A bevel bed interbedded soil cylindrical sample stacking type sample preparation device and method of use

Abstract

The application discloses a kind of inclined layer surface interbedded soil cylindrical sample stacking type sample preparation device and method, including sleeve assembly, multiple ring assembly and end plug, multiple ring assembly is tubular, by two cylindrical adapter rings and the several mutually stacked standard rings in it along axial arrangement It is formed, the opposite side of two adapter rings is inclined plane, the standard ring end face of upper and lower ends of standard ring is flush with the inclined plane of adapter ring, end plug is used to embed in adapter ring, end plug is provided with with the inclined end face of plug flush with the inclined plane of outer adapter ring, sleeve assembly is used to coaxially sleeve in the outer ring of multiple ring assembly, the central hole of several standard rings can be prepared for soil body, end plug is used to be driven by pressure device and to the soil body in middle pressure. The application solves the problem that it is not convenient to prepare inclined layer surface interbedded soil sample with inclination angle, can prepare inclined layer surface interbedded soil sample with arbitrary layer sequence and layer thickness combination, strong applicability, easy to operate.

Description

Technical Field

[0001] This invention relates to the field of geotechnical engineering testing technology, specifically to a stacked sample preparation device and method for preparing cylindrical samples of alternating layers of inclined soil. Background Technology

[0002] Interbedded soils formed by natural sedimentation, such as alternating layers of sand and clay, may have layers that are at an angle to the horizontal plane, i.e., oblique layers. The principal stresses acting on the soil also often have an angle with the sedimentary surface, i.e., oblique. Therefore, when conducting geotechnical tests (such as triaxial compression tests, resonant column tests, etc.) to study the mechanical properties of such soils, in addition to using natural specimens, it is necessary to prepare cylindrical specimens with oblique layer structures.

[0003] Currently, the existing conventional interbedded soil sample preparation methods are mainly for horizontal bedding. These methods are not convenient for preparing interbedded soil samples with inclined bedding. Furthermore, the three-lobed molds and other structures used are integral structures in the height direction of the sample, which need to be removed all at once during demolding, causing significant disturbance to the sample.

[0004] If cylindrical samples are directly cut from large interlayered soil blocks at different angles using a sleeve with a cutting edge, the following problems will occur: the sleeve sampling causes large disturbances, the soil sample is pushed out of the sleeve causing secondary disturbances, further cutting is required afterward, and the sample is prone to slipping along the layer during cutting, resulting in a lot of soil waste.

[0005] Therefore, there is an urgent need for a stacked sample preparation device and method for cylindrical samples of interlayered soil with inclined planes, in order to solve the problem that it is not convenient to prepare samples of interlayered soil with inclined planes with inclination angles in the existing technology. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a stacked sample preparation device and method for preparing cylindrical samples of interlayered soil on inclined planes, thereby solving the problem that existing technologies are not convenient for preparing samples of interlayered soil on inclined planes with an angle.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A stacked sample preparation device for cylindrical soil samples of interlayered slopes includes a sleeve assembly, a multi-ring assembly, and end plugs. The multi-ring assembly is tubular and consists of two cylindrical adapter rings and several stacked standard rings arranged axially in the middle. The opposite sides of the two adapter rings are both inclined planes. The end faces of the standard rings at both ends are flush with the inclined planes of the adapter rings. The end plugs are used to be embedded in the adapter rings and have inclined end faces that are flush with the inclined planes of the outer adapter rings. The sleeve assembly is used to be coaxially fitted onto the outer ring of the multi-ring assembly. The central holes of the several standard rings can be used for soil preparation. The end plugs are driven by a pressure application device to apply pressure to the soil in the middle.

[0008] To optimize the above technical solution, the specific measures also include: Furthermore, the sleeve assembly includes a middle sleeve and two end sleeves. One end of each of the two end sleeves is provided with a stepped annular snap-fit ​​structure that allows the end of the middle sleeve to engage. The two end sleeves are coaxially fitted onto both ends of the middle sleeve, and the middle sleeve and the two end sleeves are together fitted onto the outer ring of the multi-ring assembly.

[0009] Furthermore, the end sleeve is composed of a first end half-cylinder and a second end half-cylinder with the same structure spliced ​​together. The first end half-cylinder is provided with a male end sleeve bayonet at one end near the second end half-cylinder and a female end sleeve bayonet at the other end. The end of the second end half-cylinder near the first end half-cylinder is respectively provided with a matching female end sleeve bayonet and a male end sleeve bayonet. The outer periphery of the spliced ​​first end half-cylinder and the second end half-cylinder is tightened by an end sleeve ring.

[0010] Furthermore, the middle sleeve is composed of a first middle half-cylinder and a second middle half-cylinder with the same structure spliced ​​together. The first middle half-cylinder is provided with a male middle sleeve retainer at one end near the second middle half-cylinder and a female middle sleeve retainer at the other end. The second middle half-cylinder is provided with a matching female middle sleeve retainer and a male middle sleeve retainer at the end near the first middle half-cylinder respectively. The outer periphery of the spliced ​​first middle half-cylinder and the second middle half-cylinder is tightened by a middle sleeve ring.

