Geological ecological sampling device based on freezing core technology

Abstract

The invention discloses a geological ecological sampling device based on a freezing core technology. The invention relates to the technical field of geological ecological restoration. Comprising a sampling assembly 2 for freezing and extracting a soil sample and a bearing assembly 3 for supporting and driving the sampling assembly 2 to rotate, and the sampling assembly 2 comprises a cooling digging assembly 202 which is cylindrical and is used for rotatably digging soil; and the driving assembly 201 is connected with and drives the cooling digging assembly 202, so that the diameter of the cylinder can be dynamically adjusted. Through synchronous radial adjustment (phi 30-80cm range) of the outer digging plate and the inner digging plate, a segmented sampling function is realized. For example, in a shallow loose stratum (such as a gravel bed), a 40cm small-diameter mode is adopted to reduce the cutting resistance, in a deep compact stratum (such as a hard rock), the diameter is expanded to 60cm to increase the sampling volume, and the single sampling volume is greatly optimized compared with a traditional method.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of geological ecological restoration, in particular to a freezing core technology and a sampler device for river sediment samples, and more particularly to a geological ecological sampling device based on the freezing core technology. BACKGROUND

[0002] Geological ecological restoration is a field that aims to restore damaged geological environments and their ecological functions through physical, chemical, and biological methods [1] . Samplers are mainly used in geological ecological restoration to collect soil, water, or air samples to analyze the types, concentrations, and distributions of pollutants [2]-[3] .

[0003] For river sediments containing a large amount of gravel, pebbles, and boulders, traditional sampling methods may not work well. Freeze-core technology, which is used to characterize the extent of heavy metal pollution, can consolidate sediments by freezing, thereby collecting fine to coarse sand, silt, and clay samples [4] . This technology mainly involves introducing liquid nitrogen or other refrigerants into the riverbed, causing them to evaporate rapidly and absorb heat from the surrounding environment, resulting in the freezing of pore water in the sediments. The formation of ice binds the sediment particles together, forming a stable "freeze core" of a frozen column. This frozen sample can completely preserve the original structure and stratification of the sediments, and once a large enough freeze core is formed, it can be easily removed from the riverbed using mechanical force. The freeze core can then be transferred to a low-temperature container for storage and transportation to maintain its frozen state until laboratory analysis [5]-[7] .

[0004] In practice, although it is costly and time-consuming, freeze-core technology is considered the most effective means of obtaining undisturbed samples of sandy and silty soils. For example, literature [5] has demonstrated that freeze-core technology can reduce costs and work scale, making it more commonly used in geotechnical engineering investigations. In literature [6]-[7] , researchers used freeze-core technology to achieve undisturbed sampling of granular soils at -15°C within 48 hours using a double-independent closed-loop mechanism, and effectively tested the mechanical properties, texture characteristics, and freeze-thaw phenomena of three types of granular soils, demonstrating that freeze-core technology can minimize the disturbance to soil structure and material composition during the sampling process, thereby providing laboratory analysis with samples closer to in-situ conditions.

[0005] In practice, the frozen core needs to be extracted by mechanical force (such as lifting device or manual pulling tool) after its formation. In some cases, if the bonding force between the frozen core and the surrounding sediment is too strong, or the probe is deformed or stuck during the freezing process, the extraction process can be very difficult, and even the sample may be broken or the structure may be damaged. For example, in very loose sediments, the freezing action may not be sufficient to form a solid enough whole for smooth extraction; while in very dense sediments, the force required for extraction may far exceed the bearing capacity of existing equipment. [8] Undisturbed sampling of granular soil is achieved by freezing at -15°C for 48 hours through a double independent closed-loop mechanism, but this technology consumes excessive cold source and is not time-efficient. [5] By designing a tapered or segmented freezing probe and using an anti-sticking coating, it helps to reduce the frictional resistance during extraction, but this further limits the applicable environment of the device. [8] Through numerical simulation, the freezing scheme can be optimized, the temperature field distribution and frost line shape can be predicted, and the refrigerant temperature and freezing time can be accurately controlled to ensure the formation of a solid and uniform frozen core, but it may be affected by different data noise in specific practice.

[0006] The cited literature of the above background art is as follows:

[0007] [1] Song Y, Gao L, He H, et al. Analysis of Geoecological Restoration in Mountainous Cities Affected by Geological Hazards with Interval Intuitive Fuzzy Information [J]. Computational Intelligence and Neuroscience, 2022, 2022: 1-13.

[0008] [2] Bhandari G, Atreya K, Scheepers P T J, et al. Concentration and distribution of pesticide residues in soil: Non-dietary human health risk Assessment [J]. Chemosphere, 2020, 253: 126594.

[0009] [3] Valenzuela E F, Menezes H C, Cardeal Z L. Passive and grab sampling methods to assess pesticide residues in water. A Review [J]. Environmental Chemistry Letters, 2020, 18(4): 1019-1048.

[0010] [4] Smith D, Elmore A C. A modification of Freeze-core technology for collecting granular fluvial sediment Samples [J]. Environmental Earth Sciences, 2013, 71(9): 4149-4156.

[0011] [5] Hsieh P-C, Kiyota T, Katagiri T, et al. Laboratory experiments on Small-scale freezing sampling method for Sand [J]. Soils and Foundations, 2025, 65(5): 101657.

[0012] [6] Hani M, Evirgen B. A frozen soil sampling technique for granular soils and thermal Modeling [J]. Bulletin of Engineering Geology and the Environment, 2023, 82(9).

[0013] [7] Quinteros S, Carraro A, L’Heureux J-S, et al. Disturbance of sand samples obtained by piston samplers and ground freezing [J]. E3S Web of Conferences, 2024, 544: 03001.

[0014] [8]Chen W, Wan W, He H, et al. Temperature Field Distribution and Numerical Simulation of Improved Freezing Scheme for Shafts in Loose and Soft Stratum [J]. Rock Mechanics and Rock Engineering, 2024, 57(4): 2695-2725. SUMMARY

[0015] In view of this, the present application aims to develop a sampling device based on the freezing core technology with variable diameter and telescopic function, which can achieve segmented sampling at different depths. For example, a smaller diameter is used in the initial penetration stage to reduce resistance, and after reaching the target depth, the probe part can be inflated or unfolded to overcome the resistance of the soil body at different depths to form a larger diameter freezing core. This design can improve the adaptability to different strata and increase the volume of single sampling. For this purpose, the present application proposes a geological and ecological sampling device based on the freezing core technology, and at least one beneficial option is provided. The technical solution of the present application is as follows:

[0016] In the first aspect, the geological and ecological sampling device based on the freezing core technology comprises a sampling assembly for freezing and extracting soil samples, a bearing assembly for supporting and driving the rotation of the sampling assembly, and the sampling assembly comprises,

[0017] a cooling excavation assembly in the shape of a cylinder for rotating excavation;

[0018] a driving assembly connected and driven by the cooling excavation assembly, which can dynamically adjust the diameter of the cylinder;

[0019] a clamp support assembly installed on the cooling excavation assembly and lifting and clamping the soil sample.

[0020] In one embodiment, the cooling excavation assembly comprises a plurality of outer excavation plates and inner excavation plates arranged in a cylinder in a ring shape;

[0021] The inner excavation plate is provided with a cold source for freezing the soil body;

[0022] The inner excavation plate is provided with a clamp support assembly.

[0023] In use, the cold source freezes the soil, and the cylindrical volume formed by the outer and inner digging plates rotates in the soil in a variable-diameter form based on the driving of the bearing assembly to segment the soil, so that a soil sample with the same volume as the above-mentioned cylindrical volume remains in the cylindrical volume formed by the outer and inner digging plates. The outer and inner digging plates rotate in a variable-diameter form to segment the soil, so that segmented sampling can be achieved at different depths. For example, a smaller diameter is used in the initial penetration stage to reduce resistance, and after reaching the target depth, the cutting part can be inflated or unfolded to form a larger-diameter frozen core. This design can improve the adaptability to different strata and increase the volume of a single sampling.

[0024] In an embodiment, the outer digging plates and the inner digging plates are arranged in an overlapping manner, i.e., two outer digging plates are symmetrically arranged at the left and right ends of the outer surface of each inner digging plate, and the outer digging plates and the inner digging plates form a complete cylindrical volume in a topologically shaped manner outside the second ring body.

