Ring-shaped sample sampler and sampling method thereof

Abstract

The present invention provides a ring-shaped sample sampler and a sampling method thereof. The ring-shaped sample sampler includes a connecting ring, a pressure plate, an inner ring knife and an outer ring knife. The inner ring knife and the outer ring knife are coaxially spaced and form a cavity for placing the sample in the space. The outer ring knife is located on the outside of the inner ring knife; the connecting ring is placed on the upper end of the outer ring knife and abuts against the outer surface of the inner ring knife; the pressure plate is connected to the lower end of the connecting ring. The pressure plate is an annular structure with an inner circular wall and an outer circular wall. The inner circular wall abuts against the outer surface of the inner ring knife, and the outer circular wall abuts against the connecting ring; the lower ends of the inner ring knife and the outer ring knife are both provided with a cutting edge, and the cutting edge is set away from the cavity. The ring-shaped sample sampler provided by the present invention, the design of the inner and outer double ring knives, realizes the preparation of a complete annular original sample.

Description

Technical Field

[0001] The invention relates to the technical field of large-scale ring shear tests in the field of landslide disasters, and in particular to a ring-shaped sample sampler and a sampling method thereof. Background Art

[0002] A ring shear tester is a geotechnical testing device used to study the mechanical properties of soil under large shear displacement conditions. It is primarily used to investigate the residual strength of soil after the shear surface is formed. With advances in geotechnical testing equipment research and development, the ring shear tester has been increasingly used in the study of landslide hazard mechanisms and landslide motion processes.

[0003] In order to clarify the mechanical properties of sliding zone soil and slope failure mode, it is necessary to carry out systematic sliding zone soil ring shear tests. In order to obtain reasonable test results and correct mechanical parameters, an efficient undisturbed sample sampler is the key to the success of the test.

[0004] At present, there is no dedicated undisturbed ring sample sampler suitable for large-scale multifunctional ring shear tests. Moreover, the reshaped samples cannot reflect the structural characteristics of the on-site soil, which will lead to large differences between the test results and the undisturbed sample results. Therefore, there is an urgent need for an undisturbed sampler that is specifically used for large-scale ring shear experiments in the field of landslide disasters and has good anti-disturbance function. Summary of the Invention

[0005] The object of the present invention is to provide a ring sample sampler and a sampling method thereof, so as to solve the problem that ring samples cannot be prepared and realize on-site acquisition of complete ring samples that can maintain the structural characteristics of the samples.

[0006] The technical solution of the present invention is: a ring-shaped sample sampler includes a connecting ring, a pressure plate, an inner ring knife and an outer ring knife, the inner ring knife and the outer ring knife are coaxially spaced and a cavity for placing the sample is formed in the interval, and the outer ring knife is located on the outside of the inner ring knife; the connecting ring is placed on the upper end of the outer ring knife and abuts against the outer surface of the inner ring knife; the pressure plate is connected to the lower end of the connecting ring, and the pressure plate is an annular structure with an inner circular wall and an outer circular wall, the inner circular wall abuts against the outer surface of the inner ring knife, and the outer circular wall abuts against the connecting ring; the lower ends of the inner ring knife and the outer ring knife are both provided with a cutting edge, and the cutting edge is arranged away from the cavity.

[0007] In the above scheme, the inner ring cutter and the outer ring cutter are designed to realize the preparation of complete annular original specimens, which can be used in the original specimens of hollow torsional shear tests to solve the problem of being unable to prepare annular specimens and realize on-site acquisition of complete annular specimens that can maintain the structural characteristics of the specimens.

[0008] Preferably, the connecting ring includes a connecting portion and a clamping portion, the connecting portion is annular, the clamping portion extends axially downward on the outer ring wall of the connecting portion, the clamping portion is provided with a clamping groove that is clamped with the upper end of the outer ring knife, and the inner ring wall surface of the connecting portion abuts against the outer surface of the inner ring knife.

