A device and method for determining the soil-water characteristics of a damming soil

Abstract

The application discloses a device and method suitable for measuring soil water characteristics of dam soil quality anti-seepage body, comprising: a sampler for placing a soil sample; a soil sample rapid cutting device, comprising a cutting box body, a cutting driving mechanism and a cutting sleeve, the sampler is placed in the cutting box body, a plurality of cutting sleeves are installed on the driving end of the cutting driving mechanism and above the sampler, the cutting driving mechanism drives the cutting sleeve to insert into the sampler to cut the soil sample; an incubator; a centrifugal method suction measurement device arranged in the incubator, used for centrifuging the cutting sleeve with a drainage mesh hole containing the soil sample to form a pseudo-gravitational field environment; a steam equilibrium method suction measurement device arranged in the incubator, comprising a solution tank and a shielding plate, the solution tank has a plurality of solution cavities, each solution cavity contains a solution with different concentrations and components, the solution cavities are shielded by the shielding plate to expose the specified solution cavities to form an environment with different relative humidity and total suction.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of geotechnical engineering and water conservancy engineering, in particular to a device and method suitable for determining the soil-water characteristics of dam soil seepage prevention body. BACKGROUND

[0002] Dam soil seepage prevention body plays a crucial role in water conservancy engineering, and its permeability coefficient, water-soluble salt content, organic matter content, and expansibility have specific requirements. Seepage prevention materials include natural seepage prevention materials and artificial seepage prevention materials. Natural seepage prevention materials such as clay and bentonite have low permeability coefficient and good expansibility. Artificial seepage prevention materials such as high-density polyethylene film, bentonite composite film, and geotextile have extremely low permeability, good durability, and chemical corrosion resistance. In addition, there are cement-based seepage prevention materials, such as concrete seepage prevention wall and grouting curtain, which form seepage prevention body through cement slurry injection. Asphalt-based seepage prevention materials also have good waterproof performance and aging resistance.

[0003] Before dam construction, soil-water characteristics of different soil seepage prevention materials are measured, and appropriate materials are selected according to the measurement results and actual environment. Traditional methods have three problems, one is that traditional undisturbed soil samples need to be cut into samples one by one, which is low in efficiency; two is that when measuring the water retention characteristics, only step-by-step and point-by-point measurement can be performed, and parallel measurement cannot be performed, such as pressure plate instrument which needs to apply air pressure step by step, and then test to obtain the corresponding water content after equilibrium, so as to obtain the matric suction of the soil sample under the air pressure of this level, and the next level test can only be carried out after this level measurement; filter paper method needs to measure the water content after the filter paper and the soil sample are balanced, and each time only a single point matric suction under the water content condition can be measured, and different water content needs to be measured by dewetting and testing after re-equilibrium with the filter paper; three is that when the water content is high (such as 80%~100% saturation), it is difficult to quickly drain and quickly measure the water content or matric suction. SUMMARY

[0004] In view of this, the present application provides a device and method suitable for determining the soil-water characteristics of dam soil seepage prevention body.

[0005] To achieve the above purpose, the present application is realized by the following technical solutions:

[0006] According to the first aspect of the present application, a device suitable for determining the soil-water characteristics of dam soil seepage prevention body is provided, comprising:

[0007] A sampler for placing soil samples, which has a drainage hole;

[0008] A rapid soil sample cutting device includes a cutting box, a cutting drive mechanism, and cutting sleeves. The cutting box has an inlet and an outlet. The sampler is placed inside the cutting box. Several cutting sleeves are installed at the drive end of the cutting drive mechanism and located above the sampler. One of the cutting sleeves has a drainage mesh on its side wall. The cutting drive mechanism drives the cutting sleeve to be inserted into the sampler for soil sample cutting.

[0009] Incubator;

[0010] The centrifugal suction measuring device is set inside the constant temperature chamber and is used to centrifuge a slit sleeve containing a soil sample with drainage mesh to create a pseudo-gravity field environment.

[0011] A vapor balance suction measuring device is installed inside the constant temperature chamber, including a solution tank and a baffle plate. The solution tank has multiple solution chambers, each containing a solution of different concentrations and compositions. The baffle plate covers the solution chambers so that designated solution chambers are exposed, creating environments with different relative humidity and total suction.

