the natural pore structure and water content of the soil sample are not damaged.

[0028] See Figure 1 , Figure 4 and Figure 7A rotating sleeve 27 is rotatably mounted on the bottom of the rotating shaft 16. A scraper 28 is fixed to the outer wall of the rotating sleeve 27. A first locking block 31 is fixed to the bottom of the rotating shaft 16, and a second locking block 32 is fixed to the inner wall of the rotating sleeve 27. A compression spring 33 connects the first locking block 31 and the second locking block 32. A flexible silicone strip is provided at the bottom of the scraper 28, and a baffle 30 is fixed to the scraper 28 by a fixing rod 29. In order to ensure the accurate falling of the soil sample, the baffle 30 initially seals the bottom of the sample container 17, preventing the soil sample from falling. As the sample is discharged, one end of the scraper 28 contacts the infiltration container 2 and its inner wall. When the rotating shaft 16 rotates, the friction between the end of the scraper 28 and the inner wall of the infiltration container 2 causes the baffle 30 to detach from the bottom of the sample loading cylinder 17, the compression spring 33 is compressed, the sample loading cylinder 17 discharges material, and the scraper 28 scrapes it flat. When the rotating shaft 16 rotates one revolution, it stops rotating, the compression spring 33 gradually returns to its original position, and the baffle 30 also automatically returns to its original position. In this way, the soil sample will not fall during the process of the rotating shaft 16 rising, and the thickness of each layer of fluid mud can be precisely controlled.

[0029] A method for using a high-water-content fluid slurry head permeability test apparatus includes the following steps: S1. Fill the sample loading tube 17 with the high water content fluid mud to be tested. With the help of the adjustment mechanism, spread the high water content fluid mud in layers in the permeation container 2. At the same time, scraper 28 scrapes it flat. Then, place the pressure fixing mechanism 9 in the permeation container 2 to apply constant pressure to the high water content fluid mud. S2. Turn on the micro booster pump and the first solenoid valve 7, and in conjunction with the layered venting mechanism, perform graded saturation and venting of the soil sample to achieve full saturation of the soil sample. S3. Turn off the micro booster pump and the first solenoid valve 7, inject pure water into the variable head pipe 3 to raise the water to the preset height, record the initial head height and the initial time, open the second solenoid valve 8, and the weak infiltration of the soil sample will cause the water level in the variable head pipe 3 to drop slowly. S4. Stop the test after the infiltration reaches the predetermined time, record the termination time and termination head height, calculate the test results according to the formula, repeat three sets of parallel tests, and take the average value as the test result.

