A multi-depth in-situ stratified sampling device and method for contaminated site soil

Abstract

The application relates to the technical field of soil sampling equipment, in particular to a multi-depth in-situ layered soil sampling device for a contaminated site, which comprises a sampling pipe structure, a limiting ring, a guide pulley, a supporting structure and an auxiliary operation structure. The sampling pipe structure is composed of a plurality of sample storage pipes which are sequentially connected through threads, and each sample storage pipe is internally provided with an openable and closable sampling bin structure; when the sampling pipe is inserted into the soil downwards, the soil can enter the sample storage pipes in different layers in sequence; when the sampling pipe is lifted upwards, the opening and closing plate is automatically closed, so that the in-situ layered storage of the soil samples at different depths is realized. Meanwhile, the operator can drive the sampling pipe to be gradually pressed downwards or lifted through the treading mode, and the sampling can be completed without relying on large mechanical equipment. The application has a light structure and is convenient to carry, and is suitable for the layered sampling of the soil of the contaminated site in a soft soil environment.

Description

Technical Field

[0001] This invention relates to the field of soil sampling equipment technology, specifically to a multi-depth in-situ stratified sampling device and method for soil in contaminated sites. Background Technology

[0002] With the continuous advancement of industrialization, some industrial sites, mining areas, and chemical production areas are prone to leakage and deposition of harmful substances such as heavy metals and organic pollutants during long-term production processes, leading to varying degrees of soil pollution. To accurately determine the distribution of pollutants in the soil, stratified sampling and analysis of soil at different depths is typically required during contaminated site investigation and remediation. Existing soil sampling methods mainly include manual sampling and mechanical equipment sampling. While mechanical drilling equipment can achieve deeper sampling, its large size and weight make transportation and on-site deployment inconvenient, hindering its use at survey sites with limited space or requiring frequent relocation.

[0003] On the other hand, while some portable samplers offer a degree of flexibility, most have relatively simple structures and can typically only perform single-layer or overall sampling, making it difficult to achieve in-situ stratified preservation of samples at multiple depths. Furthermore, problems such as sample contamination, low sampling efficiency, and insufficient sampling stability easily arise during the sampling process. Especially in soft soil or topsoil environments, traditional sampling devices are prone to disturbing the sample structure during insertion and lifting, making it difficult to accurately reflect the actual pollution levels at different soil depths. Therefore, it is necessary to design a relatively lightweight, portable device capable of multi-depth in-situ stratified sampling in soft soil conditions to improve the efficiency of contaminated site investigations and the reliability of sample data. Summary of the Invention

[0004] The purpose of this invention is to provide a multi-depth in-situ stratified sampling device and method for soil in contaminated sites, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A multi-depth in-situ stratified sampling device and method for soil in contaminated sites includes a sampling tube structure, a support structure, and an auxiliary operation structure;

[0007] The sampling tube structure includes multiple coaxially detachably connected sample storage tubes and a bottom-insertion anchor block located at the bottom.

[0008] The outer wall of the sample storage tube is provided with a plurality of uniformly spaced tube wall positioning grooves along the axial direction, and the interior of the sample storage tube is provided with an openable and closable sampling chamber structure.

[0009] The outer side of the sampling tube structure is fitted with a limiting ring arranged symmetrically at the top and bottom, and multiple supporting structures are evenly arranged along the circumferential direction on the outer side of the limiting ring.

[0010] The support structure includes a support rod, an adjusting slide rod, and a support base plate. The top end of the adjusting slide rod is hinged to the upper limiting ring, and the top end of the support base plate is hinged to the bottom end of the support rod. The support rod and the adjusting slide rod are slidably connected and can be locked relative to each other.

[0011] An auxiliary operation structure is provided on one side of the sampling tube structure. The auxiliary operation structure includes a retaining ring. A limiting block is fixedly connected to the inner end face of the retaining ring. The limiting block can be inserted into the positioning groove of the tube wall to assist in lifting or pressing down the sampling tube structure.

