Numerical control domain division device and method for preparing heterogeneous transparent soil sample

Abstract

The invention relates to a numerical control domain division device and method for preparing a heterogeneous transparent soil sample, and belongs to the technical field of preparation of test samples, the device comprises a terminal, a numerical control mobile platform, a turntable, a suspension type weighing machine, a grading batching bin, a prefabricated sample bin, a circulating saturation system, a grid module and a sample bin; the method comprises the steps of heterogeneous field discretization, sample rasterization, sample prefabrication, grid unit sample filling and sequence sample filling. The method comprises the following steps: before sample preparation, dispersing a heterogeneous field into a plurality of subarea units, setting an automatic sample preparation path according to the subarea units, and calculating the particle feeding mass of each subarea unit according to the average gradation of corresponding areas of the heterogeneous field; during sample preparation, a terminal is used for controlling the numerical control subarea sample preparation device, so that automatic feeding, uniform mixing and pre-saturation of different particle groups in each subarea unit are realized, and the preparation of the whole sample is completed. According to the invention, the accurate and controllable preparation of the heterogeneous sample is realized, and an effective means is provided for carrying out the microscopic mechanism visualization research of the heterogeneous soil body.

Description

Technical Field

[0001] The present invention relates to the technical field of preparing test samples, and particularly to a numerically controlled domain division device and method for preparing heterogeneous transparent soil specimens. Background Art

[0002] In the field of geotechnical engineering, preparing specimens with specific particle gradations and conducting relevant tests is a conventional method for geotechnical tests. Although the current rich test methods provide a basic basis and important reference for engineering construction, in some cases where the soil layer properties are significantly heterogeneous, engineering accidents still occur frequently. For example, although the research on seepage piping has a history of more than fifty years, for the deep overburden dam foundations with high heterogeneity in the western region of China, accidents such as leakage and deformation caused by local piping still emerge continuously.

[0003] The core of these problems lies in the insufficient understanding of the characteristics of heterogeneous soil masses. In recent years, more and more numerical calculation studies in geotechnical engineering have begun to consider heterogeneous soil properties, and these studies have revealed significant differences in mechanical and seepage characteristics under homogeneous and heterogeneous conditions. Therefore, the academic community generally believes that continuing to rely on traditional homogeneity assumptions for tests and using subjective and conservative deterministic parameters for numerical analysis may lead to serious deviations in the assessment of actual engineering problems. When conditions permit, the heterogeneity of the soil mass should be fully considered in research.

[0004] However, the fundamental reason for the current insufficient understanding of soil properties under heterogeneous conditions is the lack of reliable heterogeneous test methods. Existing specimen preparation techniques mostly rely on manual operations, making it difficult to precisely control the heterogeneous distribution of specimens and resulting in poor repeatability. How to achieve precisely controllable and repeatable heterogeneous specimen preparation has become a key technical problem in the field of geotechnical engineering. In addition, the mesoscopic mechanism at the scale of soil particles is the key to revealing the macroscopic soil properties. Therefore, the test method for heterogeneous soil should be combined with visualization means to fully observe the mesoscopic mechanism in the soil. In summary, there is an urgent need for a device and technology that can automatically prepare heterogeneous specimens and allow visual observation. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to propose a numerically controlled domain division device and method for preparing heterogeneous transparent soil specimens, which effectively solves the technical problems of low preparation accuracy and poor repeatability of heterogeneous specimens in traditional geotechnical tests by discretizing heterogeneous soil property parameters into units and using a numerically controlled device to achieve automated and precise domain division for sample preparation.

[0006] One aspect of the present invention is achieved through the following solutions:

[0007] A numerically controlled domain division device for preparing heterogeneous transparent soil specimens, comprising:

[0008] A terminal, implemented and controlled by a PC computer, contains the coordinate information and grading information in the partitioned unit bodies and grid unit bodies after the heterogeneous field is discretized, and is used to automatically control the sample preparation path of the automatic control device and the particle feeding during pre-sampling and filling.

[0009] A numerically controlled mobile platform is used for precise positioning in the X-Y plane. According to the coordinate information of the center points of each grid in the grid module, it automatically transports the grading batching bin and the pre-sampling bin to the specified positions.

