An in-situ sand extractor

Abstract

This invention discloses an undisturbed sand sampler, relating to the field of geological engineering exploration and sampling technology. It includes a double-wing sampling tube mechanism, a piston mechanism, a propulsion mechanism, a protective mechanism, a tail locking assembly, and sampling auxiliary components. The double-wing sampling tube mechanism is used to rotate and cut soil layers and accommodate sand samples. The piston mechanism, located inside the double-wing sampling tube mechanism, is used to keep the sample fixed during sampling to prevent crushing. The propulsion mechanism is connected to the double-wing sampling tube mechanism and is used to transmit rotational torque and axial pressure. The protective mechanism is fitted outside the propulsion mechanism to protect internal components and achieve a tail dust seal. The tail locking assembly is used to axially lock and fix the piston device. The sampling auxiliary components are used to limit the extraction of sand samples. This invention is applicable to various loose Quaternary sand layers, effectively preserving the undisturbed structure of the sand sample and achieving a high sampling success rate.

Description

Technical Field

[0001] This invention relates to the field of geological engineering exploration and sampling technology, and in particular to an undisturbed sand sampler. Background Technology

[0002] The compaction and relative density of sandy soils are key engineering geological properties, with relative density being a crucial technical indicator for evaluating the liquefaction tendency of sandy soils under vibration. Obtaining undisturbed sand samples is essential for acquiring these indicators. With my country's rapid economic development, an increasing number of cross-sea and cross-river bridges are being built. The foundations of these large bridges are often 70% sandy soil layers. The physical and mechanical properties of sand directly affect the stability and safety of bridges, frequently necessitating dynamic property tests on undisturbed sand samples. Therefore, preparing undisturbed sand samples is undoubtedly crucial to the success of these tests.

[0003] Currently, undisturbed sand samples are generally prepared by methods such as pressing or rotary pressing. These methods are widely used because they cause less disturbance to the soil sample and maintain good soil sample integrity. An existing technology provides an undisturbed vacuum piston sand extractor, suitable for saturated silt, fine sand, and medium sand formations. It uses vacuum negative pressure to support the sand sample and prevent it from falling off during the sampling process.

[0004] However, the existing technical solutions have the following obvious drawbacks: First, the original vacuum piston sand sampler is only suitable for saturated silt, fine sand, and medium sand formations. It is difficult to extract sand from coarse gravel, dry sand, and dense thick sand layers, as the sand is easily scattered, limiting its applicable formation range. Second, when the sample is extracted from the formation, due to the weight of the sand and the lack of cohesion, some sand may be missed or collapse. In severe cases, all sand samples in the sleeve may be lost, resulting in sampling failure. Third, the existing sand sampler is prone to squeezing and disturbing the sand sample during the sampling process, which cannot guarantee the natural structure of the original sample. Furthermore, the vacuum negative pressure lifting capacity has an upper limit, making it difficult to meet the needs of deep sampling.

[0005] Based on the above-mentioned technical problems, those skilled in the art urgently need to develop a sand sampler that can adapt to various loose sand layers in the Quaternary period (including coarse gravel sand, dry sand, and dense thick sand), has a high sampling success rate, and can maintain the original structure of the sand sample. Summary of the Invention

[0006] The purpose of this invention is to provide an undisturbed sand sampler to solve the problem that existing technologies are unable to obtain high-quality undisturbed sand samples from various loose Quaternary sand layers (especially coarse gravel sand, dry sand, and dense thick sand layers).

[0007] To achieve the above objectives, the present invention provides the following technical solution: The present invention provides an undisturbed sand extractor, the sand extractor comprising: A dual-wing sampling tube mechanism is used to rotate and cut the soil layer and contain the collected sand sample; A piston mechanism is provided inside the double-wing sampling tube mechanism to keep it relatively fixed during the sampling process, so as to avoid squeezing the sand sample entering the double-wing sampling tube mechanism. The propulsion mechanism, connected to the dual-wing sampling tube mechanism, is used to transmit rotational torque and axial pressure; A protective mechanism, fitted onto the outside of the propulsion mechanism, is used to protect internal components and achieve a dustproof seal at the tail. The sand extractor also includes: A tail locking assembly, disposed at the end of the dual-wing sampling tube mechanism, is used to axially lock and fix the piston mechanism; and A sampling auxiliary component is used to enter the interior of the dual-wing sampling tube mechanism and extract sand samples.