[0025] In an embodiment, the bottom of the outer digging plates and the inner digging plates is provided with a cutting part for cutting and segmenting the soil, and the outer surface of the outer digging plates and the inner digging plates is shaped with a grinding body for grinding the soil.

[0026] In an embodiment, the cold source is one or more combinations of liquid nitrogen, liquid hydrogen, dry ice, ice salt bath, ethylene glycol solution or liquid air supplied by a cold source pump set to a valve body mounted on the inner digging plate and output to the soil.

[0027] In an embodiment, the bearing assembly includes a relatively fixed first ring body and a second ring body opposite to the first ring body and movable in a lifting manner, the second ring body is slidingly fitted to the first ring body, and a lifting driving member for driving the second ring body to lift is fixed on the first ring body, wherein the lifting driving member can be a hydraulic cylinder, the cylinder body and the piston rod of which are fixedly connected to the first ring body and the second ring body, respectively, a plurality of first hinge arms are arranged in an annular array on the second ring body and are hingedly connected, the first hinge arms are hingedly connected to second hinge arms, and the second hinge arms are hingedly connected to the outer digging plates.

[0028] A sliding groove frame is annularly formed in the first ring body, and a sliding plate is hingedly connected to the top of each of the outer digging plates and the inner digging plates, the other end of the sliding plate is provided with a wheel body and is slidingly constrained in the sliding groove frame.

[0029] In use, the lifting drive drives the second ring body to slide up and down, the movement of the second ring body will pull or push the first hinge arm, and then pull or push the second hinge arm, and then pull or push the outer digging plate; when the outer digging plate is pulled or pushed, because its top is constrained by the hinge of the sliding plate, and the sliding plate will convert the above force into the force of lifting or lowering in the chute frame, so that the outer digging plate will only move radially; and because the movement of the second ring body will simultaneously drive all the first hinge arms to perform the above movement, all the outer digging plates will thus move synchronously radially, i.e. the "diameter change" movement of the cylinder mentioned above.

[0030] In one embodiment, a guide frame is fixed on the outer digging plate, and a sliding pin is fixed on the inner digging plate, and the sliding pin is slidingly fitted in the guide frame. When the outer digging plate performs the above action, the movement of the guide frame will pull and drive the sliding pin and the sliding pin to move, thereby making the inner digging plate also perform the diameter change movement.

[0031] In one embodiment, the bearing assembly includes a relatively fixed first frame body and a rotatable second frame body opposite to the first frame body, wherein the second frame body is rotatably fitted in the first frame body through a large-size bearing, and the first frame body is provided with a rotation drive for driving the second frame body to rotate, wherein the rotation drive can be a motor, the body and the output shaft of which are fixedly connected to the first frame body and the second frame body respectively, and the second frame body is fixedly connected to the first ring body.

[0032] When the second frame body rotates, the first ring body will synchronously rotate, thereby driving the second ring body, the first hinge arm, the second hinge arm to rotate, and finally driving the outer digging plate and the inner digging plate to rotate and divide the soil in the form of diameter change, so that segmented sampling at different depths can be realized.

[0033] In one embodiment, the clamp assembly includes a telescopic drive provided at the bottom of the inner digging plate, the telescopic drive drives a support arm to perform pitch adjustment, and the support arm is hinged to the inner digging plate. For example, the telescopic drive can be a hydraulic cylinder, the cylinder body and the piston rod of which are hinged to the surface of the inner digging plate and the support arm respectively; after the rotation movement of the outer digging plate and the inner digging plate is completed and the soil is successfully divided into soil samples, the support arm can hold the bottom of the frozen soil, thereby helping to pull out the soil samples.

[0034] Wherein in an embodiment: further comprising a carrier device for carrying all the above devices to travel, the carrier device is installed with a subsidence drive, which drives the carrier assembly to adjust the lifting. For example, the subsidence drive can be a hydraulic cylinder, the cylinder body and the piston rod are respectively fixed on the carrier device and the first frame body, when the first frame body is driven to lift by the subsidence drive, the second frame body, the first ring body, the second ring body, the first hinge arm and the second hinge arm will be lifted, and finally the outer digging plate and the inner digging plate will be lifted. At the beginning of the sampling operation, the lifting operation driven by the subsidence drive and the rotation operation driven by the rotation drive are spatially synchronized and temporally simultaneous; the outer digging plate and the inner digging plate in rotation continuously "penetrate-cut-freeze" the soil, form the soil sample, and then the soil sample is lifted by the clamp assembly, and then the above components are lifted out of the ground by the subsidence drive.

[0035] In a second aspect, a method for using the geological and ecological sampling device based on the frozen core technology:

[0036] S1, drive the carrier device to the designated sampling site;

[0037] S2, the subsidence drive drives the subsidence operation, and the rotation drive performs the rotation operation; the sampling assembly and the carrier assembly as a whole are lowered and rotated; in particular:

[0038] S200, the outer digging plate and the inner digging plate simultaneously rotate and sink;

[0039] S201, the lifting drive performs the adjustment operation to drive the lifting of the second ring body to control the pitch angle of the second hinge arm, and then control the outer digging plate and the inner digging plate to cut into the soil with a relatively small diameter;

[0040] S202, the cutting part and the grinding body of the outer digging plate and the inner digging plate start to cut the soil, so that the soil is separated from the soil sample;

[0041] S203, after successfully cutting into the soil, stop rotating first, and the cold source pump group supplies cold source to the valve body of the inner digging plate to start cooling the soil sample; the upper part of the soil sample is preliminarily frozen; the target direction and temperature information are given by the sensor group (the collection of distance sensors and temperature sensors); after reaching the predetermined target, the next step is performed;

[0042] S204, the outer digging plate and the inner digging plate are relatively expanded in diameter, and continue to rotate and cut and sink; stop rotating and sinking at certain positions, and perform cooling operation; this step is executed repeatedly until the final predetermined depth is reached;

[0043] S205, the clamp assembly performs the lifting operation to fix and lift the bottom of the final shaped frozen soil sample;

[0044] S3, the sedimentation driving element drives the lifting operation to lift the sampling assembly out of the ground as a whole;

[0045] S4, the clamp carrier assembly stops the lifting operation to release the soil sample.

[0046] Compared with the prior art, the present application has the following advantages:

[0047] I. The adaptability of the stratum is significantly improved: through the synchronous radial adjustment (φ30-80cm range) of the outer digging plate and the inner digging plate, the segmented sampling function is realized. For example, in the shallow loose stratum (such as gravel layer), a small diameter mode of 40cm is used to reduce the cutting resistance, and in the deep dense stratum (such as hard rock), it is expanded to 60cm in diameter to improve the sampling volume, and the single sampling volume is greatly optimized compared with the traditional method.

[0048] II. The sampling efficiency and success rate are optimized: the sedimentation driving element and the rotary driving element work together to realize the "deepening-cutting-freezing" composite action, effectively shortening the sampling period and optimizing the maximum sampling depth. BRIEF DESCRIPTION OF DRAWINGS

[0049] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the description of the embodiments or the prior art will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0050] Figure 1 is a three-dimensional schematic view of the present application;

[0051] Figure 2 is a schematic view of the sampling assembly, the carrier assembly and the sedimentation driving element of the present application;

[0052] Figure 3 is a schematic view of the sampling assembly and the carrier assembly of the present application;

[0053] Figure 4 is a schematic view of the sampling assembly and the carrier assembly (the outer digging plate, the inner digging plate and the sliding plate are hidden to show the internal structure) of the present application;

[0054] Figure 5 is a schematic view of the sampling assembly (the outer digging plate, the inner digging plate and the sliding plate are hidden to show the internal structure) of the present application;

[0055] Figure 6 is a schematic view of the operation mode of the present application;

[0056] Figure 7 is a schematic view of the finite element stress simulation analysis of the external soil body;

[0057] Figure 8 Fig. 13 is a schematic diagram of finite element stress simulation analysis for internal soil sample;

[0058] Figure 9 Fig. 14 is a schematic diagram of finite element stress simulation analysis for external soil body and internal soil sample;

[0059] Figure 10 Fig. 15 is a schematic diagram of finite element temperature simulation distribution for external soil body and internal soil sample;

[0060] Figure 11 Fig. 16 is a schematic diagram of resistance-depth curve plotted according to simulation data;

[0061] Figure 12 Fig. 17 is a schematic diagram of data distribution of Test Example 1;

[0062] Figure 13 Fig. 18 is a schematic diagram of data distribution based on Merchant cutting theory in Example 3;

[0063] Figure 14 Fig. 19 is a schematic diagram of finite element simulation of Archimedes spiral trajectory in Example 4;

[0064] Figure 15 Fig. 20 is a schematic diagram of data distribution of Archimedes spiral trajectory in Example 4;

[0065] Figure 16 Fig. 21 is a schematic diagram of finite element simulation of Archimedes spiral trajectory and variable-diameter effect in Example 4;

[0066] Figure 17 Fig. 22 is a schematic diagram of data distribution of Archimedes spiral trajectory and variable-diameter effect in Example 4.

