Rapid soil engineering ring shear sample preparation device and method

Abstract

The invention relates to the technical field of geotechnical engineering, in particular to a rapid sample preparation device and method for a geotechnical ring shear sample. The sample preparation device comprises a sample preparation mold and a sample pressing assembly; the sample preparation mold comprises a sample preparation shell, a sample pushing ring, a limiting column and a central column, the sample pushing ring is installed in the sample preparation shell, the limiting column and the central column are sequentially installed in the sample pushing ring, and a sample preparation cavity is defined by the sample pushing ring, the central column and the sample preparation shell; the sample pressing assembly comprises a pressure frame, an operation table and a limiting component, the sample preparation shell is installed on the operation table and can move upwards under the jacking action of the sample preparation table, the limiting component is installed on the pressure frame, and the bottom of the limiting component can abut against the top of the center column. The device realizes one-time filling of the soil material, ensures uniform and accurate density and moisture content of the prepared sample, is simple in structure and convenient to operate, and lays a foundation for development of a subsequent ring shear test and determination of mechanical properties of the soil sample.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of geotechnical engineering, and particularly relates to a device and method for rapidly preparing a soil ring shear sample. BACKGROUND

[0002] In the field of geotechnical engineering, the shear strength of soil and the evolution of its parameters during long-term shear deformation are key factors for evaluating the stability of slopes, foundations and other projects. As an important indoor soil test method, ring shear tests can effectively obtain the peak and residual shear strength of soil by maintaining a constant shear area and achieving continuous large displacement shear. The preparation of a circular ring-shaped soil sample with accurate geometric dimensions, uniform density and water content, and undisturbed internal structure is a prerequisite for this test. The quality of the sample directly determines the reliability of the final test data.

[0003] Currently, the mainstream method for preparing ring shear samples is drilling. This method usually forms a cylindrical or block-shaped soil body using compaction or compaction methods, and then uses a specially designed ring-shaped drill to drill out a ring-shaped sample from the soil body in the form of a double-tube sleeve drill with an inner and outer ring. The drill generally consists of an inner and outer hollow cylinder, the inner cylinder is used to form the inner hole of the sample, and the outer cylinder is used to form the outer wall of the sample, which is cut into the soil by rotating or pressing. After the drill is removed, the ring-shaped soil core wrapped in it is carefully pushed out, and the required ring shear sample is obtained.

[0004] However, this drilling method has the following technical problems in practical application: During the cutting and rotating process of the drill, the cutting edge will cut and extrude the soil, and this strong mechanical action inevitably destroys the original microstructure and stress state of the soil sample, resulting in pre-shearing or structural disturbance of the sample, which makes the measured strength parameters deviate from the true value. Moreover, it is very difficult to ensure that the inner and outer drill cylinders always maintain strict coaxial relationship during drilling operation, any slight deviation will cause the ring-shaped sample to be out of concentricity, and the geometric shape does not meet the requirements of a standard circular ring, introducing additional test errors. In addition, from soil preparation, installation of the drill to completion of drilling and removal of the sample, the whole process is complicated and time-consuming. During this period, the internal moisture of the soil will continue to evaporate and dissipate, it is difficult to maintain the target water content required by the test design, which also affects the uniformity and controllability of the sample properties. SUMMARY

[0005] In view of the deficiencies of the prior art, the purpose of the embodiments of the present application is to provide a soil ring shear sample rapid sample preparation device and method to solve the problems of disturbed soil sample structure, non-standard geometry and difficult accurate control of water content and density during preparation caused by drilling method, so as to provide a device capable of quickly and accurately preparing high-quality standard samples for ring shear test, realize one-time filling of soil, ensure uniform and accurate sample preparation density and water content, and lay a foundation for subsequent ring shear test and determination of soil mechanical properties.

