Longitudinally stratified bed sand sampling method

Abstract

The present invention relates to the technical field of bed sand sampling and discloses a longitudinal layered bed sand sampling method, comprising the following steps: 1) connecting a sand sampling rod to the top of a sand sampling tube, wherein the interior of the sand sampling tube is provided with a sand sampling cavity and the side of the sand sampling tube is provided with a sand outlet; 2) closing the sand outlet by a side sealing plate, and operating the sand sampling rod until the entire sand sampling tube is inserted into the riverbed; the bottom sealing plate opens the bottom opening until the bed sand fills the sand sampling cavity to form a bed sand sample; 3) lifting the sand sampling tube by the sand sampling rod and rotating it in situ; during the process of lifting the sand tube, the bottom sealing plate closes the bottom opening; 4) lifting the sand sampling tube to the riverbed and water body in sequence by the sand sampling rod; 5) disconnecting the sand sampling rod from the sand sampling tube, swinging the side sealing plate, and pouring out the bed sand sample through the sand outlet; through the above steps, not only the sampling efficiency is improved, but also the integrity and accuracy of the sample are ensured, thereby providing a high-efficiency and accurate sampling method for bed sand research.

Description

Technical Field

[0001] The patent of this invention relates to the technical field of bed sand sampling, specifically, to a longitudinally layered bed sand sampling method. Background Art

[0002] Bed sediment sampling technology is an important component of water conservancy projects and river dynamics research. Traditional bed sediment sampling methods include surface sampling and subsurface sampling. Both methods are mostly scattered sampling, with a small number of samples, and the sampling process is likely to cause interference to sediment at different lateral positions on the same section.

[0003] For fields such as river sediment research and hydrogeological surveys, especially when it is necessary to accurately obtain vertical distribution data of riverbed sediment, a new bed sediment sampling method is also needed to provide support.

[0004] Among the existing sampling methods, there is no device that can automatically open and close the sampling chamber, which cannot avoid the loss of sediment during the process of inserting into and lifting out of the riverbed, thereby reducing the sampling accuracy and the sampling efficiency of bed sand, resulting in the risk of sediment sample loss in actual operation, which in turn affects the reliability of the data and the accuracy of scientific research.

[0005] In addition, traditional sampling methods often require multiple people to operate manually or involve large sampling equipment, which is not only time-consuming and labor-intensive, increasing costs, but also significantly increases the difficulty and risk of sampling under high flow rates or deep water conditions. Summary of the Invention

[0006] The purpose of the present invention is to provide a longitudinally layered bed sand sampling method, aiming to solve the problem of poor bed sand sampling efficiency in the prior art.

[0007] The present invention is achieved by comprising the following steps:

[0008] 1) Connect the sand collecting rod to the top of the sand collecting tube. The sand collecting tube is in a cubic shape. The interior of the sand collecting tube has a cubic sand collecting cavity. The cavity passes through the bottom of the sand collecting tube to form a bottom opening. A sand outlet is formed on the side of the sand collecting tube.

[0009] The sand outlet cover has a side cover plate that is swingably arranged to close or open the sand outlet; the bottom opening cover of the sand taking tube has a bottom cover plate that is swingably arranged to close or open the bottom opening;

[0010] 2) Close the sand outlet of the side cover plate, operate the sand taking rod, and lower the sand taking barrel into the water until the bottom of the barrel contacts the riverbed. Then, apply a longitudinal downward driving force to the barrel through the sand taking rod until the entire barrel is inserted into the riverbed.

[0011] When the sand collecting cylinder is inserted into the riverbed, the bottom cover plate is pressed upward by the bed sand, and swings upward to open the bottom opening. The bed sand enters the sand collecting cavity through the bottom opening until the bed sand fills the sand collecting cavity, forming a bed sand sample.