[0012] Preferably, the openable sampling chamber structure includes a horizontally arranged connecting shaft fixedly connected to the inside of the sample storage tube. A main collar and auxiliary side rings symmetrically arranged on both sides of the main collar are sleeved on the outside of the connecting shaft. A right-side opening and closing plate is fixedly connected to one side of the main collar, and a left-side opening and closing plate is fixedly connected to one side of the auxiliary side ring. Both the right-side and left-side opening and closing plates are semi-circular plate structures, which are joined together in a horizontal state to form a circular partition.

[0013] Preferably, the inner wall of the sample storage tube is fixedly connected with a sealing buffer pad arranged in an annular shape, the inner end face of the sealing buffer pad is arc-shaped, and the right opening plate and the left opening plate are in contact with the top of the sealing buffer pad in a horizontal state.

[0014] Preferably, the sample storage tube has threaded grooves on both the inner side of the top end and the outer side of the bottom end, and two adjacent sample storage tubes are detachably threaded together through the threaded grooves; the bottom insert anchor block has a threaded groove on the inner side of the top end, which is threaded to the bottom end of the bottommost sample storage tube, and the bottom side of the inner end face of the bottom insert anchor block is inclined.

[0015] Preferably, there are two limiting rings in total, and the inner side of each limiting ring is connected to a guide pulley that is evenly arranged at the same angle along the circumference through a pulley seat. The guide pulley rolls and fits against the outer surface of the sampling tube structure.

[0016] Preferably, the support rod is a hollow tube, and the adjusting slide rod is slidably inserted into the inner side of the support rod; the outer surface of the adjusting slide rod has a groove along the axial direction, and a threaded rod is helically connected to the outer side of the support rod. One end of the threaded rod is fixedly connected to an adjusting handwheel, and the other end of the threaded rod is rotatably connected to a locking block, which engages with the groove of the adjusting slide rod; a positioning pin is slidably connected to the inner side of the support base plate, and the bottom end of the positioning pin is conical.

[0017] Preferably, the auxiliary operating structure further includes a base plate, fixed side plates, a balance bar, and hydraulic spring rods; the top of the base plate is fixedly connected to symmetrically arranged fixed side plates, the balance bar is rotatably connected between the two fixed side plates, and hydraulic spring rods are rotatably connected to the bottom ends of both sides of the balance bar, with the bottom ends of the hydraulic spring rods rotatably connected to the base plate; the top of the balance bar is fixedly connected to symmetrically arranged foot pedals.

[0018] Preferably, a telescopic rod is slidably connected to the inner side of one end of the balance rod near the sampling tube structure. One end of the telescopic rod is connected to the inner side of the balance rod through a return compression spring. An adjusting rod is inserted into the inner side of the other end of the telescopic rod. A connecting lug is rotatably connected to the outer side of the adjusting rod. The other end of the connecting lug is fixedly connected to the retaining ring.

[0019] Preferably, the inner sides of the pipe wall positioning groove are both right-angled, the cross-section of the limiting block is triangular, the distance between two adjacent pipe wall positioning grooves is equal to the distance between two adjacent limiting blocks, and the limiting block can be inserted into the pipe wall positioning groove and engaged with it.

[0020] Preferably, it includes the following steps:

[0021] S1. Device positioning: Unfold the support structure, adjust the support height by adjusting the slide bar, and fix the support base plate to the ground by positioning pins;

[0022] S2. Assemble the sampling tubes: Select the corresponding number of sample storage tubes according to the preset sampling depth and connect them in sequence, with the bottom end connected to the bottom insertion anchor block;

[0023] S3. Downward Sampling: Insert the adjusting rod with the inclined surface facing upward, step on the left foot pedal, and drive the sampling tube structure downward into the soil through the cooperation of the retaining ring and the positioning groove of the tube wall; after releasing, the auxiliary operation structure will automatically reset.

[0024] S4. Automatic sampling: During the insertion process, the soil from bottom to top pushes open the right and left opening plates of each layer upwards, and enters the sample storage tube of each layer.

[0025] S5. Sampling: After reaching the depth, pull out the adjusting rod, rotate it 180° so that the inclined surface is facing down, and reinsert it. Step on the right foot pedal to drive the sampling tube structure to lift upward; after releasing, the auxiliary operation structure will automatically reset.