[0006] In order to achieve the above-mentioned purpose, the embodiments of the present application provide the following technical solutions: A soil ring shear sample rapid sample preparation device, comprising: a sample preparation mold and a sample compression assembly; the sample preparation mold comprises a sample preparation shell, a sample pushing ring, a limiting column and a center column, the sample pushing ring is installed in the sample preparation shell, the limiting column and the center column are installed in the sample pushing ring in sequence, and the sample pushing ring, the center column and the sample preparation shell surround a sample preparation cavity; the sample compression assembly comprises a pressure frame, an operation table and a limiting member, the sample preparation shell is installed on the operation table and can move upward under the jacking action of the sample preparation table, and the limiting member is installed on the pressure frame and can abut against the top of the center column.

[0007] Optionally, the sample preparation shell comprises a jacking plate, a limiting ring, a sample preparation cylinder and a cover plate, the limiting ring and the sample preparation cylinder are installed on the jacking plate in sequence, and the cover plate is installed on the sample preparation cylinder; an upper positioning groove is arranged on the top surface of the jacking plate, the lower end of the limiting ring is installed in the upper positioning groove, and a recess is arranged on the bottom surface of the cover plate, and the upper end of the sample preparation cylinder is embedded in the recess.

[0008] Optionally, the limiting ring comprises a sample pushing limiting ring and a sample compression limiting ring, the sample pushing limiting ring is installed on the jacking plate, and the sample compression limiting ring is installed on the sample pushing limiting ring; the sample compression limiting ring, the sample pushing limiting ring and the cover plate are all split structures.

[0009] Optionally, a door hole is formed in one side of the bottom of the sample pushing ring, the jacking plate is provided with a movable groove, the movable groove communicates with the upper positioning groove, the door hole of the sample pushing ring is aligned with the movable groove of the jacking plate, and the limiting column can be pushed into or pulled out along the movable groove and the door hole.

[0010] Optionally, the pressure frame comprises a stand column, a limiting plate and a mounting plate, the stand column is connected with the operation table, the limiting plate and the mounting plate, the mounting plate is located on the upper side of the limiting plate, and the limiting member is installed on the mounting plate.

[0011] Optionally, a circular hole is formed in the middle of the limiting plate, the diameter of the circular hole is greater than the inner diameter of the sample preparation cylinder and smaller than the outer diameter of the sample preparation cylinder.

[0012] Optionally, the limiting component includes a movable pressure rod, a bushing, and a limiting screw. The bushing is fixedly installed on the mounting plate, the movable pressure rod is inserted into the bushing, and an annular limiting groove is provided on the outer wall of the push rod. The limiting screw is installed on the bushing and can abut against the limiting groove of the movable pressure rod.

[0013] Optionally, the control panel includes a motor control box and a telescopic column, the bottom surface of the lifting plate is provided with a lower positioning groove, and the telescopic column is installed in the lower limit groove of the lifting plate.

[0014] Optionally, the sampling device further includes a sampling assembly, which includes a sampling clamp and a sample tray. The sampling clamp has two semi-circular plates, which are used to clamp the outer wall of the soil sample, and the sample tray is used to place the soil sample.

[0015] This invention also provides a sample preparation method for the rapid geotechnical shear specimen preparation device described above, comprising: Install the pusher ring in the upper positioning groove of the lifting plate and align the doorway of the pusher ring with the movable groove of the lifting plate. Insert the limiting post into the doorway of the pusher ring along the movable groove. Place the center post above the limiting post and make the groove of the center post face upward. Install the pusher limiting ring and the pressing limiting ring in sequence on the outside of the pusher ring. Install the sample preparation cylinder above the pressing limiting ring. The soil material is added into the sample preparation cylinder all at once; Place the cover plate on the upper end of the sample preparation cylinder, press down the movable pressure rod so that its bottom end contacts the groove of the central column, drive the operating table to rise, so that the cover plate abuts against the limit plate, remove the sample pressing limit ring, continue to raise the lifting plate, so that the soil in the sample preparation cylinder is compacted and maintained for the set time. Lower the operating platform, remove the cover plate and the sample pushing limit ring, pull out the limit column from the movable groove, fix the position of the movable pressure bar, continue to raise the lifting plate, and push the sample pushing ring to move the soil sample upward until the soil sample is completely separated from the sample preparation cylinder. Release the limit on the movable pressure bar and lift the movable pressure bar. Use the sampling clamp to hold the outer wall of the soil sample and transfer the soil sample to the sample tray.