[0012] 3) The sand taking tube is lifted to a set length by the sand taking rod, and the sand taking tube is rotated in situ; in the process of lifting the sand taking tube, the bottom sealing plate is pressed by the bed sand sample and swings downward to close the bottom opening;

[0013] 4) Sequentially lift the sand collecting tubes out of the riverbed and water body through the sand collecting rods;

[0014] 5) Disconnect the sand taking rod from the sand taking barrel, swing the side cover plate, open the sand outlet, and pour the bed sand sample out through the sand outlet.

[0015] Furthermore, in step 1), the top of the sand taking tube has a connector, and the sand taking rod is threadedly connected to the connector; the bottom of the sand taking rod is threadedly connected to the connector, and the top of the sand taking rod is connected to a pressure rod, and the pressure rod is arranged vertically to the sand taking rod; in step 2), a downward driving force is applied to the sand taking tube by the pressure rod.

[0016] Furthermore, in step 2), after the bottom of the sand collecting cylinder abuts against the riverbed, the sand collecting cylinder is inserted into the riverbed to a set depth, and the driving cylinder is driven up and down, and the bottom covering plate is synchronously swung up and down to close or open the bottom opening.

[0017] Furthermore, in step 3), after the sand taking tube is lifted to a set length by the sand taking rod, the sand taking tube is rotated back and forth in situ.

[0018] Furthermore, the sand taking tube has an air outlet for discharging air in the sand taking cavity, the sand taking cavity is connected to the outside through the air outlet, the air outlet is located above the sand outlet, and along the circumference of the sand taking tube, the air outlet and the sand outlet are staggered;

[0019] In the step 2), when the sand collecting tube is inserted into the riverbed, the air outlet is opened and the air in the sand collecting chamber is discharged through the air outlet; in the step 4), when the sand collecting tube is lifted, the air outlet is closed.

[0020] Furthermore, the sand collecting tube is connected to a rubber cover plate supported by a colloid material and closing or opening the air outlet. The rubber cover plate is arranged on the outer wall of the sand collecting tube, one side of the rubber cover plate is fixedly connected to the sand collecting tube, and the other side of the rubber cover plate is freely arranged.

[0021] In step 2), when the sand collecting tube is inserted into the riverbed, the rubber cover swings away from the sand collecting tube and the air outlet is opened; in step 4), when the sand collecting tube is lifted, the rubber cover swings toward the sand collecting tube and the air outlet is closed.

[0022] Furthermore, the inner side wall of the sand taking cavity has a facing portion arranged toward the sand outlet, the facing portion is covered with an elastic film layer, the outer periphery of the elastic film layer is fixedly connected to the facing portion, and the elastic film layer is arranged to bulge toward the sand outlet to surround and form a bulging area;

[0023] In the step 2), when the sand collecting tube is inserted into the riverbed, the bed sand is squeezed to fill the sand collecting cavity, and the elastic membrane layer is compressed and deformed; in the step 5), when the side cover plate opens the sand outlet, the elastic membrane layer expands toward the sand outlet and recovers the deformation, driving the bed sand sample toward the sand outlet.

[0024] Furthermore, the bottom opening is provided with a restriction ring, which is arranged around the circumference of the bottom opening. One side of the bottom cover plate is hinged to the sand collecting tube, and the other side of the bottom cover plate is freely arranged. The other side of the bottom cover plate has a pressing portion.

[0025] In step 2), during the process of inserting the sand collecting barrel into the riverbed, the bottom cover plate swings upward, the pressing portion disengages from the pressing against the restriction ring, and the bottom opening opens; in step 4), during the process of lifting the sand collecting barrel, the bottom cover plate swings downward, the pressing portion presses against the restriction ring from top to bottom, the bottom opening is closed, and the restriction ring restricts the bottom cover plate from continuing to swing downward.