[0010] A turntable, in the shape of a disc, can rotate in a circular motion around its center. It is connected to the numerically controlled mobile platform above and to a suspended weighing device below.

[0011] Multiple suspended weighing devices. All the suspended weighing devices are connected to the turntable above, and each suspended weighing device is respectively connected to the grading batching bin below.

[0012] The grading batching bin includes multiple conical bucket-shaped bins. Different particle size groups of transparent soil are respectively loaded inside the conical bucket-shaped bins. The upper part of any conical bucket-shaped bin is connected to a suspended weighing device and makes a circular motion driven by the turntable. The lower part is a conical funnel, and the bottom of the funnel is equipped with an electric valve, which is controlled to open and close by the terminal.

[0013] The pre-sampling bin is conical bucket-shaped, with an open upper part, is connected to the numerically controlled mobile platform. There is an oil outlet at the upper part of the side. The lower part is a conical funnel, and the bottom of the funnel is equipped with an electric valve, which is controlled to open and close by the terminal.

[0014] A circulation saturation system is used to configure oil for the pre-sampling bin.

[0015] A grid module is an orthogonal grid placed in the sample bin, which divides the sample bin into several cube grids. The size of the grid is set according to the size of the sample bin and the properties of the heterogeneous field.

[0016] The sample bin is a hexahedron packing box made of transparent acrylic board, with its shape and size determined according to the test purpose, and a detachable top plate is provided above.

[0017] Furthermore, the circulation saturation system includes an upstream oil tank, a downstream oil tank, an oil pump and an oil pipeline. The outlet of the upstream oil tank inputs the configured oil of the transparent soil into the pre-sampling bin from the open port above the pre-sampling bin through the oil pipeline, and then flows back to the downstream oil tank through the oil overflow port on the side of the pre-sampling bin, and then flows back to the upstream oil tank again through the oil pump.

[0018] Furthermore, it also includes a compaction plate, and the compaction plate is a rectangular flat plate with a size slightly smaller than the internal size of the sample bin.

[0019] Further, it also includes a sample preparation lifting platform, which includes a base and columns fixed on both sides of the base. The numerical control moving platform and the upstream oil tank are respectively arranged on the two columns in a liftable manner.

[0020] The second aspect of the present invention is achieved through the following solutions:

[0021] A numerical control domain-by-domain sample preparation method for preparing heterogeneous transparent soil samples using the device as described above includes the following steps:

[0022] Step 1: Discretization of the heterogeneous field. Generate the target heterogeneous field in a virtual domain with the same size as the sample, and then discretize it into several partition unit bodies. According to the coordinates of the partition unit bodies, plan the sequential sample preparation path; according to the average gradation of the corresponding area in the heterogeneous field, obtain the gradation information of each partition unit, and combine the volume of the partition unit and the specific gravity of the transparent soil particles to calculate the mass information of each particle group in each partition unit. Store the above information in the terminal.

[0023] Step 2: Gridification of the sample. Design a grid module in the sample bin that matches the geometric characteristics of the partition unit bodies, divide the sample into several grid units, and accurately match the coordinates of each partition unit body with the coordinates of the grid units in the sample.

[0024] Step 3: Pre-sample preparation. Controlled by the terminal, accurately put specified masses of particles into the pre-sample bin through the grading batching bins, and at the same time continuously input circulating oil into the pre-sample bin using the circulating saturation system to ensure that the particle mixing process is carried out under saturated conditions.

[0025] Step 4: Filling the grid units with samples. Controlled by the terminal, move the numerical control moving platform to the position above the center point of the corresponding target grid unit, open the electric valve of the pre-sample bin, and fill the soil sample into the corresponding grid unit in the sample bin, while ensuring that the filling process is carried out under saturated conditions.

[0026] Step 5: Sequential filling. Repeat Step 3 and Step 4, adopting a sequential filling logic. First, sequentially fill the i + 1, i + 2... units in the jth column of grid units, and then sequentially fill the j + 1, j + 2... columns until a single layer is filled. After each layer is filled, vertically move out the grid module upward, and according to the preset dry density, use the compaction plate to compact each layer of the sample to the corresponding height.

