Groundwater level observation device for geotechnical investigation

Abstract

The application provides a groundwater level observation device for geotechnical investigation, which comprises a connecting pipe, a water isolation pipe, a pressure detection mechanism and a sealing plug. The water isolation pipe comprises a pipe body, a medium injection pipe and a capsule. The medium injected through the medium injection pipe can support the capsule, thereby separating the target aquifer from other aquifers and reducing the interference of other aquifers on the target aquifer. The pressure detection mechanism comprises an osmotic pressure meter and an electric connecting wire. The electric connecting wire is sequentially arranged in the connecting pipe and the water isolation pipe. The osmotic pressure meter is arranged at the end of the water isolation pipe away from the connecting pipe. The sealing plug is at least partially arranged in the pipe body. The electric connecting wire is arranged in the wire hole of the sealing plug and is sealed with the sealing plug, thereby isolating the osmotic pressure meter from the external environment, avoiding the damage of the atmosphere to the pure water pressure environment and causing measurement errors.

Description

Technical Field

[0001] This application relates to the field of groundwater observation technology, and in particular to a groundwater level observation device for rock and soil exploration. Background Technology

[0002] In geotechnical engineering investigations, it is necessary to determine the groundwater level of the aquifers in the site. When there is only one aquifer, the groundwater level can be measured directly in the borehole. When there are multiple aquifers, there are three commonly used methods for groundwater level measurement. The first method involves using a hammer to drive a casing into the strata during drilling. The casing is tightly fitted against the aquitard to prevent the flow of groundwater between different aquifers. After the groundwater level stabilizes, it is measured inside the casing. The second method involves lowering a water level observation tube into the borehole. Clay balls are filled between the observation tube and the borehole wall to prevent the flow of groundwater between different aquifers. After the groundwater level stabilizes, it is measured inside the observation tube. The third method involves burying a pore water pressure gauge in the borehole. Clay balls are filled at the top of the target aquifer to prevent the flow of groundwater between different aquifers. After the groundwater level stabilizes, readings are taken and the groundwater level is calculated.

[0003] In related technologies, when using pore water pressure gauges for water level detection, the results are easily affected by external environmental interference. Utility Model Content

[0004] This application provides a groundwater level observation device for geotechnical investigation, which can solve the problem that in related technologies, when using pore water pressure gauges for water level detection, the results are easily affected by external environmental interference.

[0005] This application provides a groundwater level monitoring device for geotechnical investigation, including: Connecting pipe; A water-proof pipe includes a pipe body, a medium injection pipe, and a bladder disposed on the outer peripheral wall of the pipe body. The medium injection pipe is at least partially disposed in the pipe body, passes through the pipe body, and communicates with the bladder. The pipe body and the connecting pipe are detachably connected. A pressure testing mechanism includes a piezometer and an electrical connection wire electrically connected to the piezometer. The electrical connection wire is sequentially passed through the connecting pipe and the water-proof pipe. The piezometer is located at the end of the water-proof pipe away from the connecting pipe. A sealing plug, at least partially disposed within the tube body, the sealing plug forming a through hole, the electrical connection wire passing through the through hole and sealing it with the sealing plug.

[0006] In some embodiments, the connecting pipe includes a plurality of connecting segments that are detachably connected along the length of the connecting pipe.

[0007] In some embodiments, the plurality of connecting segments include a first connecting segment at the end away from the riser pipe, the first connecting segment being connected to a support frame for installation on the ground.

[0008] In some embodiments, the sealing plug has a first end face located inside the tube and a second end face located outside the tube, wherein the cross-sectional area of ​​the sealing plug gradually increases in the direction from the first end face to the second end face.

[0009] In some embodiments, a water inlet pipe is also included, which is connected to the end of the pipe body away from the connecting pipe, and the water inlet pipe has a through hole. The electrical connection wire extends into the water inlet pipe, and the osmotic pressure gauge is located inside the water inlet pipe.

[0010] In some embodiments, the surface of the through-hole is provided with a filter screen.

[0011] In some embodiments, the tube body includes two first tube segments and a second tube segment connected between the two first tube segments. The outer diameter of the first tube segment is larger than the outer diameter of the second tube segment, and the two first tube segments and the second tube segment form a limiting interval on the outer periphery of the second tube segment. The bladder is installed in the limiting interval and abuts against the first tube segment.

[0012] In some embodiments, at least one of the first pipe segments is provided with an internal thread, and the connecting pipe is provided with an external thread that mates with the internal thread, wherein the internal thread does not extend to the second pipe segment.