[0026] S6. Automatic closing: During the lifting process, each layer of sample presses down on the right and left opening and closing plates under the action of gravity, automatically closing the sample and sealing it in each layer of tube.

[0027] S7. Sample separation: Repeat step S5 until the sampling tube structure is completely removed, disassemble each layer of sample storage tube in sequence, and collect soil samples from different depths.

[0028] Compared with the prior art, the beneficial effects of the present invention are:

[0029] 1. In this invention, by setting up a sampling tube structure formed by multiple sample storage tubes connected by threads in sequence, and setting an openable and closable sampling chamber structure inside each sample storage tube, the soil can enter the sample storage tubes from bottom to top in sequence during the process of inserting the device downward into the soft soil. When the sampling tube is lifted upward, it is automatically closed by the opening and closing plate, thereby sealing soil samples at different depths into the corresponding sample storage tubes. This realizes in-situ stratified collection of soil samples, effectively avoids interference between samples at different layers, and improves the accuracy of sampling results.

[0030] 2. In this invention, by setting a limiting ring and multiple support structures on the outside of the sampling tube structure, and adjusting the support height by adjusting the sliding rod, the device can form a stable support state during the sampling process. The positioning pins set at the bottom of the support base plate can be inserted into the ground for fixation, thereby effectively preventing the sampling tube from tilting or shifting during the pressing process, improving the overall stability of the device, and making the sampling process more stable and reliable.

[0031] 3. In this invention, an auxiliary operating structure is set up, utilizing a lever drive mechanism formed by a foot pedal, a balance bar, and a hydraulic spring rod. This mechanism, along with a retaining ring and a limiting block, engages with the positioning groove on the outer wall of the sampling tube, allowing the operator to gradually lower or raise the sampling tube structure by stepping on it. This structure eliminates the need for large mechanical equipment to complete sampling operations. Its overall structure is relatively lightweight, easy to carry and deploy on-site, and is particularly suitable for sampling work in contaminated sites with soft soil, thereby improving the flexibility and efficiency of on-site sampling. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0033] Figure 2 This is a schematic diagram of the internal structure of the sample storage tube of the present invention;

[0034] Figure 3 This is a schematic diagram of the sealing buffer pad installation structure of the present invention;

[0035] Figure 4 This is a schematic diagram of the bottom excavation block structure of the present invention;

[0036] Figure 5 This is a schematic diagram of the internal structure of the limiting ring of the present invention;

[0037] Figure 6This is a schematic diagram of the support structure of the present invention;

[0038] Figure 7 This is a schematic diagram of the card block installation structure of the present invention;

[0039] Figure 8 This is a schematic diagram of the auxiliary operation structure of the present invention;

[0040] Figure 9 This is a schematic diagram of the telescopic pole installation structure of the present invention;

[0041] Figure 10 This is a schematic diagram of the installation structure of the limiting block of the present invention;

[0042] Figure 11 This is a physical image of the present invention.

[0043] In the diagram: 1. Sampling tube structure; 101. Sample storage tube; 102. Tube wall positioning groove; 103. Sealing buffer pad; 104. Connecting shaft; 105. Main collar; 106. Auxiliary side ring; 107. Right side opening plate; 108. Left side opening plate; 109. Bottom excavation block; 2. Limiting ring; 3. Guide pulley; 4. Support structure; 401. Support rod; 402. Adjusting slide rod; 403. Support base plate; 4 04. Positioning pin; 405. Adjusting handwheel; 406. Threaded rod; 407. Locking block; 408. Connecting rod; 5. Auxiliary operating structure; 501. Base plate; 502. Fixed side plate; 503. Balance bar; 504. Hydraulic spring rod; 505. Foot pedal; 506. Telescopic rod; 507. Adjusting rod; 508. Connecting lug; 509. Snap ring; 510. Limiting block; 511. Return compression spring. Detailed Implementation

[0044] The technical solutions of 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. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0046] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0047] Please see Figure 1-11 The present invention provides a technical solution:

[0048] A multi-depth in-situ stratified sampling device and method for soil at contaminated sites includes a sampling tube structure 1, a limiting ring 2, a guide pulley 3, a support structure 4, and an auxiliary operation structure 5. The sampling tube structure 1 is the main structure of the device and is used to collect and store soil samples at different depths.