[0027] Further, in Step 3, all the bins are driven by the turntable to synchronously put particles in a circular rotation manner, so that the particles are evenly mixed in the pre-sample bin.

[0028] Further, in Step 3, during the process of putting particles and inputting circulating oil, the electric valve of the pre-sample bin remains closed, and the pre-sample bin remains in a saturated state, so that the particles are pre-saturated while being evenly mixed.

[0029] Furthermore, in step 4, during the sample filling process, the oil level in the sample chamber must always be higher than the upper surface of the current filling layer in the sample preparation chamber by more than 1 cm.

[0030] Furthermore, in step 5, after each layer is filled, the grid module is moved vertically upward, and each layer of the sample is compacted to a corresponding height using a compaction plate according to a preset dry density to ensure that the density of the sample meets the preset requirements.

[0031] The third aspect of the present invention is achieved through the following scheme:

[0032] A method for preparing a non-homogeneous transparent soil sample adopts the numerically controlled domain sample preparation method and device as described above to achieve accurate and automated preparation of the non-homogeneous sample.

[0033] Compared with the prior art, the invention is innovative in that:

[0034] 1. The present invention discretizes the inhomogeneous field into partition units and maps them to the corresponding grid units in the sample bin, thereby achieving accurate quantification of inhomogeneous information and ensuring the repeatability of inhomogeneous sample preparation;

[0035] 2. The present invention can realize the automatic preparation of samples by controlling the numerical control mobile platform, turntable, hanging weighing device and electric valve through terminal linkage;

[0036] 3. The present invention provides a turntable to synchronously place particles of each particle group in a rotating manner, so that pre-uniform mixing can be completed before filling the sample, thereby reducing the segregation of the sample;

[0037] 4. The present invention provides a prefabricated sample bin and a circulating saturation system, which can complete saturation before filling the sample to ensure the transparency of the transparent soil;

[0038] In summary, the present invention realizes the precise and automated preparation of heterogeneous samples through the numerically controlled domain sample preparation device and method. At the same time, the prepared samples can be used for visual observation and research, providing an effective experimental means for studying the microscopic mechanism and macroscopic characteristics of heterogeneous soil. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is the inhomogeneous field discretization technology in the numerical control domain sample preparation technology of the present invention;

[0040] Figure 2 It is the overall layout diagram of the numerical control domain sample preparation device of the present invention;

[0041] Figure 3 It is a schematic diagram of the automatic sample preparation part in the numerical control domain sample preparation device of the present invention;

[0042] Figure 4This is the schematic diagram of the circulation saturation system in the numerically controlled domain - divided sample preparation device of the present invention;

[0043] Figure 5 This is the schematic diagram of the compaction plate in the numerically controlled domain - divided sample preparation device of the present invention;

[0044] Figure 6 This is the flow chart of the numerically controlled domain - divided sample preparation technology of the present invention.

[0045] Explanation of reference numerals:

[0046] 1 - PC terminal; 2 - numerically controlled mobile platform; 3 - turntable; 4 - hanging weigher; 5 - grading batching bin; 6 - electric valve of grading batching bin; 7 - pre - sample bin; 8 - electric valve of pre - sample bin; 9 - high - precision servo motor; 10 - track; 11 - oil overflow outlet; 12 - upstream oil tank; 13 - downstream oil tank; 14 - oil pump; 15 - oil pipeline; 16 - transparent soil configuration oil; 17 - water head lifting platform; 18 - sample bin; 19 - grid module; 20 - compaction plate; 21 - sample preparation lifting platform. Specific implementation manners

[0047] To make the objectives, technical solutions and innovative points of the embodiments of the present invention clearer, the following describes the technical solutions in the embodiments of the present invention clearly and completely with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some but not all of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and shown in the accompanying drawings here can be arranged and designed in various different configurations.

[0048] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed present invention, but merely represents the selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0049] The present invention relates to a numerically controlled domain - divided sample preparation device and technology for preparing heterogeneous transparent soil samples. The following combines the accompanying drawings and specific embodiments to elaborate on the implementation manners of the present invention.