[0026] Furthermore, the side cover plate has an inward side wall facing the sand extraction cavity, and a plurality of elastically arranged curved pieces are provided on the inward side wall, wherein the lower ends of the curved pieces are fixed to the inward side wall, and the upper ends of the curved pieces are bent upward and arranged freely, and an elastic gap is formed between the curved pieces and the inward side wall;

[0027] In step 2), when the sand taking chamber is filled with the bed sand sample, the elastic sheet is elastically deformed under pressure and embedded in the bed sand; when the side cover plate is opened, the elastic sheet elastically returns to its original position, applying an elastic pulling force to the bed sand sample toward the sand outlet.

[0028] Furthermore, the outer periphery of the lower part of the sand collecting tube is provided with an outer peripheral elastic ring and a movable ring that can elastically move up and down. The outer peripheral elastic ring is arranged around the circumference of the sand collecting tube and is located above the bottom opening.

[0029] The movable ring is sleeved on the outer circumference of the peripheral elastic ring and is fixedly connected to the peripheral elastic ring. The movable ring is arranged around the circumference of the sand collecting tube. A plurality of pointed protruding teeth extend downward from the bottom of the movable ring. The plurality of protruding teeth are arranged around the circumference of the movable ring. Adjacent protruding teeth are staggered up and down along the height direction of the movable ring.

[0030] The inner side of the movable ring has a movable inner wall arranged toward the bottom opening. Along the movable ring from bottom to top, the movable inner wall is arranged inwardly and the movable inner part is located below the bottom opening. The top of the movable inner wall has a top step, which is arranged along the circumference of the sand collecting tube and is located below the sand collecting tube. A bottom gap is formed between the top step and the bottom of the sand collecting tube, and the bottom gap is filled with a bottom elastic ring, which respectively abuts against the bottom of the sand collecting tube and the top step.

[0031] In the construction step 2), when the sand taking barrel is drilling into the riverbed to take sand, the movable ring is compressed, elastically moves up and down along the height direction of the movable ring, and elastically deflects along the circumference direction of the movable ring.

[0032] Compared with the prior art, the longitudinal stratified bed sand sampling method provided by the present invention has the following advantages:

[0033] 1) By automatically controlling the bottom and side cover plates of the sand sampling tube, automatic opening and closing are achieved during the insertion and extraction process of the riverbed, effectively preventing bed sand loss, ensuring the integrity and representativeness of the sample, significantly improving the efficiency and accuracy of bed sand sampling, and solving the problems of low efficiency and easy sample damage in traditional methods;

[0034] 2) By rotating and lifting the sand sampling tube in situ, the bed sand at different depths can be sampled in layers, providing more accurate data for river dynamics and sedimentology research. This vertical layered sampling technology enhances the understanding of the vertical distribution characteristics of riverbed sediment and improves the scientific value of the sampling method.

[0035] 3) The connection between the sand sampling rod and the sand sampling barrel is simple. The operator only needs to use the sand sampling rod to control the insertion, rotation and lifting of the sand sampling barrel from the riverbed, which simplifies the sampling process, reduces the difficulty of operation, and makes the sampling process more convenient and quick. In addition, the sampling steps are applicable to riverbeds of different depths and hardnesses. Whether it is a shallow water area or a deep water area, whether it is a soft bottom or a hard bottom riverbed, it can effectively carry out bed sand sampling and has good environmental adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 1 is a flow chart of the longitudinally stratified bed sand sampling method provided by the present invention;

[0037] Figure 2 This is a front view of the exterior of the sand collecting tube provided by the present invention;

[0038] Figure 3 It is a schematic diagram demonstrating the bed sand sampling provided by the present invention;

[0039] Figure 4 It is a schematic diagram demonstrating the bed sand sampling provided by the present invention;

[0040] Figure 5 It is a structural schematic diagram of the peripheral elastic ring and the movable ring provided by the present invention;

[0041] Figure 6 It is a structural schematic diagram of the convex teeth provided by the present invention;

[0042] In the figure: sand taking barrel 100, side cover plate 101, curved piece 102, air outlet 103, rubber cover plate 104, elastic membrane layer 105, bottom opening 200, bottom cover plate 201, limiting ring 202, pressing portion 203, sand bed 300, sand taking rod 301, connector 302, pressure rod 303, peripheral elastic ring 400, movable ring 401, protruding teeth 402, movable inner wall 403, top step 404, bottom elastic ring 405. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0044] The implementation of the present invention is described in detail below with reference to specific embodiments.

