LU504243B1 - A triaxial compression specimen making device and method for making specimens of in-situ soils - Google Patents
A triaxial compression specimen making device and method for making specimens of in-situ soils Download PDFInfo
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- LU504243B1 LU504243B1 LU504243A LU504243A LU504243B1 LU 504243 B1 LU504243 B1 LU 504243B1 LU 504243 A LU504243 A LU 504243A LU 504243 A LU504243 A LU 504243A LU 504243 B1 LU504243 B1 LU 504243B1
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- 239000002689 soil Substances 0.000 title claims abstract description 296
- 238000011065 in-situ storage Methods 0.000 title claims abstract description 35
- 230000006835 compression Effects 0.000 title claims abstract description 28
- 238000007906 compression Methods 0.000 title claims abstract description 28
- 238000000034 method Methods 0.000 title claims abstract description 19
- 238000005520 cutting process Methods 0.000 claims abstract description 70
- 238000002360 preparation method Methods 0.000 claims description 10
- 230000000712 assembly Effects 0.000 claims description 8
- 238000000429 assembly Methods 0.000 claims description 8
- 239000012780 transparent material Substances 0.000 claims description 5
- 238000004519 manufacturing process Methods 0.000 claims description 3
- 238000012805 post-processing Methods 0.000 claims description 3
- 238000007781 pre-processing Methods 0.000 claims description 2
- 230000013011 mating Effects 0.000 claims 1
- 238000012360 testing method Methods 0.000 abstract description 16
- 238000010586 diagram Methods 0.000 description 5
- 239000002184 metal Substances 0.000 description 4
- 229910000831 Steel Inorganic materials 0.000 description 3
- 239000010959 steel Substances 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 2
- 238000009434 installation Methods 0.000 description 2
- 238000002203 pretreatment Methods 0.000 description 2
- 101100008048 Caenorhabditis elegans cut-4 gene Proteins 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 235000014121 butter Nutrition 0.000 description 1
- 238000012669 compression test Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 235000019271 petrolatum Nutrition 0.000 description 1
- 239000005341 toughened glass Substances 0.000 description 1
- 238000009966 trimming Methods 0.000 description 1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
- G01N1/286—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q involving mechanical work, e.g. chopping, disintegrating, compacting, homogenising
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
- G01N1/286—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q involving mechanical work, e.g. chopping, disintegrating, compacting, homogenising
- G01N2001/2873—Cutting or cleaving
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/0014—Type of force applied
- G01N2203/0016—Tensile or compressive
- G01N2203/0019—Compressive
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/02—Details not specific for a particular testing method
- G01N2203/026—Specifications of the specimen
- G01N2203/0262—Shape of the specimen
- G01N2203/0266—Cylindrical specimens
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/02—Details not specific for a particular testing method
- G01N2203/026—Specifications of the specimen
- G01N2203/0298—Manufacturing or preparing specimens
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- Life Sciences & Earth Sciences (AREA)
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- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
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- Sampling And Sample Adjustment (AREA)
Abstract
The present invention discloses a triaxial compression specimen making device and method for making specimens of in-situ soils, wherein the triaxial compression specimen making device for in-situ soils comprises: a fixed frame; a soil cutting knife with a mounting section and a knife blade section at each end of the knife The sample lifting device is provided for lifting the sample in the direction of the knife blade. The invention enables the sample to be cut out of the sample for triaxial testing by driving the sample in a straight line close to the cutter so that the cutter can move in a straight line with respect to the sample. The diameter of the specimen is precisely defined by the diameter of the inner cavity of the cutter.
Description
A triaxial compression specimen making device and method for making" specimens of in-situ soils
The present invention relates to the technical field of geotechnical testing, in particular to a triaxial compression specimen making device and method for making specimens of in-situ soils.
Background technology
The measurement of stress-strain relationships in conventional triaxial compression specimens of in-situ soils is one of the most common methods for studying the mechanical properties of soils and obtaining strength indices of soils. The effective preparation of the specimen is the key to obtaining accurate mechanical properties of soils based on the conventional triaxial compression test described above. Irregularities in the shape of the specimen or deviations in the actual dimensions from the expected values can affect the test results. In particular, in-situ soil specimens must not only meet the relevant requirements of the geotechnical test code, but also be prepared with as little disturbance as possible.
According to the Geotechnical Test Specification (GBT50123-2019), a conventional triaxial test-based in-situ soil specimen is cylindrical in shape with geometrical dimensions of 39. 1mm, 61.8mm or 101.0mm in diameter at the base and 2.0 to 2.5 times the diameter at the base. In order to obtain in-situ soil specimens of the above specifications, the geotechnical test specification gives the corresponding sample preparation apparatus and its method of operation.
In particular, the sample preparation device mainly comprises a top plate, a base plate located below the top plate and a support column connecting the top plate and the base plate, with a base on the side of the base plate facing the top surface and a positioning slot on the side of the base plate facing the top plate for positioning the soil sample by putting the end of the soil sample in.