[0049] The sampling tube structure 1 includes multiple sample storage tubes 101 and a bottom-insertion anchor block 109 at the bottom. The multiple sample storage tubes 101 are coaxially arranged sequentially along the axial direction and are detachably connected by threads, allowing for flexible increases or decreases in the number of connections based on the actual sampling depth. Each sample storage tube 101 has threaded grooves on its inner top and outer bottom sides, and adjacent sample storage tubes 101 are connected to each other through these grooves to form an integral structure. The bottom-insertion anchor block 109 has a threaded groove on its inner top side, which is threaded to the bottom end of the bottom sample storage tube 101. The bottom side of the inner end face of the bottom-insertion anchor block 109 is inclined to facilitate smooth entry into the soil layer and provide guidance when the device is inserted downwards into the soil.

[0050] The outer wall of the sample storage tube 101 is provided with a plurality of uniformly spaced tube wall positioning grooves 102 along the axial direction. The tube wall positioning grooves 102 are used to cooperate with the limiting block 510 in the auxiliary operation structure 5, thereby realizing the step-by-step pressing down or lifting of the sampling tube structure 1. The inner wall of the sample storage tube 101 is fixedly connected with a ring-shaped sealing buffer pad 103, and the inner end face of the sealing buffer pad 103 is arc-shaped.

[0051] Each sample storage tube 101 has an internally closable sampling chamber structure. This sampling chamber structure includes a horizontally positioned connecting shaft 104 fixedly connected to the inside of the sample storage tube 101. A main collar 105 and auxiliary side rings 106 symmetrically arranged on both sides of the main collar 105 are sleeved on the outside of the connecting shaft 104. A right-side opening plate 107 is fixedly connected to one side of the main collar 105, and a left-side opening plate 108 is fixedly connected to one side of the auxiliary side rings 106. Both the right-side and left-side opening plates 107 and 108 are semi-circular plate structures that can be joined together to form a circular partition in a horizontal state, fitting snugly against the sealing buffer pad 103. When soil enters the sample storage tube 101, the two opening plates can open upwards, and when the sampling tube structure 1 is lifted upwards, they automatically close under the influence of soil gravity, thus achieving layered sealing of the sample.

[0052] Two symmetrically arranged limiting rings 2 are sleeved on the outer side of the sampling tube structure 1. Each limiting ring 2 has multiple guide pulleys 3 evenly arranged in the circumferential direction installed on the inner side of the pulley seat. The guide pulleys 3 roll and fit against the outer surface of the sampling tube structure 1, thereby playing a guiding and friction-reducing role during the lifting and lowering process of the sampling tube structure.

[0053] Multiple support structures 4 are evenly connected along the circumferential direction on the outer side of the limiting ring 2. Each support structure 4 includes a support rod 401, an adjusting slide rod 402, and a support base plate 403. The support rod 401 is a hollow tube, and the adjusting slide rod 402 is slidably inserted inside it. The top end of the adjusting slide rod 402 is hinged to the upper limiting ring 2, and the top end of the support base plate 403 is hinged to the bottom end of the support rod 401. A groove is formed along the axial direction on the outer surface of the adjusting slide rod 402. A threaded rod 406 is spirally connected to the outer side of the support rod 401. One end of the threaded rod 406 is fixedly connected to an adjusting handwheel 405, and the other end is rotatably connected to a locking block 407. The locking block 407 can engage with the groove on the adjusting slide rod 402, thereby adjusting and locking the support height. A positioning pin 404 is slidably connected to the inner side of the support base plate 403. The bottom end of the positioning pin 404 is conical and can be inserted into the ground to improve the stability of the device.