[0012] Optionally, the slitting box includes:

[0013] Slitting operation box;

[0014] The cover plate has one end pivotally connected to the cutting operation box and has a threaded through hole.

[0015] Optionally, the slitting drive mechanism includes:

[0016] A pressure-cutting screw is provided, and a threaded through hole is provided on the cover plate, and the pressure-cutting screw is screwed onto the threaded through hole;

[0017] A pressure-cutting mounting plate is rotatably mounted on the bottom of the pressure-cutting screw.

[0018] Optionally, the centrifugal suction measuring device includes:

[0019] A centrifugal motor is mounted on the constant temperature chamber, with its shaft extending into the constant temperature chamber;

[0020] The disc holder is mounted on the rotating shaft;

[0021] An outer frame, mounted on the tray frame, is used to install a slitting sleeve with drainage mesh holes.

[0022] Optionally, the steam balance suction measuring device further includes:

[0023] A partition plate is fixedly separated in the middle of the constant temperature chamber, and the partition plate has mesh openings.

[0024] A steam support is arranged above the partition plate, and the steam support is provided with a mesh;

[0025] A clamping mechanism is fixed in the thermostat for clamping filter paper.

[0026] Optionally, the solution tank is provided with a plurality of partition plates, and the solution tank is divided into a plurality of solution cavities.

[0027] Optionally, the thermostat is provided with a clamping groove, and when the clamping groove is arranged transversely along the upper edge of the solution tank, the shielding plate is inserted into the clamping groove to cover the solution cavities; when the clamping groove is arranged vertically along the upper edge of the solution tank, the shielding plate is inserted into the clamping groove to separate the upper spaces of the solution cavities, and each solution cavity forms an independent detection space.

[0028] Optionally, the thermostat further comprises a plurality of micro magnetic motor modules arranged in the bottom wall of the thermostat and a plurality of magnetic stirring capsules, and each solution cavity is provided with a micro magnetic motor module and a magnetic stirring capsule.

[0029] According to a second aspect of the embodiment of the present application, a method suitable for measuring soil-water characteristics of dam soil is provided, and the method is implemented in the device suitable for measuring soil-water characteristics of dam soil.

[0030] S1: a sampler is used to make a soil sample, and the prepared soil sample is placed in the slitting box;

[0031] S2: water is injected into the slitting box through the water inlet, and after the soil sample in the sampler is saturated, the excess water is discharged through the water outlet, and the slitting sleeve is inserted into the sampler to perform soil sample slitting by using the slitting driving mechanism;

[0032] S3: the slitting sleeve with a drainage mesh is removed, a soil moisture measuring instrument based on TDR technology is inserted into the soil sample, the soil sample is placed into a centrifugal suction measuring device, and a centrifugal force is generated by rotation; the TDR soil moisture measuring instrument is used to monitor the water content of the soil sample in real time during centrifugation, and the soil-water characteristics of the soil sample at a low suction section are obtained according to the water content and the suction calibration curve;

[0033] S4: the solution in the solution tank is evaporated to create a required experimental environment in the thermostat, the steam pressure and water vapor balance method are used, the slitting sleeve is driven to rotate by the centrifugal suction measuring device, the water content of the soil sample is accelerated to the vicinity of the target water content, and the overall time of the steam balance method is reduced.

[0034] S5: Weigh the cut sleeves without drainage mesh and place them in a constant temperature chamber. Place at least three stacked first filter papers at the bottom of one of the cut sleeves without drainage mesh. Suspend another single-layer second filter paper above another cut sleeve without drainage mesh. Using the vapor pressure and water vapor balance method, after a period of time, when the first filter paper is in equilibrium with the water vapor inside the constant temperature chamber, remove the second filter paper and the first filter paper in the middle of the stack. Measure the weight of the first and second filter papers after the test, and the weight of the first and second filter papers after drying, to obtain the matrix suction and total suction of the soil sample in the medium-high suction range. The total suction is measured for the second filter paper, and the matrix suction is measured for the first filter paper.