[0016] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages: 1. The sample preparation device of the present invention includes a sample preparation mold and a sample pressing assembly. The sample preparation mold forms a cavity for containing and shaping soil material. The central column determines the shape and size of the inner hole of the future soil sample, while the sample preparation shell determines the outer contour of the soil sample. The limiting column is used to support and position the central column in the initial stage of sample preparation. The sample pressing assembly provides power and constraint for the entire sample preparation process. The operating table is responsible for providing upward lifting force to drive the movement of the sample preparation shell and its internal components. The pressure frame constitutes a stable support structure. The bottom of the limiting member can abut against the top of the central column, so that during the sample pushing process, the central column remains relatively stationary due to the obstruction from the upper limiting member, resulting in relative movement between the sample preparation shell, the central column, and the sample, thereby pushing out the sample compacted into a ring shape. Through a one-time compaction forming method, the cutting and disturbance of the soil structure caused by traditional drilling methods is fundamentally avoided. The structural layout of the entire device ensures that the sample is directly formed inside the mold, and the coaxiality of its inner and outer rings is guaranteed by the machining accuracy of the mold, thereby solving the problem of non-standard sample geometry. Meanwhile, because the sample preparation process is rapid and the soil is handled in a closed chamber, the time for soil moisture to dissipate is effectively reduced, which is conducive to maintaining the target moisture content.

[0017] 2. With the setting of limiting columns and movable pressure bars, the ring sample can be completely pushed out during demolding without the need for drilling, which reduces the disturbance to the soil sample. Moreover, the mold size is more controllable and the sample size is more in line with the standard, effectively improving the accuracy of the parameters measured when using the ring shear tester.

[0018] Advantages of additional aspects of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In addition, the dimensions or spacing between the components are exaggerated to show the position of each component, and the schematic diagrams are for illustrative purposes only.

[0020] Figure 1 This is a schematic diagram of the overall sample preparation device provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the sample pressing assembly provided in an embodiment of the present invention; Figure 3 These are partial cross-sectional views of the device in its initial state, viewed from the left and front, provided in this embodiment of the invention. Figure 4 These are a left partial cross-sectional view and a front view of the sample pressing process of the device provided in this embodiment of the invention; Figure 5 These are a left partial cross-sectional view and a front view of the sample pushing process of the device provided in the embodiment of the present invention; Figure 6 This is a schematic diagram of the pusher ring provided in an embodiment of the present invention; Figure 7 This is a schematic diagram of the limiting post provided in an embodiment of the present invention; Figure 8 This is a schematic diagram of the lifting plate provided in an embodiment of the present invention; Figure 9 This is a schematic diagram of the sampling component provided in an embodiment of the present invention; In the diagram: 1. Pressure frame; 2. Operating platform; 3. Lifting plate; 4. Limiting component; 5. Column; 6. Nut; 7. Sample preparation mold; 8. Limiting plate; 9. Pressure bar platform; 10. Telescopic column; 11. Motor control box; 12. Bushing; 13. Movable pressure bar; 14. Limiting groove; 15. Limiting screw; 16. Cover plate; 17. Sample preparation cylinder; 18. Pushing ring; 19. Pressure bar limiting ring; 20. Pushing ring limiting ring; 21. Limiting column; 22. Center column; 23. Upper positioning groove; 24. Soil sample; 25. Sampling clamp; 26. Sample tray; 27. Lower positioning groove; Detailed Implementation It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0021] Example 1 like Figure 1 , Figure 2 , Figure 3 As shown in the figure, this embodiment proposes a rapid sample preparation device for geotechnical ring shear specimens, including a sample preparation mold 7 and a sample pressing assembly. The sample preparation mold 7 includes a sample preparation shell, a pusher ring 18, a limiting post 21, and a central post 22. The pusher ring 18 is installed inside the sample preparation shell, and the limiting post 21 and the central post 22 are sequentially installed inside the pusher ring 18. The pusher ring 18, the central post 22, and the sample preparation shell form a sample preparation chamber. The sample pressing assembly includes a pressure frame 1, an operating platform 2, and a limiting member 4. The sample preparation shell is installed on the operating platform 2 and can move upward under the lifting action of the sample preparation platform. The limiting member 4 is installed on the pressure frame 1, and the bottom of the limiting member 4 can abut against the top of the central post 22.