[0008] Furthermore, the dual-wing sampling tube mechanism includes a sampling tube and two wings, with the two wings symmetrically arranged on both sides of the sampling tube.

[0009] Furthermore, the piston mechanism includes a piston body, a plug, an O-ring, a thrust bearing, and a piston nut; wherein, An annular sealing groove is formed on the outer wall of the piston, and the O-ring is embedded in the sealing groove and sealed to the inner wall of the sampling tube. The thrust bearing is sleeved on the outer wall of the piston body, and the plug and the piston nut lock the thrust bearing and the O-ring from both ends of the axial direction, respectively.

[0010] Furthermore, the propulsion mechanism includes a propulsion joint, a lead screw, and a baffle; wherein, The pusher joint is connected between the sampling tube and the lead screw, and the lead screw end is provided with the baffle.

[0011] Furthermore, the protective mechanism includes a protective tube, a light bar, a protective cap, and a protective ring; wherein, The lead screw is fitted with a protective tube, and the end of the lead screw is coaxially connected to the optical rod. The protective cap is set at the end of the protective tube, and the protective ring is embedded in the protective cap and hugs the outer wall of the optical rod.

[0012] Furthermore, the tail locking assembly includes a countersunk screw, a stop cap, and a fastener; wherein, The stop cap is fitted onto the outer wall of the sampling tube and locked in place by the fasteners, and the countersunk screw passes through the wall of the sampling tube and abuts against the piston body.

[0013] Furthermore, the sampling auxiliary component includes a sand-taking scale and a sand-taking baffle, which are vertically aligned.

[0014] Furthermore, the thrust bearing is an 8204 type thrust bearing, and there are two O-rings, which are respectively set on both sides of the thrust bearing in the axial direction; the sampling tube has two length specifications, namely 550mm and 350mm.

[0015] Furthermore, the protective ring is made of wool felt, and the inner hole of the protective cap is fitted with the optical bar through a gap, forming a rotary dynamic seal through the protective ring; The countersunk screws are M4×10 countersunk screws, two in number, and are symmetrically arranged around the circumference of the sampling tube. The fasteners are M10×50 socket head cap screws.

[0016] Furthermore, the lead screw, the push joint, the piston body, the plug, the piston nut, the stop cap, and the protective cap are all machined from 45# steel. The wing, the sand-collecting scale, and the sand-collecting baffle are all formed by cutting and welding steel plates; The protective casing is a Φ73 core tube, and the optical rod is a Φ42 drill pipe.

[0017] The original sand extractor provided by the present invention, as described above, has the following beneficial effects: The present invention provides an original sand sampler. During the sand sampling process, the screw rotates and applies pressure to facilitate the insertion of the sampling tube. The piston is fixed at a certain elevation to prevent the sand sample from being squeezed and compacted by the piston, thus effectively maintaining the original structure of the sand sample. The sampling tube is provided with two specifications of length (550mm and 350mm), and the residue at the bottom of the hole does not exceed 30cm. The longer tube can be selected to take the original sand sample according to the actual working conditions to speed up the work progress. This invention has a high sampling success rate. It took 81 original sand samples from 21 boreholes and obtained 66 sets of original sand samples, with a sampling success rate of 81.49%. The bulk density measured by the ring cutter method differed by 1.1-5.6% and the bulk density measured by the isotope γ-γ method differed by 1.8%, which verifies that the sample can truly maintain the natural structure of the original sand. This invention is applicable to various loose sand layers in the Quaternary period, including saturated silt, fine sand, medium sand, and even coarse gravel, dry sand, and dense thick sand. Original sand samples can be obtained, which significantly broadens the applicable strata range of the sand sampler. Moreover, this invention has a simple structure, low cost, and is easy to operate, making it easy to promote and use. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0019] Figure 1 This is a schematic diagram of the overall structure of an undisturbed sand extractor provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of a sampling auxiliary component in an undisturbed sand extractor provided in an embodiment of the present invention.