In terms of operation, the soil sample is generally positioned on the base and then manually cut by means of a wire saw or soil chipper to obtain a sample of the required size. It should be noted that when cutting the specimens based on the above-mentioned sample making device, the specimen has to be manually repositioned on the base continuously, i.e. the specimen is cut as it rotates. From a practical point of view, this method of specimen production suffers from low efficiency and imprecise dimensions. Therefore, a new type of conventional triaxial compression specimen making device and method for in-situ soils is needed to solve these problems.
Summary of the invention 0006863
In response to the existing technical problems, the present invention provides A triaxial compression specimen making device and method for making specimens of in-situ soils, which is simpler to operate, more efficient to make and has a high accuracy of making.
In order to achieve the above objectives, the technical solutions used in the present invention are
A triaxial compression specimen making device for in-situ soils, comprising a fixed frame; soil cutter for cutting a cylindrical specimen from a soil sample, said soil cutter being in the form of a cylinder with open ends, said soil cutter comprising at least two curved plates, said curved plates being disassembled to form said soil cutter and being removable after the specimen has been cut and shaped to allow the specimen to be removed, said soil cutter having a mounting section and a blade section at each end, said mounting section being mounted on said fixed frame a soil sample lifting device, provided corresponding to said knife blade section, for lifting the soil sample in a straight line in the direction of said knife blade section to allow said soil cutting knife to cut the soil sample.
The beneficial effect of the present invention is that by providing a hollow soil cutter in the form of a cylinder and a sample lifting device for driving the soil sample in the direction of the soil cutter, and by providing that the soil cutter is made of at least two curved plates which can be disassembled to move the soil sample in a straight line, the soil cutter can move in a straight line relative to the soil sample to cut a cylindrical sample of a specified diameter on the soil sample. After the cutter has been cut, the sample is removed by dismantling the cutter and the ends of the sample are cut by means of a metal wire to produce a final specimen of a predetermined length for conventional triaxial testing. In contrast to the conventional method of cutting cylindrical specimens of a specified diameter while rotating, the present invention enables the cutting of specimens of a specified diameter from the soil sample by moving the sample in a straight line with a barrel-shaped cutter.
In one embodiment, said fixed frame comprises a top plate, a bottom plate and at least two support posts connecting said top plate and said bottom plate; said soil cutting knife and said soil sample lifting device are mounted on said top plate and said bottom plate, respectively, and are located between said top plate and said bottom plate. The fixing frame has a simple structural 02 set-up and is easy to make.
In one of the embodiments, said top plate is provided with at least two annular walls for mounting said soil cutter on the side facing said soil lifting device, said annular walls being set in the same circle and spaced towards the radius of said annular walls, each said annular wall being provided with internal threads on the inner wall; said mounting part of said soil cutter extends into said corresponding annular wall and fits into the internal threads of said corresponding annular wall. the internal threads of the corresponding annular wall. By providing that the number of annular walls for mounting the soil cutter is at least two and that none of the annular walls is of the same size, it is possible to selectively mount at least two different sizes of soil cutter, thus enabling the in-situ soil triaxial compression specimen making device of the present invention to cut and shape specimens of at least two different diameter sizes.
In one of the embodiments, the smallest diameter annular wall is provided with an air hole in the top plate. By providing air holes in the top part of the smallest diameter annular wall, it is possible to release the gas, remove the air pressure difference during the cutting process and reduce the resistance to cutting caused by the gas in the cavity of the cutter.
In one of the embodiments, the cutter is made of transparent material. By providing that the cutter is made of transparent material, it is possible to easily observe the state of the soil sample as it enters the cutter.
In one embodiment, said soil sample lifting device comprises a base for placing the soil sample and a lifting mechanism mounted on said fixed frame, said lifting mechanism being located on the side of the base away from said top plate.
In one embodiment, said lifting mechanism comprises two linkage assemblies, screws and drive members, each said linkage assembly comprising two first links, two second links and a slider, each said first linkage being pivoted at one end to the base and at the other end to said slider, each said second linkage being pivoted at one end to said base plate and at the other end to said slider; said screws being threaded to said sliders of both said linkage assemblies, both said sliders being pivoted at one end to said base plate. said screws are threaded to said sliders of both said rod assemblies, both said sliders being threaded in opposite directions to said screws, said drive member being connected to one end of said screws.
A method for making a triaxial compressive specimen of in-situ soil, based on a a compressive specimen making device for in-situ soil as described above, comprising the steps of assembling and mounting said soil cutter: assembling said curved plate of the desired size into said soil cutter of the desired size, and mounting said soil cutter on a fixed frame assembling and commissioning said soil sample lifting device: mounting said soil sample lifting device on the fixed frame and, once mounted, commissioning said soil sample lifting device; pre-processing and placing the soil sample: providing the soil sample to be cut, pre-cutting said soil sample to the size that said soil sample lifting device allows to be placed, forming the pre-processed soil sample, placing the pre-processed soil sample on said lifting device for the soil sample cutting the pre-treated soil sample: driving said soil sample lifting device to lift the soil sample, causing said soil cutter to cut into said soil sample, cutting away said portion of said soil sample that does not pass through the outer wall of said soil cutter as said soil cutter enters said soil sample, stopping cutting when said soil cutter enters said soil sample to a specified depth, dismantling said soil cutter and obtaining a preformed specimen of the desired diameter size
Post-processing of the initial formed specimen: cutting off the ends of the initial formed specimen to obtain a final specimen of a predetermined length.