[0035] Optionally, salt solutions of different concentrations and compositions are injected into different solution chambers. A baffle is used to select which solution is exposed, thereby controlling the air humidity generated in the constant temperature chamber and thus controlling the suction in the constant temperature chamber. By measuring the soil moisture content under different suction, a soil-water characteristic curve is plotted.

[0036] The technical solutions provided by the embodiments of this application may include the following beneficial effects:

[0037] As described in the above embodiments, this application rapidly saturates and divides soil samples into multiple parallel samples using a rapid soil sample cutting device. Centrifugal suction measurement devices and steam equilibrium suction measurement devices are used to test the soil-water characteristics of the soil samples under different suction levels. Filter paper is used, and multiple solutions of different concentrations can be set within the steam equilibrium suction measurement device to quickly create environments with different relative humidity levels, facilitating faster experiments. This invention uses a cutting chamber to place the soil sample inside. Water is injected and drained from the cutting chamber through inlets and outlets to saturate the soil sample. A cutting drive mechanism presses down the cutting sleeve, enabling rapid cutting of the soil sample through the cutting sleeve. This invention, through the use of a constant temperature chamber in conjunction with a centrifugal suction measurement device, can accelerate the simultaneous testing of matrix soil-water characteristics under different suction levels. The solution tank has multiple solution chambers, each containing a solution of different concentrations and compositions. The solution chambers are shielded by the baffle plate to expose specific solution chambers, creating environments with different relative humidity and total suction. By measuring the soil moisture content under different suction conditions, the soil-water characteristic curve of the substrate can be plotted.

[0038] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0039] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0040] Figure 1 This is a first perspective view of an apparatus suitable for measuring the soil-water characteristics of a dam-building soil impermeable body, according to an exemplary embodiment.

[0041] Figure 2 This is a second perspective view of an apparatus suitable for measuring the soil-water characteristics of a dam-building soil impermeable body, according to an exemplary embodiment.

[0042] Figure 3 This is a schematic diagram of a rapid soil sample cutting device according to an exemplary embodiment.

[0043] Figure 4 This is a schematic diagram illustrating the installation of a slitting sleeve on a slitting drive mechanism according to an exemplary embodiment.

[0044] Figure 5 This is a schematic diagram of a centrifugal suction measuring device according to an exemplary embodiment.

[0045] Figure 6 This is a schematic diagram illustrating the installation of a split sleeve on an outer casing according to an exemplary embodiment.

[0046] Figure 7 This is a schematic diagram of a steam balance suction measuring device according to an exemplary embodiment.

[0047] Figure 8 This is a schematic diagram of the structure of a solution tank according to an exemplary embodiment.

[0048] Figure 9 This is a schematic diagram of the internal structure of a constant temperature chamber according to an exemplary embodiment.

[0049] Figure 10 This is a schematic diagram of a clamping bracket structure according to an exemplary embodiment.

[0050] The attached figures are labeled as follows:

[0051] 1. Sampler; 11. Drainage hole;

[0052] 2. Soil sample rapid cutting device; 21. Cutting box; 211. Cutting operation box; 212. Cover plate; 213. Water inlet pipe; 214. Water outlet pipe; 215. Sealing cover; 22. Cutting drive mechanism; 221. Pressing screw; 222. Pressing mounting plate; 2221. Threaded end; 23. Cutting sleeve; 231. Drainage mesh; 24. Immersion support; 241. Support mesh;

[0053] 3. Constant temperature chamber; 31. Circulation connection pipe; 32. Circulation fan;

[0054] 4. Centrifugal suction measuring device; 41. Centrifugal motor; 411. Threaded end; 42. Disc frame; 43. Outer frame; 431. Hollowed-out; 432. Bottom cross support; 433. Side wall support; 44. Nut;

[0055] 5. Vacuum measuring device for steam balance method; 51. Solution tank; 511. Solution chamber; 512. Dividing plate; 52. Baffle plate; 53. Dividing plate; 54. Steam support; 55. Clamping support; 551. Clamping plate; 552. Sliding groove; 553. Adjusting bolt; 56. Slot; 57. Miniature magnetic motor module; 58. Magnetic stirring capsule. Detailed Implementation

[0056] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0057] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The singular forms “a,” “the,” and “the” used in this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0058] It should be understood that although the terms first, second, third, etc., may be used in this application to describe various information, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, without departing from the scope of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to determination."