[0045] The same or similar numbers in the drawings of this embodiment correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings. This is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0046] Reference Figure 1-6 The figure shows a preferred embodiment of the present invention.

[0047] The longitudinally stratified bed sand sampling method comprises the following steps:

[0048] 1) Connect the sand collecting rod 301 to the top of the sand collecting tube 100. The sand collecting tube 100 is in a cubic shape. The interior of the sand collecting tube 100 has a cubic sand collecting cavity. The sand collecting cavity runs through the bottom of the sand collecting tube 100 to form a bottom opening 200. A sand outlet is formed on the side of the sand collecting tube 100.

[0049] The sand outlet is covered with a side cover plate 101 that is arranged to swing and close or open the sand outlet; the bottom opening 200 of the sand taking tube 100 is covered with a bottom cover plate 201 that is arranged to swing up and down and close or open the bottom opening 200;

[0050] 2) Close the sand outlet of the side cover plate 101, operate the sand taking rod 301, and lower the sand taking tube 100 into the water until the bottom of the sand taking tube 100 touches the riverbed. Then, apply a longitudinal downward driving force to the sand taking tube 100 through the sand taking rod 301 until the entire sand taking tube 100 is inserted into the riverbed;

[0051] When the sand collecting tube 100 is inserted into the riverbed, the bottom cover plate 201 is pressed upward by the bed sand 300, and swings upward to open the bottom opening 200. The bed sand 300 enters the sand collecting chamber through the bottom opening 200 until the bed sand 300 fills the sand collecting chamber, forming a bed sand 300 sample body.

[0052] 3) The sand collecting tube 100 is lifted to a set length by the sand collecting rod 301 and rotated in situ. During the process of extracting the sand collecting tube 100, the bottom cover plate 201 is pressed by the bed sand 300 sample and swings downward to close the bottom opening 200.

[0053] 4) Sequentially lift the sand collecting tube 100 out of the riverbed and water body through the sand collecting rod 301;

[0054] 5) Disconnect the sand taking rod 301 from the sand taking tube 100, swing the side cover plate 101, open the sand outlet, and pour the bed sand 300 sample out through the sand outlet.

[0055] The longitudinally layered bed sand sampling method provided above has the following advantages:

[0056] 1) By automatically controlling the bottom and side cover plates 101 of the sand sampling tube 100, automatic opening and closing are achieved during the insertion and extraction process of the riverbed, effectively preventing the loss of bed sand 300, ensuring the integrity and representativeness of the sample, significantly improving the efficiency and accuracy of bed sand 300 sampling, and solving the problems of low efficiency and easy sample damage in traditional methods;

[0057] 2) By rotating and lifting the sand sampling tube 100 in situ, the bed sand 300 at different depths of the riverbed can be sampled in layers, providing more accurate data for river dynamics and sedimentology research. This vertical layered sampling technology enhances the understanding of the vertical distribution characteristics of riverbed sediment and improves the scientific value of the sampling method;

[0058] 3) The connection between the sand sampling rod 301 and the sand sampling tube 100 is simple. The operator only needs to control the insertion, rotation and withdrawal of the sand sampling tube 100 from the riverbed through the sand sampling rod 301, which simplifies the sampling process, reduces the difficulty of operation, and makes the sampling process more convenient and quick. In addition, the sampling procedure is applicable to riverbeds of different depths and hardnesses. Whether it is shallow water area or deep water area, whether it is soft bottom or hard bottom riverbed, the bed sand 300 can be effectively sampled, and it has good environmental adaptability.