[0030] The working principle of this invention is as follows: First, the initial debugging and preparation of the device are completed to ensure that the components are in normal condition. In the initial state, the baffle 30 seals the bottom of the sample loading cylinder 17, and one end of the scraper 28 contacts the inner wall of the permeation container 2. Then, an appropriate amount of high-water-content fluid mud is loaded into the sample loading cylinder 17. The lifting rod 11 is controlled by an external drive source (not shown) to drive the cylinder 12 to rise and fall, fixing it at a suitable height so that the sample loading cylinder 17 is accurately located inside the permeation container 2. Next, the adjustment mechanism is started to realize automatic layered sample loading. In the initial state, the piston plate 13 is located at the bottom of the cylinder 12, and the spring 14 is in a stretched state. Air is injected into the cylinder 12 through the air inlet pipe 25, so that a high-pressure environment is formed above the piston plate 13. At this time, the first through hole 22 on the rotating ring 21 is misaligned with the second through hole 24 on the cylinder 12, and the gas in the cylinder 12 cannot be discharged. The motor 15 is started to drive the rotating shaft 16 to rotate. During the rotation of the rotating shaft 16, due to the contact between the end of the scraper 28 and the inner wall of the permeation container 2, the sample loading is accelerated. Due to friction, the rotating sleeve 27 rotates relative to the rotating shaft 16, the second locking block 32 compresses the spring 33, and the baffle 30 disengages from the bottom of the sample loading cylinder 17. The high water content fluid mud in the sample loading cylinder 17 continues to fall into the infiltration container 2. At the same time, the scraper 28, which rotates with the rotating shaft 16, scrapes the falling soil sample synchronously. When the motor 15 drives the rotating shaft 16 to rotate nearly one revolution, the first through hole 22 and the second through hole 24 are precisely aligned. The high pressure gas in the cylinder 12 is discharged through the first through hole 22 and the second through hole 24. The motor 15 is then turned off, and the mass of the soil sample in the sample loading cylinder 17 is reduced. Under the restoring force of the spring 14, the piston plate 13 drives the rotating shaft 16 and the sample loading cylinder 17 to rise synchronously. The interval time is calculated according to the preset air output. When the piston plate 13 rises by 3cm, the motor 15 is started again, and the above feeding and scraping process is repeated to complete the automatic laying of multiple layers of soil samples in sequence, ensuring that the thickness of each layer of soil sample is uniform and that the natural pore structure and water content are not damaged. After the soil sample is loaded, the pressure fixing mechanism 9 is placed inside the permeation container 2, so that the flexible silicone pad 903 fits against the top surface of the soil sample. The permeable holes on the flexible silicone pad 903 can ensure smooth subsequent seepage. According to the soil sample stability requirements, an appropriate amount of weight is placed on the pressure tray 901 to ensure that a constant pressure is applied to the high water content fluid mud, balancing the supporting force of subsequent reverse seepage to prevent the soil sample from floating. Then, the staged saturation and venting process is started. The venting valves on the middle venting pipe 202 and the upper venting pipe 203 are closed, and the venting valve of the lower venting pipe 201 and the first solenoid valve 7 are opened. The micro booster pump is started to introduce pure water into the permeation container 2 at a low head. The water flows through the first inlet pipe 5 into the bottom of the permeation container 2, and through the bottom layer permeation... Water structure 10 (coarse filter screen, permeable stone, and fine filter screen fixed by stainless steel rings from top to bottom to prevent soil particles from entering the pipeline) permeates upwards. Air in the pores of the soil sample gathers downwards with the water flow and is eventually discharged from the lower exhaust pipe 201. When water continuously flows from the lower exhaust pipe 201 and no air bubbles overflow, its exhaust valve is closed, and the exhaust valve of the middle exhaust pipe 202 is opened. The micro booster pump is controlled to gradually increase the water head and maintain this water head state for 2-4 hours to allow the residual air in the middle of the soil sample to be fully discharged and overflow from the exhaust pipe. Finally, the exhaust valve of the upper exhaust pipe 203 is opened to continue to increase the water head until no air bubbles overflow from the lower, middle, and upper exhaust pipes, indicating that the soil sample is fully saturated. The micro booster pump and the first solenoid valve 7 are then closed. After saturation, the variable head permeability test stage begins. Pure water is injected into the variable head pipe 3 to raise the water level to the preset height. The initial head height and initial time are recorded. The second solenoid valve 8 is opened. Due to the extremely low permeability coefficient of the high-water-content fluid mud, only weak permeation occurs, causing the water level in the variable head pipe 3 to slowly decrease. The test is stopped after the permeation reaches the preset time, and the termination time and termination head height are recorded. The single test result is calculated according to the variable head permeability coefficient calculation formula (k=(2.303×a×L) / (A×Δt)×log(h1 / h2), where a is the cross-sectional area of ​​the variable head pipe 3, L is the average thickness of the soil sample, A is the cross-sectional area of ​​the permeation container, Δt is the test time, h1 is the initial head height, and h2 is the termination head height). To ensure data reliability, the above sample loading, pressurization, saturation, and test process is repeated for three sets of parallel tests. After removing abnormal data, the average value is taken as the final permeability coefficient result.

[0031] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the claims of this invention should still fall within the patent coverage of this invention.

Claims

1. A high-water-content fluidized mud head permeability test device, comprising a base (1), wherein a permeation container (2), a variable head pipe (3), and a water tank (4) are respectively fixed on the base (1) by a bracket, characterized in that, A first inlet pipe (5) is connected between the water tank (4) and the permeation container (2). A second inlet pipe (6) is connected between the variable head pipe (3) and the first inlet pipe (5). A micro booster pump and a first solenoid valve (7) are installed on the first inlet pipe (5). A second solenoid valve (8) is installed on the second inlet pipe (6). A bottom permeable structure (10) is provided at the bottom of the permeation container (2). A pressurizing and fixing mechanism (9) is placed on the base (1). A layered exhaust mechanism is provided for the permeation container (2). It also includes two lifting rods (11), the top of the two lifting rods (11) is connected to an external drive source, and a cylinder (12) is fixed at the bottom of the two lifting rods (11). A rotating shaft (16) is movably arranged at the bottom of the cylinder (12). A sample loading cylinder (17) is fixed on the rotating shaft (16). The top of the sample loading cylinder (17) is funnel-shaped. An adjustment mechanism is provided between the rotating shaft (16) and the cylinder (12) for automatically adjusting the height of the rotating shaft (16). A scraper (28) is provided at the bottom of the rotating shaft (16).