[0009] Preferably, the annular sample sampler also includes a first connecting member; a plurality of arc-shaped through holes are circumferentially provided on the connecting portion; threaded holes corresponding to the number of the plurality of arc-shaped through holes are circumferentially provided on the pressure plate, one end of the first connecting member is threadedly connected to the threaded hole, and the other end is located in the arc-shaped through hole.

[0010] Preferably, the annular sample sampler also includes an upper cover plate and a lower cover plate, the upper cover plate is pressed onto the upper surface of the inner ring knife, and the middle part of the upper cover plate extends into the inner ring of the inner ring knife; the lower cover plate is pressed onto the lower ends of the outer ring knife and the inner ring knife, and the middle part of the lower cover plate extends into the inner ring of the inner ring knife.

[0011] Preferably, a first boss is provided in the middle of the upper cover plate, and a second boss is provided in the middle of the lower cover plate, and both the first boss and the second boss are adapted to the inner ring diameter of the inner ring cutter.

[0012] Preferably, the annular sample sampler further comprises a second connecting member connecting the upper cover plate and the lower cover plate, and the second connecting member is passed through the inner ring of the inner ring knife.

[0013] Preferably, an annular ring knife ear is provided on the outer wall of the outer ring knife.

[0014] Preferably, the bottom of the cutting edge is 1 mm thick.

[0015] The present invention also provides a sampling method of the above-mentioned ring-shaped sample sampler, comprising:

[0016] 1) First, artificially prepare the block: When sampling, first remove the soil layer about 0.5m thick on the surface, and then prepare the block soil sample;

[0017] 2) Use the outer ring knife to cut the block soil sample and embed the outer ring knife into the soil sample to form a ring knife sample;

[0018] 3) Place the ring knife sample in step 2) on a clay table;

[0019] 4) Place the pressing plate on the upper surface of the ring knife specimen;

[0020] 5) Connect the inner ring cutter to the connecting ring;

[0021] 6) Use a soil chipper to dig through the soil in the middle of the ring knife specimen to form a circular hole;

[0022] 7) Apply vaseline to the inner ring knife; place the inner ring knife in the circular hole, and then press down the connecting ring and the inner ring knife until the inner ring knife sinks and is flush with the bottom of the outer ring knife;

[0023] 8) At this time, the sample is contained in the cavity;

[0024] 9) Clean the soil at the bottom, install the upper cover and the lower cover respectively, and then connect the upper cover and the lower cover with a second connecting piece to seal the sample in the cavity.

[0025] Compared with the related art, the present invention has the following beneficial effects:

[0026] 1. The ring sampler has a design of inner and outer double ring cutters, which enables the preparation of complete ring-shaped original samples;

[0027] 2. The inner and outer ring cutters have cutting edges, which is beneficial for cutting specimens and avoids structural damage caused by cutting original specimens;

[0028] 3. Connecting the upper cover and the lower cover through connectors can ensure the sealing of the sample. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic diagram of the three-dimensional structure of the annular sample sampler provided by the present invention;

[0030] Figure 2 A schematic diagram of the internal structure of the annular sample sampler provided by the present invention;

[0031] Figure 3 for Figure 1 A schematic diagram of the structure from above with the upper cover removed;

[0032] Figure 4 Schematic diagram of the obtained ring experiment.

[0033] In the accompanying drawings: 1. Upper cover plate; 2. Connecting ring; 3. Test specimen; 4. Lower cover plate; 5. Pressing plate; 6. Ring knife ear; 7. Inner ring knife; 8. Outer ring knife; 9. Cutting edge; 10. Second connecting piece; 11. Arc-shaped through hole; 12. First connecting piece; 13. Cavity; 14. Inner circular wall; 15. Outer circular wall; 16. Threaded hole; 17. Connecting part; 18. Clamping part; 19. Clamping groove; 20. Ring groove; 21. First boss; 22. Second boss. DETAILED DESCRIPTION

[0034] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments. It should be noted that the embodiments and features of the embodiments may be combined unless they conflict. For ease of description, the words "upper," "lower," "left," and "right" appear below merely to indicate the directions of upper, lower, left, and right in the accompanying drawings and do not limit the structure.