[0022] The sample preparation mold 7, consisting of the pusher ring 18, the central column 22, and the outer shell, forms a ring-shaped sample preparation chamber. The radial dimension of this chamber directly corresponds to the inner and outer diameters of the final sample. The pressure frame 1 in the compression assembly provides a rigid support reference. The operating platform 2 moves upward through a lifting action, while the limiting member 4 limits the central column 22 from the top. Unlike existing technologies where drill cutting of soil causes structural disturbance, this static pressure molding method avoids mechanical impact and shear damage. The entire operation cycle of the device is significantly shortened compared to drilling methods. The soil material is continuously added and molded within the sealed chamber, effectively blocking the moisture evaporation path and controlling the moisture content variation within the allowable range of experimental error. During demolding, the pusher ring 18 can move upward relative to the outer shell, pushing the sample out completely without secondary processing.

[0023] The sample preparation shell includes a lifting plate 3, a limiting ring, a sample preparation cylinder 17, and a cover plate 16. The limiting ring and the sample preparation cylinder 17 are sequentially installed on the lifting plate 3, and the cover plate 16 is installed on the sample preparation cylinder 17. The top surface of the lifting plate 3 is provided with an upper positioning groove 23, the lower end of the limiting ring is installed in the upper positioning groove 23, the bottom surface of the cover plate 16 is provided with a groove, and the upper end of the sample preparation cylinder 17 is embedded in the groove.

[0024] The lifting plate 3, serving as a basic support component, is directly connected to the power output end of the operating platform 2. Its upper positioning groove 23 is used for precise installation and positioning of the limiting ring, preventing it from shifting under stress. The cover plate 16, through its bottom groove, engages with the upper end of the sample preparation cylinder 17, preventing soil spillage and aiding in the initial positioning of the cylinder. The groove of the cover plate 16 and the upper positioning groove 23 form two positioning structures, ensuring the coaxial relationship between the sample preparation cylinder 17, the limiting ring, and the lifting plate 3.

[0025] The limiting ring includes a sample pressing limiting ring 19 and a sample pushing limiting ring 20. The sample pushing limiting ring 20 is mounted on the lifting plate 3, and the sample pressing limiting ring 19 is mounted on the sample pushing limiting ring 20. The sample pressing limiting ring 19, the sample pushing limiting ring 20, and the cover plate 16 are all split structures. Specifically, it can be designed as a two-half splicing structure. Furthermore, each half ring can have a quick-connect buckle or magnetic structure to facilitate quick assembly and disassembly during sample preparation.

[0026] After the sample is pressed, the sample pressing retaining ring 19 needs to be removed for subsequent sample pushing. Before pushing the sample, the sample pushing retaining ring 20 needs to be removed. The split ring structure can be easily removed directly from the side without having to be slipped from the top of the sample or the central column 22. This simplifies the operation process, improves efficiency, and reduces the potential collision risk to the formed sample.