[0059] refer to Figures 1-10This invention provides an apparatus suitable for determining the soil-water characteristics of dam-built soil seepage barriers, comprising: a sampler 1, a rapid soil sample cutting device 2, a constant temperature chamber 3, a centrifugal suction measuring device 4, and a steam balance suction measuring device 5. The sampler 1 is used to hold the soil sample and has a drainage hole 11. The rapid soil sample cutting device 2 includes a cutting box 21, a cutting drive mechanism 22, and cutting sleeves 23. The cutting box 21 has an inlet and an outlet. The sampler 1 is placed inside the cutting box 21. Several cutting sleeves 23 are installed at the drive end of the cutting drive mechanism 22 and located above the sampler 1. One of the cutting sleeves 23 has a drainage mesh on its side wall. 231, the cutting drive mechanism 22 drives the cutting sleeve 23 to be inserted into the sampler 1 for soil sample cutting; the centrifugation suction measuring device 4 is set in the constant temperature chamber 3 and is used to centrifuge the cutting sleeve 23 containing soil sample with drainage mesh 231 to form a pseudo-gravity field environment; the steam balance suction measuring device 5 is set in the constant temperature chamber 3 and includes a solution tank 51 and a shielding plate 52. The solution tank 51 has multiple solution chambers 511, each solution chamber 511 containing solutions of different concentrations and compositions. The shielding plate 52 shields the solution chambers 511 so that the designated solution chambers 511 are exposed, forming environments with different relative humidity and total suction.

[0060] The soil sample is quickly saturated and divided into multiple parallel soil samples by the soil sample rapid cutting device 2. The soil water characteristics of the soil sample under different suction ranges are tested by the centrifugal suction measuring device 4 and the steam balance suction measuring device 5. By using filter paper, multiple solutions of different concentrations can be set in the steam balance suction measuring device 5, so that different relative humidity environments can be quickly created in the steam balance suction measuring device 5, which facilitates the acceleration of the experiment.

[0061] This invention utilizes a cutting chamber 21 to place soil samples inside. Water is injected and drained from the chamber through inlets and outlets to saturate the soil samples. A cutting drive mechanism 22 presses down on a cutting sleeve 23, enabling rapid cutting of the soil sample via the sleeve. The invention also incorporates a constant temperature chamber 3 and a centrifugal suction measurement device 4 to accelerate simultaneous experiments on the soil-water characteristics of the substrate under different suction levels. The solution tank 51 contains multiple solution chambers 511, each holding solutions of different concentrations and compositions. A shielding plate 52 covers each solution chamber 511, exposing specific chambers and creating environments with varying relative humidity and total suction. By measuring the soil moisture content under different suction levels, soil-water characteristic curves for the substrate can be plotted.

[0062] In one embodiment, the cutting box 21 includes a cutting operation box 211 and a cover plate 212. One end of the cover plate 212 is pivotally connected to the cutting operation box 211 for easy opening. The water inlet is located on the top side of the cutting operation box 211, and a water inlet pipe 213 is installed on the water inlet. The water outlet is located at the bottom of the cutting operation box 211, and a water outlet pipe 214 is connected to the water outlet. A sealing cap 215 is installed on the water outlet pipe 214. Water is injected into the cutting box 21 through the water inlet to saturate the soil sample, and then excess water is discharged through the water outlet.

[0063] In one embodiment, the cutting drive mechanism 22 includes a cutting screw 221 and a cutting mounting plate 222. A threaded through hole is formed in the cover plate 212, and the cutting screw 221 is screwed onto the threaded through hole. The cutting mounting plate 222 is rotatably mounted on the bottom of the cutting screw 221 via bearings. The cutting mounting plate 222 is raised or lowered by rotating the cutting screw 221. Without loss of generality, a structure capable of linear pressurization, such as a cylinder, can also be used instead of the cutting screw 221.

