A true triaxial undisturbed soil sample sampling device

Abstract

This utility model relates to the technical field of geotechnical engineering test sampling devices, specifically to a true triaxial undisturbed soil sampling device, comprising: a support assembly including a C-shaped panel and a lower panel fixedly connected by a fixed support column, the lower panel having a square hole at its center; two sampling counterweights, detachably and symmetrically installed on both sides of the lower panel; a sampling section including a sampling mold installed above the square hole via a power source; and a sample loading mold including two symmetrically arranged sleeves, with metal hoops fixedly installed on the outside of the two sleeves by adjusting bolts. This application can reduce disturbance to the soil sample, achieve low-disturbance sampling, maintain the original structure and stress state of the soil sample, meet the requirements of true triaxial testing for soil samples, obtain mechanical parameters that are difficult to measure through conventional testing through true triaxial testing, establish a more accurate soil constitutive model, describe the nonlinear relationship between stress-strain-strength, and provide key technical support for practical engineering.

Description

Technical Field

[0001] This utility model relates to the technical field of geotechnical engineering test sampling devices, specifically to a true triaxial undisturbed soil sampling device. Background Technology

[0002] In geotechnical engineering, the physical and mechanical properties of soil are the core basis for actual engineering projects. Soil is usually in a three-dimensional stress state in the actual environment, and the stress in each of the three dimensions is not equal. Traditional uniaxial compression tests can only simulate the stress on one side, and conventional triaxial tests cannot fully reproduce the real stress environment of soil. This leads to deviations between the mechanical parameters obtained from these tests, such as internal friction angle, cohesion and deformation modulus, and the actual engineering conditions, which directly affects the applicability and safety of the project.

[0003] Therefore, to accurately represent the true stress environment of soil, extremely high quality requirements are placed on soil samples. The original structure, stress state, and physical properties of the soil sample must be kept consistent across all three directions. This makes the sampling of undisturbed soil samples a critical factor limiting experimental accuracy. Current sampling devices and methods have significant drawbacks: most are designed for cylindrical soil samples, requiring secondary processing and shaping into cubes or cuboids after sampling, which easily causes secondary disturbance and is inefficient. Furthermore, the lack of effective sealing and fixing measures during sample loading leads to moisture loss or structural damage, causing significant disturbance to the soil sample and easily disrupting its original structure and stress state, making it difficult to guarantee the stability of sampling parameters. Therefore, we propose a true triaxial undisturbed soil sampling device. Utility Model Content

[0004] The purpose of this invention is to address the shortcomings mentioned in the background art and provide a true triaxial undisturbed soil sampling device.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A true triaxial undisturbed soil sampling device includes: The bracket assembly includes a C-shaped panel and a lower panel that are fixedly connected vertically by a fixed support column, wherein the lower panel has a square hole at its center; Two sampling counterweights are detachably and symmetrically installed on both sides of the lower panel to provide counterweights to maintain sampling stability. The sampling unit includes a sampling mold that is lifted and installed above the square hole by a power source, and a panel cover for detachably installing the sampling mold; The sample container is used to hold the original soil sample. It includes two symmetrically arranged sleeves, and metal hoops are fixed to the outside of the two sleeves by adjusting bolts.

[0006] Preferably, the power source is a hydraulic cylinder fixedly installed inside the C-shaped panel. The hydraulic cylinder is provided with an output shaft for fixing and connecting the transmission connecting rod. The bottom end of the transmission connecting rod is detachably installed on the panel cover.

[0007] Preferably, the sampling mold adopts two symmetrically arranged half-cavity structures, the mating surfaces of the half-cavity structures are provided with serrated seams, and each half-cavity structure is provided with symmetrically arranged outer edge protrusions along its upper edge.

[0008] Preferably, the panel cover has a wedge-shaped groove that matches the outer edge protrusion for horizontally inserting the sampling mold, and the panel cover has a connecting hole for threaded installation of the transmission connecting rod; The sampling mold has a trapezoidal wedge at its bottom.

[0009] Preferably, the panel cover has symmetrically arranged threaded holes, and a fixing clamp is detachably installed on the outside of the transmission connecting rod and on the panel cover, and the fixing clamp is provided with a screw for threaded installation in the threaded holes.

[0010] Preferably, the fixing clamp has an inverted U-shaped structure with the inner spacing gradually decreasing from bottom to top, and the fixing clamp is used to clamp the sampling mold.

[0011] Preferably, a hydraulic switch for controlling the opening and closing of the hydraulic cylinder is installed on the C-shaped panel, and a T-shaped level is installed on the C-shaped panel.