[0013] In some embodiments, the medium injection tube includes a first tube segment and a second tube segment that are perpendicular to each other, the second tube segment passing through the tube body and communicating with the capsule, and the first tube segment extending along the length direction of the tube body.

[0014] In some embodiments, the first tube segment has an end located outside the tube body.

[0015] The groundwater level monitoring device for geotechnical investigation based on the embodiments of this application includes a connecting pipe, a water-proof pipe, a pressure detection mechanism, and a sealing plug. The water-proof pipe includes a pipe body, a medium injection pipe, and a capsule. The medium injected through the medium injection pipe can support the capsule, thereby separating the target aquifer from other aquifers and reducing the interference of other aquifers on the target aquifer. The pressure detection mechanism includes a piezometer and an electrical connection wire, which are at least partially disposed in the pipe body through the sealing plug. The electrical connection wire passes through a wire hole on the sealing plug, thereby isolating the piezometer from the external environment and preventing atmospheric damage to the pure water pressure environment, which could lead to measurement errors. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the groundwater level monitoring device for geotechnical investigation provided in the embodiments of this application; Figure 2 This is a schematic diagram of the structure of the water-proof pipe provided in the embodiments of this application; Figure 3 This is a schematic diagram of the tube structure provided in the embodiments of this application; Figure 4 This is a cross-sectional structural diagram of the water-proof pipe provided in the embodiments of this application; Figure 5 This is a schematic diagram of the structure of the connection segment provided in an embodiment of this application; Figure 6 This is a schematic diagram of the structure of the water inlet pipe provided in the embodiment of this application.

[0017] Explanation of reference numerals in the attached figures: 10. Connecting pipe; 11. Connecting section; 20. Waterproof pipe; 21. Pipe body; 21a. Limiting zone; 211. First pipe section; 212. Second pipe section; 212a. Connecting hole; 22. Medium injection pipe; 221. First pipe body section; 2211. End; 222. Second pipe body section; 23. Bladder body; 23a. Bladder cavity; 30. Pressure testing mechanism; 31. Electrical connection cable; 32. Measuring instrument; 40. Sealing plug; 40a. Wire hole 50. Water inlet pipe; 50a. Through hole; 60. Support frame; 100. Medium connecting pipe. Detailed Implementation

[0018] The technical solutions in this application will be clearly and thoroughly described below with reference to the accompanying drawings. In the description of the embodiments of this application, unless otherwise stated, " / " means "or," for example, A / B can mean A or B. "And / or" in the text is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Furthermore, in the description of the embodiments of this application, "multiple" refers to two or more than two.

[0019] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0020] In geotechnical engineering investigations, it is necessary to determine the groundwater level of the aquifers in the site. When there is only one aquifer, the groundwater level can be measured directly in the borehole. When there are multiple aquifers, there are three commonly used methods for groundwater level measurement. The first method involves using a hammer to drive a casing into the strata during drilling. The casing is tightly fitted against the aquitard to prevent the flow of groundwater between different aquifers. After the groundwater level stabilizes, it is measured inside the casing. The second method involves lowering a water level observation tube into the borehole. Clay balls are filled between the observation tube and the borehole wall to prevent the flow of groundwater between different aquifers. After the groundwater level stabilizes, it is measured inside the observation tube. The third method involves burying a pore water pressure gauge in the borehole. Clay balls are filled at the top of the target aquifer to prevent the flow of groundwater between different aquifers. After the groundwater level stabilizes, readings are taken and the groundwater level is calculated.

[0021] In existing technologies, water level detection using pore water pressure gauges is easily affected by external environmental interference, which in turn affects the detection results.

[0022] To resolve the above issues, please refer to [link / reference]. Figures 1 to 4 This application provides a groundwater level monitoring device for geotechnical investigation, including a connecting pipe 10, a water-proof pipe 20, a pressure detection mechanism 30, and a sealing plug 40.

[0023] Specifically, the water-proof pipe 20 includes a pipe body 21, a medium injection pipe 22, and a bladder 23 disposed on the outer peripheral wall of the pipe body 21. The medium injection pipe 22 is at least partially disposed inside the pipe body 21, passes through the pipe body 21, and communicates with the bladder 23. The pipe body 21 is detachably connected to the connecting pipe 10.

[0024] The pressure testing mechanism 30 includes a piezometer and an electrical connection line 31 electrically connected to the piezometer. The electrical connection line 31 is sequentially threaded through a connecting pipe 10 and a water-proof pipe 20. The piezometer is located at the end of the water-proof pipe 20 away from the connecting pipe 10, that is, during the actual measurement process, the piezometer is located within the target aquifer.