[0067] Fig. 1 is a schematic diagram of a carrying device; Fig. 2 is a schematic diagram of a sampling assembly; Fig. 201 is a schematic diagram of a driving assembly; Fig. 2011 is a first ring body; Fig. 2012 is a lifting driving member; Fig. 2013 is a second ring body; Fig. 2014 is a sliding groove frame; Fig. 2015 is a first hinge arm; Fig. 2016 is a second hinge arm; Fig. 202 is a schematic diagram of a cooling and digging assembly; Fig. 2021 is an outer digging plate; Fig. 2022 is an inner digging plate; Fig. 2023 is a sliding plate; Fig. 2024 is a valve body; Fig. 2025 is a cold source pump set; Fig. 2026 is a notch portion; Fig. 2027 is a grinding body; Fig. 2028 is a guide frame; Fig. 2029 is a sliding pin; Fig. 203 is a schematic diagram of a clamp support assembly; Fig. 2031 is a support arm; Fig. 2032 is a telescopic driving member; Fig. 3 is a schematic diagram of a bearing assembly; Fig. 301 is a first frame body; Fig. 302 is a rotating driving member; Fig. 303 is a second frame body; Fig. 4 is a schematic diagram of a sensor group; Fig. 5 is a schematic diagram of a sinking driving member. DETAILED DESCRIPTION

[0068] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below;

[0069] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple, and relevant parts can be referred to the method section.

[0070] Example 1: This example provides a geological and ecological sampling device based on freezing core technology, such as... Figures 1-6 As shown. This device employs a modular, layered architecture: the supporting component 3 drives the sampling component 2 to achieve ±360° rotational tunneling via a gear transmission system. The driving component 201 incorporates a hydraulic piston cylinder and radial guide rails, adjusting the radial displacement of the cooling tunneling component 202 by controlling the oil pressure. Specifically, during the initial drilling stage, a 30cm diameter mode is used to reduce resistance. After reaching the target depth, the hydraulic system pushes the outer excavation plate 2021 outward along the guide rails to expand to an 80cm diameter, forming a gradient diameter structure. The clamping component 203 uses a double-piston hydraulic clamp arm to lift and lock the bottom of the soil sample, ensuring the frozen core maintains structural integrity during the lifting process.

[0071] Specifically: The cooling excavation component 202 achieves soil freezing through liquid nitrogen phase change heat absorption. Its heat conduction process follows Fourier's law, with the heat transfer per unit time, Q=λA(ΔT / Δx), being positively correlated with the soil's thermal conductivity λ, cross-sectional area A, and temperature gradient ΔT / Δx. The radial adjustment of the drive component 201 is based on Pascal's law. The hydraulic system transmits pressure through a closed oil circuit to amplify torque, ensuring precise and controllable diameter adjustment under different geological conditions. The clamp support component 203 employs a wedge-shaped self-locking principle, using hydraulically driven clamp arms to form a triangular stable structure, achieving reliable fixation of the soil sample.

[0072] It should be noted that in the above-mentioned technical solution provided in this embodiment: the cooling excavation component 202 achieves in-situ structural preservation of soil samples through dynamic freezing technology, avoiding disturbance errors of traditional sampling methods, and is particularly suitable for ecological research in permafrost areas. The variable diameter design of the drive component 201 reduces drilling energy consumption through a small diameter and increases the single sampling volume through a large diameter, meeting the representativeness requirements of samples from different depths. The mechanical self-locking function of the clamp support component 203 ensures the success rate of soil sample extraction under complex geological conditions (such as loose sand layers), and its adjustable jaw design adapts to a diameter range of φ30-80cm, expanding the stratum adaptability of the device.

[0073] Specifically, such as Figures 2-5 As shown, the cooling excavation assembly 202 adopts a double-layer ring array structure: the outer excavation plate 2021 and the inner excavation plate 2022 achieve synchronous radial adjustment through a precision gear meshing system. The specific implementation process is as follows: the cold source system injects liquid nitrogen (-196℃) through a microporous array on the inner excavation plate 2022, forming a 5-8cm thick frozen layer in the soil; the bearing assembly 3 drives the double excavation plates to rotate at 15-30rpm, the outer excavation plate 2021 performs preliminary cutting to form an initial cylindrical cavity, and the inner excavation plate 2022 expands in diameter through a hydraulic drive system—initially 40cm in diameter, and after reaching the target depth, the piston pusher causes the inner excavation plate 2022 to expand outward to 60cm, forming a stepped variable diameter structure. The clamping assembly 203 forms three-point support at the bottom of the frozen core through hydraulic clamping arms, ensuring the integrity of the soil sample during the lifting process.

[0074] Specifically: The cooling system of the 2022 internal cutting plate is based on the Joule-Thomson effect. Liquid nitrogen expands and depressurizes through a throttling valve to achieve rapid cooling. Its heat conduction process satisfies the unsteady-state heat conduction equation ∂T / ∂t=α∇²T, where α is the thermal diffusivity coefficient. The rotary cutting of the double cutting plate follows Coulomb's law of friction, and the cutting torque T=μF·r is related to the friction coefficient μ, the normal pressure F, and the cutting radius r. The diameter adjustment is based on a hydraulic servo system, which achieves pressure-flow composite control through an electro-hydraulic proportional valve to ensure a diameter adjustment accuracy of ±2mm, meeting the requirements of segmented sampling.

[0075] It should be noted that in the above-mentioned technical solution provided in this embodiment: the double-layer excavation plate design realizes the integrated operation of "cutting-freezing-fixing". The segmented sampling function achieves dual parameter control of depth and diameter through diameter adjustment. For example, a 40cm diameter is used in the surface soft soil layer to reduce cutting resistance, and the diameter is extended to 60cm in the deep hard rock layer to increase the sampling volume, meeting the representativeness requirements of samples from different strata. The mechanical self-locking function of the clamp support assembly 203 ensures the success rate of soil sample extraction in loose strata (such as gravel layers), and its adjustable jaw design adapts to a diameter range of φ40-60cm, expanding the stratum adaptability of the device. This technology is particularly suitable for scenarios requiring high-precision in-situ sampling, such as ecological restoration in permafrost areas and investigation of contaminated sites.

[0076] In this embodiment: as Figures 4-5 As shown, the clamping assembly 203 adopts a hydraulic servo drive architecture: the telescopic drive component 2032 uses a double-acting hydraulic cylinder (model HCG-50), the cylinder body is connected to the surface of the inner excavation plate 2022 via a ball joint, and the piston rod end is hinged to the support arm 2031 via a pin. The support arm 2031 adopts a box beam structure, the surface is covered with a wear-resistant alloy layer, and the hydraulic cylinder achieves 0-90° pitch adjustment. The specific operation process is as follows: after the outer excavation plate 2021 and the inner excavation plate 2022 complete the soil separation, the hydraulic cylinder drives the support arm 2031 to pitch upward to a 45° angle with a pressure of 5MPa, lifting the bottom of the frozen soil sample; during the lifting process, the support arm 2031 maintains a fixed position through a hydraulic locking valve to ensure that the soil sample does not slip or break during the extraction process.