[0020] Explanation of reference numerals in the attached figures: 1—Dual-wing sampling tube mechanism; 101—Sampling tube; 102—Wing; 2—Piston mechanism; 201—Piston body; 202—Plug; 203—O-ring; 204—Thrust bearing; 205—Piston nut; 3—Propulsion mechanism; 301—Propulsion joint; 302—Lead screw; 303—Baffle plate; 4—Protective mechanism; 401—Protective tube; 402—Light bar; 403—Protective cap; 404—Protective ring; 5—Tail locking assembly; 501—Counterhead screw; 502—Cap; 503—Fastener; 6—Sampling auxiliary components; 601—Sand sampling ruler; 602—Sand sampling baffle. Detailed Implementation

[0021] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0022] See Figures 1-2 As shown; The present invention provides an undisturbed sand extractor, the sand extractor comprising: The components include: a dual-wing sampling tube mechanism 1, a piston mechanism 2, a propulsion mechanism 3, a protective mechanism 4, a tail locking assembly 5, and a sampling auxiliary assembly 6.

[0023] The dual-wing sampling tube mechanism 1 is used to rotate and cut the soil layer and to contain the collected sand sample. The dual-wing sampling tube mechanism 1 includes a sampling tube 101 and two wings 102, which are symmetrically arranged on both sides of the sampling tube 101. The sampling tube 101 has specifications of Φ90 / Φ86×550 / 350 and is made from Φ91 drill bit material. The wings 102 are formed by cutting and welding ordinary steel plates.

[0024] The piston mechanism 2 is disposed inside the sampling tube 101 to maintain relative fixation during sampling, thereby avoiding compression of the sand sample entering the sampling tube 101. The piston mechanism 2 includes a piston body 201, a plug 202, an O-ring 203, a thrust bearing 204, and a piston nut 205. An annular sealing groove is formed on the outer wall of the piston body 201, and the O-ring 203 is embedded in the sealing groove and seals tightly against the inner wall of the sampling tube 101. The thrust bearing 204 is sleeved on the outer wall of the piston body 201, and the plug 202 and piston nut 205 lock the thrust bearing 204 and O-ring 203 from both axial ends, respectively. The thrust bearing 204 is an 8204 type thrust bearing, and the O-ring 203 has a specification of Φ73×4, with two pieces, respectively disposed on both axial sides of the thrust bearing 204. The piston body 201, plug 202, and piston nut 205 are all machined from 45# steel.

[0025] The propulsion mechanism 3 is connected to the sampling tube 101 and is used to transmit rotational torque and axial pressure. The propulsion mechanism 3 includes a propulsion joint 301, a lead screw 302, and a baffle 303. The propulsion joint 301 is connected between the sampling tube 101 and the lead screw 302, and the baffle 303 is provided at the end of the lead screw 302. The insertion and mating positions of the sampling tube 101 and the propulsion joint 301 are fixed circumferentially by threads. The propulsion joint 301, the lead screw 302, and the baffle 303 are all machined from 45# steel.

[0026] The protective mechanism 4 is fitted onto the outside of the propulsion mechanism 3 to protect internal components and achieve a dustproof seal at the tail. The protective mechanism 4 includes a protective tube 401, a guide rod 402, a protective cap 403, and a protective ring 404. The protective tube 401 is fitted onto the outside of the guide rod 302, and the end of the guide rod 302 is coaxially connected to the guide rod 402. The protective cap 403 is located at the end of the protective tube 401, and the protective ring 404 is embedded inside the protective cap 403 and tightly grips the outer wall of the guide rod 402. The protective ring 404 is a felt sealing ring with a d=40 mm diameter made of wool felt. The inner hole of the protective cap 403 has a clearance fit with the guide rod 402, and a rotational dynamic seal is achieved through the protective ring 404. The protective tube 401 is a Φ73 core tube, and the guide rod 402 is a Φ42 drill rod. The protective cap 403 is made of 45# steel.