[0012] Compared with the prior art, the beneficial effects of this utility model are: 1. This true triaxial undisturbed soil sampling device can reduce disturbance to the soil sample, achieve low-disturbance sampling, and maintain the original structure and stress state of the soil sample; by providing sampling power through a power source, it can reduce manual intervention, improve sampling efficiency and accuracy, and achieve automated and reliable sampling. 2. Both the sampling mold and the sample loading mold adopt a cubic design, which can completely obtain undisturbed true triaxial soil samples, meet the requirements of true triaxial tests for soil samples, and establish a more accurate soil constitutive model through true triaxial tests to describe the nonlinear relationship between stress-strain-strength, providing key technical support for practical engineering. Attached Figure Description

[0013] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an undue limitation of the present invention. In the drawings: Figure 1 This is a front view of the overall structure of this utility model; Figure 2 This is a rear view of the overall structure of this utility model; Figure 3 This is a schematic diagram of the bracket assembly of this utility model; Figure 4 This is a schematic diagram of the panel cover and sampling mold of this utility model; Figure 5 This is a schematic diagram of the fixing clamp of this utility model; Figure 6 This is a schematic diagram of the sample mold of this utility model.

[0014] The meanings of the labels in the diagram are as follows: 1. Bracket assembly; 101. Lower panel; 102. C-shaped panel; 1021. T-shaped level; 1022. Hydraulic switch; 103. Fixed support column; 104. Square hole; 2. Sampling counterweight; 3. Hydraulic cylinder; 4. Transmission connecting rod; 5. Panel cover; 501. Threaded hole; 502. Connecting hole; 503. Wedge-shaped groove; 6. Sampling mold; 601. Outer edge protrusion; 602. Serrated slit; 603. Trapezoidal wedge opening; 7. Fixture; 701. Screw; 702. Wrench; 8. Sample mold; 801. Sleeve; 802. Metal hoop; 803. Adjusting bolt. Detailed Implementation

[0015] The technical solutions of this utility model will be clearly and completely described below with reference to the embodiments of this utility model. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0016] Please see Figures 1-6 The present invention will describe the above technical solution in detail through the following embodiments: The true triaxial undisturbed soil sampling device of this embodiment includes: Support assembly 1, including as follows Figures 1-3 The C-shaped panel 102 and the lower panel 101 are fixedly connected vertically by a fixed support column 103. The lower panel 101 has a square hole 104 at its center. In this embodiment, a hydraulic cylinder 3 is fixedly installed inside the C-shaped panel 102 as a power source. The hydraulic cylinder 3 is fixedly connected to a transmission connecting rod 4 via an output shaft. A panel cover 5 is detachably installed at the bottom end of the transmission connecting rod 4. A sampling mold 6, aligned with the square hole 104, is detachably installed below the panel cover 5. Figures 1-3 The structure shown has two sampling counterweights 2 symmetrically installed on both sides of the lower panel 101.

[0017] To better hold the soil sample, the device is also equipped with a sample loading mold 8, such as... Figure 6 The structure shown includes two symmetrically arranged sleeves 801 for holding soil samples, which can ensure that the two half-cubic blocks are accurately aligned when sealing the soil sample, improving the sealing accuracy and stability. Metal hoops 802 are fixedly installed on the outside of the two sleeves 801 by adjusting bolts 803.

[0018] Specifically, such as Figures 1-2 as well as Figure 4 As shown in the embodiment, to facilitate the removal of soil samples, the sampling mold 6 adopts two symmetrically arranged semi-cavity structures. The mating surface of the semi-cavity structures is provided with a serrated slit 602, and the bottom end of the sampling mold 6 is provided with a trapezoidal wedge 603. This design can minimize the compression disturbance to the soil sample while ensuring that the sampling mold cuts into the soil, so that the surface of the soil sample is flat. At the same time, each semi-cavity structure is provided with symmetrically arranged outer edge protrusions 601, and the panel cover 5 is provided with a wedge-shaped groove 503. The sampling mold 6 is inserted into the wedge-shaped groove 503 through the outer edge protrusions 601. In order to avoid excessive gas pressure in the cavity during the sampling process, the panel cover 5 is provided with a threaded hole 501 for venting.

[0019] This implementation example Figure 1 , Figure 2 as well as Figure 5 As shown, a fixing clamp 7 is detachably installed on the outside of the transmission connecting rod 4 and on the panel cover 5. The fixing clamp 7 is provided with a screw 701 for threaded installation in the threaded hole 501. In order to clamp the two half-cavity structures, the fixing clamp 7 in this embodiment has an inverted U-shaped structure with the inner spacing gradually decreasing from bottom to top.