[0059] In this embodiment, in step 1), the top of the sand collecting tube 100 has a connector 302, and the sand collecting rod 301 is threadedly connected to the connector 302. In this way, the connection between the sand collecting rod 301 and the sand collecting tube 100 is more stable, which facilitates the operator to perform precise control during the sampling process and improves the reliability and safety of sampling.

[0060] In this embodiment, in step 1), the bottom of the sand taking rod 301 is threadedly connected to the connecting head 302, and the top of the sand taking rod 301 is connected to the pressure rod 303, and the pressure rod 303 is arranged vertically to the sand taking rod 301; in step 2), a downward driving force is applied to the sand taking barrel 100 by the pressure rod 303. The vertical arrangement of the pressure rod 303 makes the applied driving force more direct and effective, which helps to improve the efficiency of inserting the sand taking barrel 100 into the riverbed.

[0061] In this embodiment, in step 2), after the bottom of the sand collecting barrel 100 abuts against the riverbed, the sand collecting barrel 100 is inserted into the riverbed to a set depth, and the driving barrel is driven up and down, and the bottom covering plate 201 is synchronously swung up and down to close or open the bottom opening 200. In this way, it is ensured that the bottom opening 200 of the sand collecting barrel 100 can respond in time during the sampling process, accurately control the entry and closure of the bed sand 300, and improve the accuracy of sampling.

[0062] In this embodiment, in step 3), after the sand collecting tube 100 is lifted to a set length by the sand collecting rod 301, the sand collecting tube 100 is rotated back and forth in situ. This reciprocating forward and reverse rotation operation helps to evenly distribute the bed sand 300 in the sand collecting chamber, reduces deviations in the sampling process, and improves the uniformity and accuracy of sampling.

[0063] In this embodiment, the sand collecting tube 100 has an air outlet 103 for discharging air from the sand collecting chamber. The sand collecting chamber is connected to the outside through the air outlet 103. The air outlet 103 is located above the sand outlet. Along the circumference of the sand collecting tube 100, the air outlet 103 and the sand outlet are staggered.

[0064] In step 2), when the sand collecting tube 100 is inserted into the riverbed, the air outlet 103 is opened and the air in the sand collecting chamber is discharged through the air outlet 103; in step 4), when the sand collecting tube 100 is pulled up, the air outlet 103 is closed.

[0065] In this way, it is ensured that when the sand sampling tube 100 is inserted into the riverbed, the air in the cavity can be discharged in time, avoiding the change in the sample volume caused by air compression, thereby ensuring the accuracy and representativeness of the sample. At the same time, the air outlet 103 is closed during the lifting process to prevent water and sediment from flowing back, ensuring the smoothness of the sampling process and the reliability of the equipment.

[0066] In this embodiment, a rubber cover 104 is connected to the sand collecting tube 100 and is supported by a colloid material and closes or opens the air outlet 103. The rubber cover 104 is arranged on the outer wall of the sand collecting tube 100. One side of the rubber cover 104 is fixedly connected to the sand collecting tube 100, and the other side of the rubber cover 104 is freely arranged.

[0067] In step 2), when the sand collecting tube 100 is inserted into the riverbed, the rubber cover 104 swings away from the sand collecting tube 100 and the air outlet 103 is opened; in step 4), when the sand collecting tube 100 is extracted, the rubber cover 104 swings toward the sand collecting tube 100 and the air outlet 103 is closed.

[0068] The provision of the rubber cover 104 provides a flexible and reliable method for controlling the air outlet 103, which helps to accurately control the exhaust and sealing of air at different stages, further improving the efficiency and accuracy of bed sand 300 sampling.

[0069] In this embodiment, the inner side wall of the sand taking chamber has a facing portion arranged toward the sand outlet. The facing portion is covered with an elastic membrane layer 105. The outer periphery of the elastic membrane layer 105 is fixedly connected to the facing portion. The elastic membrane layer 105 is arranged to bulge toward the sand outlet, surrounding a bulging area.