The beneficial effect of a triaxial compression specimen making method for in-situ soils of the present invention is that the specimen is driven linearly by the sample lifting device close to the barrel-shaped cutter, enabling the cutter to cut the specimen from the soil sample linearly for conventional triaxial testing and to precisely define the cross-sectional dimensions of the specimen by the diameter of the inner cavity of the cutter, which is not only easy to operate, but also highly efficient and accurate.
In one embodiment, before said step of assembling and commissioning the soil sample lifting device and after said step of cutting the pre-treated soil sample, further comprising the step of: calculating the maximum height that said soil sample lifting device can lift
On the basis of said first linkage length being equal to said second linkage length, step said calculating the height that said soil sample lifting device can lift is calculated by means of the following formula: the maximum height of said soil sample lifting device:
AHno=2,|12 — LD" }, wherein L is the length of the first link (or second link), b is the horizontal distance between two adjacent first links (or second links) away from the end of the slider, a is the length of the slider and hO is the initial height position of the soil sample lifting device. 5 In one embodiment, said drive member is a rocking handle; said curved plates are connected to each other by means of a tongue and groove joint;
Step said cutting pre-treatment of the soil sample, specifically comprising the steps of rocking said drive member to drive the rise of said base, slowing down when the soil sample is about to come into contact with said cutting knife, causing said cutting knife to slowly pierce the soil sample observing the cutting process and at any time chipping away the soil sample which does not pass the outer wall of said soil cutting knife if said blade portion of said soil cutter comes into contact with said base, or when a predetermined scale is reached, stop cranking said drive member, peel off said uncut soil sample from said base, and then crank the drive member in reverse to lower said base removing said soil cutting knife from said top plate, slowly pushing out one of said curved plates horizontally in the direction of the mortise and tenon interface, and removing the remaining curved plates in sequence in the manner described above, to obtain a primary formed test with a diameter dimension corresponding to a predetermined diameter dimension.
Description of attached figures
Figure 1 is a front view of the structure of a triaxial compression specimen making device for in-situ soils as described in an embodiment of the present invention
Figure 2 is an elevation view of the top plate in Figure 1;
Figure 3 is a top view of the soil cutting knife in Figure 1;
Figure 4 shows a schematic diagram of the three-dimensional structure of the soil cutting knife in Figure 1;
Figure 5 shows a front view of the soil sample lifting device in Figure 1;
Figure 6 shows a top view of the soil sample lifting device with the base removed;
Figure 7 shows a schematic diagram of the structure of the fixing frame of a triaxial compression specimen making device for in-situ soils of the present invention in another 204243 embodiment;
Figure 8 shows a schematic view of the structure of an assembly comprising a base and a pin of an in-situ soil triaxial compression specimen preparation device of the present invention in another embodiment;
Figure 9 shows a simplified front view of the upper left portion of the soil sample lifting device with the base removed;
Figure 10 shows a simplified top view of the upper left part of the soil sample lifting device with the base removed;
Figure 11 shows a simplified side view of the upper left portion of the soil sample lifting device with the base removed;
Figure 12 shows a simplified view of the rear part of the soil sample lifting device with the base removed.
In the drawings: 1, fixed frame; 11, top plate; 111, annular wall; 112, air hole; 113, first mounting barrel; 12, bottom plate; 121, second mounting barrel; 13, support column; 14, fixing nut; 2, soil cutting knife; 21, curved plate; 22, mounting part; 23, knife blade part; 24, scale; 3, soil sample lifting device; 31, base; 311, first plate 312, second plate; 32, linkage assembly; 321, first linkage; 322, second linkage; 323, slider; 33, screw; 34, drive member; 35, pin; 4, soil sample.
Specific embodiments
Example 1:
Referring to Figures 1 to 8, a triaxial compression specimen making device for in-situ soils as described in an embodiment of the present invention, comprising a fixed frame 1, a soil cutting knife 2 and a soil sample lifting device 3, the soil cutting knife 2 and the soil sample lifting device 3 being mounted on the fixed frame 1; the soil cutting knife 2 being in the form of a hollow cylinder with open ends, the soil cutting knife 2 comprising at least two curved plates 21, the curved plates 21 being removable to form the soil cutting knife 2 and removable after the specimen is The soil cutter 2 is provided with a mounting part 22 and a blade part 23 at both ends, the mounting part 22 is mounted on the fixed frame 1 and the blade part 23 is used to cut the cylindrical specimen 4 for conventional triaxial testing from the soil sample 4; the soil sample lifting device 3 is provided corresponding to the blade part 23 of the soil cutter 2, located on the 204243 side of the blade part 23 away from the mounting part 22, for placing the soil sample to be cut 4 and drive the soil sample 4 in the direction of the blade 23 of the cutter 2 so that the cutter 2 cuts the soil sample 4.