2. The high water content fluid slurry head permeability test device according to claim 1, characterized in that, The permeation container (2) is a cylindrical structure made of transparent plexiglass, with graduations marked on the side wall and a polytetrafluoroethylene coating on the inner wall.

3. The high water content fluid slurry head permeability test device according to claim 1, characterized in that, The pressurizing and fixing mechanism (9) consists of a pressurizing tray (901), a permeable plate (902), and a flexible silicone pad (903). The pressurizing tray (901), the permeable plate (902), and the flexible silicone pad (903) are connected in sequence from top to bottom. The flexible silicone pad (903) has multiple permeable holes. The pressurizing tray (901) is equipped with a handle (904) and is used to place weights.

4. The high water content fluid slurry head permeability test device according to claim 3, characterized in that, The permeable plate (902) has the same structure as the bottom permeable structure (10), consisting of a coarse filter screen, permeable stones and a fine filter screen. The coarse filter screen, permeable stones and fine filter screen are distributed from top to bottom, and the three are fixed by stainless steel rings.

5. The high water content fluid slurry head permeability test device according to claim 1, characterized in that, The layered exhaust mechanism includes a lower exhaust pipe (201), a middle exhaust pipe (202) and an upper exhaust pipe (203) connected to the side wall of the permeation container (2), and exhaust valves are installed on the lower exhaust pipe (201), the middle exhaust pipe (202) and the upper exhaust pipe (203).

6. The high water content fluid slurry head permeability test device according to claim 1, characterized in that, The adjusting mechanism includes a piston plate (13) located inside the cylinder (12). A motor (15) is installed on the upper surface of the piston plate (13). The output shaft of the motor (15) is connected to the rotating shaft (16). A spring (14) is connected between the piston plate (13) and the top wall of the cylinder (12). A support plate (18) is symmetrically installed on the rotating shaft (16). A sleeve rod (19) is fixed on the support plate (18). A movable rod (20) is movably arranged inside the sleeve rod (19). A rotating ring (21) is fixed at the top of the two movable rods (20). A first through hole (22) is opened on the rotating ring (21). A second through hole (24) with the same height as the first through hole (22) is opened on the cylinder (12). Limit blocks (23) are symmetrically fixed on the top wall of the cylinder (12).

7. The high water content fluid slurry head permeability test device according to claim 6, characterized in that, An air inlet pipe (25) is connected to the top of the cylinder (12), an air inlet valve is installed on the air inlet pipe (25), and a protruding box (26) is provided on the top wall of the cylinder (12).

8. The high water content fluid slurry head permeability test device according to claim 6, characterized in that, A rotating sleeve (27) is rotatably mounted on the bottom of the rotating shaft (16). The scraper (28) is fixed on the outer wall of the rotating sleeve (27). A first locking block (31) is fixed on the bottom of the rotating shaft (16). A second locking block (32) is fixed on the inner wall of the rotating sleeve (27). A compression spring (33) is connected between the first locking block (31) and the second locking block (32). A flexible silicone strip is provided on the bottom of the scraper (28). A baffle (30) is fixed on the scraper (28) by a fixing rod (29).

9. The method of using the high water content fluid slurry head permeability test device according to claim 1, characterized in that, Includes the following steps: S1. Fill the sample container (17) with the high water content fluid mud to be tested. With the adjustment mechanism, spread the high water content fluid mud in layers in the permeation container (2). At the same time, scraper (28) scrapes it flat. Then, place the pressure fixing mechanism (9) in the permeation container (2) to apply constant pressure to the high water content fluid mud. S2. Turn on the micro booster pump and the first solenoid valve (7), and in conjunction with the layered venting mechanism, perform graded saturation and venting of the soil sample to complete the full saturation of the soil sample. S3. Close the micro booster pump and the first solenoid valve (7), inject pure water into the variable head pipe (3) to raise the water to the preset height, record the initial head height and the initial time, open the second solenoid valve (8), and the weak infiltration of the soil sample causes the water level in the variable head pipe (3) to drop slowly. S4. Stop the test after the infiltration reaches the predetermined time, record the termination time and termination head height, calculate the test results according to the formula, repeat three sets of parallel tests, and take the average value as the test result.

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