[0064] In one embodiment, the pressure-cutting mounting disc 222 has a threaded opening 2221 fixedly provided, and the cutting sleeve 23 is threadedly engaged with the threaded opening 2221. The cutting sleeve 23 and the pressure-cutting mounting disc 222 are connected by the threaded engagement of the threaded opening 2221, which makes disassembly and reassembly convenient and quick, and can quickly prepare and cut out the soil samples required for the experiment.

[0065] It is worth noting that: This embodiment takes three cutting sleeves 23 as an example. The number of cutting sleeves is not limited to the three shown in the figure. Different numbers of cutting sleeves 23 can be designed as needed to meet the soil sample cutting requirements of different scenarios. When increasing the number of cutting sleeves 23, it is necessary to consider whether the size of the pressing and cutting installation plate 222 can meet the installation conditions. More cutting sleeves 23 can be installed by reducing the diameter of the cutting sleeves 23 or increasing the size of the pressing and cutting installation plate 222.

[0066] In one embodiment, an immersion support 24 is also installed at the inner bottom of the cutting box 21. The sampler 1 is placed on the immersion support 24. The immersion support 24 is mainly used to support the sampler 1 and the soil in the sampler 1. The sampler 1 is used to collect external soil. Furthermore, the immersion support 24 has support mesh holes 241 to facilitate drainage.

[0067] In one embodiment, the centrifugal suction measuring device 4 includes a centrifugal motor 41, a tray frame 42, and an outer frame 43. The centrifugal motor 41 is mounted on the constant temperature chamber 3, and its hexagonal shaft extends into the constant temperature chamber 3. A threaded end 411 is fixedly mounted on the shaft, and a nut 44 is threaded onto the threaded end 411. The tray frame 42 is mounted on the threaded end 411 of the shaft and fixed by the nut 44. The outer frame 43 is mounted on the tray frame 42 and is used to install a slitting sleeve 23 with drainage mesh holes 231. The centrifugal motor drives the slitting sleeve to rotate centrifugally, thereby accelerating the sample moisture content to near the target moisture content and reducing the overall time for gas-water balance in the steam balance method.

[0068] Furthermore, the bottom of the outer frame 43 is hollowed out 431, and a support member is provided inside to support the slitting sleeve 23 with drainage mesh 231. Specifically, the outer frame 43 supports the slitting sleeve 23 through the bottom cross support 432 and the side wall support 433, so that it maintains a gap with the inner wall of the outer frame 43, so as to ensure that water can flow out smoothly through the mesh and gap of the sleeve during centrifugation.

[0069] In one embodiment, the steam balance suction measuring device 5 further includes a partition plate 53, a steam support 54, and a clamping mechanism. The partition plate 53 is located in the middle of the constant temperature chamber 3 and has mesh openings. The steam support 54 is positioned above the partition plate 53 and also has mesh openings. The clamping mechanism is fixed inside the constant temperature chamber 3 and is used to clamp filter paper. When the clamped filter paper is suspended above the soil sample without direct contact with it, the moisture reaches equilibrium through the migration of water vapor. At this time, the moisture content of the filter paper reflects the total suction of the soil sample (including matrix suction and solute suction).

[0070] In one embodiment, the constant temperature chamber 3 has a circulation connecting pipe 31 and a circulation fan 32. Both ends of the circulation connecting pipe 31 are connected to the constant temperature chamber 3, and the circulation fan 32 is disposed at one end or in the middle of the circulation connecting pipe 31.

[0071] Specifically, the end of the connecting pipe furthest from the fan is fixedly installed inside the constant temperature chamber 3, the fan is installed above the partition plate 53, and the end of the connecting pipe furthest from the fan is installed below the partition plate 53. This arrangement of the fan and connecting pipe allows for air circulation within the constant temperature chamber 3, ensuring that the vapor pressure remains balanced throughout the chamber.

[0072] In one embodiment, the clamping mechanism includes a clamping bracket 55 and a clamping plate 551, wherein the clamping plate 551 is adjustablely mounted on the clamping bracket 55.

[0073] Specifically, the clamping bracket 55 has a sliding groove 552 inside, and one end of the clamping plate 551 is slidably installed in the sliding groove 552. Adjusting bolts 553 are threaded on the clamping bracket 55 and the clamping plate 551.