In operation, the soil sample 4 to be cut 1s placed on the soil sample lifting device 3, and the soil sample lifting device 3 drives the soil sample 4 to move in a straight line in the direction of the blade part 23 of the soil cutter 2; during the lifting of the soil sample 4, the blade part 23 of the soil cutter 2 approaches the soil sample 4 and cuts into the soil sample 4, and the part of the soil sample 4 corresponding to the inner cavity of the soil cutter 2 enters into the inner cavity of the soil cutter 2 to form a cylindrical specimen, and at the same time, the At the same time, the part of the sample 4 that does not reach the outer wall of the cutter 2 is removed; when the cutter 2 has entered the sample 4 to a specified depth, the sample lifting device 3 stops driving the sample 4; the remaining uncut part of the sample 4 is then stripped from the base 31 and the sample lifting device 3 is driven back to its original position; after the sample lifting device 3 has returned to its original position, the cutter 2 is dismantled and the first formed sample is removed.
After the sample lifting device 3 has returned to its original position, the cutter 2 is dismantled and the initial specimen is removed, the ends of the specimen are removed to bring the specimen to a predetermined length and the final specimen is then ready for the conventional triaxial test.
As shown in Figure 1, the fixed frame 1 comprises a top plate 11, a bottom plate 12 and at least two support posts 13 connecting the top plate 11 and the bottom plate 12. In this embodiment, the ends of the support posts 13 are removably connected to the top plate 11 and the bottom plate 12 respectively. Specifically, the top plate 11 is provided with a fixing nut 14 for each support post 13, which is fixed to the top plate 11 and located on the side of the top plate 11 away from the bottom plate 12, and the bottom plate 12 is provided with a threaded hole for each support post 13, one end of the support post 13 is threaded to the threaded hole and located in the threaded hole without protruding from the threaded hole, and the other end is threaded through the top plate 11 and connected to the fixing nut 14. The other end passes through the top plate 11 and is threaded to the fixing nut 14.
In other embodiments, as shown in Figure 7, the fixing nut 14 on the top plate 11 can be replaced with a first mounting barrel 113 and the threaded hole on the bottom plate 12 with a second mounting barrel 121, i.e. the first mounting barrel 113 is provided on the top plate 11 and 204243 the second mounting barrel 121 1s provided on the bottom plate 12, both the first mounting barrel 113 and the second mounting barrel 121 are located between the top plate 11 and the bottom plate 12, and the first internal thread and the second internal thread are provided in the The first and second mounting barrels are provided with a first female thread and a second female thread in the first and second mounting barrels 121 respectively, with the first and second female threads having opposite thread rotation, and the two ends of the support column 13 extend into the first and second mounting barrels 113 and 121 respectively, and are threaded into the first and second female threads respectively. The distance between the top plate 11 and the bottom plate 12 can be adjusted by rotating the support column 13 in the opposite direction, so that the distance between the top plate 11 and the bottom plate 12 can be adjusted according to the lifting height of the soil sample lifting device 3 and the length of the soil sample 4 cut by the soil cutter 2, so that the soil cutter 2 can complete the cutting of a cylindrical sample 4 from the soil sample 4. The distance between the top plate 11 and the bottom plate 12 1s adjusted so that the cutter 2 can complete the cutting of a cylindrical sample from the sample 4 within a specified length.
Further, as shown in Figure 2, the side of the top plate 11 facing the soil lifting device 3 1s provided with at least two annular walls 111 for mounting the soil cutter 2, the annular walls 111 are all set in the same circle and spaced towards the radius of the annular walls 111, the inner wall of each annular wall 111 is provided with internal threads, the mounting part 22 of the soil cutter 2 extends into the corresponding annular wall 111 and fits into the corresponding The mounting part 22 of the cutter 2 extends into the corresponding annular wall 111 and fits into the internal threads of the corresponding annular wall 111. By setting the number of annular walls 111 for mounting the soil cutter 2 to at least two, and the dimensions of the annular walls 111 are all different, it is possible to selectively mount at least two different sizes of soil cutter 2, thus enabling the in-situ soil triaxial compression specimen making device of the present invention to cut and shape specimens of at least two different diameter sizes. In this embodiment, the number of annular walls 111 is three and the inner diameters of the three annular walls 111 are ® 1=39. 1mm ,® 2=61.8mm and © 3=101.0mm, the thickness of each annular wall 111 is chosen to be Imm-5mm, preferably 3mm.