[0027] like Figure 6 , Figure 7 ,Figure 8 As shown, a doorway is provided on one side of the bottom of the pusher ring 18, and a movable groove is provided on the lifting plate 3. The movable groove is connected to the upper positioning groove 23. The doorway of the pusher ring 18 is aligned with the movable groove of the lifting plate 3, and the limiting post 21 can be pushed in or pulled out along the movable groove and the doorway.

[0028] The opening at the bottom of the pusher ring 18 and the movable groove on the lifting plate 3, which communicates with the upper positioning groove 23, form a channel for the limiting post 21. When the limiting post 21 needs to be installed to support the central post 22, the limiting post 21 is pushed in laterally along the movable groove, passes through the opening of the pusher ring 18, and reaches below the central post 22. When the limiting post 21 needs to be pulled out to release the central post 22, it can also be pulled out laterally along this channel. The operation of pulling out the limiting post 21 can be completed without moving or disassembling the entire sample preparation mold 7. The operator only needs to operate from the side, avoiding the disturbance to the compacted soil sample 24 that may be caused by disassembly in the vertical direction.

[0029] The pressure frame 1 includes a column 5, a limiting plate 8, and a mounting plate. The column 5 connects the operating table 2, the limiting plate 8, and the mounting plate. The mounting plate is located on the upper side of the limiting plate 8, and the limiting component 4 is mounted on the mounting plate.

[0030] This frame structure provides robust rigid support for the entire compaction and pushing process, ensuring that the components do not undergo significant deformation or displacement under stress. The limiting plate 8, located in the middle layer, acts as an upward stop for the cover plate 16 during compaction. When the operating platform 2 lifts the sample preparation shell, the cover plate 16 eventually abuts against the lower surface of the limiting plate 8. At this point, continued lifting force is applied, and the soil begins to be compacted within the enclosed chamber. The mounting plate, located at the top, is used to secure the limiting component 4.

[0031] The limiting plate 8 has a circular hole in the middle. The diameter of the circular hole is larger than the inner diameter of the sample preparation cylinder 17 and smaller than the outer diameter of the sample preparation cylinder 17. This ensures that during the sample pushing stage, the pushing ring 18 moves upward under the drive of the lifting plate 3, while the sample preparation cylinder 17 is blocked by the limiting plate 8 and remains relatively stationary. The pushing ring 18 then smoothly pushes the pressed annular soil sample 24 out of the sample preparation cylinder 17.

[0032] The limiting component 4 includes a movable pressure rod 13, a bushing 12, and a limiting screw 15. The bushing 12 is fixedly installed on the mounting plate. The movable pressure rod 13 is inserted into the bushing 12. An annular limiting groove 14 is provided on the outer wall of the push rod. The limiting screw 15 is installed on the bushing 12 and can abut against the limiting groove 14 of the movable pressure rod 13.

[0033] When it is necessary to fix the movable pressure rod 13, adjust the movable pressure rod 13 to a suitable height so that the end of the limiting screw 15 is just engaged in the limiting groove 14. Tightening the screw will restrict the up and down movement of the movable pressure rod 13. During the sampling stage, fix the position of the movable pressure rod 13, thereby fixing the top position of the central column 22. At this time, the lifting sampling ring 18 moves upward, which can smoothly push out the soil sample 24. After the sampling is completed, loosen the limiting screw 15, and the movable pressure rod 13 can be lifted to make room for sampling.

[0034] The operating platform 2 includes a motor operating box 11 and a telescopic column 10. The bottom surface of the lifting plate 3 is provided with a lower positioning groove 27, and the telescopic column 10 is installed in the lower limit groove 14 of the lifting plate 3.

[0035] The motor control box 11 integrates a motor, control system, etc., and is used to drive the telescopic column 10 to perform precise telescopic movements. The top of the telescopic column 10 is connected to the lifting plate 3 through the lower positioning groove 27 on the bottom surface of the lifting plate 3.