[0070] In step 2), when the sand collecting tube 100 is inserted into the riverbed, the bed sand 300 is squeezed to fill the sand collecting cavity, and the elastic membrane layer 105 is compressed and deformed; in step 5), when the side cover plate 101 opens the sand outlet, the elastic membrane layer 105 expands toward the sand outlet and recovers the deformation, driving the bed sand 300 sample toward the sand outlet.

[0071] In this way, during the sand collection process, the bed sand 300 can fill the sand collection cavity more tightly, reduce gaps, and improve the integrity of the sample. When the sample is taken out, the recovery deformation of the elastic membrane layer 105 helps to promote the smooth discharge of the sample, thereby improving the efficiency and convenience of sampling.

[0072] In this embodiment, the bottom opening 200 is provided with a restriction ring 202, which is arranged around the circumference of the bottom opening 200. One side of the bottom cover plate 201 is hinged to the sand collecting tube 100, and the other side of the bottom cover plate 201 is freely arranged. The other side of the bottom cover plate 201 has a pressing portion 203;

[0073] In step 2), during the process of inserting the sand barrel 100 into the riverbed, the bottom cover plate 201 swings upward, the pressing portion 203 disengages from the pressure on the restriction ring 202, and the bottom opening 200 opens; in step 4), during the process of extracting the sand barrel 100 from above, the bottom cover plate 201 swings downward, the pressing portion 203 presses on the restriction ring 202 from top to bottom, the bottom opening 200 is closed, and the restriction ring 202 restricts the bottom cover plate 201 from continuing to swing downward.

[0074] By providing the limiting ring 202 and the bottom cover plate 201 , the bottom opening 200 can be opened quickly when sampling and reliably closed during the lifting process to prevent the sample from being lost, thereby ensuring the integrity of the sample and the accuracy of sampling.

[0075] In this embodiment, the side cover plate 101 has an inward side wall facing the sand extraction cavity. A plurality of elastically arranged curved pieces 102 are provided on the inward side wall. The lower ends of the curved pieces 102 are fixed to the inward side wall, and the upper ends of the curved pieces 102 are bent upward and arranged freely. There is an elastic gap between the curved pieces 102 and the inward side wall.

[0076] In step 2), when the sand collection chamber is filled with the bed sand 300 samples, the elastic sheet is elastically deformed under pressure and embedded in the bed sand 300; when the side cover plate 101 is opened, the elastic sheet elastically resets and applies an elastic pulling force to the bed sand 300 samples toward the sand outlet. In this way, the elastic sheet makes it easier to discharge the samples when the side cover plate 101 is opened, reducing the need for manual operation and improving the efficiency and convenience of sampling.

[0077] In this embodiment, the outer periphery of the lower portion of the sand collecting tube 100 is provided with an outer elastic ring 400 and a movable ring 401 that elastically moves up and down. The outer elastic ring 400 is arranged around the circumference of the sand collecting tube 100 and is located above the bottom opening. The movable ring 401 is sleeved around the outer periphery of the outer elastic ring 400 and is fixedly connected to the outer elastic ring 400. The movable ring 401 is arranged around the circumference of the sand collecting tube 100.

[0078] A plurality of pointed protruding teeth 402 extend downward from the bottom of the movable ring 401 . The plurality of protruding teeth 402 are arranged around the circumference of the movable ring 401 . Adjacent protruding teeth 402 are staggered vertically along the height direction of the movable ring 401 .

[0079] The inner side of the movable ring 401 has a movable inner wall 403 arranged toward the bottom opening. From bottom to top along the movable ring 401, the movable inner wall 403 is arranged to tilt inward, and the movable inner portion is located below the bottom opening.

[0080] The top of the movable inner wall 403 has 404, which is arranged around the circumference of the sand collecting tube 100 and is located below the sand collecting tube 100. There is a bottom gap between 404 and the bottom of the sand collecting tube 100. The bottom gap is filled with a bottom elastic ring 405, which respectively abuts against the bottom of the sand collecting tube 100 and 404.