[0020] The working principle of the true triaxial undisturbed soil sampling device in this embodiment is as follows: First, the sampling site is cleaned to ensure that the ground at the sampling location is flat. The support assembly 1 is placed on the cleaned and flat sampling site. The support assembly 1 is adjusted so that the T-shaped level 1021 set on the C-shaped panel 102 is in a horizontal and vertical position, so that the entire sampling device is horizontal, ensuring low disturbance and integrity of the undisturbed sample. The sampling mold 6 is inserted under the panel cover 5. Vaseline or lubricating oil is evenly applied to the inside of the sampling mold 6, and the serrated slit 602 on the sampling mold 6 is opened by 2mm, so that the sampling mold 6 is lowered through the square hole 104 to the position directly above the sampling location. The hydraulic cylinder 3 drives the sampling mold 6 to move up and down through the transmission connecting rod 4, controlling the descent of the sampling mold 6. The trapezoidal wedge 603 at its bottom cuts into the soil. During the sampling process, the air in the cavity of the sampling mold 6 passes through the threaded hole 501. The soil sample is discharged until the sampling mold 6 is fully inserted into the soil to the predetermined depth; the soil sample is sheared. This design enables efficient sampling and minimizes the compression disturbance to the soil sample while ensuring that the sampling mold is inserted into the soil. The screws 701 in the fixing clamp 7 are tightened with the wrench 702, so that the fixing clamp 7 presses the sampling mold 6 to completely close the sawtooth slit 602, completing the shearing of the soil. The hydraulic cylinder 3 controls the sampling mold 6 to rise, thereby bringing out the sampling mold 6 together with the soil sample after shearing. After rising to a certain height, the connection between the transmission connecting rod 4 and the connecting hole 502 is loosened, and the soil at the bottom of the sampling mold is cut away to ensure that the bottom of the sampled soil is flat. Then, the sampling mold 6 with the panel cover 5 is removed as a whole. The fixing clamp 7 and the panel cover 5 are removed in sequence. The sampling mold 6 is opened with the sawtooth slit 602 to obtain a complete original soil sample.

[0021] Finally, the complete soil sample is wrapped in plastic wrap and placed into the sample mold 8, which is formed by splicing two sleeves 801. The degree of fixation is controlled by adjusting the adjusting bolts 803 on the metal hoop 802 to ensure that the soil sample is securely sealed in the sample mold 8, preventing moisture evaporation. The soil sample is also marked and protected to avoid disturbance during transportation and storage. During the soil sample sealing process, the tightening degree of the metal hoop 802 is controlled by adjusting the bolts 803 to ensure that the original stress state of the soil sample is not destroyed. After the soil sample is removed, the sample mold 8 is immediately sealed to prevent moisture evaporation and the entry of outside air, which would affect the physical and mechanical properties of the soil sample.

[0022] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0023] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention.

Claims

1. A true triaxial undisturbed soil sampling device, characterized in that: include: The bracket assembly (1) includes a C-shaped panel (102) and a lower panel (101) that are fixedly connected vertically by a fixed support column (103), and the lower panel (101) has a square hole (104) at the center. Two sampling counterweights (2) are detachably and symmetrically installed on both sides of the lower panel (101) to provide counterweights to maintain sampling stability; The sampling unit includes a sampling mold (6) that is lifted and installed above the square hole (104) by a power source, and a panel cover (5) for detachably installing the sampling mold (6). The sample container (8) is used to hold the original soil sample taken. It includes two symmetrically arranged sleeves (801). The two sleeves (801) are fixedly installed with metal hoops (802) by adjusting bolts (803).

2. The true triaxial undisturbed soil sampling device as described in claim 1, characterized in that: The power source is a hydraulic cylinder (3) fixedly installed in the C-shaped panel (102). The hydraulic cylinder (3) is provided with an output shaft for fixing the transmission connecting rod (4). The bottom end of the transmission connecting rod (4) is detachably installed on the panel cover (5).

3. The true triaxial undisturbed soil sampling device as described in claim 2, characterized in that: The sampling mold (6) adopts two symmetrically arranged half-cavity structures. The mating surface of the half-cavity structures is provided with a sawtooth slit (602), and each half-cavity structure is provided with a symmetrically arranged outer edge protrusion (601) along its upper edge.

4. The true triaxial undisturbed soil sampling device as described in claim 3, characterized in that: The panel cover (5) is provided with a wedge-shaped groove (503) that fits with the outer edge protrusion (601) for horizontally inserting the sampling mold (6), and the panel cover (5) is provided with a connection hole (502) for threaded installation of the transmission connecting rod (4). The sampling mold (6) has a trapezoidal wedge (603) at its bottom end.

5. The true triaxial undisturbed soil sampling device as described in claim 4, characterized in that: The panel cover (5) is provided with symmetrically arranged threaded holes (501). The transmission connecting rod (4) is externally located on the panel cover (5) and is detachably mounted with a fixing clamp (7). The fixing clamp (7) is provided with a screw (701) for threaded installation in the threaded hole (501).

6. The true triaxial undisturbed soil sampling device as described in claim 5, characterized in that: The fixing clamp (7) has an inverted U-shaped structure with the inner spacing gradually decreasing from bottom to top, and the fixing clamp (7) is used to clamp the sampling mold (6).

7. The true triaxial undisturbed soil sampling device as described in claim 2, characterized in that: The C-shaped panel (102) is equipped with a hydraulic switch (1022) for controlling the opening and closing of the hydraulic cylinder (3), and a T-shaped level (1021) is also installed on the C-shaped panel (102).

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