[0036] The sample preparation device also includes a sampling component, such as... Figure 9 As shown, the sampling assembly includes a sampling clamp 25 and a sample tray 26. The sampling clamp 25 has two semi-circular pieces, which are used to clamp the outer wall of the soil sample 24. The sample tray 26 is used to place the soil sample 24.

[0037] The sampling clamp 25 consists of two semi-ring plates, whose inner arc surface fits against the outer cylindrical surface of the soil sample 24. This fitting design increases the contact area, allowing the clamping force to be evenly distributed on the outer wall of the soil sample 24. This avoids localized stress concentration that may be caused by point or line contact, effectively protecting the soil sample 24 from damage or cracking during clamping and transfer. The sample tray 26 provides a stable temporary platform for the transferred soil sample 24, facilitating its subsequent overall transfer into the ring shear apparatus for testing.

[0038] Four columns 5 connect the electric lifting and pressurizing operating platform 2, the sample preparation and removal limiting plate 8, and the pressure bar platform 9 to form a pressure frame 1. The platform height can be adjusted by nuts 6.

[0039] The bushing 12 in the sample pressing assembly is fitted with a limiting screw 15. The movable pressure rod 13 can be pushed up and down via the handle on top, or pushed upward as the sample center column 22 rises. When the limiting screw 15 is tightened and fixed in the limiting groove 14, the movable pressure rod 13 is fixed, which can restrict the movement of the center column 22. The top of the center column 22 has a spherical groove that can fit tightly against the bottom of the movable pressure rod 13, facilitating pressure application.

[0040] The lower part of the pusher ring 18 has a doorway for the limiting post 21 to enter and exit. The limiting post 21 can be easily and quickly removed without moving the sample preparation mold 7, providing space for the central post 22 to move and allowing the sample to be successfully pushed out. The lifting plate 3 is located directly above the electric lifting and pressurizing operating platform 2 and is fixed to the telescopic post 10 joint through the lower positioning groove 27, ensuring that it is always on a horizontal plane during the pressing process. The positioning groove 23 on the lifting plate 3 can fix the position of the pusher ring 18 and has a movable groove for the limiting post 21 to enter and exit. When placing it, the doorway of the pusher ring 18 should be aligned with the movable groove of the lifting plate 3 to facilitate the subsequent removal of the limiting post 21.

[0041] The cover plate 16 has a groove at the bottom, which can be fixed on the top of the sample preparation cylinder 17 after the soil sample 24 is installed; the cover plate 16, the pressing limit ring 19, and the pushing limit ring 20 are all spliced ​​structures divided into two halves, which can be easily installed and disassembled; the pressing limit ring 19 and the pushing limit ring 20 are installed on the outside of the pushing ring 18 and have handles for easy disassembly.

[0042] In summary, by setting up the sample preparation mold and other structures, soil material can be added in one go, improving the success rate of sample preparation, reducing the sample preparation time, and simplifying the operation while ensuring the integrity and uniformity of the sample. This overcomes the defects of not being able to control the moisture content and density during the ring shear sample preparation process, and is an effective method for controlling ring shear sample preparation.

[0043] Example 2 This embodiment provides a sample preparation method for the rapid geotechnical ring shear specimen preparation device as described above, including: Install the pusher ring in the upper positioning groove of the lifting plate and align the doorway of the pusher ring with the movable groove of the lifting plate. Insert the limiting post into the doorway of the pusher ring along the movable groove. Place the center post above the limiting post and make the groove of the center post face upward. Install the pusher limiting ring and the pressing limiting ring in sequence on the outside of the pusher ring. Install the sample preparation cylinder above the pressing limiting ring. The soil material is added into the sample preparation cylinder all at once; Place the cover plate on the upper end of the sample preparation cylinder, press down the movable pressure rod so that its bottom end contacts the groove of the central column, drive the operating table to rise, so that the cover plate abuts against the limit plate, remove the sample pressing limit ring, continue to raise the lifting plate, so that the soil in the sample preparation cylinder is compacted and maintained for the set time. Lower the operating platform, remove the cover plate and the sample pushing limit ring, pull out the limit column from the movable groove, fix the position of the movable pressure bar, continue to raise the lifting plate, and push the sample pushing ring to move the soil sample upward until the soil sample is completely separated from the sample preparation cylinder. Release the limit on the movable pressure bar and lift the movable pressure bar. Use the sampling clamp to hold the outer wall of the soil sample and transfer the soil sample to the sample tray.