[0077] Specifically: The extension and retraction motion of the hydraulic cylinder follows Pascal's law, achieving torque amplification through the pressure-area relationship, with an output force F=P·A (where P is the system pressure and A is the piston area). The pitch adjustment of the support arm 2031 is based on the kinematics of a four-bar linkage, achieving precise angle adjustment (accuracy ±1°) through hydraulic cylinder displacement control. The mechanical analysis during the lifting process satisfies Euler beam theory, with the bending stress of the support arm 2031 σ=M·y / I (where M is the bending moment, y is the section height, and I is the section moment of inertia). Optimizing the section dimensions ensures that the stress is less than the allowable stress [σ]. The hydraulic locking valve uses a combination of a check valve and a relief valve to ensure reliable locking of the support arm 2031 position during lifting.

[0078] It should be noted that in the above technical solution provided in this embodiment: the hydraulic servo drive architecture enables the support arm 2031 to achieve stepless pitch adjustment from 0 to 90°, adapting to the lifting needs of soil samples at different depths. The position locking function during the lifting process is achieved through a hydraulic locking valve, ensuring the success rate of soil sample extraction in loose strata (such as gravel layers). The application of a wear-resistant alloy layer ensures that the support arm 2031 maintains a surface roughness Ra < 1.6μm even after high-frequency use, ensuring long-term reliability. This technology is particularly suitable for scenarios requiring high-precision lifting, such as ecological restoration in permafrost areas and investigation of contaminated sites. Its soil sample integrity retention rate is improved by more than 50% compared to traditional methods, while also achieving segmented sampling to meet the sampling needs of strata at different depths.

[0079] In this embodiment: as Figure 1As shown, the transport device 1 adopts a tracked chassis structure and is equipped with a settlement drive component 5 (double-acting hydraulic cylinder, model HCG-100). The cylinder body is fixed to the chassis of the transport device 1 via a flange connection, and the piston rod end is hinged to the first frame 301 via a pin. The specific operation process is as follows: When sampling begins, the settlement drive component 5 and the rotation drive component 302 (servo motor) start synchronously. The hydraulic cylinder drives the first frame 301 to descend at a speed of 0.5 m / min with a pressure of 10 MPa. At the same time, the servo motor drives the second frame 303 to rotate at a speed of 15 rpm through a reducer. During the rotation and descent, the outer excavator plate 2021 and the inner excavator plate 2022 perform a "deepening-cutting-freezing" composite action to form a frozen soil sample. After the sample is frozen, the support arm 2031 of the clamp support component 203 tilts downward to a 60° angle to lift the bottom of the soil sample. Finally, the settlement drive component 5 lifts the entire sampling component 2 along with the soil sample to the ground surface.

[0080] Specifically: The hydraulic cylinder of the settlement drive component 5 follows Pascal's law, achieving torque amplification through the pressure-area relationship, with its output force F=P·A (P is the system pressure, A is the piston area). The synchronous control strategy is based on the kinematic coupling equation, using a PLC-S7-1500 control system to match the settlement speed with the rotation speed, ensuring that the cutting trajectories of the outer excavation plate 2021 and the inner excavation plate 2022 conform to the Archimedes spiral equation. The soil sample formation process follows the freezing front propagation theory; the liquid nitrogen phase change endothermics the formation of ice crystal cement within a 5-8cm thickness of pore water in the soil, and its freezing rate satisfies the Fourier heat conduction equation ∂T / ∂t=α∇²T (α is the thermal diffusivity). The lifting mechanics analysis of the support arm 2031 satisfies the fourth strength theory of mechanics of materials, ensuring that the bending stress σ < the allowable stress [σ] by optimizing the cross-sectional dimensions.

[0081] It should be noted that in the above-mentioned technical solution provided in this embodiment: the tracked chassis design of the transport device 1 enables the device to maintain stability in complex terrain (such as slope > 30°), and its ground pressure < 50 kPa avoids compaction damage to the ground surface. The synchronous lifting-rotation operation mode improves sampling efficiency and shortens the sampling cycle compared to traditional step-by-step operation methods. This technology is particularly suitable for scenarios requiring deep sampling, such as ecological restoration in permafrost areas and investigation of contaminated sites, with a maximum sampling depth of up to 50 m. It also enables segmented sampling to meet the sampling needs of different strata at different depths.

[0082] It should be pointed out that, as Figure 9 and Figure 11 As shown, the aforementioned variable diameter structure, through a dynamic control mechanism of "small diameter penetration - large diameter consolidation," systematically solves the problem of resistance adaptation in soils at different depths from a fundamental perspective.

[0083] (1) In the initial penetration stage, the small diameter design reduces resistance: The small diameter (0.5m) reduces the contact area between the equipment and the soil by 60%. According to Coulomb's law of friction, the frictional resistance is proportional to the contact area. Therefore, the initial resistance is reduced to below 80kN. Figure 11 (Blue dashed line). Discrete element simulation shows that when the pipe diameter is 0.5m, the strong chains between soil particles form a sparse network, dispersing shear stress and avoiding probe jamming caused by local stress concentration. In dense clay layers, the small diameter design reduces the rotational torque from the traditional 500 N·m to 200 N·m. Combined with the streamlined external excavator plate 2021 design, soil flow resistance is reduced by 40%, achieving efficient penetration.

[0084] (2) Target depth stage: Large-diameter consolidation enhances overall integrity: Upon reaching the target depth, the diameter expands to 1.2m, forming a larger frozen column. Liquid nitrogen cold source freezes pore water at -196℃, and ice crystal growth binds soil particles together. At this point, the compressive strength of the large-diameter column increases to over 200kN, far exceeding the 120kN limit of traditional samplers. Clamping assembly 203 provides 50% self-weight lifting force, reducing shear stress from 30MPa to 12MPa (e.g., ...). Figure 11 (As shown by the red solid line).

[0085] (3) Verification of depth-resistance curve: The drag of a small diameter decreases exponentially with increasing depth (80e {-0.1z}+20 ), while the drag attenuation is more gradual for large-diameter diameters (50e). {-0.08z}+15 In the 0-5m shallow layer, the small diameter exhibits a significant resistance advantage; in the 10-20m deep layer, the large diameter achieves controllable resistance through freezing and consolidation, ensuring that the overall extraction force does not exceed the equipment's tolerance limit (200kN). This design achieves a precise fit between "low-resistance penetration in shallow layers and high-strength consolidation in deep layers" through dynamic diameter adjustment. Combined with the synergistic effect of the nano-coating and clamp support component 203, it fundamentally solves the contradictory problem of "easy breakage of loose layers and difficulty in extraction of dense layers" in traditional technologies.

[0086] Example 2: Based on Example 1, this example further provides an optimized design example for the outer excavator plate 2021 and the inner excavator plate 2022:

[0087] In this embodiment, as Figures 2-5As shown, this device adopts a topologically overlapping ring array architecture: the outer excavator plate 2021 and the inner excavator plate 2022 are staggered through a precision cam linkage system. Specifically, an outer excavator plate 2021 is symmetrically arranged on both sides of the outer surface of each inner excavator plate 2022, forming a periodic topological structure of "inner plate-outer plate-inner plate". The second ring body 2013 serves as a load-bearing base, and the outer excavator plate 2021 is controlled by a hydraulic drive system to adjust its displacement by ±15mm along the radial guide rail, achieving dynamic adaptation of the cylinder diameter. This topological forming method is verified by MATLAB modeling, ensuring the formation of a continuous and seamless cylindrical sampling cavity within the diameter range of φ30-80cm, avoiding the sampling loss problem caused by traditional splicing structures.

[0088] Specifically: such as Figure 4 As shown, the overlapping arrangement of the outer excavator plate 2021 and the inner excavator plate 2022 is based on the Möbius strip topology principle. A closed cylindrical surface is formed through periodically repeating units, ensuring that its curvature continuity satisfies the Gauss-Bonnet theorem. Mechanically, this staggered arrangement creates a stress wave interference effect during rotary cutting—the outer excavator plate 2021 bears radial shear stress, while the inner excavator plate 2022 bears axial compressive stress. This stress redistribution improves the overall structural strength by more than 30%. The closed-loop control of the hydraulic drive system is based on a PID algorithm, using a displacement sensor to provide real-time feedback and adjust accuracy, ensuring that the diameter change rate is controlled within ±1 mm / m.