[0025] In this embodiment of the application, the groundwater level monitoring device for geotechnical investigation follows the following steps: Drill a hole to the predetermined depth, depending on the exploration depth and the location of the target aquifer. Based on the depth of the target aquifer, select a suitable length of connecting pipe 10 and lower it into the borehole. Ensure that the piezometer is located in the target aquifer, while the riser 20 is located above the target aquifer to achieve physical isolation between the target aquifer and other aquifers above it.

[0026] After the riser 20 injects a high-pressure medium (such as water or gas) into the bladder 23 through the medium injection pipe 22, the bladder 23 expands radially like a balloon and eventually presses tightly against the borehole wall to form a permanent or semi-permanent and very reliable sealing ring.

[0027] The sealing ring completely isolates the target aquifer located below from other aquifers or non-target sections above, eliminating hydraulic communication (crosstalk) between different water layers, thus ensuring that the monitored water pressure data comes from the target aquifer and guaranteeing the accuracy of the data.

[0028] Among them, the bladder 23 is an expandable sealed bag installed on the outer wall of the tube 21, and its material is generally supported by flexible materials such as high-strength rubber.

[0029] The pressure of the target aquifer is measured by a piezometer, thereby calculating the water head and water depth. The other end of the electrical connection line 31 can be connected to a measuring instrument 32, which can be located on the ground. Relevant data, such as the pressure of the target aquifer, water head, and water depth, can be directly read through the measuring instrument 32. It should be understood that the piezometer in this application, i.e., the pore water pressure gauge, is a commercially available product. Its measurement of water pressure and the calculation of water head and water depth based on water pressure are existing technologies. Therefore, its principle will not be described further here.

[0030] In this embodiment, a sealing plug 40 is at least partially disposed within the pipe body 21. The sealing plug 40 forms a wire-passing hole 40a through which the electrical connection wire 31 passes and is sealed with the sealing plug 40. This prevents external gas from entering the target aquifer through the connecting pipe 10 and the water-proof pipe 20, thus avoiding air from entering the target aquifer and interfering with the water pressure environment around the piezometer, leading to lower readings (because air occupies space and pressure cannot be fully transmitted) or instability. Furthermore, the sealing plug 40 also reduces the possibility of debris such as gravel falling onto the piezometer through the connecting pipe 10 and the water-proof pipe 20, thereby preventing damage to the piezometer or affecting its measurements.

[0031] That is, by setting the sealing plug 40, the stability and accuracy of the piezometer during testing can be guaranteed.

[0032] Furthermore, the sealing plug 40 has a first end face located inside the tube body 21 and a second end face located outside the tube body 21. In the direction from the first end face to the second end face, the cross-sectional area of ​​the sealing plug 40 gradually increases, that is, the entire sealing plug 40 forms a frustum-shaped sealing plug. And when the sealing plug 40 is made of rubber, the design of one end being small and the other end being large makes it easier for the sealing plug 40 to be inserted into the tube body 21.

[0033] In addition, the frustum-shaped design can produce a self-tightening effect. When the connecting pipe 10 is inserted into the borehole, the pressure at the bottom of the ground is relatively large. Under the pressure, the sealing plug 40 will be pushed, so that the conical surface of the sealing plug 40 fits more tightly, forming a dynamic sealing effect. This means that the greater the pressure, the better the sealing performance.

[0034] It is understood that, in the embodiments of this application, the sealing plug 40 is preferably located at the end of the pipe body 21 away from the connecting pipe 10. This can more directly block the target monitoring layer, reduce potential leakage points, and reduce the risk of other aquifers or fluids seeping in along the pipe wall and interfering with the monitoring results, thus helping to obtain more accurate groundwater data.

[0035] Furthermore, after the electrical connection cable 31 is led out from the piezometer, it needs to pass through the inside of the pipe body 21 to connect to the surface reading device. The sealing plug 40 at the end of the pipe body 21 away from the connecting pipe 10 can effectively prevent moisture, humidity and corrosive media from entering the inside of the pipe body 21 along the gap between the pipe wall and the cable, protecting the electrical connection cable 31 from corrosion and damage, and ensuring the stability of signal transmission.

[0036] In addition, it can effectively prevent pollutants such as mud and impurities from entering the interior of the pipe body 21, prevent blockage and wear, and protect the medium injection pipe 22 and electrical connection line 31, etc.