[0011] Furthermore, the outer circumferential surface of the standard ring is provided with two first semi-cylindrical protrusions, each with a circular hole extending along its axial direction; the outer circumferential surface of the adapter ring is provided with a second semi-cylindrical protrusion corresponding to the position of the first semi-cylindrical protrusion on the standard ring and having the same radius; the inner surfaces of the end sleeve and the middle sleeve are respectively provided with axially extending recesses, the recesses being size-matched to the first semi-cylindrical protrusion of the standard ring and the second semi-cylindrical protrusion of the adapter ring, allowing for corresponding insertion with either the first or second semi-cylindrical protrusion.

[0012] Furthermore, the standard ring is detachably spliced ​​from a first half-ring and a second half-ring with the same structure through a snap-fit ​​structure. The first half-ring has a male snap-fit ​​at one end near the second half-ring and a female snap-fit ​​at the other end. The second half-ring has a matching female snap-fit ​​and a male snap-fit ​​at the end near the first half-ring, respectively. The outer periphery of the spliced ​​first half-ring and the second half-ring is tightened by an annular rubber band.

[0013] Furthermore, the standard ring formed by splicing the first half-ring and the second half-ring has an annular groove extending circumferentially on its outer circumferential surface, which can be used to tighten the annular rubber band.

[0014] Furthermore, it also includes an annular base, which is a three-step cross-section ring structure. The annular base has a lower step ring cylinder surface, a middle step ring cylinder surface, and an upper step ring cylinder surface with gradually increasing diameter from bottom to top. The diameter of the lower step ring cylinder surface is adapted to the diameter of the end plug, the diameter of the middle step ring cylinder surface is adapted to the outer diameter of the lower end of the multi-ring assembly, and the diameter of the upper step ring cylinder surface is adapted to the outer diameter of the lower end of the sleeve assembly.

[0015] Furthermore, it also includes a loading cap, which is a combination of a first cylinder and a second cylinder. The diameter of the first cylinder is larger than the diameter of the second cylinder, and the diameter of the second cylinder is adapted to the diameter of the end plug. The first cylinder is used to contact the pressure application device, and the second cylinder is used to contact the end plug.

[0016] Furthermore, a method of using a stacked sample preparation device for the aforementioned interlayered soil cylindrical samples on an inclined plane includes the following steps: Based on the required thickness of each soil layer, select several standard rings of corresponding height; select different numbers of standard rings as needed, fill each standard ring with the corresponding soil material, and spread and flatten it evenly so that its upper surface is flush with the end face of the standard ring to obtain the corresponding soil layer. Next, on the workbench, an end plug is placed into an adapter ring with its beveled end facing upwards. The end plug is aligned with the top of the adapter ring. Then, standard rings filled with soil are stacked alternately in a predetermined order. After the designed number of alternating soil layers on the inclined surface is reached, a sleeve assembly is fitted on the outside, and the corresponding adapter ring and end plug are placed on the top standard ring. Then, use the pressure application device as needed to apply pressure to the end plug at the top, and use this to apply a preload to the interlayered soil of the inclined surface inside the device until the sample deformation stabilizes, and then remove the mold.

[0017] The beneficial effects of this invention are: This invention, through the setting of adapter rings and standard rings, allows for the preset of adapter rings and standard rings with specific inclination angles as needed, and the selection of standard rings of different heights. This enables convenient and precise control of the thickness and inclination angle of each soil layer in the soil sample, truly reflecting the structural characteristics of interlayered soils. The stacked standard rings, combined with end plugs, and the stacked sample preparation and overall pressing process ensure that each soil layer is tightly bonded under compaction, avoiding interlayer gaps and guaranteeing the integrity and uniformity of the sample. This device is applicable to sandy and cohesive soils with different particle sizes and moisture contents. By adjusting the height combination of several standard rings, inclined interlayered soil samples with arbitrary layer sequence and thickness combinations can be prepared. Furthermore, the sample preparation method is clear, easy to operate and implement, highly applicable, and simple to operate.

[0018] This invention achieves the preparation of cylindrical soil samples of interlayered slopes with precise control over the slope inclination angle and layer thickness, tight interlayer contact, and minimal demolding disturbance by stacking standard rings and adapter rings with inclined end faces, combined with a split sleeve structure and pre-compression process. It can be used for sample preparation for geotechnical tests such as triaxial compression and resonant column tests.