[0054] An auxiliary operating structure 5 is provided on one side of the sampling tube structure 1. The auxiliary operating structure 5 includes a base plate 501, fixed side plates 502, a balance bar 503, a hydraulic spring rod 504, a foot pedal 505, a telescopic rod 506, an adjusting rod 507, a connecting lug 508, and a retaining ring 509. The top of the base plate 501 is fixedly connected to two symmetrically arranged fixed side plates 502, and the balance bar 503 is rotatably connected between the two fixed side plates 502. Hydraulic spring rods 504 are rotatably connected to the bottom ends of both sides of the balance bar 503, and the bottom ends of the hydraulic spring rods 504 are rotatably connected to the base plate 501, thus forming an elastic reset structure. The top of the balance bar 503 is fixedly connected to two symmetrically arranged foot pedals 505.

[0055] A telescopic rod 506 is slidably connected to the inner side of the end of the balance rod 503 near the sampling tube structure 1. One end of the telescopic rod 506 is connected to the inner side of the balance rod 503 via a return compression spring 511, and an adjusting rod 507 is inserted into the inner side of the other end. A connecting lug 508 is rotatably connected to the outer side of the adjusting rod 507, and a retaining ring 509 is fixedly connected to the other end of the connecting lug 508. A limiting block 510 is fixedly connected to the inner end face of the retaining ring 509. The limiting block 510 can be inserted into the positioning groove 102 on the outer wall of the sampling tube structure 1, thereby realizing the locking and driving of the sampling tube structure.

[0056] Both ends of the pipe wall positioning groove 102 are set at right angles, and the cross-section of the limiting block 510 is a triangular structure. When the limiting block 510 is inserted into the pipe wall positioning groove 102, the sampling tube structure 1 can be driven downward or upward by different inclined directions.

[0057] Instructions for use: First, select a suitable sampling location based on the needs of the on-site pollution investigation, and move the device to the sampling point. Unfold each support structure 4. Rotate the adjusting handwheel 405 to engage the threaded rod 406 with the locking block 407, thus adjusting the height of the support structure 4 and ensuring device stability. Then, insert the positioning pin 404 downwards into the ground to firmly fix the support base plate 403 to the ground, ensuring the stability of the device during the sampling process.

[0058] According to the preset sampling depth, the corresponding number of sample storage tubes 101 are sequentially threaded together, and a bottom-insertion anchor block 109 is installed at the bottom to form a complete sampling tube structure 1. The assembled sampling tube structure 1 is inserted into the center of the limiting ring 2, so that its outer surface makes rolling contact with the guide pulley 3.

[0059] Then, the adjusting rod 507 in the auxiliary operation structure 5 is inserted into the telescopic rod 506 in the first direction, so that the inclined surface of the limiting block 510 faces upward, and the retaining ring 509 is engaged in the positioning groove 102 on the outer wall of the sampling tube structure 1. The operator steps on the left foot pedal 505, which, through the lever action of the balance rod 503, drives the retaining ring 509 downward, thereby driving the sampling tube structure 1 to gradually insert downward into the soil. After releasing the foot pedal 505, the balance rod 503 automatically resets under the elastic action of the hydraulic spring rod 504, and the retaining ring 509 moves upward and disengages from the positioning groove, thus completing one step-down pressing action. By repeatedly stepping on the pedal, the sampling tube structure can be gradually inserted to the preset depth.

[0060] During the process of inserting the sampling tube structure 1 downward into the soil, the soil first enters the bottom sample storage tube 101 from the bottom insertion anchor block 109, and gradually pushes open the right opening plate 107 and the left opening plate 108 in each layer of sample storage tubes, so that the soil enters the corresponding storage space.

[0061] Once the sampling tube structure reaches the preset depth, pull out the adjusting rod 507, rotate it 180°, and reinsert it into the telescopic rod 506, so that the inclined surface of the limiting block 510 faces downward. Then, insert the retaining ring 509 into the positioning groove 102 on the tube wall. The operator steps on the right-side foot pedal 505, causing the balance bar 503 to drive the retaining ring 509 downward, thereby gradually lifting the sampling tube structure 1 upward.

[0062] During the upward lifting of the sampling tube structure 1, the soil in each layer of the sample storage tube is pressed downward by gravity, causing the right opening plate 107 and the left opening plate 108 to close automatically downward, thereby sealing soil samples at different depths into the corresponding sample storage tubes 101.