[0081] During the sand extraction process, the sand extraction barrel 100 can easily drill into the riverbed by using the multiple protruding teeth 402, and the multiple protruding teeth 402 are arranged in a high-low staggered manner, which facilitates the drilling of the multiple protruding teeth 402 and avoids getting stuck. Secondly, during the drilling process, after the movable ring 401 is compressed, it can elastically move up and down in the height direction under the action of the bottom elastic ring 405 and the outer elastic ring 400, and can achieve circumferential elastic offset within a set range, so that the sand extraction barrel 100 can drill into the riverbed in an elastic vibration state, thereby improving drilling efficiency.

[0082] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A longitudinally layered bed sand sampling method, characterized in that: The following steps are involved: 1) Connect the sand collecting rod to the top of the sand collecting tube. The sand collecting tube is in a cubic shape. The interior of the sand collecting tube has a cubic sand collecting cavity. The cavity passes through the bottom of the sand collecting tube to form a bottom opening. A sand outlet is formed on the side of the sand collecting tube. The sand outlet cover has a side cover plate that is swingably arranged to close or open the sand outlet; the bottom opening cover of the sand taking tube has a bottom cover plate that is swingably arranged to close or open the bottom opening; 2) Close the sand outlet of the side cover plate, operate the sand taking rod, and lower the sand taking barrel into the water until the bottom of the barrel contacts the riverbed. Then, apply a longitudinal downward driving force to the barrel through the sand taking rod until the entire barrel is inserted into the riverbed. When the sand collecting cylinder is inserted into the riverbed, the bottom cover plate is pressed upward by the bed sand, and swings upward to open the bottom opening. The bed sand enters the sand collecting cavity through the bottom opening until the bed sand fills the sand collecting cavity, forming a bed sand sample. 3) The sand collecting tube is lifted to a set length by the sand collecting rod, and the sand collecting tube is rotated in situ; in the process of lifting the sand collecting tube, the bottom sealing plate is pressed by the bed sand sample and swings downward to close the bottom opening; 4) Using the sand collecting rod, the sand collecting tubes are sequentially lifted out of the riverbed and water body; 5) Disconnect the sand taking rod from the sand taking barrel, swing the side cover plate to open the sand outlet, and pour the bed sand sample out through the sand outlet; The inner side wall of the sand taking cavity has a facing portion arranged toward the sand outlet, the facing portion is covered with an elastic film layer, the outer periphery of the elastic film layer is fixedly connected to the facing portion, and the elastic film layer is arranged to bulge toward the sand outlet to surround and form a bulging area; In step 2), when the sand collecting tube is inserted into the riverbed, the bed sand is squeezed to fill the sand collecting cavity, and the elastic membrane layer is compressed and deformed; in step 5), when the side cover plate opens the sand outlet, the elastic membrane layer expands toward the sand outlet and recovers the deformation, driving the bed sand sample toward the sand outlet; The outer periphery of the lower part of the sand collecting tube is provided with an outer peripheral elastic ring and a movable ring that moves elastically up and down. The outer peripheral elastic ring is arranged around the circumference of the sand collecting tube and is located above the bottom opening. The movable ring is sleeved on the outer circumference of the peripheral elastic ring and is fixedly connected to the peripheral elastic ring. The movable ring is arranged around the circumference of the sand collecting tube. A plurality of pointed protruding teeth extend downward from the bottom of the movable ring. The plurality of protruding teeth are arranged around the circumference of the movable ring. Adjacent protruding teeth are staggered up and down along the height direction of the movable ring. The inner side of the movable ring has a movable inner wall arranged toward the bottom opening. Along the movable ring from bottom to top, the movable inner wall is arranged inwardly and is located below the bottom opening. The top of the movable inner wall has a top step, which is arranged along the circumference of the sand collecting tube and is located below the sand collecting tube. A bottom gap is formed between the top step and the bottom of the sand collecting tube, and the bottom gap is filled with a bottom elastic ring, which respectively abuts against the bottom of the sand collecting tube and the top step. In the step 2), during the sand extraction process of the sand extraction barrel in the riverbed, the movable ring is compressed, elastically moves up and down along the height direction of the movable ring, and elastically deflects along the circumference direction of the movable ring.