[0035] like Figure 1 、 Figure 2 As shown, the ring-shaped sample sampler provided in this embodiment includes an upper cover plate 1, a connecting ring 2, a lower cover plate 4, a pressure plate 5, a ring knife ear 6, an inner ring knife 7, an outer ring knife 8, a cutting edge 9, a second connecting member 10 and a first connecting member 12.

[0036] The inner ring cutter 7 and the outer ring cutter 8 are coaxially spaced and form a cavity 13 for placing the sample 3 within the space, and the outer ring cutter 8 is located on the outside of the inner ring cutter 7. The lower ends of the inner ring cutter 7 and the outer ring cutter 8 are both provided with a cutting edge 9, and the cutting edge 9 is set away from the cavity 13. The cutting edge 9 is set obliquely downward at a distance of 20 mm from the bottom of each ring cutter. The bottom of the cutting edge 9 (i.e., the thickness of the bottom ring of the ring cutter) is 1 mm thick, which is conducive to cutting the original soil and ensuring the integrity and anti-disturbance of the ring shape of the sample 3 (such as Figure 4 An annular ring blade ear 6 is provided on the outer wall of the outer ring blade 8.

[0037] The connecting ring 2 is placed on the upper end of the outer ring knife 8 and abuts against the outer surface of the inner ring knife 7. The pressure plate 5 is connected to the lower end of the connecting ring 2. The connecting ring 2 includes a connecting portion 17 and a clamping portion 18. The connecting portion 17 is annular and has a plurality of arc-shaped through holes 11 circumferentially provided thereon. The clamping portion 18 extends axially downward on the outer ring wall of the connecting portion 17. The clamping portion 18 is provided with a clamping groove 19 that is clamped with the upper end of the outer ring knife 8. The clamping groove 19 is arranged inwardly so that the outer wall of the clamping portion 18 forming the clamping groove 19 can be covered on the outside of the outer ring knife 8. The inner ring wall surface of the connecting portion 17 abuts against the outer surface of the inner ring knife 7. The connecting ring 2 ensures that the outer ring knife 8 and the inner ring knife 7 are coaxial, and plays a role in positioning and supporting the inner ring knife 7.

[0038] The pressure plate 5 is an annular structure having an inner circular wall 14 and an outer circular wall 15. The inner circular wall 14 abuts against the outer surface of the inner ring knife 7, and the outer circular wall 15 abuts against the inner wall surface of the clamping portion 18 of the connecting ring 2. The lower surface of the pressure plate 5 is a smooth plane, which fits the upper end of the sample 3. The pressure plate 5 is provided with threaded holes 16 in a circumferential manner corresponding to the number of the plurality of arc-shaped through holes 11. The first connecting member 12 is a bolt, which is threadedly connected to the threaded holes 16, and the bolt head is located in the arc-shaped through hole 11. If it is necessary to fix the connecting ring 2 to the pressure plate 5, a horizontally extending sink is provided at the bottom of the arc-shaped channel 11, and the bolt head of the first connecting member 12 is clamped with the sink. The first connecting member 12 needs to be installed and fixed when the sampler is not sampling. The first connecting member 12 needs to be removed during the sampling process or when the sampling is completed and stored.

[0039] A first boss 21 is provided in the middle of the upper cover plate 1, and a second boss 22 is provided in the middle of the lower cover plate 4. Both the first boss 21 and the second boss 22 are adapted to the inner ring diameter of the inner ring cutter 7. An annular groove 20 is provided on the edge of the lower cover plate 4. Both the upper cover plate 1 and the lower cover plate 4 have through holes in their middles.