[0027] The tail locking assembly 5 is located at the end of the sampling tube 101 and is used to axially lock and fix the piston mechanism 2. The tail locking assembly 5 includes a countersunk screw 501, a stop cap 502, and a fastener 503. The stop cap 502 is fitted onto the outer wall of the sampling tube 101 and locked and fixed by the fastener 503. The countersunk screw 501 passes through the wall of the sampling tube 101 and abuts against the piston body 201. The countersunk screw 501 is an M4×10 countersunk screw, two in number, symmetrically arranged around the circumference of the sampling tube 101; the fastener 503 is an M10×50 socket head cap bolt. The stop cap 502 is machined from 45# steel.

[0028] The sampling auxiliary component 6 is used to enter the sampling tube 101 and limit the extraction of sand samples. The sampling auxiliary component 6 includes a sand sampling ruler 601 and a sand sampling baffle 602, which are vertically fitted together. Both the sand sampling ruler 601 and the sand sampling baffle 602 are made of ordinary steel plate cut and welded.

[0029] The overall assembly length of the device is no less than 1470mm. In use, the drill rod of the engineering drilling rig is connected externally via the guide rod 402. The rotational torque and axial drilling pressure output by the drilling rig are sequentially transmitted to the sampling tube 101 via the guide rod 402, lead screw 302, and feed joint 301. The blades 102 rotate with the sampling tube 101 to cut the soil layer. This combination of blade rotation cutting and static pressure injection allows for the selection of slightly dense to medium-dense sand layers compared to a purely static pressure soil sampler, resulting in a greater sampling depth. The sand enters the sampling tube 101 and is contained by the sampling auxiliary component 6, enabling the collection of undisturbed sand samples.

[0030] The working principle of the piston mechanism 2 is as follows: The piston body 201 is axially positioned by the end plugs 202 and piston nuts 205, and forms a radial multi-seal structure with the two sets of O-rings 203 on the outer wall, effectively preventing drilling fluid and sand from entering the piston's internal moving parts. The thrust bearing 204 is used to bear the axial load during the rotation of the piston body 201, reducing the frictional resistance between the piston body 201 and the sampling tube 101.

[0031] It should be noted that the sampling tube 101 is a long specification with a length of 550mm, which is suitable for working conditions where the residue at the bottom of the hole does not exceed 30cm, and can speed up the sampling process. The sampling tube 101 is a short specification with a length of 350mm, which is suitable for shallow sampling or working conditions where precise control of the sampling length is required.

[0032] This invention's undisturbed sand sampler is applicable to various loose Quaternary sand layers, including saturated silt, fine sand, medium sand, coarse gravel, dry sand, and dense thick-layered sand, and can extract undisturbed sand samples. Actual engineering verification showed that undisturbed sand samples were taken 81 times from 21 boreholes, yielding 66 sets of undisturbed sand samples, with a sampling success rate of 81.49%. The bulk density measured by the sampler differed from that measured by the ring cutter by 1.1-5.6%, and from that measured by the isotope gamma-ray method by 1.8%, verifying that the extracted samples truly preserve the natural structure of the original sand. This invention is rationally designed, simple in construction, low in cost, and easy to operate, possessing broad prospects for industrial application.