[0019] The device of this invention is easy to demold and has minimal sample disturbance. The standard ring, end sleeve, and middle sleeve of the device are all designed with a split structure and are temporarily fixed with annular rubber bands and collars. During demolding, each component can be removed sequentially and orderly. Combined with the auxiliary round holes on the half ring, it achieves low-disturbance demolding of the sample, which greatly improves the survival rate and quality of the sample. Attached Figure Description

[0020] Figure 1 This is a structural breakdown diagram of a stacked sample preparation device for interlayered soil cylindrical samples on an inclined plane, as proposed in this invention. Figure 2 This is a schematic diagram of the structural assembly of a stacked sample preparation device for interlayered soil cylindrical samples on an inclined plane, as proposed in this invention. Figure 3 This is a partial structural schematic diagram of a stacked sample preparation device for interlayered soil cylindrical samples on an inclined plane, as proposed in this invention. Figure 4 This is a schematic diagram of the end sleeve of a stacked sample preparation device for interlayered soil cylindrical samples on an inclined plane, as proposed in this invention. Figure 5 This is a schematic diagram of the middle sleeve of a stacked sample preparation device for interlayered soil cylindrical samples on an inclined plane, as proposed in this invention. Figure 6 This is a schematic diagram of the standard ring structure of a stacked sample preparation device for interlayered soil cylindrical samples on an inclined plane, as proposed in this invention. Figure 7 This is a schematic diagram showing the structural breakdown of the standard ring of a stacked sample preparation device for interlayered soil cylindrical samples on an inclined plane, as proposed in this invention. Figure 8 This is a schematic diagram of the structure of the adapter ring of a stacked sample preparation device for interlayered soil cylindrical samples on an inclined plane, as proposed in this invention. Figure 9 This is a side view of the structure of the adapter ring of a stacked sample preparation device for interlayered soil cylindrical samples on an inclined plane, as proposed in this invention. Figure 10 This is a schematic diagram of the end plug structure of a stacked sample preparation device for interlayered soil cylindrical samples on an inclined plane, as proposed in this invention. Figure 11 This is a schematic diagram of the annular base of a stacked sample preparation device for interlayered soil cylindrical samples on an inclined plane, as proposed in this invention. Figure 12This is a side wall cross-sectional view of the annular base of a stacked sample preparation device for interlayered soil cylindrical samples of inclined planes, as proposed in this invention. Figure 13 This is a schematic diagram of the loading cap of a stacked sample preparation device for interlayered soil cylindrical samples on an inclined plane, as proposed in this invention. Figure 14 This is a flowchart illustrating a method of use proposed in this invention.

[0021] Reference numerals: End sleeve 1; Middle sleeve 2; Standard ring 3; Adaptor ring 4; End plug 5; End collar 6; Middle collar 7; Annular base 8; Recess 9; Loading cap 11; First end half-sleeve 101; Second end half-sleeve 102; End sleeve male bayonet 103; End sleeve female bayonet 104; Inner diameter enlargement section 105; First middle half-sleeve 201; Second middle half-sleeve 202; Middle sleeve male bayonet 203; Middle sleeve female bayonet 204; First half-ring 301; Second half-ring 302; Male ring retainer 303; Female ring retainer 304; Standard ring end face 305; First semi-cylindrical protrusion 307; Circular hole 308; Annular groove 309; Annular rubber band 310; Adaptor ring flat end face 405; Adaptor ring inclined end face 406; Second semi-cylindrical protrusion 407; Plug flat end face 501; Plug inclined end face 502; Upper stepped annular cylindrical surface 801; Middle stepped annular cylindrical surface 802; Lower stepped annular cylindrical surface 803; First cylinder 1101; Second cylinder 1102. Detailed Implementation

[0022] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0023] As attached Figure 1 Appendix Figure 2 Appendix Figure 3 and attached Figure 10 As shown in the figure, a stacked sample preparation device for cylindrical soil samples of interlayered slopes according to an embodiment of the present invention includes a sleeve assembly, a multi-ring assembly, and an end plug 5. The multi-ring assembly is tubular and consists of two cylindrical adapter rings 4 and several stacked standard rings 3 arranged axially in the middle. The opposite sides of the two adapter rings 4 are both inclined planes. The standard ring end faces 305 at both ends of the standard rings 3 are flush with the inclined planes of the adapter rings 4. The end plug 5 is coaxially embedded in the adapter rings 4. The end plug 5 has a plug inclined end face 502 that is flush with the inclined planes of the outer adapter rings 4. The sleeve assembly is coaxially fitted onto the outer ring of the multi-ring assembly. The central holes of the several standard rings 3 can be used for soil preparation. The end plug 5 is driven by a pressure application device to apply pressure to the soil in the middle.

[0024] This invention, through the setting of adapter ring 4 and standard ring 3, can preset adapter ring 4 and standard ring 3 with specific inclination angles as needed, and select standard rings of different heights, thereby conveniently and accurately controlling the thickness and inclination angle of each soil layer in the soil sample, and can truly reflect the structural characteristics of interlayered soil. Through the stacked standard rings 3, in conjunction with the setting of end plugs 5, the stacked sample preparation and overall pressing process ensure that each soil layer is tightly bonded under the action of compaction, avoiding interlayer gaps and ensuring the integrity and uniformity of the sample. This device is applicable to sandy soil and cohesive soil with different particle sizes and different moisture contents. By adjusting the height combination of several standard rings 3, inclined interlayered soil samples with arbitrary layer sequence and layer thickness combinations can be prepared. Moreover, the sample preparation method is clear, easy to operate and implement, highly applicable, and simple to operate.