In the process of cutting the soil sample 4 by the cutter 2, the gas inside the cavity of the cutter 2 is squeezed as the soil sample 4 gradually increases, if the gas is not discharged, the 204243 pressure of the gas inside the cavity of the cutter 2 will increase, increasing the resistance to cutting. By providing air holes 112 in the top plate 11 circled by the smallest diameter annular wall 111, it is possible to release the gas, eliminate the air pressure difference generated during cutting and reduce the resistance to cutting caused by the gas inside the cavity of the cutter 2. In this embodiment, air holes 112 are provided only on the part of the top plate 11 circled by the smallest annular wall 111. In other embodiments, air holes 112 can be provided on the part of the top plate 11 circled by the smallest annular wall 111, on top of the air holes 112 on the part of the top plate 11 located between the annular walls 111.
In this embodiment, the air holes 112 are cylindrical, in other embodiments, the air holes 112 may be provided in a conical shape, the diameter of the air holes 112 gradually increasing in the direction away from the annular wall 111, this shape of the air holes 112 can be provided to achieve further rapid release of gas.
In this embodiment, as shown in Figure 3, the curved plates 21 of the soil cutting knife 2 are preferably three, and the angle of each of the three curved plates 21 is 120°. The curved plates 21 are connected to each other by means of mortise and tenon joints. Further, as shown in Figure 4, the soil cutter 2 is made of transparent material and a scale 24 is provided on the outer wall of the soil cutter 2. By making the soil cutter 2 of transparent material and providing the scale 24 on the outer wall of the soil cutter 2, it is possible to observe the state of the soil sample 4 entering into the soil cutter 2 on the one hand, and to read the depth of the soil sample 4 entering the cavity of the soil cutter 2 in real time on the other hand. In this embodiment, the soil cutter 2 is preferably made of transparent tempered glass.
As shown in Figures 5 and 6, the soil sample lifting device 3 comprises a base 31 for placing the soil sample 4 and a lifting mechanism mounted on the fixed frame 1, the lifting mechanism being located on the side of the base 31 away from the top plate 11. In this embodiment, the base 31 is preferably square in shape and the shortest side dimension of the base 31 is larger than the diameter dimension of the soil sample 4 in cylindrical form of the largest size.
In order to prevent the sample 4 placed on the base 31 from collapsing at the edges, pins 35 are provided on the side of the base 31 near the top plate 11 for insertion into the sample 4 when the sample 4 is placed on the base 31 to hold the sample 4. In this embodiment, steel pins are 904243 preferably used for the pins 35.
In other embodiments, as shown in Figure 8, in order to facilitate the replacement of the pins 35 after deformation, the base 31 comprises a first plate 311 and a second plate 312, the first plate 311 is connected to the lifting mechanism, the second plate 312 is located on the side of the first plate 311 near the soil cutting knife 2, the second plate 312 is removably connected to the first plate 311, the pins 35 are located on the side of the second plate 312 near the soil cutting knife The second plate 312 is removably connected to the first plate 311 and the pins 35 are located on the side of the second plate 312 near the cutting knife 2. By setting the pin 35 on the second plate 312 and located on the side of the second plate 312 near the soil cutting knife 2, when the pin 35 is deformed and needs to be replaced, the second plate 312 can be removed from the first plate 311 and replaced with a new second plate 312 with the pin 35 mounted on the first plate 311. Regarding the connection of the first plate 311 and the second plate 312, they can be connected by means of clamping, screws, bolts or other means. Further, when only one or very few pins 35 are bent and need to be replaced or repaired, in order not to replace the entire second plate 312 with pins 35, each pin 35 can be fixed to the second plate 312 by means of a snap connection, so that the pins 35 to be replaced or repaired can simply be removed from the second plate 312. Specifically, the second plate 312 is provided with holes for each of the pins 35, and one end of the pins 35 is fixed in the holes.
The lifting mechanism comprises two rod assemblies 32, a screw 33 and a drive member 34, the two rod assemblies 32 are symmetrical about a first plane, the first plane is perpendicular to the side of the base 31 facing the base plate 12, the centre of the base 31 is located on the first plane, each rod assembly 32 comprises two first rods 321, two second rods 322 and a slider 323, the two first rods 321 and the two The two first rods 321 and the two second rods 322 are symmetrical about the second plane, the second plane is perpendicular to the first plane and the centre of the base 31 is also located on the second plane, one end of each first rod 321 is pivoted to the base 31 and the other end is pivoted to the slider 323, one end of each second rod 322 is pivoted to the base 12 and the other end is pivoted to the slider 323; the screw 33 is threaded to the slider 323 of the two rod assemblies 32, the two sliders 323 are threaded in opposite directions to the threads of screw 33; drive member 34 is connected to one end of screw 33. By driving the screw 33 with the drive member 34, the two sliders 323 are brought closer together 204243 and the horizontal distance between the two sliders 323 is shortened, so that the base 31 can be lifted and the soil sample 4 can be brought closer to the cutter 2 and pierced by the cutter 2, thus achieving the purpose of the cutter 2 cutting out the specimen for the conventional triaxial test from the soil sample 4.
In this embodiment, the length of the first connecting rod 321 1s equal to the length of the second connecting rod 322 and the driving member 34 1s a crank handle.