[0037] like Figure 1 and Figure 5 As shown, in one embodiment of this application, the connecting pipe 10 includes a plurality of connecting segments 11 detachably connected along the length of the connecting pipe 10. Thus, when working below the connecting pipe 10, an appropriate number of connecting segments 11 can be assembled and lowered into the borehole according to the depth of the target aquifer. This ensures that the piezometer is located in the target aquifer, while the riser 20 is located above the target aquifer, thereby achieving physical isolation between the target aquifer and other aquifers above it.

[0038] The connection between two adjacent connecting segments 11 can be a threaded connection or a snap-fit ​​connection, etc. In this embodiment, the connection between two adjacent connecting segments 11 is illustrated by a threaded connection, that is, one end of the connecting segment 11 is an external thread and the other end is an internal thread. In this way, the quick assembly between any two connecting segments 11 can be achieved. When the connecting segment 11 is provided with a thread, the corresponding pipe body 21 is also provided with a corresponding thread to achieve thread engagement with the connecting segment 11, thereby improving the assembly and disassembly efficiency of the connecting pipe 10 and the water-proof pipe 20.

[0039] It is also understandable that, since the tube body 21 in this application is equipped with a sealing plug 40, even if water from other aquifers seeps into the connecting section 11 through the gap between two adjacent connecting sections 11, it will be blocked by the sealing plug 40 and will hardly affect the normal detection of the piezometer.

[0040] The connecting pipe 10 and the water-proof pipe 20 are suspended in the borehole. To ensure that the connecting pipe 10 remains vertical at all times, in one embodiment of this application, please refer to... Figure 1 The plurality of connecting sections 11 include a first connecting section at the end away from the riser pipe 20, on which a support frame 60 for ground installation is connected.

[0041] The support frame 60 can provide an installation foundation for the connecting pipe 10 and the water-proof pipe 20, ensuring stability. In addition, since the piezometer is generally required to enter the target aquifer and remain stationary for a period of time before being used for testing, the support frame 60 can ensure the stability of the piezometer in the target aquifer without the need for other large equipment such as hoisting equipment.

[0042] The support frame 60 provides a stable suspension point for the connecting pipe 10, preventing it from tilting, bending or sinking, and ensuring that it is always in a vertical state. This avoids friction or jamming between the piezometer and the pipe wall, and ensures the continuity and accuracy of the monitoring data.

[0043] like Figure 6 As shown in one embodiment of this application, the groundwater level monitoring device for geotechnical investigation further includes a water inlet pipe 50, which is connected to the end of the pipe body 21 away from the connecting pipe 10. A through hole 50a is provided on the water inlet pipe 50, an electrical connection line 31 extends into the water inlet pipe 50, and a piezometer is located inside the water inlet pipe 50.

[0044] The inlet pipe 50 is the part that is in direct contact with the target aquifer, and it has a through hole 50a to allow groundwater to flow freely into the device.

[0045] The inlet pipe 50 is a robust housing that protects the internal piezometer from potential damage from external mechanical forces such as ground compression, soil displacement, or construction activities. It also provides a stable local environment for the piezometer, buffering against direct water flow or other sudden disturbances, which helps the piezometer obtain more stable and accurate readings.

[0046] The inlet pipe 50 can also be detachably connected to the pipe body 21, specifically by the inlet pipe 50 and the pipe body 21 being threaded together, thereby improving the efficiency of assembling and disassembling the water-proof pipe 20 and the inlet pipe 50.

[0047] When the inlet pipe 50 and the pipe body 21 are connected by threads, and the sealing plug 40 is located at the end of the pipe body 21 away from the connecting pipe 10, in order to avoid the sealing plug 40 interfering with the installation of the pipe body 21 and the inlet pipe 50, please refer to [the relevant documentation / reference needed]. Figure 4The outer diameter of the sealing plug 40 is slightly larger than the inner diameter of the water inlet pipe 50, and also slightly larger than the outer diameter of the pipe body 21. Since the sealing plug 40 is elastic, it does not affect the threaded connection between the water inlet pipe 50 and the pipe body 21, and can ensure the sealing performance at the connection between the water inlet pipe 50 and the pipe body 21.

[0048] It is also important to understand that, considering that water from the target aquifer will flow into the inlet pipe 50, in order to prevent sand and gravel from entering the inlet pipe 50, i.e. to prevent sand inrush and blockage, and also to protect the piezometer, and to prevent the water from containing a large amount of suspended sediment, whose density will change and cause the pressure measurement value to be distorted, a filter screen (not shown in the figure) is provided on the surface of the through hole 50a. The filter screen can be made of stainless steel.