[0033] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A virgin sand extractor, characterized in that, The sand extractor includes: A double-wing sampling tube mechanism (1) is used to rotate and cut the soil layer and to hold the collected sand sample; Piston mechanism (2) is provided inside the double-wing sampling tube mechanism (1) to keep it relatively fixed during the sampling process so as to avoid squeezing the sand sample entering the double-wing sampling tube mechanism (1); The propulsion mechanism (3) is connected to the double-wing sampling tube mechanism (1) and is used to transmit rotational torque and axial pressure; The protective mechanism (4) is fitted onto the outside of the propulsion mechanism (3) to protect the internal components and achieve a dustproof seal at the tail. The sand extractor also includes: A tail locking assembly (5) is disposed at the end of the double-wing sampling tube mechanism (1) for axially locking and fixing the piston mechanism (2); and The sampling auxiliary component (6) is used to enter the interior of the double-wing sampling tube mechanism (1) and limit the extraction of sand samples.

2. The original sand extractor according to claim 1, characterized in that, The dual-wing sampling tube mechanism (1) includes a sampling tube (101) and two wings (102), with the two wings (102) symmetrically arranged on both sides of the sampling tube (101).

3. The original sand extractor according to claim 2, characterized in that, The piston mechanism (2) includes a piston body (201), a plug (202), an O-ring (203), a thrust bearing (204), and a piston nut (205); wherein, The piston body (201) has an annular sealing groove on its outer wall, and the O-ring (203) is embedded in the sealing groove and seals against the inner wall of the sampling tube (101). The thrust bearing (204) is sleeved on the outer wall of the piston body (201), and the plug (202) and the piston nut (205) lock the thrust bearing (204) and the O-ring (203) from both ends of the axial direction, respectively.

4. The original sand extractor according to claim 3, characterized in that, The propulsion mechanism (3) includes a propulsion joint (301), a lead screw (302), and a baffle (303); wherein, The push joint (301) is connected between the sampling tube (101) and the lead screw (302), and the baffle (303) is provided at the end of the lead screw (302).

5. The original sand extractor according to claim 4, characterized in that, The protective mechanism (4) includes a protective tube (401), a light bar (402), a protective cap (403), and a protective ring (404); wherein, The lead screw (302) is fitted with the protective tube (401) on the outside. The end of the lead screw (302) is coaxially connected to the optical rod (402). The protective cap (403) is set at the end of the protective tube (401). The protective ring (404) is embedded in the protective cap (403) and hugs the outer wall of the optical rod (402).

6. The original sand extractor according to claim 5, characterized in that, The tail locking assembly (5) includes a countersunk screw (501), a stop cap (502), and a fastener (503); wherein, The stop cap (502) is fitted onto the outer wall of the sampling tube (101) and locked in place by the fastener (503). The countersunk screw (501) passes through the wall of the sampling tube (101) and abuts against the piston body (201).

7. The original sand extractor according to claim 6, characterized in that, The sampling auxiliary component (6) includes a sand sampling ruler (601) and a sand sampling baffle (602), which are vertically aligned.

8. The original sand extractor according to claim 3, characterized in that, The thrust bearing (204) is an 8204 type thrust bearing, and there are two O-rings (203), which are respectively set on both sides of the thrust bearing (204) in the axial direction; the sampling tube (101) has two length specifications, namely 550mm and 350mm.

9. A virgin sand extractor according to claim 6, characterized in that, The protective ring (404) is made of wool felt, and the inner hole of the protective cap (403) is fitted with the light bar (402) with a clearance and forms a rotational dynamic seal through the protective ring (404); The countersunk screw (501) is an M4×10 countersunk screw, and there are two of them, which are symmetrically arranged around the sampling tube (101). The fastener (503) is an M10×50 socket head cap screw.

10. A virgin sand extractor according to claim 7, characterized in that, The lead screw (302), the push joint (301), the piston body (201), the plug (202), the piston nut (205), the stop cap (502), and the protective cap (403) are all made of No. 45 steel. The wing (102), the sand-collecting scale (601), and the sand-collecting baffle (602) are all formed by cutting and welding steel plates; The protective casing (401) is a Φ73 core tube, and the optical rod (402) is a Φ42 drill rod.

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