The invention is based on a hollow soil cutter 2 in the form of a cylinder and a sample lifting device 3 that moves the soil sample 4 in the direction of the soil cutter 2, and on the disassembly of the soil cutter 2 from at least two curved plates 21, so that the soil cutter 2 can cut a cylindrical sample of a specified diameter on the sample 4 in a straight line relative to the sample. After the cutter 2 has been removed, the specimen is removed by cutting the ends of the specimen with a metal wire to obtain a final specimen of a predetermined length for conventional triaxial testing. In contrast to the conventional manual method of cutting cylindrical specimens of a specified diameter while rotating, the present invention allows the barrel-shaped cutter 2 to cut specimens of a specified diameter from the sample 4 by moving the sample close to the cutter 2 in a straight line, making the operation very simple and the production more efficient.
Example 2:
The present invention also discloses a method for making a triaxial compression specimen of in-situ soil, based on the triaxial compression specimen making device for in-situ soil described in Example 1, comprising the steps of:
S10, assembling and installing the soil cutting knife 2: assembling the curved plate 21 of the desired size into the soil cutting knife 2 of the desired size, and installing the soil cutting knife 2 on the fixed frame 1.
Specifically, the curved plate 21 of the cutter 2 is selected according to the pre-determined diameter of the cylindrical specimen, and butter or petroleum jelly is applied to the inner wall of the curved plate 21 to reduce the friction between the contact surface of the cutter 2 and the soil specimen 4 and to ensure that the cutter 2 can cut out the specimen from the soil specimen 4 smoothly; after the application is completed, the curved plate 21 is mortised and assembled into a cylindrical cutter 2, and then the mounting part 22 of the cutter 2 is threaded The mounting part
22 of the cutter 2 is then threaded onto the corresponding annular wall 111 on the top plate 11 or 904243 the fixed frame 1.
S20. Assembly and commissioning of the soil sample lifting device 3: The soil sample lifting device 3 is mounted on the fixed frame 1 and, once mounted, the soil sample lifting device 3 is commissioned.
Specifically, the screw 33 is passed through the two sliders 323, and the screw 33 is fixedly connected to the two sliders 323 by biting the internal threads of the screw 33 and the two sliders 323; the two ends of each first connecting rod 321 are pivoted to the base 31 for placing the soil sample 4 and the corresponding slider 323, the two ends of each second connecting rod 322 are pivoted to the base plate 12 of the fixed frame 1 and the corresponding Finally, the drive member 34 is mounted on the end of the screw 33 to complete the installation of the soil sample lifting device 3.
In this embodiment, the drive member 34 is preferably a crank handle. After the installation is completed, the drive member 34 is cranked for commissioning to ensure that the soil sample lifting device 3 can carry out the work of lifting the soil sample 4 smoothly. After the commissioning is completed, the drive member 34 is shaken to adjust the height of the base 31 to a reasonable position.
S30. Calculate the maximum height that the soil sample lifting device 3 can lift.
Specifically, this embodiment calculates the maximum height of the soil sample lifting device 3 in the case where the length of the first rod 321 is equal to the length of the second rod 322, and takes the upper left part of the soil sample lifting device 3 after removing the base 31 and makes a simplified three-view for analysis. 321 in the front view vertical plane (equivalent to the front view reference plane in the three-dimensional diagram), h is the projection length of the first link 321 in the plumb line, x is the horizontal distance between the two ends of the first link 321.
Therefore, from the simplified diagram shown in Figure 9, it follows that
Figure 10 shows a simplified top view of the upper left part of the soil sample lifting device 3 with the base removed. In Figure 10, L2 is the projected length of the first link 321 on the horizontal plane (equivalent to the lower view datum in the three-dimensional drawing), x is the horizontal distance between the two ends of the first link 321 and b is the horizontal distance 904243 between the two first links 321 away from the end of the slider 323. Therefore, from the simplified top-view diagram shown in Figure 10, it follows that
Lo?=x24H(b/2-a/2)2 ooo (1,2) 3
Figure 11 shows a simplified side view of the upper left part of the soil sample lifting device 3 with the base removed. b in Figure 11 is the horizontal distance between the two first links 321 of the link assembly 32 away from the end of the slider 323, a is the length of the slider 323, h is the projected length of the first link 321 on the plumb line and Ls is the projected length of the first link 321 on the right-view vertical plane (equivalent to the right-view in the three-dimensional view the projection length on the base plane). From Figure 11 it follows that
L3°=h#(b/2-a/2)? ooo (13) 3
It is easy to see that the following relationship exists for the length L of the first connecting rod 321
L? = (Li? +L LS ieee (1,4);
It is easy to know that the displacement AL of the screw 33 under the action of the drive 34 is (7 is the number of revolutions of the drive 34; do is the external thread pitch of the screw 33)
The rear half of the soil sample lifting device 3 with the base 31 removed gives the sketch view shown in Figure 12: from Figure 12:
Ly — Ly — AL x=—" = 2 eee (1,6)
Assuming that the initial lifting height of soil sample lifting device 3 is ho and that the height of soil sample lifting device 3 after soil sample 4 has been lifted is h after soil sample 4 has been lifted;
Then the height AA at which the upper part of the soil sample lifting device 3 is lifted after the removal of the base 31 is
Combining the above equations 1.1, 1.2, 1.3, 1.4, 1.5 and 1.6, the AH equation for the height of lift of the entire soil sample lifting device 3 can be obtained as 0006863 ; 2
AH =2Ah =2 Le 29 - Gate nd) — 2hy, 0<ndi<(Lo-Ly )
The maximum lifting height AHmax of the soil sample lifting device 3 is therefore. (a)?