[0049] In some possible embodiments, the filter screen may include a main filter screen and a protective screen. A main filter screen (typically stainless steel wire mesh, nylon mesh, or polyester mesh) is tightly wound around the outside of the inlet pipe 50 with through holes 50a. This screen primarily serves a filtering function.

[0050] Outside the main filter screen, an additional protective mesh is wrapped (usually a thicker stainless steel wire mesh with larger openings). This layer does not primarily serve a filtering function, but rather protects the internal main filter screen from direct impact and abrasion by ground sand and gravel, and also helps to distribute water pressure.

[0051] Finally, secure both ends of the wound filter assembly with metal clamps (or "clamps" or "rings") to keep them relatively fixed.

[0052] In one embodiment of this application, please refer to Figure 3 and Figure 4 The tube body 21 includes a first tube segment 211 and a second tube segment 212 connected between the two first tube segments 211. The outer diameter of the first tube segment 211 is larger than the outer diameter of the second tube segment 212, and the two first tube segments 211 and the second tube segment 212 form a limiting interval 21a on the outer periphery of the second tube segment 212. The bladder body 23 is installed in the limiting interval 21a and abuts against the first tube segment 211.

[0053] The limiting range 21a formed by the tube 21 prevents the bladder 23 from shifting axially (up and down) or slipping under high pressure, firmly confining the bladder 23 within the designed range and ensuring that its expansion direction is as radially outward as possible, thereby accurately sealing the target position.

[0054] Furthermore, by setting the limiting interval 21a, the installation position of the bladder 23 is determined, which can greatly improve the installation efficiency when installing the water-proof pipe 20.

[0055] In the first embodiment, the capsule 23 itself can form a capsule cavity 23a, and the capsule 23 has a hole so that the medium injection tube 22 can communicate with the capsule cavity 23a. In this embodiment, the medium injection tube 22 passes through the communication hole 50a on the second tube segment 212 and then communicates with the hole on the capsule 23. In the second embodiment, the capsule 23 and the side wall of the second tube segment 212 can form a capsule cavity 23a, and the medium injection tube 22 can directly communicate with the capsule cavity 23a by passing through the communication hole 50a on the second tube segment 212. The second embodiment is preferred in this application.

[0056] It should be understood that, in the embodiments of this application, the installation of the bladder 23 and the tube 21 can be as follows: the two ends of the bladder 23 usually have extended flanges or pressure edges. During factory assembly, the bladder 23 is fitted, and then the flanges at both ends are folded over and pressed tightly onto the end faces of the two first tube segments 211. Alternatively, a special high-strength adhesive can be applied to the end face of the first tube segment 211, and then the flanges of the bladder 23 can be pasted onto it. Finally, pressure rings or straps may be used for mechanical reinforcement. Of course, the connection between the bladder 23 and the tube 21 can also adopt other fixing methods in the prior art, which will not be explained in detail here.

[0057] Furthermore, in one embodiment of this application, at least one first pipe segment 211 is provided with an internal thread, and the connecting pipe 10 is provided with an external thread that mates with the internal thread, and the internal thread does not extend to the second pipe segment 212.

[0058] That is, both first pipe sections 211 can be provided with internal threads, so that when connecting the water-proof pipe 20 and the connecting pipe 10, there is no need to adjust the orientation of the two ends of the water-proof pipe 20, thereby realizing the quick connection between the connecting pipe 10 and the water-proof pipe 20.

[0059] Furthermore, since the first pipe section 211 has a larger wall thickness than the second pipe section 212, when the internal thread does not extend to the second pipe section 212, the high-strength connecting thread is only set on the first pipe section 211 with a larger wall thickness. This avoids the strength reduction caused by machining threads on the thin-walled second pipe section 212, thereby ensuring the connection strength between the connecting pipe 10 and the water-proof pipe 20.

[0060] Similarly, in order to make the water inlet pipe 50 a standard module that can be quickly replaced, one of the first pipe sections 211 is threadedly connected to the water inlet pipe 50. The first pipe section 211 can be provided with external or internal threads. When both first pipe sections 211 are provided with internal threads, the water inlet pipe 50 is provided with external threads.

[0061] In some embodiments, please refer to Figure 4The medium injection tube 22 includes a first tube section 221 and a second tube section 222 that are perpendicular to each other. The second tube section 222 passes through the tube 21 and communicates with the capsule 23. The first tube section 221 extends along the length of the tube 21.