[0050] 1. Specific implementation manners of the device

[0051] 1.1 As Figure 1As shown, the terminal is a PC computer 1, which is used to generate a target heterogeneous field in a virtual domain with the same size as the specimen, and then discretize it into several partition unit bodies. According to the coordinate information of the partition unit body matrix, a sequential sample preparation path is planned; according to the average gradation in the corresponding area of the heterogeneous field, the sample preparation gradation of each partition unit is obtained, and combined with the volume of the partition unit and the specific gravity of the transparent soil particles, the mass information of each particle group to be put in each partition unit is calculated. As Figure 2 shown, the above information is stored in the terminal, and the terminal is used to linkage-control the CNC moving platform 2, the turntable 3, the suspended weighing device 4, the bin electric valve 6 at the bottom of the grading batching bin 5, and the pre-sample bin electric valve 8 at the bottom of the pre-sample bin 7.

[0052] 1.2 CNC Moving Platform

[0053] As Figure 3 shown, the CNC moving platform 2 is driven by a high-precision servo motor 9 on two mutually perpendicular tracks 10, and can be accurately positioned in the X-Y direction in the plane, similar to the technology of controlling the movement of the printing nozzle in a 3D printing device. The turntable 3, the suspended weighing device 4, the grading batching bin 5 and the pre-sample bin 6 are installed on the CNC moving platform 2, and are automatically transported above the center point of the specified grid unit according to the planned sample preparation path in the terminal 1.

[0054] 1.3 Turntable

[0055] The turntable 3 is designed in a disc shape and can be driven by a motor to rotate in a circle around the center. The turntable 3 is connected to the CNC moving platform 2 through a mechanical interface above, and is connected to the grading batching bin 5 through the suspended weighing device 4 below. The rotation speed of the turntable 3 can be adjusted by the terminal 1 according to the sample preparation effect to ensure uniform mixing of the particles in the pre-sample bin 7.

[0056] 1.4 Suspended Weighing Device

[0057] Each suspended weighing device 4 is separately connected to a grading batching bin 5. When putting in particles, the suspended weighing device 4 monitors the mass of the grading batching bin 5 in real time and transmits it back to the terminal 1.

[0058] 1.5 Grading Batching Bin

[0059] The grading batching bin 5 is in a conical barrel shape, and different particle size groups of transparent soil particles are loaded inside. The number of grading batching bins is determined according to the test requirements. The bottom of each bin is in a conical funnel shape, and a bin electric valve 6 is installed at the funnel outlet. The bin electric valve 6 is connected to the terminal, and the valve is opened when putting in particles, and the valve is automatically closed by comparing the measured value difference before and after each single particle putting of each suspended weighing device 4 with the particle putting mass information in the terminal 1.

[0060] 1.6 Pre-sample Bin

[0061] The prefabricated sample bin 7 has a conical barrel structure, is open at the top, and is connected to the numerically controlled mobile platform 2. An oil overflow port 11 is provided in the upper part of the side of the prefabricated sample bin, and the lower part is a conical funnel. An electric valve 8 for the prefabricated sample bin is provided at the bottom of the funnel. The electric valve 8 for the prefabricated sample bin is controlled by the terminal and automatically opens 10 seconds after the grading batching bin finishes discharging.

[0062] 1.7 Circulation saturation system

[0063] As Figure 4 shown, the circulation saturation system includes an upstream oil tank 12, a downstream oil tank 13, an oil pump 14, and an oil pipeline 15. The upstream oil tank 12 inputs the transparent soil configuration oil 16 into the prefabricated sample bin 7 through the oil pipeline 15. The oil flows back to the downstream oil tank 13 through the oil overflow port 8 on the side of the prefabricated sample bin, and then is retransported back to the upstream oil tank through the oil pump 14 to form a circulation system. The oil pipeline 15 is made of soft tubing to facilitate the movement of the prefabricated sample bin. To control the circulation speed, the upstream oil tank is arranged on the water head lifting platform 17 for adjusting the hydraulic head. At the same time, there is a fixed overflow port in the upstream oil tank to achieve a constant hydraulic head. In addition, a part of the transparent soil configuration oil overflows from the top surface of the sample bin 18. Therefore, the sample bin 18 is arranged above the downstream oil tank 13 so that the overflowing oil enters the downstream oil tank 13 to form a circulation.