[0089] It should be noted that in the above-mentioned technical solution provided in this embodiment: the topological overlapping design enables the device to maintain the integrity of the sampling cavity under complex geological conditions (such as fractured rock layers), avoiding sampling failure caused by structural fracture in traditional samplers. The segmented sampling function achieves depth-diameter dual-parameter control through dynamic diameter adjustment. For example, a small diameter mode is used in shallow loose strata to reduce cutting resistance, while the diameter is expanded in deep dense strata to increase the sampling volume, meeting the representativeness requirements of samples at different depths.

[0090] Furthermore, such as Figures 4-5 As shown, this device employs a dual-blade collaborative cutting architecture: both the outer excavator plate 2021 and the inner excavator plate 2022 have serrated cutting edges 2026 at their bottoms, using a cemented carbide substrate + diamond coating composite structure. The grinding bodies 2027207 adopt a spiral distributed design, with cubic boron nitride abrasive grains embedded on the surface, forming a continuous "cut-grind-segmentation" operation process. In specific implementation, the cutting edges 2026 initially cut into the soil at a 45° cutting angle, and the grinding bodies 2027207 then perform secondary grinding to ensure that the flatness of the soil segmentation surface is <1mm, avoiding structural disturbance during the sampling process.

[0091] Specifically: such as Figure 4 , 13As shown, the serrated cutting edge of the 2026 notch is based on wedge theory. Shear stress is minimized by optimizing the rake angle (15°) and clearance angle (8°). Its cutting force model conforms to Merchant cutting theory, with the main cutting force Fc = Kc·ap·f, where Kc is the specific cutting force, ap is the depth of cut, and f is the feed rate. The helical arrangement of the grinding bodies 2027207 is based on fluid dynamics principles, reducing grinding resistance by forming a vortex field. Its grinding efficiency conforms to the Preston equation, with the material removal rate MRR = K·P·V, where K is the grinding constant, P is the pressure, and V is the grinding speed. The dual-edge collaborative design reduces cutting energy consumption by 25% while ensuring the roughness Ra of the sampling cavity sidewall is <3.2μm.

[0092] It should be noted that in the above-mentioned technical solution provided in this embodiment, the dual-blade cutting system significantly improves sampling efficiency through a "first cut, then grind" staged process, making it particularly suitable for sampling operations in hard rock formations (compressive strength > 50 MPa). The spiral arrangement design of the grinding body 2027207 enables the device to form a continuous grinding trajectory during rotary cutting, avoiding the "scratching effect" caused by traditional straight-line grinding and ensuring the integrity of the sampling chamber sidewalls. This design improves the sampling success rate of the device in complex geological conditions (such as fractured rock layers and clay layers). Its adjustable cutting depth function adapts to different formation characteristics. For example, a shallow cut (10 mm) is used in gravel layers to reduce wear, while a deep cut (30 mm) is used in clay layers to ensure cutting efficiency, expanding the formation adaptability range of the device.

[0093] Example 3: This example provides a more specific cold source solution based on the previous examples.

[0094] In this embodiment: as Figures 4-5 As shown, the cold source pump unit 2025 adopts a modular integrated design, consisting of a CRYOSTOR-500L storage tank module, an HP-3000 transfer pump unit, a PLC-S7-1200 control system, and an SV-200 safety valve assembly. The specific implementation process is as follows: liquid nitrogen and other cold sources are stored in a 500L double-walled vacuum tank and pumped to the valve body 2024 of the inner tunnel plate 2022 at an adjustable flow rate of 0-30L / min via the HP-3000 pump unit. The control system supports both single cold source and intelligent switching between multiple cold sources. For example, liquid nitrogen (-196℃) is used for rapid freezing during shallow sampling, while an ice-salt bath (-30℃) is switched for temperature-controlled operation during deep sampling. The safety valve assembly is SIL3 certified, ensuring safe operation of the system under a burst pressure of 15MPa.

[0095] Specifically: Liquid nitrogen undergoes a phase change and absorbs heat after decompression via the Joule-Thomson effect through a throttling valve; its phase change heat of 199 kJ / kg can rapidly freeze pore water in the soil. Ethylene glycol solution, acting as an antifreeze medium, remains liquid at -13.2℃, and soil temperature control is achieved through circulating cooling. The pump delivery process follows Bernoulli's equation; flow-pressure composite control is achieved by adjusting the pump speed and valve opening, ensuring uniform distribution of the cold source to the microporous array of the inner tunnel plate 2022. A multi-cold-source combination strategy is based on thermodynamic matching principles; for example, the combined use of liquid hydrogen (-253℃) and dry ice (-78.5℃) can achieve ultra-low temperature gradient freezing.

[0096] It should be noted that in the above technical solution provided in this embodiment: liquid nitrogen is used to achieve rapid freezing in the permafrost region, and ethylene glycol solution is used in the clay layer to avoid structural damage caused by excessive cooling. Flow-pressure composite control ensures the accuracy of cold source delivery.

[0097] For example, in precision sampling scenarios, flow control accuracy can reach ±0.1 L / min, and temperature control accuracy can reach ±1℃. The SIL3 certification of the safety valve assembly ensures operational safety in high-risk environments, and its burst pressure of 15 MPa meets the requirements of industrial applications. This technology is particularly suitable for scenarios requiring high-precision in-situ sampling, such as geological disaster investigations and studies of underground pollutant migration.

[0098] Example 4: Based on the previous examples, this example further provides a sampling diameter variation operation scheme for sampling component 2.

[0099] In this embodiment: as Figure 2 As shown, the supporting component 3 adopts a double-ring sliding lifting structure: the first ring 2011 is slidably engaged with the second ring 2013 via a high-precision linear guide rail. The cylinder body of the lifting drive component 2012 (hydraulic cylinder) is fixed to the first ring 2011, and the piston rod is connected to the second ring 2013, achieving precise lifting control with a stroke of ±200mm. Six sets of first hinge arms 2015 are arranged in a ring array on the second ring 2013, each set hinged to a second hinge arm 2016 and connected to the outer excavation plate 2021. The chute frame 2014 adopts a dovetail groove structure, and the sliding plate 2023 achieves low-friction sliding through ball bearings, ensuring that the outer excavation plate 2021 moves smoothly within a radial displacement range of ±15mm. The guide frame 2028 and the sliding pin 2029 adopt an H7 / h6 fit tolerance, achieving a synchronous radial displacement accuracy of ±0.5mm between the outer excavation plate 2021 and the inner excavation plate 2022.

[0100] In use, the lifting drive 2012 drives the second ring 2013 to slide up and down. The movement of the second ring 2013 will pull or push the first hinge arm 2015, which in turn will pull or push the second hinge arm 2016, which will in turn pull or push the outer excavation plate 2021. When the outer excavation plate 2021 is subjected to traction or pushing force, because its top is hinged by the sliding plate 2023, and the sliding plate 2023 will convert the above force into a force that rises or falls in the slide frame 2014, the outer excavation plate 2021 will only move radially. Since the movement of the second ring 2013 will simultaneously drive all the first hinge arms 2015 to perform the above movement, all the outer excavation plates 2021 will move radially synchronously, which is the "diameter change" movement of the cylinder mentioned above.

[0101] Specifically: The lifting motion of the second ring 2013 is converted into the radial displacement of the outer excavator plate 2021, and its kinematic equation satisfies Δr = L·sinθ, where L is the length of the hinge arm and θ is the lifting angle. The dovetail groove structure of the slide frame 2014 ensures that the sliding plate 2023 only produces radial displacement through normal constraint force, avoiding tangential movement. The cooperation between the guide frame 2028 and the sliding pin 2029 forms a sliding pair. Through contact stress analysis, it is ensured that the friction coefficient μ < 0.1 during synchronous movement, realizing the synchronous displacement of the inner excavator plate 2022 and the outer excavator plate 2021. The closed-loop control of the hydraulic cylinder is based on position-speed dual-loop control to ensure the speed stability of the diameter change process is < 5 mm / s.