[0025] In the above scheme, specifically, the end plug 5 is a solid cylinder with a flat end face 501 perpendicular to the central axis L of the sample preparation device and a sloping end face 502 at an angle α to the central axis L. The diameter of the end plug 5 is adapted to the inner diameter of the multi-ring assembly, and is used to transfer load and ensure the flatness of the end during sample preparation and preloading. When in use, the flat end face 501 faces the outside of the multi-ring assembly, and the sloping end face 502 faces the inside of the multi-ring assembly. The standard ring 3 has a standard ring end face 305 at an acute angle α to the central axis L, and is used to form the sloping surface of the soil sample. The adapter ring 4 is a whole ring structure with an adapter ring flat end face 405 and an adapter ring sloping end face 406. The adapter ring flat end face 405 is a plane perpendicular to the central axis L, and the adapter ring sloping end face 406 is an sloping plane at an angle α to the central axis L, and is used to transition the two ends of the multi-ring assembly to a plane.

[0026] The height of the standard ring 3 along the central axis L is a variable parameter. Multiple standard rings 3 with the same or different heights can be used as needed. The height corresponds to the thickness of a single soil layer along the axial direction in the prepared soil sample, thereby realizing the preparation of interlayered soil samples with different layer thickness combinations.

[0027] In a specific embodiment based on the above, the sleeve assembly includes a middle sleeve 2 and two end sleeves 1. One end of each of the two end sleeves 1 is provided with a stepped annular snap structure that can be snapped onto the end of the middle sleeve 2. The two end sleeves 1 are coaxially sleeved on both ends of the middle sleeve 2, and the middle sleeve 2 and the two end sleeves 1 are together sleeved on the outer ring of the multi-ring assembly.

[0028] In this design, the bayonet structure of the end sleeve 1 is used to connect with the outer side of the middle sleeve 2, which is the inner diameter enlargement section 105. The outer diameter of the middle sleeve 2 is adapted to the inner diameter of the inner diameter enlargement section 105. In use, the two ends of the middle sleeve 2 are respectively inserted into the inner diameter enlargement sections 105 of the two end sleeves 1 to form a sleeve assembly. This nested connection ensures the coaxiality and overall rigidity of the sleeve assembly. The inner diameter of the middle sleeve 2 is adapted to the inner diameter of the non-inner diameter enlargement section of the end sleeve 1.

[0029] As attached Figure 4 As shown, in a further specific embodiment based on the above, the end sleeve 1 is composed of a first end half-cylinder 101 and a second end half-cylinder 102 with the same structure spliced ​​together. The first end half-cylinder 101 is provided with an end sleeve male bayonet 103 at one end near the second end half-cylinder 102, and an end sleeve female bayonet 104 at the other end. The end of the second end half-cylinder 102 near the first end half-cylinder 101 is respectively provided with a matching end sleeve female bayonet 104 and an end sleeve male bayonet 103. The outer periphery of the spliced ​​first end half-cylinder 101 and the second end half-cylinder 102 is tightened by an end collar 6.

[0030] As attached Figure 5 As shown, in another specific embodiment based on the above, the middle sleeve 2 is composed of a first middle half-cylinder 201 and a second middle half-cylinder 202 with the same structure spliced ​​together. The first middle half-cylinder 201 is provided with a middle sleeve male bayonet 203 at one end near the second middle half-cylinder 202 and a middle sleeve female bayonet 204 at the other end. The second middle half-cylinder 202 is provided with a matching middle sleeve female bayonet 204 and a middle sleeve male bayonet 203 at the end near the first middle half-cylinder 201 respectively. The outer periphery of the spliced ​​first middle half-cylinder 201 and the second middle half-cylinder 202 is tightened by the middle sleeve ring 7.

[0031] As mentioned above, both the end sleeve 1 and the middle sleeve 2 are split cylindrical structures, each consisting of two half-cylinder structures that can be detachably spliced ​​together by a snap-fit ​​mechanism, thus facilitating assembly and disassembly.

[0032] As attached Figure 8 and attached Figure 9 As shown, in another specific embodiment based on the above, the outer circumferential surface of the standard ring 3 is provided with two first semi-cylindrical protrusions 307 symmetrical about the central axis L, and the first semi-cylindrical protrusions 307 are provided with circular holes 308 that pass through them along their axial direction; the outer circumferential surface of the adapter ring 4 is provided with second semi-cylindrical protrusions 407 that correspond to the position of the first semi-cylindrical protrusions 307 on the standard ring 3 and have the same radius; the inner surfaces of the end sleeve 1 and the middle sleeve 2 are respectively provided with recesses 9 that extend along the axial direction, and the recesses 9 are size-matched with the first semi-cylindrical protrusions 307 of the standard ring 3 and the second semi-cylindrical protrusions 407 of the adapter ring 4, so that they can be inserted into the first semi-cylindrical protrusions 307 or the second semi-cylindrical protrusions 407. In this design, the recessed portion 9, in conjunction with the first semi-cylindrical protrusion 307 or the second semi-cylindrical protrusion 407, serves to guide the axis and prevent rotation, ensuring that the end faces of the standard ring 3 and the adapter ring 4 are aligned.