When ndo=(Lo-Lo' ), taking this into equation 1.8 gives m2 Lo= cho where L is the length of the first link 321, b is the horizontal distance between two adjacent ends of the first link 321 away from the slider 323, a is the length of the slider 323 and ho is the initial height position of the soil sample lifting device 3, i.e. the initial height position of the base 31.
S40. Pre-treatment and placement of soil sample 4: The soil sample 4 is provided to be cut, pre-cut to the size allowed by the soil sample lifting device 3 to form the pre-treated soil sample 4, which is placed on the base 31 of the soil sample 4.
Specifically, the soil sample 4 is provided with no visible signs of disturbance and is pre-cut to the size allowed by the base 31 of the soil sample lifting device 3 using a metal wire, preferably steel wire. In the case of the pin 35 on the side of the base 31 near the top plate 11, when the soil sample 4 is placed on the base 31 of the soil lifting device 3, it is necessary to gently press the soil sample 4 in order to insert the pin 35 into the soil sample 4, for the purpose of fixing the soil sample 4.
S50, cutting pre-processed soil sample 4: drive the soil lifting device 3 to lift the soil sample 4, so that the cutter 2 cuts into the soil sample 4, and in the process of the cutter 2 entering the soil sample 4, the part of the soil sample 4 that does not reach the outer wall of the cutter 2 is cut away, and when the cutter 2 has entered the soil sample 4 to a specified depth, the cutting is stopped and the cutter 2 is removed to obtain a primary sample of the required diameter.
Specifically, step S40 comprises the steps of: (a) rocking the drive member 34 to drive the rise of the base 31, slowing down when the soil sample 4 is about to come into contact with the soil cutting knife 2, so that the soil cutting knife 2 slowly pierces the soil sample 4; (b) Observe the process of cutting and keep trimming away the soil sample 4 that does not reach the outer wall of the cutter 2.
(c) If the blade portion 23 of the cutter 2 comes into contact with the base 31 or reaches à 904243 predetermined scale 24, stop cranking the drive 34 and peel the uncut soil sample 4 off the base 31, and then reverse the cranking of the drive 34 and lower the base 31; (d) Remove the soil cutter 2 from the annular wall 111 of the top plate 11 by rotating it, slowly push out one of the curved plates 21 in the direction of the mortise and tenon interface, and remove the remaining curved plates 21 in sequence in accordance with the above method to obtain a preformed specimen with a diameter dimension in accordance with the preset diameter dimension.
S60. Post-processing of the primary specimen: The ends of the primary specimen are trimmed off to obtain a final specimen of the preset length, which can be used for the regular conventional triaxial test specimen.
Specifically, in step S60, the ends of the preformed specimen are trimmed off using a metal wire, in this case steel wire.
The in-situ soil triaxial specimen stress measurement method of the present invention enables the soil sample 4 to be driven linearly by the soil sample lifting device 3 close to the barrel-shaped cutter 2, enabling the cutter 2 to cut the specimen from the soil sample 4 in a linear manner for conventional triaxial testing, and to precisely define the cross-sectional dimensions of the specimen by the diameter of the inner cavity of the cutter 2.
Claims (10)
1. A triaxial compression specimen making device for in-situ soils, characterized in that it comprises: a fixed frame; soil cutter for cutting a cylindrical specimen from a soil sample, said soil cutter being in the form of a cylinder with open ends, said soil cutter comprising at least two curved plates, said curved plates being disassembled to form said soil cutter and being removable to allow the specimen to be removed after the specimen has been cut and shaped, said soil cutter being provided with a mounting section and a knife edge section at each end, said mounting section being mounted on said fixed frame soil sample lifting means, provided corresponding to said knife blade section, for lifting the soil sample in a straight line in the direction of said knife blade section in order to allow said soil cutting knife to cut the soil sample.
2. A triaxial compression sample preparation device for in-situ soils according to claim 1, characterized in that said fixed frame comprises a top plate, a bottom plate and at least two support posts connecting said top plate and said bottom plate; said soil cutting knife and said soil sample lifting device are mounted on said top plate and said bottom plate, respectively, and are located between said top plate and said bottom plate.
3. A triaxial compression sample preparation device for in-situ soils according to claim 2, characterized in that said top plate is provided on the side facing said soil sample lifting device with at least two annular walls for mounting said soil cutter, said annular walls being set in the same circle and spaced towards the radius of said annular walls, each of said annular walls being provided with internal threads on the inner wall; said mounting part of said soil cutter extending into into the corresponding annular wall and fits into the internal threads of the corresponding annular wall.