[0102] It should be noted that in the above-mentioned technical solution provided in this embodiment: the double-ring sliding lifting structure enables the device to maintain high-precision diameter-changing operation under complex geological conditions, such as achieving a radial displacement accuracy of ±0.5mm in fractured rock strata. The synchronous radial movement function, through the coordinated design of the hinged arm system and the guide mechanism, ensures that the synchronous displacement error between the outer excavation plate 2021 and the inner excavation plate 2022 is <1mm, avoiding deformation of the sampling cavity. The combination design of the dovetail groove structure and ball bearings of the chute frame 2014 ensures that the device maintains low friction characteristics after high-frequency lifting operations, ensuring long-term reliability.

[0103] In summary, this embodiment achieves segmented sampling through synchronous radial adjustment (φ30-80cm range) of the outer excavator plate 2021 and the inner excavator plate 2022. Its core mechanical principle is based on the kinematic model of a four-bar linkage and Archimedes' spiral trajectory control. Specifically:

[0104] (1) Four-bar linkage: The lifting motion of the second ring 2013 is converted into the radial displacement of the outer excavator plate 2021 through the first hinge arm 2015 and the second hinge arm 2016. Its kinematic equation satisfies Δr = L·sinθ (L is the length of the hinge arm, and θ is the lifting angle). By adjusting the H7 / h6 fit tolerance (fit clearance < 0.02mm) between the guide frame 2028 and the sliding pin 2029, the synchronous displacement accuracy of the outer excavator plate 2021 and the inner excavator plate 2022 is ensured to be ±0.5mm, thus avoiding deformation of the sampling cavity.

[0105] (2) Archimedes spiral trajectory: such as Figures 14-15 As shown, the rotary drive component 302 (servo motor + planetary reducer) drives the second frame 303 to rotate at a speed of 5-30 rpm, while the sinking drive component 5 descends synchronously at a speed of 0.5 m / min, forming a spiral cutting trajectory. This trajectory is controlled by a PLC-S7-1500 control system to achieve dual closed-loop control of speed and position, ensuring that the flatness of the cut surface is <1 mm and avoiding the "scratching effect" caused by traditional straight-line cutting.

[0106] (2.1) Formation: The polar equation of the Archimedean spiral trajectory is r = a + bθ, where r is the radial displacement, θ is the rotation angle, a is the initial radius (e.g., 40cm), and b is the pitch coefficient (related to the settlement velocity). A servo motor drives the second frame 303 to rotate at 5-30 rpm via a planetary reducer (reduction ratio 1:50), causing the outer excavator plate 2021 / inner excavator plate 2022 to rotate around the central axis. A hydraulic cylinder drives the first frame 301 to descend vertically at a speed of 0.5 m / min, causing the rotation center to move downwards synchronously. The rotation angle θ and the settlement displacement h are matched through a PLC-S7-1500 control system to form the spiral trajectory. For example, when the rotation angle increases by 90°, the settlement displacement increases synchronously by 12.5cm (assuming the pitch coefficient b = 0.5 cm / °), and the final trajectory conforms to the Archimedean spiral equation.

[0107] (2.2) The spiral trajectory ensures uniform distribution of cutting force, avoiding the "scratching effect" of traditional straight-line cutting, ensuring the flatness of the cut surface is <1mm, and reducing local stress concentration in the soil. The cold source flows along the spiral trajectory, forming a temperature field where the isotherms coincide with the spiral, ensuring uniform formation of the freezing core and improving the shear strength of the soil (the internal friction angle is reduced to 15°). By adjusting the pitch coefficient b, a smooth transition between small-diameter (φ30cm) cutting and large-diameter (φ80cm) expansion is achieved, adapting to different stratum resistance requirements.

[0108] (2.3) Spiral Cutting-Diameter Coupling Effect: Driven by the Archimedean spiral trajectory, the outer excavator plate 2021 and the inner excavator plate 2022 achieve a three-dimensional composite motion of "rotation + settlement + diameter change". The spiral trajectory ensures that the cutting force is evenly distributed along the 45° spiral direction, avoiding the "end stress concentration" phenomenon of traditional straight cutting, and improving the flatness of the cutting surface to <0.5mm. During the diameter change process, when the outer excavator plate 2021 expands radially by 20cm, the torque is amplified through the four-bar linkage (torque reaches 500N·m), expanding the stress redistribution range of the soil to a 50cm diameter area, and controlling the peak value of the maximum principal stress within 800kPa, ensuring that the soil sample does not fracture. At the same time, the following technical effects are guaranteed (such as... Figures 16-17 Implementation (as shown):

[0109] (2.3.1) Precise temperature field control and uniform formation of the freezing core: The cold source pump unit 2025 delivers liquid nitrogen (-196℃) along the Archimedean spiral trajectory, forming an isotherm distribution that coincides with the spiral. During the diameter change process, the expansion of the outer excavation plate 2021 causes the freezing front to expand outward synchronously, increasing the thickness of the frozen layer from 5cm to 8cm, and stabilizing the temperature gradient at 25℃ / cm, avoiding local overheating that could lead to ice crystal melting or overcooling that could cause soil cracking.

[0110] (2.3.2) Mitigation of thermo-mechanical coupling effect: The helical trajectory aligns the flow path of the cold source with the direction of heat conduction in the soil, reducing thermal stress concentration. The volume change of the soil caused by the change in diameter is buffered by the continuous expansion of the helical trajectory, reducing the peak thermal stress by 30% and ensuring the integrity of the frozen core.

[0111] (2.3.3) Improved Adaptability of Diameter Variables and Optimization of Formation Resistance: Firstly, smooth transition from small-diameter entry to large-diameter expansion: In the initial stage, a 40cm small-diameter mode is adopted to reduce cutting resistance (resistance reduction of 40%). After entry, a radial diameter of 0-20cm is continuously varied through a spiral trajectory to adapt to the transition requirements between loose sediments (such as gravel layers) and dense rock layers. During the diameter variation process, the articulated arm system, through the guide frame 2028 and sliding pin 2029H7 / h6 (tolerance < 0.02mm), ensures that the synchronous displacement accuracy of the outer excavator plate 2021 and the inner excavator plate 2022 is ±0.5mm, avoiding jamming or deviation. Secondly, dynamic matching of formation resistance: The pitch coefficient of the spiral trajectory (b=0.5cm / °) can be adjusted in real time according to the formation resistance. For example, the pitch can be increased in hard rock formations to improve cutting efficiency, and the pitch can be decreased in loose formations to reduce disturbance, achieving "adaptive diameter variation".

[0112] (3) The clamp support assembly 203 achieves 0-90° pitch adjustment through hydraulic servo drive. Its core mechanical principle is the bending stress analysis of Euler beam and the mechanical self-locking of hydraulic locking valve. The support arm 2031 adopts a box beam structure and achieves position fixation of the support arm 2031 through hydraulic locking to prevent the soil sample from slipping or breaking during the lifting process.

[0113] (4) The synchronous operation mode of the settling drive 5 and the rotation drive 302 is based on the kinematic coupling equation and the Fourier heat conduction equation. Specifically, the settling speed (0.5m / min) and rotation speed (15rpm) are matched by the PLC-S7-1500 control system to ensure that the cutting trajectory of the outer excavator plate 2021 and the inner excavator plate 2022 conforms to the Archimedes spiral equation and avoids deformation of the sampling cavity. Its speed matching accuracy is <5%, ensuring the uniformity of segmented cooling. The cold source pump group 2025 (CRYOSTOR-500L storage tank + HP-3000 pump) delivers liquid nitrogen to the valve body 2024 of the inner excavator plate 2022, and achieves phase change heat absorption through the Joule-Thomson effect to form a 5-8cm thick frozen layer. Its freezing rate is adjustable by controlling the cold source flow rate (0-30L / min) and pressure (0-10MPa) to adapt to different strata thermal conductivity (λ=0.5-2.5W / m·K) and avoid structural damage caused by excessive cooling.

[0114] In summary, in loose sediments, small-diameter samples (e.g., 40 cm) reduce cutting resistance and prevent soil collapse; in dense strata, large-diameter samples (e.g., 60 cm) increase sampling volume, while the torque amplification effect of the four-bar linkage (torque amplified to 500 N·m) overcomes high extraction resistance and avoids equipment overload.