[0033] As attached Figure 6 and attached Figure 7As shown, in another specific embodiment based on the above, the standard ring 3 is detachably spliced ​​from a first half-ring 301 and a second half-ring 302 with identical structures via a snap-fit ​​structure. The first half-ring 301 has a male snap-fit ​​303 at one end near the second half-ring 302 and a female snap-fit ​​304 at the other end. The second half-ring 302 has corresponding female snap-fit ​​304 and male snap-fit ​​303 at the end near the first half-ring 301. The outer periphery of the spliced ​​first half-ring 301 and second half-ring 302 is tightened by an annular rubber band 310. In this scheme, the standard ring 3 is a split-type ring structure, spliced ​​using the stepped female snap-fit ​​304 and male snap-fit ​​303 as a snap-fit ​​structure, and tightened with the annular rubber band 310, ensuring the stability and alignment accuracy of the splicing and enhancing its overall integrity.

[0034] In a further specific embodiment based on the above, a circumferential groove 309 extending in the circumferential direction is provided on the outer circumferential surface of the standard ring 3 formed by splicing the first half-ring 301 and the second half-ring 302, and the circumferential groove 309 can be used to tighten the annular rubber band 310.

[0035] As attached Figure 11 and attached Figure 12 As shown, in another specific embodiment based on the above, it also includes an annular base 8. The annular base 8 is a complete ring structure with a three-step cross-section. The annular base 8 is provided with a lower step annular cylindrical surface 803, a middle step annular cylindrical surface 802 and an upper step annular cylindrical surface 801 with gradually increasing diameter from bottom to top. The diameter of the lower step annular cylindrical surface 803 is adapted to the diameter of the end plug 5. The diameter of the middle step annular cylindrical surface 802 is adapted to the outer diameter of the adapter ring 4 at the lower end of the multi-ring assembly. The diameter of the upper step annular cylindrical surface 801 is adapted to the outer diameter of the end sleeve 1 at the lower end of the sleeve assembly.

[0036] In this design, the annular base 8 provides stable bottom support for the sample preparation process. Specifically, considering the aforementioned multi-ring assembly and sleeve assembly structures, the adapter ring 4 is securely connected to the annular base 8 by inserting into the middle stepped annular cylindrical surface 802, the end sleeve 1 is securely connected to the annular base 8 by inserting into the upper stepped annular cylindrical surface 801, and the end plug 5 is securely inserted into the lower stepped annular cylindrical surface 803 and directly contacts the worktable surface. In the design incorporating the second semi-cylindrical protrusion 407, the middle stepped annular cylindrical surface 802 has a recess 9 that matches the second semi-cylindrical protrusion 407 of the adapter ring 4.

[0037] As attached Figure 13As shown, in another specific embodiment based on the above, a loading cap 11 is also included. The loading cap 11 is an integral solid structure composed of a first cylinder 1101 and a second cylinder 1102. The diameter of the first cylinder 1101 is larger than the diameter of the second cylinder 1102. The diameter of the second cylinder 1102 is adapted to the diameter of the end plug 5. The first cylinder 1101 is used to contact the pressure application device, and the second cylinder 1102 is used to contact the plug flat end face 501 of the end plug 5.

[0038] A method of using a stacked sample preparation device for the above-mentioned inclined interlayered soil cylindrical sample includes the following steps: According to the required thickness of each soil layer, select several standard rings 3 of corresponding height; select different numbers of standard rings 3 as needed, fill each standard ring 3 with the corresponding soil material, and spread and flatten it evenly so that its upper surface is flush with the end face 305 of the standard ring to obtain the corresponding soil layer. Then, on the workbench, an end plug 5 is placed into an adapter ring 4 with its inclined end face 502 facing upwards. The top of the end plug 5 and the adapter ring 4 are aligned. Then, standard rings 3 filled with soil are stacked alternately in a predetermined order. After the designed number of alternating soil layers on the inclined surface is reached, a sleeve assembly is fitted on the outside, and the corresponding adapter ring 4 and end plug 5 are placed on the top standard ring 3. Alternatively, in a design where the combined sleeve assembly includes a middle sleeve 2 and two end sleeves 1, the configuration would be: Next, on the workbench, an end plug 5 is placed into an adapter ring 4 with its inclined end face 502 facing upwards. The top of the end plug 5 is aligned with the top of the adapter ring 4. Then, standard rings 3 filled with soil are stacked alternately in a predetermined order. During the stacking process, as the multi-ring assembly increases in height, end sleeves 1 and middle sleeves 2 are gradually assembled around the outside of the multi-ring assembly to form a sleeve assembly, which is used to constrain the multi-ring assembly. After the designed number of interlayered soil layers on the inclined surface is reached, the corresponding adapter ring 4 and end plug 5 are placed on the top standard ring 3. Afterwards, use the pressure application device to apply pressure to the end plug 5 at the top, and use this to apply a preload to the interlayer soil of the inclined surface inside the device until the sample deformation stabilizes, and then remove the mold.