[0044] The specific implementation includes the following steps: Step 1: Prepare the soil for the test. Prepare the target moisture content sample according to the following formula.

[0045]

[0046] In the formula: m The total mass of the sample is expressed in grams. w The moisture content of the sample is %; p d The dry density of the sample is given in g / cm³. 3 ; V The total volume of the sample is in cm³. 3 .

[0047] Step Two: As Figure 3 As shown, the electric lifting and pressurizing operating platform is lowered to its lowest position. The lifting plate is fixed to the telescopic column joint through the lower positioning groove. The sample pushing ring is installed on the positioning groove on the lifting plate. When placing it, the doorway of the sample pushing ring should be aligned with the movable groove of the lifting plate. The limiting column is placed into the center of the sample pushing ring along the movable groove. The groove of the center column is placed directly above the limiting column with its groove facing upward. The sample pushing limiting ring and the sample pressing limiting ring are installed on the outside of the sample pushing ring in sequence. The sample preparation cylinder is installed above the sample pressing limiting ring.

[0048] Step 3: According to the sample size required for the test, add the soil material into the sample preparation cylinder all at once and cover it with the cover plate.

[0049] Step Four: As Figure 4 As shown, push down the movable pressure rod to contact the central column, and operate the electric lifting and pressurizing operating platform to press the cover plate to the sample preparation and removal limiting plate. Remove the pressing limiting ring. At this time, the upper end of the sample preparation cylinder is still in the groove of the cover plate. Continue to raise the lifting plate to compact the soil sample and maintain it for a period of time.

[0050] Step 5: Slightly lower the electric lifting and pressurizing operating platform, remove the cover plate and the sample pushing limit ring, take out the limit column, and fix the limit screw to the groove of the movable pressure rod to limit the displacement of the movable pressure rod before continuing to rise. Raise the lifting plate so that the top of the sample preparation cylinder presses against the sample preparation and removal limit plate, and the sample pushing ring pushes the soil sample upwards until the soil sample is completely pushed out. Figure 5 As shown.

[0051] Step Six: Loosen the limit screw and pull the movable pressure rod handle away from the soil sample. Use the sampling clamp to pick up the soil sample and transfer it to the sample tray.

[0052] While the specific embodiments of the present invention have been described above, they are not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A rapid sample preparation device for geotechnical ring shear test specimens, characterized in that, include: Sample preparation molds and sample pressing components; The sample preparation mold includes a sample preparation shell, a sample ejector ring, a limiting post, and a central post. The sample ejector ring is installed inside the sample preparation shell, and the limiting post and the central post are sequentially installed inside the sample ejector ring. The sample ejector ring, the central post, and the sample preparation shell form a sample preparation chamber. The sample pressing assembly includes a pressure frame, an operating table, and a limiting component. The sample preparation shell is mounted on the operating table and can move upward under the lifting action of the sample preparation table. The limiting component is mounted on the pressure frame, and the bottom of the limiting component can abut against the top of the central column.

2. The rapid sample preparation device for geotechnical ring shear test specimens as described in claim 1, characterized in that, The sample preparation shell includes a lifting plate, a limiting ring, a sample preparation cylinder, and a cover plate. The limiting ring and the sample preparation cylinder are sequentially installed on the lifting plate, and the cover plate is installed on the sample preparation cylinder. The top surface of the lifting plate is provided with an upper positioning groove, the lower end of the limiting ring is installed in the upper positioning groove, the bottom surface of the cover plate is provided with a groove, and the upper end of the sample preparation cylinder is embedded in the groove.