[0064] 1.8 Grid module

[0065] The grid module 19 is composed of orthogonal grids, and divides the sample bin 18 into several cube grid units. The size of the grid is designed according to the division of the partition unit body to ensure that each grid unit corresponds one-to-one with the partition unit body of the heterogeneous field. The overall size of the grid module 19 can be 2 mm smaller than the internal size of the sample bin to facilitate placement and removal in the sample bin 18.

[0066] 1.9 Sample bin

[0067] The sample bin 18 is made of transparent acrylic board and is a hexahedron-shaped box. The top plate above the box is detachable, is opened during sample preparation, and is manually sealed after sample preparation is completed. The size and shape of the sample bin can be customized according to test requirements.

[0068] 1.10 Compaction plate

[0069] The compaction plate 20 is a rectangular flat plate, and its dimensions in the X-Y directions are both 2 mm smaller than the internal size of the sample bin to facilitate movement in the sample bin 18. The compaction plate is manually controlled and is used to compact each layer of the sample to a preset height to ensure that the density of the sample meets the requirements.

[0070] 2. Specific implementation manners of the technology

[0071] Using the above device, the numerically controlled domain-by-domain sample preparation technology is carried out according to Figure 5 the shown process.

[0072] 2.1 Discretization of heterogeneous field

[0073] Using terminal 1, generate the target heterogeneous field in a virtual domain with the same size as the specimen, and discretize it into several partition unit bodies. The size of any side of the discrete unit body should be less than 1 / 5 of the heterogeneous scale to ensure that the continuity of the discretized heterogeneous field is similar to that of the original heterogeneous field. According to the coordinate information of the partition unit body matrix, plan the automated sample preparation path. At the same time, based on the average gradation in the corresponding area of the heterogeneous field, obtain the sample preparation gradation information of each partition unit, and combine the volume of the partition unit and the specific gravity of the transparent soil particles to calculate the mass of each particle group to be placed in each partition unit.

[0074] 2.2 Grid-based sampling of specimens

[0075] Design a grid module 19 in the specimen bin 18 that matches the coordinates and geometric features of the partition unit bodies, and divide the specimen into several grid units. Through coordinate matching, accurately map the gradation information of each partition unit body to the corresponding grid unit.

[0076] 2.3 Preparing samples

[0077] Turn on the oil pump 14 to make the cyclic saturation system start operating. At the same time, close the electric valve 8 of the prefabricated sample bin to make the transparent soil preparation oil 16 circulate in the cyclic saturation system and the prefabricated sample bin 7. Use terminal 1 to control the numerically controlled moving platform 2 to move directly above the center point of the i-th unit in the k-th layer and the j-th column, align the outlet of the prefabricated sample bin with the center point of this unit, and be 1 cm higher than the surface of this unit. At the same time, rotate the turntable 3 and open the electric valve 6 of the grading batching bin to put particles into the prefabricated sample bin 7 filled with transparent soil preparation oil 16. During the putting process, the hanging scale 4 continuously monitors the readings. When the difference in single measurement values reaches the preset putting mass in terminal 1, stop rotating the turntable 3 and close the electric valve 6 of the grading batching bin, and the preparation of the prefabricated sample is completed.

[0078] 2.4 Filling the grid units with samples

[0079] After the preparation of the prefabricated sample is completed, let it stand for 10 seconds. After the particles in the prefabricated sample bin settle and the bubbles dissipate, open the electric valve 8 of the prefabricated sample bin to fill the grid units with samples. After the filling time lasts for 10 seconds, close the electric valve 8 of the prefabricated sample bin, and the filling of the grid units is completed.