[0039] As attached Figure 14 As shown, a specific embodiment of the present invention is as follows: This device is used to prepare cylindrical sand-clay interlayer samples with a layer inclination angle of 15°, corresponding to α = 75°. According to the design, the standard ring 3 has a standard ring end face 305 at an angle of α = 75° to the central axis L; the adapter ring 4 has an adapter ring flat end face 405 perpendicular to the central axis L and an adapter ring inclined end face 406 at an angle of α = 75° to the central axis L; the end plug 5 has a plug flat end face 501 perpendicular to the central axis L and a plug inclined end face 502 at an angle of α = 75° to the central axis L.

[0040] Step S1: Preparation of Standard Ring 3 Based on the preset soil layer thickness, such as 10mm for cohesive soil and 5mm for sandy soil, select standard rings 3 of corresponding heights, such as standard rings 3 with a height of 10mm or 5mm and an inner diameter of 50mm. Engage the first half-ring 301 and the second half-ring 302 of each standard ring 3 with the male ring clamp 303 and the female ring clamp 304 to form a complete ring. Then, insert an annular rubber band 310 into the annular groove 309 on the outer circumference of each standard ring 3 to tighten the first half-ring 301 and the second half-ring 302, preventing them from coming apart during subsequent operations.

[0041] Step S2: Preparation of sandy soil layer Take a standard ring 3 with a height of 5mm and place it on a flat glass plate, as shown in the attached figure. Figure 14 Part a of the process: Fill the ring with a predetermined amount of dried and sieved sand particles. Spread the sand evenly and flatten it with a scraper until its upper surface is flush with the end face 305 of the standard ring. Then, slowly inject water from the bottom outer side of the standard ring 3 using a syringe, gradually wetting the entire sand layer through capillary action until a water film appears on the surface of the soil sample. Wipe away excess water from the outer circumference of the ring with absorbent paper. Place the sand-filled standard ring 3, along with the glass slide, in a refrigerator and freeze at -10°C for 10 hours to obtain a frozen sandy soil layer.

[0042] Step S3: Preparation of cohesive soil layer Take a standard ring 3 with a height of 10mm and place it on a flat glass plate, as shown in the attached figure. Figure 14 Part b. Fill the ring with a predetermined amount of cohesive soil with a certain moisture content. Use a trowel to spread the clay evenly and flatten it so that its upper surface is flush with the end face 305 of the standard ring, forming a cohesive soil layer.

[0043] Step S4: Preparation of the sleeve assembly Place the annular base 8 on a flat operating table, and insert an end plug 5 into the lower stepped annular cylindrical surface 803 of the annular base 8 with its beveled end face 502 facing upwards, as shown in the attached figure. Figure 14 Part c. An adapter ring 4 is placed into the stepped annular cylindrical surface 802 of the annular base 8 with its beveled end face 406 facing upwards. The end plug 5 is aligned with the beveled surface of the adapter ring 4, as shown in the attached figure. Figure 14 Part d in the diagram. A first end half-cylinder 101 is placed into the upper stepped annular cylindrical surface 801 of the annular base 8, as shown in the attached diagram. Figure 14 The 'e' part.

[0044] Step S5: Stacking and Assembling Within the semi-enclosed space formed by the first end half-cylinder 101, the adapter ring 4, and the end plug 5, layers are stacked alternately in a predetermined order: "cohesive soil layer - sandy soil layer - cohesive soil layer - ...". The specific process is as follows: (see attached image) Figure 14 In part f, a prepared cohesive soil standard ring 3 is placed into the sleeve assembly, ensuring that its first semi-cylindrical protrusion 307 is aligned with the second semi-cylindrical protrusion 407 of the adapter ring 4, and both are embedded in the recess 9 on the inner surface of the first end half-cylinder 101, and that the end face 305 of the standard ring is tightly fitted with the inclined end face 406 of the adapter ring below. Next, a frozen sandy soil standard ring 3 is stacked on the cohesive soil layer, again ensuring that its first semi-cylindrical protrusion 307 is aligned with the recess 9, and that the inclined end faces of adjacent standard rings 3 are fitted together.

[0045] Repeat the stacking process described above. When the stacking height exceeds the height of the first end half-cylinder 101, place the second end half-cylinder 102 into the upper stepped annular surface 801 of the annular base 8 to form a complete end sleeve 1 and fit it with the end collar 6. Then, insert the first middle half-cylinder 201 of a middle sleeve 2 into the assembled end sleeve 1, ensuring that the recesses 9 on the inner wall of the sleeve are aligned, as shown in the attached figure. Figure 14 The g-section continues stacking of standard rings 3. When the stacking height exceeds the height of the first middle half-cylinder 201, the second middle half-cylinder 202 is installed to form a complete middle sleeve 2, and the middle collar 7 is fitted on, as shown in the attached diagram. Figure 14 The h part; another first end half-cylinder 101 is installed on the upper end of the sleeve 2 and the standard ring 3 continues to be stacked, as shown in the attached figure. Figure 14 Part i. After reaching the designed number of interlayered soil layers, the second end half-cylinder 102 is installed to form a complete top end sleeve 1, and the end collar 6 is fitted on it. An adapter ring 4 and an end plug 5 are placed inside the top end sleeve 1, as shown in the attached diagram. Figure 14 The j part.