[0063] Once the sampling tube structure 1 is completely removed, the sample storage tubes 101 of each layer are disassembled in sequence to obtain soil samples from different depths, thereby completing the multi-depth in-situ stratified sampling process of soil at the contaminated site.

[0064] The above structural design enables the device to achieve in-situ stratified collection of soil samples at multiple depths while maintaining a lightweight overall structure, and ensures a stable and reliable sampling process.

[0065] Contents not described in detail in this specification are existing technologies known to those skilled in the art. Standard parts used in this invention can be purchased commercially, and irregularly shaped parts can be custom-made according to the description and drawings. The specific connection methods for each part all employ conventional methods such as bolts, rivets, and welding, which are already mature technologies. The machinery, parts, and equipment all use conventional models from the prior art, and the circuit connections also employ conventional connection methods from the prior art, which will not be detailed here.

[0066] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A multi-depth in-situ stratified sampling device for contaminated soil, comprising a sampling tube structure (1), a support structure (4), and an auxiliary operation structure (5), characterized in that: The sampling tube structure (1) includes multiple coaxially detachably connected sample storage tubes (101) and a bottom-insertion anchor block (109) located at the bottom. The outer wall of the sample storage tube (101) is provided with a plurality of uniformly spaced tube wall positioning grooves (102) along the axial direction, and the interior of the sample storage tube (101) is provided with an openable sampling chamber structure. The outer side of the sampling tube structure (1) is fitted with a limiting ring (2) arranged symmetrically up and down, and a plurality of supporting structures (4) are evenly arranged on the outer side of the limiting ring (2) along the circumferential direction. The support structure (4) includes a support rod (401), an adjusting slide rod (402), and a support base plate (403). The top end of the adjusting slide rod (402) is hinged to the upper limiting ring (2), and the top end of the support base plate (403) is hinged to the bottom end of the support rod (401). The support rod (401) and the adjusting slide rod (402) are slidably connected and can be locked relative to each other. The sampling tube structure (1) has an auxiliary operation structure (5) on one side. The auxiliary operation structure (5) includes a retaining ring (509). The inner end face of the retaining ring (509) is fixedly connected to a limiting block (510). The limiting block (510) can be inserted into the positioning groove (102) of the tube wall to assist in lifting or pressing down the sampling tube structure (1).

2. The in-situ multi-depth stratified sampling device for contaminated site soil according to claim 1, characterized in that: The openable sampling chamber structure includes a horizontally arranged connecting shaft (104) fixedly connected to the inside of the sample storage tube (101). A main collar (105) and auxiliary side rings (106) symmetrically arranged on both sides of the main collar (105) are sleeved on the outside of the connecting shaft (104). A right opening and closing plate (107) is fixedly connected to one side of the main collar (105), and a left opening and closing plate (108) is fixedly connected to one side of the auxiliary side ring (106). The right opening and closing plate (107) and the left opening and closing plate (108) are both semi-circular plate structures, which are spliced ​​together in a horizontal state to form a circular partition.

3. The in-situ multi-depth stratified sampling device for contaminated site soil according to claim 2, characterized in that: The inner wall of the sample storage tube (101) is fixedly connected with a sealing buffer pad (103) arranged in an annular shape. The inner end face of the sealing buffer pad (103) is arc-shaped, and the right opening plate (107) and the left opening plate (108) are in contact with the top of the sealing buffer pad (103) in a horizontal state.

4. The in-situ multi-depth stratified sampling device for contaminated site soil according to claim 1, characterized in that: The sample storage tube (101) has a threaded groove on the inner side of the top end and the outer side of the bottom end. Two adjacent sample storage tubes (101) are detachably threaded together through the threaded groove. The bottom insert anchor block (109) has a threaded groove on the inner side of the top end, which is threaded together with the bottom end of the bottom sample storage tube (101). The bottom side of the inner end face of the bottom insert anchor block (109) is inclined.

5. The in-situ multi-depth stratified sampling device for contaminated site soil according to claim 1, characterized in that: There are two limiting rings (2). The inner side of each limiting ring (2) is connected to a guide pulley (3) that is evenly arranged at the same angle along the circumference through a pulley seat. The guide pulley (3) rolls and fits against the outer surface of the sampling tube structure (1).