[0040] The upper cover plate 1 is pressed onto the upper surface of the inner ring knife 7, and the first boss 21 of the upper cover plate 1 extends into the inner ring of the inner ring knife 7. The lower cover plate 4 is pressed onto the lower ends of the outer ring knife 8 and the inner ring knife 7, so that the cutting edges 9 of the outer ring knife 8 and the inner ring knife 7 are both located in the annular groove 20. The second boss 22 of the lower cover plate 4 extends into the inner ring of the inner ring knife 7. The second connecting member 10 is located in the inner ring of the inner ring knife 7 and is adapted to the through holes on the upper cover plate 1 and the lower cover plate 4 before being tightened. The upper cover plate 1 and the lower cover plate 4 are connected together by the second connecting member 10, which facilitates the transportation of the test to the laboratory and ensures the effective closure of the sample 3.

[0041] In this embodiment, the first connecting member 12 and the second connecting member 10 include bolts, nuts and washers.

[0042] After the sample is taken, to ensure sealing and prevent moisture loss, the pressing plate 5, the lower cover plate 4, the inner ring blade 7, and the outer ring blade 8 together form the closed cavity 13. In another embodiment, the lower cover plate 4 can also be omitted, so that the cavity 13 is formed by only the pressing plate 5, the inner ring blade 7, and the outer ring blade 8 on three sides, and the other end is opened and pressed tightly and sealed with another sealing film.

[0043] In this embodiment, a lower cover plate 4 is provided to enclose the cavity 13 on all sides, which can not only support the annular sample 3, but also better prevent the bottom of the sample 3 from losing water and causing disturbance, thereby ensuring the accuracy of the test and the validity of the results.

[0044] like Figure 4As shown, the original sample 3 obtained by the sampler is a ring-shaped soil sample with different inner and outer diameters. The diameters of the ring cutters of different sampler specifications are different, resulting in different inner and outer diameter differences of the ring sample. Therefore, when designing and manufacturing the sampler, the experimental purpose and parameter requirements must be considered.

[0045] The sampling process of the ring sampler is as follows: To ensure the structural characteristics of sample 3 in its natural state, a block sample method is used. First, approximately 0.5m of soil is removed from the surface of the soil layer. A 250mm x 250mm x 250mm block of soil is then formed. The block of soil is then cut using an outer ring cutter 8 with an inner diameter of 200mm and a height of 60mm. The outer ring cutter 8 is then embedded in the soil sample to form a ring cutter sample.

[0046] Place the prepared original ring knife sample on the soil-digging platform to facilitate the removal of the soil in the middle of the sample when preparing the ring sample. At this time, the first connecting piece 12 does not need to be installed. Place the pressing plate 5 on the upper surface of the ring knife sample soil. Then clamp the inner ring knife 7 into the slot 19 of the connecting ring 2. Use a soil-cutting knife (sharp knife) to dig through a part of the middle soil of the ring knife sample soil to form a circular hole. Apply vaseline on the inner ring knife 7. Place the inner ring knife 7 at the circular hole, and then slowly press down the connecting ring 2 and the inner ring knife 7 until the inner ring knife 7 is completely sunk to be flush with the lower part of the outer ring knife 8. The connecting ring 2 fits the pressing plate 5. Remove the debris, and the sample 3 is placed in the cavity 13. Make the prepared sample 3 as follows Figure 4 The ring shown.

[0047] The upper cover plate 1 and the lower cover plate 4 are installed separately, and then connected and fixed with the second connecting member 10 to ensure that the moisture content of the sample 3 does not change significantly during transportation and storage.