[0046] Step S6: Pre-compression After the sand layer inside the device has completely melted at room temperature, install the loading cap 11 on top of the device, as shown in the attached diagram. Figure 14 The k-section of the sample preparation device is then placed into a one-dimensional compression apparatus used in standard geotechnical testing. The position is adjusted so that the end face of the first cylinder 1101 of the loading cap 11 at the top is in contact with the loading head of the one-dimensional compression apparatus, and the bottom of the device is in contact with the support platform. A preload of 20 kPa is applied to the interlayered soil of the inclined surface within the sample preparation device, and this load is maintained until the sample deformation stabilizes, i.e., the deformation per hour is less than 0.01 mm.

[0047] Step S7: Demolding Remove the pre-compressed sample preparation device from the one-dimensional compressor, and sequentially remove the top loading cap 11, end plug 5, end collar 6, and second end half-cylinder 102. Next, remove the middle collar 7 and second middle half-cylinder 202 from the middle sleeve 2, and remove the bottom end collar 6 and second end half-cylinder 102 to expose the multi-ring assembly formed by stacked standard rings 3. Cut the annular rubber band 310 in the annular groove 309 of each standard ring 3 with a knife. Then, remove the top first end half-cylinder 102, the first middle half-cylinder 201, the bottom first end half-cylinder 102, and the top adapter ring 4. Remove the standard rings 3 one by one. When removing them, first insert a thin iron wire into the round hole 308 on the first semi-cylindrical protrusion 307, and use the thin iron wire to slide the first half-ring 301 upward along the axial direction of the sample by one ring height, and then smoothly remove it to the side. Next, remove the second half-ring 302 in the same way. After all standard rings 3 were removed, a cylindrical soil sample with a sloping surface structure was fully exposed, as shown in the attached figure. Figure 14 The l part.

[0048] Step S8: Sample trimming After all standard rings are removed, immediately surround and clamp the soil sample from both sides using a 100mm high double-lobed mold used in standard geotechnical testing. Carefully cut away the excess soil from both ends of the sample using a wire saw along the two end faces of the double-lobed mold. Then, remove the double-lobed mold to obtain a precisely sized, clearly defined, 15° inclined cylindrical sample of sand-clay interbedded soil, as shown in the attached diagram. Figure 14 The 'm' part can be used for subsequent mechanical property tests such as triaxial compression tests.

[0049] The device of this invention can prepare cylindrical soil samples of inclined interlayered soil with stable structure, low disturbance, controllable inclination angle and thickness, and close interlayer contact.

[0050] It should be noted that the terms such as "upper", "lower", "left", "right", "front", and "back" used in the invention are only for clarity of description and are not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

[0051] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0052] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that those skilled in the art will understand that various changes, modifications, substitutions, refinements, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and these variations should be considered within the scope of protection of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A stacked sample preparation device for cylindrical soil samples from alternating layers of inclined planes, characterized in that: The assembly includes a sleeve assembly, a multi-ring assembly, and an end plug (5). The multi-ring assembly is tubular and consists of two columnar adapter rings (4) and several stacked standard rings (3) arranged axially in the middle. The two adapter rings (4) have opposite sides that are inclined planes. The standard ring end faces (305) at the upper and lower ends of the standard rings (3) are flush with the inclined planes of the adapter rings (4). The end plug (5) is used to be embedded in the adapter rings (4). The end plug (5) has a plug inclined end face (502) that is flush with the inclined planes of the outer adapter rings (4). The sleeve assembly is used to be coaxially fitted on the outer ring of the multi-ring assembly. The central holes of the several standard rings (3) can be used for soil preparation. The end plug (5) is used to be driven by a pressure device to apply pressure to the soil in the middle.

2. The stacked sample preparation device for cylindrical soil samples of interlayered slopes according to claim 1, characterized in that: The sleeve assembly includes a middle sleeve (2) and two end sleeves (1). One end of each of the two end sleeves (1) is provided with a stepped annular snap structure that can be snapped onto the end of the middle sleeve (2). The two end sleeves (1) are coaxially fitted onto both ends of the middle sleeve (2), and the middle sleeve (2) and the two end sleeves (1) are fitted together on the outer ring of the multi-ring assembly.

3. The stacked sample preparation device for cylindrical soil samples of interlayered slopes according to claim 2, characterized in that: The end sleeve (1) is composed of a first end half-cylinder (101) and a second end half-cylinder (102) with the same structure spliced ​​together. The first end half-cylinder (101) is provided with a male end sleeve bayonet (103) at one end near the second end half-cylinder (102) and a female end sleeve bayonet (104) at the other end. The second end half-cylinder (102) is provided with a matching female end sleeve bayonet (104) and a male end sleeve bayonet (103) at the end near the first end half-cylinder (101). The outer periphery of the spliced ​​first end half-cylinder (101) and the second end half-cylinder (102) is tightened by an end collar (6).