4. A triaxial compression sample preparation device for in-situ soils according to claim 3, characterized in that said top part of said annular wall ringed by said smallest diameter is provided with air holes.
5. A triaxial compression sample preparation device for in-situ soils according to claim 2,
characterized in that said soil cutting knife is made of transparent material. 10506263
6. À triaxial compression sample preparation device for in-situ soils according to claim 2, characterized in that said soil sample lifting means comprises a base for placing the soil sample and a lifting mechanism mounted on said fixed frame, said lifting mechanism being located on the side of the base away from said top plate.
7. À triaxial compression sample preparation device for in-situ soils according to claim 6, characterized in that said lifting mechanism comprises two linkage assemblies, screws and drive members, each said linkage assembly comprising two first links, two second links and a slider, each said first linkage being pivoted at one end to the base and at the other end to said slider, each said second linkage being pivoted at one end to said base plate and at the other end pivoted to said slider, said screw threaded to said slider of both said linkage assemblies, the threads of both said sliders mating with said screw rotating in opposite directions; said drive member connected to one end of said screw.
8. À method for making a triaxial compression specimen of in-situ soil, based on a triaxial compression specimen making device for in-situ soil as described in claim 7, characterized in that it comprises the steps of, assembling and mounting said soil cutting knife: assembling said curved plate of the desired size into said soil cutting knife of the desired size and mounting said soil cutting knife on a fixed frame; assembling and commissioning said soil sample lifting device: mounting said soil sample lifting device on the fixed frame and, once mounted, commissioning said soil sample lifting device; pre-processing and placing the soil sample: providing the soil sample to be cut, pre-cutting said soil sample to the size that said soil sample lifting device allows to be placed, forming the pre-processed soil sample, placing the pre-processed soil sample on said lifting device for the soil sample cutting the pre-treated soil sample: driving said soil sample lifting device to lift the soil sample, causing said soil cutter to cut into said soil sample, cutting away said portion of said soil sample that does not pass through the outer wall of said soil cutter as said soil cutter enters said soil sample, stopping cutting when said soil cutter enters said soil sample to a specified depth,
dismantling said soil cutter and obtaining a preformed specimen of the desired diameter size; 0006863 Post-processing of the initial formed specimen: cutting off the ends of the initial formed specimen to obtain a final specimen of predetermined length.
9. A method for making a triaxial compression specimen of in-situ soil according to claim 8, characterized in that, before said step of assembling and commissioning the soil sample lifting device and after said step of cutting a pre-treated soil sample, further comprising the step of: calculating the maximum height that said soil sample lifting device can lift , On the basis of said first linkage length being equal to said second linkage length, in the step said calculating the height said soil sample lifting device can lift, the maximum height of said soil sample lifting device 1s calculated by means of the following formula: (b-a)” AHmax=2 L? Ta -h; Where L is the length of the first link (or second link), 4 is the horizontal distance between two adjacent first links (or second links) away from the end of the slider, a is the length of the slider and ho is the initial height position of the soil sample lifting device.
10. A method of making a triaxial compressed specimen of in-situ soil according to claim 8, characterized in that said driving member is a rocking handle; said curved plates are connected to each other by means of a mortise and tenon joint, Step said cutting of a pre-treated soil sample, specifically comprising the steps of rocking said drive member to drive the rise of said base, slowing down when the soil sample is about to come into contact with said cutting knife, so that said cutting knife slowly pierces the soil sample, observing the cutting process and at any time chipping away the soil sample which does not pass the outer wall of said soil cutting knife, if said blade portion of said soil cutter comes into contact with said base, or when a predetermined scale is reached, stop cranking said drive member, peel off said uncut soil sample from said base, and then crank the drive member in reverse to lower said base, Removing said soil cutting knife from said top plate, slowly pushing out one of said curved plates in a flat manner in the direction of the mortise and tenon interface, removing the remaining curved plates in sequence in the manner described above to obtain an initial formed
. . . . . . . . . . LU504243 specimen with a diameter dimension matching the predetermined diameter dimension.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210948801.5A CN115219304A (en) | 2022-08-09 | 2022-08-09 | Undisturbed soil triaxial compression sample preparation device and preparation method |
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| Publication Number | Publication Date |
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| LU504243B1 true LU504243B1 (en) | 2023-12-01 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| LU504243A LU504243B1 (en) | 2022-08-09 | 2023-05-17 | A triaxial compression specimen making device and method for making specimens of in-situ soils |
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| Country | Link |
|---|---|
| CN (1) | CN115219304A (en) |
| LU (1) | LU504243B1 (en) |
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2022
- 2022-08-09 CN CN202210948801.5A patent/CN115219304A/en active Pending
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- 2023-05-17 LU LU504243A patent/LU504243B1/en active IP Right Grant
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| CN115219304A (en) | 2022-10-21 |
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