2. The longitudinally stratified bed sand sampling method according to claim 1, characterized in that: In step 1), the top of the sand collecting tube is provided with a connector, and the sand collecting rod is threadedly connected to the connector; the bottom of the sand collecting rod is threadedly connected to the connector, and the top of the sand collecting rod is connected to a pressure rod, and the pressure rod is arranged perpendicular to the sand collecting rod; in step 2), a downward driving force is applied to the sand collecting tube by the pressure rod.

3. The longitudinally stratified bed sand sampling method according to claim 1, characterized in that: In step 2), after the bottom of the sand collecting tube abuts against the riverbed, the sand collecting tube is inserted into the riverbed to a set depth and driven up and down, and the bottom covering plate is synchronously swung up and down to close or open the bottom opening.

4. The longitudinally stratified bed sand sampling method according to any one of claims 1 to 3, characterized in that: In step 3), after the sand collecting tube is lifted up to a set length by the sand collecting rod, the sand collecting tube is rotated back and forth in situ.

5. The longitudinally stratified bed sand sampling method according to any one of claims 1 to 3, characterized in that: The sand taking tube has an air outlet for discharging air in the sand taking cavity. The sand taking cavity is connected to the outside through the air outlet. The air outlet is located above the sand outlet and is staggered with the sand outlet along the circumference of the sand taking tube. In step 2), when the sand collecting tube is inserted into the riverbed, the air outlet is opened and the air in the sand collecting chamber is discharged through the air outlet; in step 4), when the sand collecting tube is lifted, the air outlet is closed.

6. The longitudinally layered bed sand sampling method according to claim 5, characterized in that: The sand collecting tube is connected to a rubber cover plate supported by a colloid material and closing or opening the air outlet. The rubber cover plate is arranged on the outer wall of the sand collecting tube. One side of the rubber cover plate is fixedly connected to the sand collecting tube, and the other side of the rubber cover plate is freely arranged. In step 2), when the sand collecting tube is inserted into the riverbed, the rubber cover swings away from the sand collecting tube and the air outlet is opened; in step 4), when the sand collecting tube is lifted, the rubber cover swings toward the sand collecting tube and the air outlet is closed.

7. The longitudinally stratified bed sand sampling method according to any one of claims 1 to 3, characterized in that: The bottom opening is provided with a restriction ring, which is arranged around the circumference of the bottom opening. One side of the bottom cover plate is hinged to the sand collecting tube, and the other side of the bottom cover plate is freely arranged. The other side of the bottom cover plate has a pressing portion. In step 2), during the process of inserting the sand collecting tube into the riverbed, the bottom cover plate swings upward, the pressing portion disengages from the pressing against the restriction ring, and the bottom opening opens; in step 4), during the process of lifting the sand collecting tube, the bottom cover plate swings downward, the pressing portion presses against the restriction ring from top to bottom, the bottom opening is closed, and the restriction ring restricts the bottom cover plate from continuing to swing downward.

8. The longitudinally stratified bed sand sampling method according to any one of claims 1 to 3, characterized in that: The side cover plate has an inward side wall facing the sand taking cavity, and a plurality of elastically arranged curved pieces are provided on the inward side wall. The lower ends of the curved pieces are fixed to the inward side wall, and the upper ends of the curved pieces are bent upward and arranged freely, with elastic spacing between the curved pieces and the inward side wall. In step 2), when the sand taking cavity is filled with the bed sand sample, the elastic sheet is elastically deformed under pressure and embedded in the bed sand; when the side cover plate is opened, the elastic sheet elastically returns to its original position, applying an elastic pulling force to the bed sand sample toward the sand outlet.

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