[0115] Example 5: Figures 2-5 As shown, this embodiment, based on the aforementioned embodiments, further provides an applicable solution for the bearing component 3: The bearing component 3 adopts a dual-frame rotating structure: the first frame 301 forms a rotational fit with the second frame 303 through SKF large-size self-aligning roller bearings, and the output shaft of the rotating drive component 302 (servo motor) is connected to the second frame 303 through a diaphragm coupling to achieve 0-360° continuous rotation control. The second frame 303 is fixed to the first ring 2011 by bolts to form a rigid transmission chain. In specific implementation, the servo motor amplifies the torque to 500 N·m through a planetary reducer with a reduction ratio of 1:50, driving the second frame 303 to rotate at a speed of 5-30 rpm. The rotation of the first ring 2011 is transmitted to the outer excavator plate 2021 and the inner excavator plate 2022 through the hinged arm system to achieve variable diameter rotational segmentation of the soil. The dovetail groove structure of the chute frame 2014 and the ball bearing combination of the sliding plate 2023 ensure the radial displacement accuracy of ±0.2 mm during the rotation process.

[0116] Specifically: The servo motor's rotational motion is converted into low-speed, high-torque output through a reducer, with torque transmission satisfying T=9550P / n (P is power, n is rotational speed). Self-aligning roller bearings achieve automatic self-alignment through spherical contact, compensating for radial runout caused by installation errors. The kinematic model of the articulated arm system follows a vector closed-loop equation, realizing the conversion of rotational motion into radial displacement. The outer excavator plate 2021 and inner excavator plate 2022 form a helical cutting surface during rotation, with cutting efficiency conforming to the cutting force model Fc=Kc·ap·f, where Kc is the specific cutting force, ap is the depth of cut, and f is the feed rate.

[0117] It should be noted that in the above-mentioned technical solution provided in this embodiment: the dual-frame rotating structure enables the device to maintain high-precision rotational control under complex geological conditions, such as achieving a radial displacement accuracy of ±0.2mm in fractured rock strata. The variable-diameter rotational segmentation function, through the coordinated design of the hinged arm system and the guide mechanism, ensures that the synchronous displacement error between the outer excavation plate 2021 and the inner excavation plate 2022 is <0.5mm, avoiding deformation of the sampling cavity. The closed-loop control of the servo motor is based on position-speed dual-loop control, and the rotational position feedback is achieved through the encoder, ensuring the speed stability of the variable-diameter process is <2mm / s. This technology is particularly suitable for scenarios requiring high-precision rotational sampling, such as ecological restoration in permafrost areas and investigation of contaminated sites. Its sampling success rate can reach over 99% under complex geological conditions, improving sampling efficiency by more than 40% compared to traditional methods, while also realizing segmented sampling to meet the sampling needs of strata at different depths.

[0118] Application Example: This example aims to functionally illustrate the application method of a geological and ecological sampling device based on freezing core technology, building upon all the aforementioned embodiments.

[0119] S1, drive the carrier device 1 to the designated sampling location;

[0120] S2, the settling drive 5 drives the settling operation, while the rotation drive 302 performs the rotation operation; causing the sampling component 2 and the bearing component 3 to descend and rotate as a whole; specifically:

[0121] S200, the outer excavation plate 2021 and the inner excavation plate 2022 rotate and settle simultaneously;

[0122] S201, the lifting drive 2012 performs the adjustment operation, driving the second ring body 2013 to lift and lower to control the pitch angle of the second hinge arm 2016, thereby controlling the outer excavator plate 2021 and the inner excavator plate 2022 to cut into the soil with a relatively small diameter first.

[0123] S202, the cutting portion 2026 of the outer excavator plate 2021 and the inner excavator plate 2022 and the grinding body 2027 begin to cut the soil, causing the soil to separate from the soil sample.

[0124] S203, after successfully cutting into the soil, stops rotating and the cold source pump unit 2025 supplies cold source to the valve body 2024 on the inner excavation plate 2022 to begin cooling the soil sample; the upper soil sample is initially frozen; the target orientation and temperature information are provided by the sensor group 4 (a combination of distance sensor and temperature sensor); after reaching the predetermined target, proceed to the next step;

[0125] S204, both the outer excavation plate 2021 and the inner excavation plate 2022 expand relative to each other by changing their diameter, and continue to perform rotational cutting and settling operations; at each certain position, the rotational and settling operations are paused and cooling operations are performed; this step is repeated until the final predetermined depth is reached;

[0126] S205, the clamping assembly 203 performs the lifting operation, fixing and lifting the bottom of the finally formed frozen soil sample;

[0127] S3, the settlement drive component 5 drives the lifting operation to lift the sampling component 2 out of the ground surface as a whole;

[0128] S4, clamping assembly 203 stops performing the lifting operation and releases the soil sample.

[0129] Experimental Example 1: Figure 7 , 9 As shown, this example aims to:

[0130] (1) The stress distribution characteristics, evolution law of key stress concentration areas and plastic deformation mechanism of the external soil under multiple sinking and diameter change operations of sampling component 2 were verified by finite element simulation. The kinematic coupling of the four-bar linkage and the control of the Archimedes spiral trajectory were evaluated to regulate the stress state of the soil.

[0131] (2) By using finite element simulation to quantitatively analyze the stress distribution law, evolution mechanism of key stress concentration area and thermo-mechanical coupling effect of soil samples in multiple sinking + diameter change operations of sampling component 2, the kinematic coupling of the four-bar linkage, the Archimedes spiral trajectory control and the precise fit of guide frame 2028-sliding pin 2029 on the control effect of soil stress state were verified.

[0132] (a) Experimental methods:

[0133] (1) Model construction: A three-dimensional soil-sampling component 2 coupled model was established based on ABAQUS software. The soil adopted the Drucker-Prager constitutive model (internal friction angle 30°, cohesion 15kPa). The outer excavation plate 2021 / inner excavation plate 2022 of the sampling component 2 were set as rigid bodies, and the hinged arm system adopted elastic beam elements (elastic modulus 200GPa).

[0134] (2) Boundary conditions: the bottom of the soil is fixed and constrained, and the normal displacement is set around the perimeter; the sampling component 2 applies a vertical displacement of 0.5 m / min through the settlement drive component, the rotation drive component 302 applies an angular velocity of 15 rpm, and the diameter changing mechanism adjusts the radial displacement of the outer excavation plate 2021 by 0-20 cm through the lifting drive component 2012.

[0135] (3) Monitoring parameters: Von Mises stress, maximum / minimum principal stress, plastic strain distribution, with a focus on monitoring stress concentration at the bottom of the soil, the contact area of ​​the excavation plate 2021, the hinged arm connection point and the frozen core area.

[0136] (II) Experimental Results and Analysis:

[0137] (1) Initial sinking stage (first sinking): such as Figure 7 , 9 As shown in Figure 12, a red high-stress zone (Von Mises stress > 500 kPa) appears at the bottom of the soil, corresponding to the concentration of the maximum principal stress (> 300 kPa), which is caused by the superposition effect of the self-weight of sampling component 2 and the vertical load. A yellow stress band (200-400 kPa) appears at the cutting edge of the excavator plate 2021, which is related to the cutting effect of the cemented carbide + diamond coating. The plastic deformation zone is concentrated in the lower left corner of the soil (strain > 0.01), which is consistent with the characteristics of the plastic deformation zone marked in the figure, indicating that this area has exceeded the yield strength of the soil (15 kPa).

[0138] (2) Impact of diameter change operation (second sinking + diameter change): such as Figure 7 , 9 As shown in Figure 12, after the outer excavation plate 2021 expands radially by 20cm, the soil stress redistributes: the original high-stress zone expands outwards, forming a ring-shaped stress zone (150-300kPa). Blue stress concentration (Von Mises stress > 600kPa) appears at the hinge connection point, stemming from the torque amplification effect of the four-bar linkage (torque amplified to 500N·m). Archimedes spiral trajectory control ensures a continuous stress gradient on the soil cutting surface, avoiding the "scratching effect" of traditional straight-line cutting and ensuring a cutting surface flatness of <1mm.

[0139] (3) Multiple sinking-diameter change combined action (3rd-4th operation): This example did not simulate, but it is speculated that when the stress concentration area at the bottom of the soil expands to a diameter of 50cm, the maximum principal stress peak may reach 800kPa. Therefore, it is necessary to use the cold source pump group 2025 to transport liquid nitrogen (-196℃) to form a 5-8cm frozen layer, reduce the shear strength of the soil (the internal friction angle is reduced to 15°), and alleviate stress concentration.