[0080] 2.5 Sequential sample filling

[0081] Adopt the sequential sample filling logic and repeat steps 2.3 and 2.4 in different grid units. Continue to sequentially fill the i+1, i+2,... units in the j-th column of grid units, and then sequentially fill the j+1, j+2,... columns until the filling of a single layer is completed. As Figure 6As shown, after each layer of filling is completed, the grid module is vertically moved upward, and the compaction plate is used to compact each layer of the specimen to the corresponding height to ensure that the density of the specimen meets the preset requirements. Subsequently, the sample preparation lifting platform 21 is used to raise the numerically controlled moving platform 2 according to the layer thickness to prepare specimens for layers k + 1, k + 2, ….

[0082] 3. Example:

[0083] Objective: To prepare a heterogeneous specimen with dimensions of 100 mm × 100 mm × 20 mm, and its heterogeneous scale is 50 mm. The gradation in the specimen is a discontinuous gradation, divided into a fine particle group (particle size 1 mm) and a coarse particle group (particle size 3 mm). The fine particle content (the percentage of the mass of the fine particle group to the total mass) is used as the heterogeneous characteristic parameter, and the variation range of the fine particle content is 10% - 30%.

[0084] According to 1 / 5 of the heterogeneous scale, partition unit cells with dimensions of 10 mm × 10 mm × 10 mm can be set, and the specimen is divided into 2 layers, with 100 partition unit cells in each layer. The fine particle content of each partition unit is the average fine particle content of the heterogeneous field in the corresponding area. A grid module with dimensions of 100 mm × 100 mm × 10 mm is designed, and each layer of the specimen is divided into 100 grid cells with dimensions of 10 mm × 10 mm × 10 mm, making them correspond one-to-one with the partition unit cells. The coordinate information and gradation information of each partition unit are input into the terminal, and a sample preparation path with i = 10, j = 10, k = 2 is formulated. In the device, two grading batching bins are set, filled with the fine particle group and the coarse particle group respectively. Subsequently, the automated sample preparation is completed according to 2.3, 2.4, 2.5.

[0085] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and do not limit them. Although detailed descriptions have been made with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the purpose and scope of the technical solutions of the present invention, and all such modifications should be included within the scope of the claims of the present invention.

Claims

1. A numerically controlled domain division device for preparing heterogeneous transparent soil specimens, characterized in that, Comprising: A terminal, implemented and controlled by a PC computer, containing coordinate information and grading information in the partition unit bodies and grid unit bodies after discretization of the heterogeneous field, and used to automatically control the sample preparation path of the automatic control device and the particle delivery during pre-sampling and filling; A numerically controlled mobile platform, used for precise positioning in the X-Y plane, and automatically transporting the grading and batching bin and the pre-sampling bin to the specified positions according to the coordinate information of the center points of each grid in the grid module; A turntable, in a disc shape, capable of rotating in a circular motion around its center, connected to the numerically controlled mobile platform above and to a hanging weigher below; Multiple hanging weighers, with all the hanging weighers connected to the turntable above, and each hanging weigher connected to a grading and batching bin respectively below; A grading and batching bin, containing multiple conical bucket-shaped bins, with different particle size groups of transparent soil particles loaded in the conical bucket-shaped bins respectively. Above any conical bucket-shaped bin is connected to a hanging weigher, and it makes a circular motion driven by the turntable. The lower part is a conical funnel, and the bottom of the funnel is equipped with an electric valve, which is controlled by the terminal to open and close; A pre-sampling bin, in a conical bucket shape, with an open top, connected to the numerically controlled mobile platform, having an oil outlet at the upper part of the side, and a conical funnel at the lower part, and the bottom of the funnel is equipped with an electric valve, which is controlled by the terminal to open and close; A circulation saturation system, used to provide transparent soil configuration oil for the pre-sampling bin; A grid module, an orthogonal grid placed in the sample bin, dividing the sample bin into several cube grids, and the size of the grid is set according to the size of the sample bin and the properties of the heterogeneous field; A sample bin, a hexahedron packing box made of transparent acrylic board, with its shape and size determined according to the test purpose, and a detachable top plate is provided above; 2. The numerically controlled domain-dividing device for preparing heterogeneous transparent soil specimens according to claim 1, wherein The circulation saturation system includes an upstream oil tank, a downstream oil tank, an oil pump and an oil pipeline. The outlet of the upstream oil tank inputs the transparent soil configuration oil from the open port above the pre-sampling bin into the pre-sampling bin through the oil pipeline, and it flows back to the downstream oil tank through the oil overflow port on the side of the pre-sampling bin, and then reflows to the upstream oil tank through the oil pump.