[0074] In one embodiment, the solution tank 51 is provided with a plurality of dividing plates 512, dividing the solution tank 51 into multiple solution chambers 511, thereby enabling the use of various solutions of different concentrations and compositions to create different relative humidity.

[0075] In one embodiment, a slot 56 is provided on one side of the constant temperature chamber 3. When the slot 56 is arranged laterally along the upper edge of the solution tank 51, the baffle plate 52 is inserted into the slot 56 to cover the solution cavity 511. When the slot 56 is arranged vertically along the upper edge of the solution tank 51, the baffle plate 52 is inserted into the slot 56 to separate the spaces above each solution cavity 511, forming an independent detection space above each solution cavity 511.

[0076] In one embodiment, the system further includes several miniature magnetic motor modules 57 and several magnetic stirring capsules 58 installed in the bottom wall of the constant temperature chamber 3. One miniature magnetic motor module 57 is arranged at the bottom of each solution chamber 511, and one magnetic stirring capsule 58 is disposed within each solution chamber 511. The magnetic stirring capsules 58 are polytetrafluoroethylene magnetic stirrers (capsules), with models ranging from A6 to A150, B6 to B100, and C2 to C100, etc. These models primarily represent the type and size, and can be selected according to actual needs. The magnetic stirring capsules 58 can quickly and evenly stir the solution, achieving 50% or more higher efficiency in both uniformity and stirring time compared to conventional glass rod stirring.

[0077] This invention also provides a method for determining the soil-water characteristics of dam-building soil seepage barriers. This method is implemented in the aforementioned apparatus for determining the soil-water characteristics of dam-building soil seepage barriers, and includes:

[0078] S1: Use sampler 1 to prepare a soil sample and place the prepared soil sample inside the cutting box 21;

[0079] S2: Water is injected into the cutting box 21 through the inlet. After a period of time, that is, after the soil sample in the sampler 1 is saturated, excess water is discharged through the outlet. The cutting sleeve 23 is threaded onto the pressure cutting mounting plate 222 through the threaded port 2221, and the cover plate 212 is covered. The pressure cutting screw 221 is rotated. By controlling the direction and number of rotations of the pressure cutting screw 221, the pressure cutting mounting plate 222 and the cutting sleeve 23 are driven down by the pressure cutting screw 221 and inserted into the sampler 1 for soil sample cutting.

[0080] S3: After cutting, unscrew the cutting sleeve 23 from the threaded end 2221 to remove the cut soil sample. Remove the cutting sleeve 23 with drainage mesh 231, insert the soil moisture meter based on TDR technology into the soil sample, place the soil sample in the outer frame 43 and place the outer frame 43 on the plate frame 42. The plate frame 42 is fitted on the hexagonal rotating shaft. Use the nut 44 to limit the plate frame 42 and fix it on the hexagonal rotating shaft. The centrifugal motor 41 drives the plate frame 42 to rotate through the hexagonal rotating shaft to generate centrifugal force. During centrifugation, the soil moisture content is monitored in real time by the TDR soil moisture meter. The soil and water characteristics under low suction range are obtained by the TDR moisture content and suction calibration curve.

[0081] S4: The required experimental environment is created in the constant temperature chamber 3 by evaporating the solution in the solution tank 51. The vapor pressure and water vapor balance method is used in conjunction with the centrifugal motor 41 to drive the split sleeve 23 to rotate centrifugally, so that the soil moisture content is accelerated to near the target moisture content, reducing the overall time of vapor-water balance in the vapor balance method.