3. The rapid sample preparation device for geotechnical ring shear test specimens as described in claim 2, characterized in that, The limiting ring includes a pressing limiting ring and a pushing limiting ring. The pushing limiting ring is installed on the lifting plate, and the pressing limiting ring is installed on the pushing limiting ring. The pressing limiting ring, the pushing limiting ring, and the cover plate are all separate structures.

4. The rapid sample preparation device for geotechnical ring shear test specimens as described in claim 3, characterized in that, The bottom side of the pusher ring has a doorway, and the lifting plate has a movable groove. The movable groove is connected to the upper positioning groove. The doorway of the pusher ring is aligned with the movable groove of the lifting plate, and the limiting post can be pushed in or pulled out along the movable groove and the doorway.

5. The rapid sample preparation device for geotechnical ring shear test specimens as described in claim 2, characterized in that, The pressure frame includes a column, a limiting plate, and a mounting plate. The column connects the operating table, the limiting plate, and the mounting plate. The mounting plate is located above the limiting plate, and the limiting component is mounted on the mounting plate.

6. The rapid sample preparation device for geotechnical ring shear test specimens as described in claim 5, characterized in that, The limiting plate has a circular hole in the middle, the diameter of which is larger than the inner diameter of the sample preparation cylinder and smaller than the outer diameter of the sample preparation cylinder.

7. The rapid sample preparation device for geotechnical ring shear test specimens as described in claim 5, characterized in that, The limiting component includes a movable pressure rod, a bushing, and a limiting screw. The bushing is fixedly installed on the mounting plate, the movable pressure rod is inserted into the bushing, and an annular limiting groove is provided on the outer wall of the push rod. The limiting screw is installed on the bushing and can abut against the limiting groove of the movable pressure rod.

8. The rapid sample preparation device for geotechnical ring shear test specimens as described in claim 2, characterized in that, The control panel includes a motor control box and a telescopic column. The bottom surface of the lifting plate is provided with a lower positioning groove, and the telescopic column is installed in the lower limit groove of the lifting plate.

9. The rapid sample preparation device for geotechnical ring shear test specimens as described in claim 1, characterized in that, The sampling device also includes a sampling component, which includes a sampling clamp and a sample tray. The sampling clamp has two semi-circular plates, which are used to clamp the outer wall of the soil sample. The sample tray is used to place the soil sample.

10. A method for preparing a geotechnical ring shear specimen using a rapid specimen preparation device as described in any one of claims 1-9, characterized in that, include: Install the pusher ring in the upper positioning groove of the lifting plate and align the doorway of the pusher ring with the movable groove of the lifting plate. Insert the limiting post into the doorway of the pusher ring along the movable groove. Place the center post above the limiting post and make the groove of the center post face upward. Install the pusher limiting ring and the pressing limiting ring in sequence on the outside of the pusher ring. Install the sample preparation cylinder above the pressing limiting ring. The soil material is added into the sample preparation cylinder all at once; Place the cover plate on the upper end of the sample preparation cylinder, press down the movable pressure rod so that its bottom end contacts the groove of the central column, drive the operating table to rise, so that the cover plate abuts against the limit plate, remove the sample pressing limit ring, continue to raise the lifting plate, so that the soil in the sample preparation cylinder is compacted and maintained for the set time. Lower the operating platform, remove the cover plate and the sample pushing limit ring, pull out the limit column from the movable groove, fix the position of the movable pressure bar, continue to raise the lifting plate, and push the sample pushing ring to move the soil sample upward until the soil sample is completely separated from the sample preparation cylinder. Release the limit on the movable pressure bar and lift the movable pressure bar. Use the sampling clamp to hold the outer wall of the soil sample and transfer the soil sample to the sample tray.

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