4. The stacked sample preparation device for cylindrical soil samples of interlayered slopes according to claim 2, characterized in that: The middle sleeve (2) is composed of a first middle half-cylinder (201) and a second middle half-cylinder (202) with the same structure spliced ​​together. The first middle half-cylinder (201) is provided with a middle sleeve male bayonet (203) at one end near the second middle half-cylinder (202) and a middle sleeve female bayonet (204) at the other end. The second middle half-cylinder (202) is provided with a matching middle sleeve female bayonet (204) and a middle sleeve male bayonet (203) at the end near the first middle half-cylinder (201) respectively. The outer periphery of the spliced ​​first middle half-cylinder (201) and the second middle half-cylinder (202) is tightened by a middle sleeve ring (7).

5. The stacked sample preparation device for cylindrical soil samples of interlayered slopes according to claim 2, characterized in that: The standard ring (3) has two first semi-cylindrical protrusions (307) on its outer circumferential surface. The first semi-cylindrical protrusions (307) have a circular hole (308) that passes through it along its axial direction. The adapter ring (4) has a second semi-cylindrical protrusion (407) on its outer circumferential surface that corresponds to the position of the first semi-cylindrical protrusions (307) on the standard ring (3) and has the same radius. The inner surfaces of the end sleeve (1) and the middle sleeve (2) are respectively provided with recesses (9) that extend along the axial direction. The recesses (9) are adapted to the size of the first semi-cylindrical protrusions (307) of the standard ring (3) and the second semi-cylindrical protrusions (407) of the adapter ring (4), and can be inserted into the first semi-cylindrical protrusions (307) or the second semi-cylindrical protrusions (407).

6. The stacked sample preparation device for cylindrical soil samples of interlayered slopes according to claim 1, characterized in that: The standard ring (3) is detachably spliced ​​from a first half-ring (301) and a second half-ring (302) with the same structure through a snap-fit ​​structure. The first half-ring (301) has a male ring snap (303) at one end near the second half-ring (302) and a female ring snap (304) at the other end. The second half-ring (302) has a matching female ring snap (304) and a male ring snap (303) at the end near the first half-ring (301). The outer periphery of the spliced ​​first half-ring (301) and second half-ring (302) is tightened by an annular rubber band (310).

7. The stacked sample preparation device for cylindrical soil samples of interlayered slopes according to claim 6, characterized in that: The standard ring (3) formed by splicing the first half-ring (301) and the second half-ring (302) has an annular groove (309) extending in the circumferential direction on its outer circumferential surface. The annular groove (309) can be used to tighten the annular rubber band (310).

8. The stacked sample preparation device for cylindrical soil samples of interlayered slopes according to claim 1, characterized in that: It also includes an annular base (8), which is a three-step cross-section ring structure. The annular base (8) is provided with a lower step annular cylindrical surface (803), a middle step annular cylindrical surface (802) and an upper step annular cylindrical surface (801) with gradually increasing diameter from bottom to top. The diameter of the lower step annular cylindrical surface (803) is matched with the diameter of the end plug (5), the diameter of the middle step annular cylindrical surface (802) is matched with the outer diameter of the lower end of the multi-ring assembly, and the diameter of the upper step annular cylindrical surface (801) is matched with the outer diameter of the lower end of the sleeve assembly.

9. The stacked sample preparation device for cylindrical soil samples of interlayered slopes according to claim 1, characterized in that: It also includes a loading cap (11), which is composed of a first cylinder (1101) and a second cylinder (1102). The diameter of the first cylinder (1101) is larger than the diameter of the second cylinder (1102), and the diameter of the second cylinder (1102) is adapted to the diameter of the end plug (5). The first cylinder (1101) is used to contact the pressure application device, and the second cylinder (1102) is used to contact the end plug (5).

10. A method of use, applied to the stacked sample preparation device for cylindrical samples of interlayered soil on inclined planes as described in any one of claims 1 to 9, characterized in that, Includes the following steps: According to the required thickness of each soil layer, select several standard rings (3) of corresponding height; select different numbers of standard rings (3) as needed, fill each standard ring (3) with the corresponding soil material, and spread and flatten it evenly so that its upper surface is flush with the end face (305) of the standard ring to obtain the corresponding soil layer; Then, on the workbench, an end plug (5) is placed into an adapter ring (4) with its oblique end face (502) facing upwards. The end plug (5) is aligned with the top of the adapter ring (4). Then, standard rings (3) filled with soil are stacked alternately in a predetermined order. After the designed number of alternating soil layers on the inclined surface is reached, a sleeve assembly is fitted on the outside, and the corresponding adapter ring (4) and end plug (5) are placed on the top standard ring (3). Afterwards, the pressure device is used to apply pressure to the end plug (5) at the top as needed, and in this way, a preload is applied to the interlayer soil of the inclined surface in the device until the sample deformation is stable, and then the mold can be removed.

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