[0082] S5: After removing the tray 42, weigh the other two slit sleeves 23 without drainage mesh holes 231 and place them on the steam support 54 inside the constant temperature chamber 3. Place at least three stacked first filter papers (generally three are chosen, but more than three can be used; after water vapor equilibrium is achieved, the middle filter paper can be used to measure the moisture increase. However, if there are more than three filter papers, the equilibrium time will theoretically be longer. In addition, the top and bottom filter papers are indispensable for filtering soil particles) at the bottom of one of the slit sleeves 23 without drainage mesh holes 231. A single-layer second filter paper is suspended above another slit sleeve 23 without drainage mesh 231. Using the method of vapor pressure and water vapor balance, after a period of time, when the first filter paper is in equilibrium with the water vapor inside the constant temperature chamber, the second filter paper and the first filter paper stacked in the middle are taken out. By measuring the weight of the first and second filter papers after the test, and the weight of the first and second filter papers after drying, the matrix suction and total suction of the soil sample under medium and high suction range are obtained. The total suction is measured for the second filter paper, and the matrix suction is measured for the first filter paper.

[0083] To obtain different characteristics of soil samples under different suction levels, salt solutions of different concentrations and compositions can be injected into different solution chambers 511 of the solution tank 51. During the experiment, the operation of the micro magnetic motor module 57 will cause the magnetic stirring capsule 58 to rotate in the solution. The magnetic stirring capsule 58 can stir the solution and prevent it from settling. By sliding the baffle 52, you can select which solution to expose, thereby controlling the generation of different air humidity in the constant temperature chamber 3. The vapor pressure in the constant temperature chamber 3 will be in equilibrium with the solution. The composition and concentration of the chemical solution determine the relative humidity in the constant temperature chamber 3, which in turn controls the suction in the constant temperature chamber 3. By measuring the soil moisture content under different suction levels, a soil-water characteristic curve can be plotted. This curve reflects the water holding capacity of the soil under different suction levels.

[0084] It is worth noting that: in the above method, the slot 56 is arranged horizontally along the upper edge of the solution tank 51, and the baffle plate 52 is inserted into the slot 56 to cover the solution cavity 511. When the slot 56 is arranged vertically along the upper edge of the solution tank 51, a baffle plate 52 of appropriate size is selected and respectively clamped on the upper and lower sides of the partition plate 53 (that is, the slot 56 is arranged vertically on the upper and lower sides of the partition plate 53). When installing the baffle plate 52, the clamping mechanism and the steam support 54 need to be removed. By setting the baffle plate 52 on the upper and lower sides of the partition plate 53, the baffle plate 52 separates the solution cavities 511 of different concentrations. At this time, a soil sample can be placed in each corresponding solution cavity 511. By selecting a suitable solution, the relative humidity can be made to show a gradient change, so that multiple soil samples can be processed at the same time, and the multi-site testing effect can be achieved.

[0085] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the disclosure herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and embodiments are to be considered exemplary only, and the true scope and spirit of this application are indicated by the claims.

[0086] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A device suitable for determining the soil-water characteristics of dam-building soil seepage barriers, characterized in that, include: A sampler, used to hold soil samples, has drainage holes on it; A rapid soil sample cutting device includes a cutting box, a cutting drive mechanism, and cutting sleeves. The cutting box has an inlet and an outlet. The sampler is placed inside the cutting box. Several cutting sleeves are installed at the drive end of the cutting drive mechanism and located above the sampler. One of the cutting sleeves has a drainage mesh on its side wall. The cutting drive mechanism drives the cutting sleeve to be inserted into the sampler for soil sample cutting. Incubator; The centrifugal suction measuring device is set inside the constant temperature chamber and is used to centrifuge a slit sleeve containing a soil sample with drainage mesh to create a pseudo-gravity field environment. A vapor balance suction measuring device is installed inside the constant temperature chamber, including a solution tank and a baffle. The solution tank has multiple solution chambers, each containing a solution of different concentrations and compositions. The baffle blocks the solution chambers so that designated solution chambers are exposed, creating environments with different relative humidity and total suction. The steam balance suction measuring device also includes: A partition plate is fixedly separated in the middle of the constant temperature chamber, and the partition plate has mesh openings. A steam support is disposed above the partition plate, and the steam support has mesh openings. The clamping mechanism is fixed inside the constant temperature chamber and is used to clamp the filter paper.

2. The device for determining the soil-water characteristics of dam-building soil seepage barriers according to claim 1, characterized in that, The slitting box includes: Slitting operation box; The cover plate has one end pivotally connected to the cutting operation box and has a threaded through hole.