[0048] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A sampling method for an annular sample sampler, which is performed using an annular sample sampler, wherein the annular sample sampler comprises a connecting ring (2), a pressing plate (5), an inner ring knife (7) and an outer ring knife (8), wherein the inner ring knife (7) and the outer ring knife (8) are coaxially spaced and a cavity (13) for placing the sample is formed in the space, and the outer ring knife (8) is located outside the inner ring knife (7); the connecting ring (2) is placed on the upper end of the outer ring knife (8) and is in contact with the inner ring knife ( 7); the pressure plate (5) is connected to the lower end of the connecting ring (2), and the pressure plate (5) is an annular structure having an inner circular wall (14) and an outer circular wall (15), the inner circular wall (14) abuts the outer surface of the inner ring knife (7), and the outer circular wall (15) abuts the connecting ring (2); the lower ends of the inner ring knife (7) and the outer ring knife (8) are provided with a cutting edge (9), and the cutting edge (9) is arranged away from the cavity (13); it is characterized in that, include: 1) First, artificially prepare the block: When sampling, first remove the soil layer about 0.5m thick on the surface, and then prepare the block soil sample; 2) using an outer ring knife (8) to cut the block soil sample, and embedding the outer ring knife (8) into the soil sample to form a ring knife sample; 3) Place the ring knife sample from step 2) on the clay table; 4) Place the pressing plate (5) on the upper surface of the ring knife specimen; 5) Connect the inner ring cutter (7) to the connecting ring (2); 6) Use a soil chipper to dig through the soil in the middle of the ring knife specimen to form a circular hole; 7) Apply vaseline on the inner ring knife (7); place the inner ring knife (7) on the circular hole, and then press down the connecting ring (2) and the inner ring knife (7) until the inner ring knife (7) sinks and is flush with the lower part of the outer ring knife (8); 8) At this time, the sample is contained in the cavity (13); 9) Clean the soil at the bottom, install the upper cover plate (1) and the lower cover plate (4) respectively, and then connect the upper cover plate (1) and the lower cover plate (4) with a second connecting piece to seal the sample in the cavity (13).

2. The sampling method of the ring sampler according to claim 1, characterized in that: The connecting ring (2) includes a connecting portion (17) and a clamping portion (18), wherein the connecting portion (17) is annular, and the clamping portion (18) extends axially downward on the outer ring wall of the connecting portion (17). The clamping portion (18) is provided with a clamping groove (19) clamped with the upper end of the outer ring knife (8), and the inner ring wall surface of the connecting portion (17) abuts against the outer surface of the inner ring knife (7).

3. The sampling method of the ring sampler according to claim 2, characterized in that: The annular sample sampler further comprises a first connecting member (12); a plurality of arc-shaped through holes (11) are circumferentially provided on the connecting portion (17); threaded holes (16) corresponding in number to the plurality of arc-shaped through holes (11) are circumferentially provided on the pressing plate (5); one end of the first connecting member (12) is threadedly connected to the threaded hole (16), and the other end is located in the arc-shaped through hole (11).

4. The sampling method of the ring sampler according to claim 1, characterized in that: The annular sample sampler further comprises an upper cover plate (1) and a lower cover plate (4), wherein the upper cover plate (1) is pressed onto the upper surface of the inner ring knife (7), and the middle portion of the upper cover plate (1) extends into the inner ring of the inner ring knife (7); and the lower cover plate (4) is pressed onto the lower ends of the outer ring knife (8) and the inner ring knife (7), and the middle portion of the lower cover plate (4) extends into the inner ring of the inner ring knife (7).

5. The sampling method of the ring-shaped sample sampler according to claim 4, characterized in that: An annular groove (20) is provided on the edge of the lower cover plate (4), and the cutting edges (9) are all located in the annular groove (20).

6. The sampling method of the ring sampler according to claim 4, characterized in that: A first boss (21) is provided in the middle of the upper cover plate (1), and a second boss (22) is provided in the middle of the lower cover plate (4). Both the first boss (21) and the second boss (22) are adapted to the inner ring diameter of the inner ring cutter (7).

7. The sampling method of the ring-shaped sample sampler according to claim 4, characterized in that: The annular sample sampler further comprises a second connecting member (10) connecting the upper cover plate (1) and the lower cover plate (4), wherein the second connecting member (10) is inserted into the inner ring of the inner ring knife (7).

8. The sampling method of the ring sampler according to claim 1, characterized in that: An annular ring blade ear (6) is provided on the outer wall of the outer ring blade (8).

9. The sampling method of the ring-shaped sample sampler according to claim 1, characterized in that: The bottom of the cutting edge (9) is 1 mm thick.

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