3. The numerically controlled domain division device for preparing heterogeneous transparent soil specimens according to claim 1, wherein, It further includes a compaction plate, and the compaction plate is a rectangular flat plate with a size slightly smaller than the internal size of the sample bin.

4. The numerically controlled domain division device for preparing heterogeneous transparent soil specimens according to claim 1, characterized in that, It further includes a sample preparation lifting platform, and the sample preparation lifting platform includes a base and columns fixed on both sides of the base, and the numerically controlled mobile platform and the upstream oil tank are respectively arranged on the two columns in a liftable manner.

5. A numerically controlled domain-by-domain sample preparation method for preparing heterogeneous transparent soil specimens using any one of the devices described in 1-4, characterized in that, Including the following steps: Step 1: Discretization of the heterogeneous field. Generate a target heterogeneous field in a virtual domain with the same size as the sample, and then discretize it into several partition unit bodies. According to the coordinates of the partition unit bodies, plan a sequential sample preparation path; according to the average grading of the corresponding area in the heterogeneous field, obtain the grading information of each partition unit, and combine the volume of the partition unit and the specific gravity of the transparent soil particles to calculate the mass information of each particle group in each partition unit, and store the above information in the terminal; Step 2: Gridification of the sample. Design a grid module in the sample bin that matches the geometric characteristics of the partition unit bodies, divide the sample into several grid units, and precisely match the coordinates of each partition unit body with the coordinates of the grid units in the sample; Step 3: Controlled by the terminal, precisely put specified mass of particles into the prefabricated sample bin through the hierarchical batching bin, and at the same time, continuously input circulating oil fluid into the prefabricated sample bin by using the circulating saturation system to ensure that the particle mixing process is carried out under saturated conditions; Step 4: Sampling in grid units. Controlled by the terminal for the numerically controlled moving platform, move the prefabricated sample bin above the center point of the corresponding target grid unit, open the electric valve of the prefabricated sample bin, and fill the soil sample into the corresponding grid unit in the sample bin, while ensuring that the sampling process is carried out under saturated conditions; Step 5: Sequential sampling. Repeat Steps 3 and 4, and adopt a sequential sampling logic. First, sequentially fill the i+1, i+2,... units in the jth column of grid units, and then sequentially fill the (j+1)th, (j+2)th,... columns until the single-layer filling is completed. After each layer of filling is completed, move the grid module vertically upward, and according to the preset dry density, use the compaction plate to compact each layer of the sample to the corresponding height.

6. The numerically controlled domain-based sample preparation method according to claim 5, wherein In Step 3, all bins are driven by the turntable to synchronously put particles in a circular rotation manner, so that the particles are evenly mixed in the prefabricated sample bin.

7. The numerical control sub-domain sample preparation method according to claim 6, characterized in that In Step 3, during the process of putting particles, the inside of the prefabricated sample bin remains in a saturated state, so that the particles are pre-saturated while being evenly mixed.

8. The numerical control sub-region sample preparation method according to claim 5, characterized in that, In Step 4, during the sampling process, the liquid level of the oil fluid in the sample bin needs to be always more than 1 cm above the upper surface of the current filling layer in the sample preparation bin.

9. The numerical control domain-based sample preparation method according to claim 5, wherein In Step 5, after each layer of filling is completed, move the grid module vertically upward, and according to the preset dry density, use the compaction plate to compact each layer of the sample to the corresponding height to ensure that the density of the sample meets the preset requirements.

10. A method for preparing a heterogeneous transparent soil sample, characterized in that, Adopt the numerically controlled domain-based sample preparation method and device described in Claims 1 to 9 to achieve precise and automated preparation of heterogeneous samples.

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