3. The device for determining the soil-water characteristics of dam-building soil seepage barriers according to claim 2, characterized in that, The slitting drive mechanism includes: A pressure-cutting screw is provided, and a threaded through hole is provided on the cover plate, and the pressure-cutting screw is screwed onto the threaded through hole; A pressure-cutting mounting plate is rotatably mounted on the bottom of the pressure-cutting screw.

4. The device for determining the soil-water characteristics of dam-building soil seepage barriers according to claim 1, characterized in that, The centrifugal suction measuring device includes: A centrifugal motor is mounted on the constant temperature chamber, with its shaft extending into the constant temperature chamber; The disc holder is mounted on the rotating shaft; An outer frame, mounted on the tray frame, is used to install a slitting sleeve with drainage mesh holes.

5. The device for determining the soil-water characteristics of dam-building soil seepage barriers according to claim 1, characterized in that, The solution tank is equipped with several dividing plates, which divide the solution tank into multiple solution chambers.

6. The device for determining the soil-water characteristics of dam-building soil seepage barriers according to claim 1, characterized in that, The constant temperature chamber has a slot on one side. When the slot is arranged horizontally along the upper edge of the solution tank, the baffle is inserted into the slot to cover the solution chamber. When the slot is arranged vertically along the upper edge of the solution tank, the baffle is inserted into the slot to separate the spaces above each solution chamber, forming an independent detection space above each solution chamber.

7. The device for determining the soil-water characteristics of dam-building soil seepage barriers according to claim 1, characterized in that, It also includes several miniature magnetic motor modules and several magnetic stirring capsules installed in the bottom wall of the constant temperature chamber. A miniature magnetic motor module is arranged at the bottom of each solution chamber, and a magnetic stirring capsule is arranged in each solution chamber.

8. A method for determining the soil-water characteristics of dam-building soil seepage barriers, characterized in that, This method uses the apparatus described in claim 1, suitable for determining the soil-water characteristics of dam-built soil seepage barriers, and the method includes: S1: Use a sampler to prepare a soil sample and place the prepared soil sample inside the cutting box; S2: Water is injected into the cutting box through the inlet. After the soil sample in the sampler is saturated, the excess water is discharged through the outlet. The cutting drive mechanism drives the cutting sleeve to be inserted into the sampler to cut the soil sample. S3: Remove the slit sleeve with drainage mesh, insert the soil moisture meter based on TDR technology into the soil sample, place the soil sample into the centrifugal suction measuring device, rotate to generate centrifugal force, monitor the soil moisture content of the soil sample in real time through the TDR soil moisture meter during centrifugation, and obtain the soil water and soil characteristics of the soil sample in the low suction range based on the moisture content and suction calibration curve. S4: The required experimental environment is created in the constant temperature chamber by evaporating the solution in the solution tank. The vapor pressure and water vapor balance method is used in conjunction with the centrifugal suction measuring device to drive the centrifugal rotation of the split sleeve, so that the soil moisture content is accelerated to near the target moisture content, reducing the overall time of vapor-water balance in the vapor balance method. S5: Weigh the cut sleeves without drainage mesh and place them in a constant temperature chamber. Place at least three stacked first filter papers at the bottom of one of the cut sleeves without drainage mesh. Suspend another single-layer second filter paper above another cut sleeve without drainage mesh. Using the vapor pressure and water vapor balance method, after a period of time, when the first filter paper is in equilibrium with the water vapor inside the constant temperature chamber, remove the second filter paper and the first filter paper in the middle of the stack. Measure the weight of the first and second filter papers after the test, and the weight of the first and second filter papers after drying, to obtain the matrix suction and total suction of the soil sample in the medium-high suction range. The total suction is measured for the second filter paper, and the matrix suction is measured for the first filter paper.

9. A method for determining the soil-water characteristics of a dam-building soil seepage barrier according to claim 8, characterized in that, Salt solutions of different concentrations and compositions are injected into different solution chambers. By using a baffle to select which solution to expose, different air humidity levels are generated in the constant temperature chamber, which in turn controls the suction in the constant temperature chamber. By measuring the soil moisture content under different suction levels, soil-water characteristic curves are plotted.

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