[0062] The first pipe section 221 and the second pipe section 222 can be connected by a two-way pipe, or the first pipe section 221 and the second pipe section 222 can be welded together. The first pipe section 221 extends along the length of the pipe body 21, which facilitates the connection of the external medium connecting pipe 100 to the first pipe section 221. The specific connection method can be a flange connection, a grooved connection, a threaded plug, or other detachable connection methods, which will not be explained here.

[0063] Following the above, the first tube segment 221 has an end 2211 located outside the tube 21.

[0064] It should be understood that when assembling the connecting pipe 10 and the water-proof pipe 20, the external medium connecting pipe 100 needs to pass through both ends of the connecting pipe 10 first, so that the medium connecting pipe 100 and the medium injection pipe 22 are connected. Then the connecting pipe 10 and the water-proof pipe 20 are assembled together. In order to facilitate the connection between the medium connecting pipe 100 and the medium injection pipe 22, in this embodiment of the application, the end 2211 of the first pipe body segment 221 is located outside the pipe body 21. Thus, the medium injection pipe 22 and the medium connecting pipe 100 are implemented outside the water-proof pipe 20, thereby improving the convenience of connecting the medium injection pipe 22 and the medium connecting pipe 100.

[0065] The above-disclosed embodiments are merely preferred embodiments of this application and should not be construed as limiting the scope of this application. Therefore, any equivalent variations made in accordance with the claims of this application shall still fall within the scope of this application.

Claims

1. A groundwater level monitoring device for rock and soil exploration, characterized in that, include: Connecting pipe; A water-proof pipe includes a pipe body, a medium injection pipe, and a bladder disposed on the outer peripheral wall of the pipe body. The medium injection pipe is at least partially disposed in the pipe body, passes through the pipe body, and communicates with the bladder. The pipe body and the connecting pipe are detachably connected. A pressure testing mechanism includes a piezometer and an electrical connection wire electrically connected to the piezometer. The electrical connection wire is sequentially passed through the connecting pipe and the water-proof pipe. The piezometer is located at the end of the water-proof pipe away from the connecting pipe. A sealing plug, at least partially disposed within the tube body, the sealing plug forming a through hole, the electrical connection wire passing through the through hole and sealing it with the sealing plug.

2. The groundwater level monitoring device for rock and soil investigation according to claim 1, characterized in that, The connecting pipe includes multiple connecting segments that are detachably connected along the length of the connecting pipe.

3. The groundwater level monitoring device for rock and soil investigation according to claim 2, characterized in that, The plurality of connecting sections include a first connecting section at the end away from the water-proof pipe, on which a support frame for installation on the ground is connected.

4. The groundwater level monitoring device for rock and soil investigation according to claim 1, characterized in that, The sealing plug has a first end face located inside the tube and a second end face located outside the tube, and the cross-sectional area of ​​the sealing plug gradually increases in the direction from the first end face to the second end face.

5. The groundwater level monitoring device for rock and soil investigation according to claim 1, characterized in that, It also includes a water inlet pipe, which is connected to the end of the pipe body away from the connecting pipe, and the water inlet pipe has a through hole. The electrical connection wire extends into the water inlet pipe, and the osmotic pressure gauge is located inside the water inlet pipe.

6. The groundwater level monitoring device for rock and soil investigation according to claim 5, characterized in that, The surface of the through hole is provided with a filter screen.

7. The groundwater level monitoring device for geotechnical investigation according to claim 1, characterized in that, The tube body includes two first tube segments and a second tube segment connected between the two first tube segments. The outer diameter of the first tube segment is larger than the outer diameter of the second tube segment, and the two first tube segments and the second tube segment form a limiting interval on the outer periphery of the second tube segment. The bladder is installed in the limiting interval and abuts against the first tube segment.

8. The groundwater level monitoring device for geotechnical investigation according to claim 7, characterized in that, At least one of the first pipe sections is provided with an internal thread, and the connecting pipe is provided with an external thread that mates with the internal thread, wherein the internal thread does not extend to the second pipe section.

9. The groundwater level monitoring device for geotechnical investigation according to claim 1, characterized in that, The medium injection tube includes a first tube segment and a second tube segment that are perpendicular to each other. The second tube segment passes through the tube and communicates with the capsule. The first tube segment extends along the length of the tube.

10. The groundwater level monitoring device for rock and soil investigation according to claim 9, characterized in that, The first tube segment has an end located outside the tube body.

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