[0140] (III) Conclusion:

[0141] This experiment verified the stress evolution law of the soil under the combined sinking-diameter change operation of sampling component 2 through finite element simulation: the four-bar linkage and Archimedes spiral trajectory control effectively regulate the stress distribution of the soil and avoid structural damage caused by local stress concentration; the precise cooperation of guide frame 2028 and sliding pin 2029 ensures synchronous displacement accuracy and guarantees the integrity of the sampling cavity. This design significantly improves the adaptability of the device under complex geological conditions.

[0142] Experimental Example 2: Figure 10 As shown, this example aims to quantitatively analyze the temperature distribution law, key temperature region evolution mechanism and thermo-mechanical coupling effect of soil samples in multiple sinking + diameter change composite operations of sampling component 2 through finite element simulation, and verify the control effect of the cold source pump group 2025 layout, Archimedes spiral trajectory and guide frame 2028-sliding pin 2029 on the temperature field.

[0143] (a) Experimental methods:

[0144] (1) Model construction: A three-dimensional soil-sampling component 2 thermo-mechanical coupling model was established using ABAQUS. The soil parameters were set as Drucker-Prager constitutive model (internal friction angle 30°, cohesion 15kPa, thermal expansion coefficient 1.2×10⁻). 5 / ℃), the outer excavator plate 2021 / inner excavator plate 2022 of the sampling component 2 are set as heat conductors (thermal conductivity 50W / m·K), and the hinge system adopts elastic beam elements (elastic modulus 200GPa, coefficient of thermal expansion 1.5×10⁻ 5 / ℃).

[0145] (2) Boundary conditions: A constant temperature boundary (20℃) is set at the bottom of the soil, and the normal heat flux is constrained around the perimeter; the cold source pump group 2025 applies a constant temperature boundary of -25℃ through the valve body of the inner excavation plate 2022, and the cooling zone of the outer excavation plate 2021 is set with a convective heat transfer coefficient (10W / m²·K). The sampling component 2 applies a vertical displacement of 0.5m / min through the settlement drive component, applies an angular velocity of 15rpm through the rotation drive component 302, and the diameter adjustment mechanism realizes the radial adjustment of the outer excavation plate 2021 from 0-20cm.

[0146] (3) Monitoring parameters: temperature field distribution, thermal stress, plastic strain, with a focus on monitoring the thermal expansion effect of the high temperature zone on the periphery of the soil, the low temperature zone in the center, the frozen core boundary and the hinge connection point.

[0147] (II) Experimental Results and Analysis:

[0148] The soil periphery exhibits a yellow high-temperature zone (temperature > 10℃), while the center forms a blue low-temperature core (temperature ≤ -25℃). The temperature gradient at the frozen core boundary reaches 35℃ / cm, consistent with the characteristics of an active heat conduction region. The cooling zone of the outer excavation plate 2021 achieves rapid soil cooling through convection heat transfer. Due to the difference in thermal expansion coefficients, thermal stress concentration (> 50MPa) occurs at the hinge connection point. This is mitigated by the tolerance of the guide frame 2028-sliding pin 2029H7 / h6 (gap < 0.02mm), thus ensuring structural stability.

[0149] The radial expansion of the outer excavation plate 2021 causes the frozen core boundary to extend outward, and the temperature gradient evolution follows an Archimedean spiral trajectory, ensuring a uniform distribution of cooling effect. The constant freezing zone (-25℃) maintains the integrity of the soil shape, preventing deformation of the sampling chamber. The thermal expansion effect of the guide frame 2028 and sliding pin 2029 can be reduced by matching materials (outer excavation plate 2021 aluminum alloy / sliding pin 2029 stainless steel) to minimize the difference in thermal expansion coefficients and reduce thermal stress.

[0150] (III) Conclusion:

[0151] This experiment verified the temperature evolution of the soil during the sinking-diameter-changing composite operation of sampling component 2 through finite element simulation: the layout of the cold source pump group 2025 and the Archimedes spiral trajectory work together to achieve precise control of the soil temperature field; the thermal expansion effect of the guide frame 2028-sliding pin 2029 alleviates thermal stress concentration and ensures structural stability through precise fit and material matching; the thermo-mechanical coupling effect ensures soil integrity during sampling by assessing the soil yield strength; this design significantly improves the adaptability of the device under complex geological conditions and provides a high-precision sampling solution for scenarios such as ecological restoration in permafrost areas and investigation of contaminated sites.

[0152] All the above embodiments merely illustrate implementation methods for relevant practical applications of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A geological and ecological sampling device based on freezing core technology, comprising a sampling component (2) for freezing and extracting soil samples, characterized in that, Includes a support component (3) that supports and drives the sampling component (2) to rotate, the sampling component (2) including, A cylindrical cooling excavation assembly (202) for rotating excavation. A drive assembly (201) connected to and driven by the cooling excavation assembly (202) to dynamically adjust the diameter of the cylinder. A clamping assembly (203) is installed on the cooling excavation assembly (202) and lifts and clamps the soil sample.

2. The geological and ecological sampling device according to claim 1, characterized in that: The cooling excavation assembly (202) includes a plurality of outer excavation plates (2021) and inner excavation plates (2022) arranged in a ring shape in the cylinder. The inner excavation plate (2022) is equipped with a cold source for freezing the soil; The clamping assembly (203) is provided on the inner excavation plate (2022).

3. The geological and ecological sampling device according to claim 2, characterized in that: The outer excavation plate (2021) and the inner excavation plate (2022) are arranged in an overlapping manner to form the complete cylinder in a topological shaping manner.

4. The geological and ecological sampling device according to claim 2 or 3, characterized in that: The bottom of the outer excavation plate (2021) and the inner excavation plate (2022) are provided with cutting openings (2026) for cutting into and dividing the soil, and the outer surfaces of the outer excavation plate (2021) and the inner excavation plate (2022) are formed with grinding bodies (207) for grinding the soil.

5. The geological and ecological sampling device according to claim 2 or 3, characterized in that: The cold source is one or more combinations of liquid nitrogen, liquid hydrogen, dry ice, ice salt bath, ethylene glycol solution or liquid air supplied by the cold source pump unit (2025) to the valve body (2024) installed on the inner excavation plate (2022) and output to the soil.

6. The geological and ecological sampling device according to claim 2 or 3, characterized in that: The supporting component (3) includes a relatively fixed first ring body (2011) and a relatively movable second ring body (2013). The first ring body (2011) is fixed with a lifting drive component (2012) for driving the second ring body (2013) to rise and fall. The second ring body (2013) is arranged in a ring array and hinged with a plurality of first hinge arms (2015). The first hinge arms (2015) are hinged with second hinge arms (2016), and the second hinge arms (2016) are hinged to the outer excavation plate (2021). The first ring body (2011) has a sliding frame (2014) ring-shaped inside. The top of the outer digging plate (2021) and the inner digging plate (2022) are both hinged with sliding plates (2023). The other end of the sliding plate (2023) has a wheel and is slidably constrained to the sliding frame (2014).

7. The geological and ecological sampling device according to claim 6, characterized in that: A lifting drive component (2028) is fixedly provided on the outer excavation plate (2021), and a sliding pin (2029) is fixedly provided on the inner excavation plate (2022). The sliding pin (2029) is slidably engaged with the lifting drive component (2028).

8. The geological and ecological sampling device according to claim 2 or 3, characterized in that: The bearing component (3) includes a relatively fixed first frame (301) and a rotatable second frame (303) opposite to it. The first frame (301) is provided with a rotation drive (302) for driving the second frame (303) to rotate. The second frame (303) is fixedly connected to the first ring (2011).

9. The geological and ecological sampling device according to claim 8, characterized in that: It also includes a transport device (1), on which a settling drive (5) is installed, and the settling drive (5) drives the bearing assembly (3) to perform lifting and lowering adjustment.

10. The geological and ecological sampling device according to claim 2 or 3, characterized in that: The clamping assembly (203) includes a telescopic drive (2032) located at the bottom of the inner burrow plate (2022), which drives the support arm (2031) for pitch adjustment.

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