6. The in-situ multi-depth stratified sampling device for contaminated site soil according to claim 1, characterized in that: The support rod (401) is hollow tubular, and the adjusting slide rod (402) is slidably inserted into the inner side of the support rod (401). The outer surface of the adjusting slide rod (402) is provided with a groove along the axial direction. The outer side of the support rod (401) is spirally connected with a threaded rod (406). One end of the threaded rod (406) is fixedly connected to an adjusting handwheel (405), and the other end of the threaded rod (406) is rotatably connected to a locking block (407). The locking block (407) engages with the groove of the adjusting slide rod (402). The inner side of the support base plate (403) is slidably connected with a positioning pin (404), and the bottom end of the positioning pin (404) is conical.

7. The in-situ multi-depth stratified sampling device for contaminated site soil according to claim 1, characterized in that: The auxiliary operation structure (5) further includes a base plate (501), fixed side plates (502), a balance bar (503), and a hydraulic spring bar (504); the top of the base plate (501) is fixedly connected to a symmetrically arranged fixed side plate (502), the balance bar (503) is rotatably connected between the two fixed side plates (502), and the bottom ends of the left and right sides of the balance bar (503) are rotatably connected to a hydraulic spring bar (504), the bottom end of the hydraulic spring bar (504) is rotatably connected to the base plate (501); the top of the balance bar (503) is fixedly connected to a symmetrically arranged foot pedal (505).

8. The in-situ multi-depth stratified sampling device for contaminated site soil according to claim 7, characterized in that: The balance bar (503) is slidably connected to a telescopic rod (506) on the inner side of one end near the sampling tube structure (1). One end of the telescopic rod (506) is connected to the inner side of the balance bar (503) through a reset compression spring (511). An adjusting rod (507) is inserted into the inner side of the other end of the telescopic rod (506). A connecting ear (508) is rotatably connected to the outer side of the adjusting rod (507). The other end of the connecting ear (508) is fixedly connected to the retaining ring (509).

9. A multi-depth in-situ stratified sampling device for contaminated site soil according to claim 8, characterized in that: The inner sides of the groove of the pipe wall positioning groove (102) are both set at right angles. The cross-section of the limiting block (510) is triangular. The distance between two adjacent pipe wall positioning grooves (102) is equal to the distance between two adjacent limiting blocks (510). The limiting block (510) can be inserted into the pipe wall positioning groove (102) and engaged with it.

10. A method for multi-depth in-situ stratified sampling of soil at contaminated sites using the apparatus described in any one of claims 1-9, characterized in that, Includes the following steps: S1. Device positioning: Unfold the support structure (4), adjust the support height by adjusting the slide bar (402), and fix the support base plate (403) to the ground by positioning pins (404); S2. Assemble the sampling tubes: According to the preset sampling depth, select the corresponding number of sample storage tubes (101) and connect them in sequence, with the bottom end connected to the bottom insertion anchor block (109). S3, Press down to sample: Insert the adjusting rod (507) with the inclined surface facing up, step on the left foot pedal (505), and drive the sampling tube structure (1) downward into the soil through the cooperation of the retaining ring (509) and the positioning groove (102) on the tube wall; after releasing, the auxiliary operation structure (5) automatically resets; S4. Automatic sampling: During the insertion process, the soil pushes open the right side opening plate (107) and the left side opening plate (108) of each layer from bottom to top, and enters the sample storage tube (101) of each layer. S5. Sampling: After reaching the depth, pull out the adjusting rod (507), rotate it 180° so that the inclined surface is facing down and reinsert it. Step on the right foot pedal (505) to drive the sampling tube structure (1) to lift upward. After being released, the auxiliary operation structure (5) automatically resets; S6. Automatic closing: During the lifting process, each layer of sample presses down on the right opening and closing plate (107) and the left opening and closing plate (108) under the action of gravity to automatically close, sealing the sample in each layer of tube; S7. Sample separation: Repeat step S5 until the sampling tube structure (1) is completely removed, and disassemble each layer of sample storage tube (101) in sequence to collect soil samples from different depths.

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