Geotechnical engineering investigation drilling water level measuring instrument

Abstract

The invention discloses a geotechnical engineering investigation drill hole water level measuring instrument which comprises a support, a main machine is arranged at the top of the support, a measuring assembly is arranged below the support, and a battery pack is detachably arranged at the bottom of the support. The measuring assembly comprises a barrel, a second connecting line and a measuring device, an opening is formed in the top of the barrel, an inner pipe is arranged on the inner side of the barrel, the top of the inner pipe is connected with the support, the second connecting line is wound on the inner pipe, one end of the second connecting line is connected with the measuring device, and the other end of the second connecting line is electrically connected with the host; the measuring device comprises a pressure sensor; the device is provided with the storable support, the top of the support is provided with the host, and the inner side of the support is provided with the measuring assembly, so that the device is small in size, convenience is provided for adjusting the position of the device according to requirements, and the current situation that an existing measuring device is inconvenient to transfer is changed.

Description

Technical Field

[0001] The present invention relates to the field of water level measuring devices, and particularly to a water level measuring instrument for geotechnical engineering investigation boreholes. Background Technique

[0002] The physical properties of rock and soil are important contents of geotechnical engineering investigation. Through boreholes, rock and soil samples can be taken from different depths, and these samples can intuitively show the types of rock and soil, such as cohesive soil, sandy soil, gravelly soil, etc. Boreholes can also reveal the stratification of the stratum and assist in detecting geological structures, such as faults, folds, and so on.

[0003] Permeability is an important parameter in geotechnical engineering. In projects involving groundwater seepage, such as foundation pit dewatering projects, anti-seepage designs of landfills, etc., it is very crucial to understand the permeability of rock and soil masses. In order to know the permeability of rock and soil masses and judge the rock and soil properties of adjacent boreholes, the water level of groundwater can be measured after drilling. If there are obvious differences in the water levels measured in two adjacent boreholes and the types of rock and soil are similar, it may mean that the permeability of the rock and soil mass is relatively large.

[0004] In order to measure the water level of boreholes, devices for measuring the underground water level are disclosed in the prior art. For example, a water level measuring instrument for geotechnical engineering investigation boreholes disclosed in a Chinese patent with the publication number CN118622257B includes an L-shaped push plate and universal wheels movably installed at the four corners of the bottom of the L-shaped push plate. A stabilizing component is installed at the top of the L-shaped push plate. Through the mutual cooperation of components such as the outer shell, fixed seat, electromagnet, magnet block, telescopic spring B, movable plate, T-shaped pressing rod, rack plate, movable gear, and rotating gear, the T-shaped pressing rod can be moved to press the switch button to cut off the power when the servo motor fails. At the same time, through the mutual cooperation of components such as the hollow ring A, arc plate, arc rack, arc connecting bar, hollow ring B, transmission gear, driven bevel gear, driving bevel gear, and belt, the arc plate can move inward synchronously to clamp and lock the worm, avoiding the detector from continuously moving downward under its own gravity due to motor failure.

[0005] Although the water level measuring instrument provided by the above patent can measure the water level of boreholes, it has some defects. For example, from the technical solution and its attached drawings disclosed in the above patent, the size of this water level measuring instrument is relatively large and it is not convenient to disassemble. Therefore, it is difficult to transfer this water level measuring instrument according to requirements, that is, the flexibility of this water level measuring instrument is relatively poor. In addition, this water level measuring instrument has more electrical components. In order to meet the long-term measurement task, more batteries need to be equipped, or this water level measuring instrument needs to be connected to the mains. Equipping multiple batteries increases the cost and is more unfavorable for the transfer of this device; connecting to the mains is restricted by engineering conditions and requires connecting long wires, with poor practicability and being unfavorable for transferring this device according to requirements. Summary of the Invention

[0006] The object of the present invention is to provide a measuring instrument for the water level in a borehole of geotechnical engineering exploration, aiming to improve the problem that the device for measuring the water level in a borehole has a large size and is inconvenient to transfer.

[0007] The present invention is implemented as follows:

[0008] A measuring instrument for the water level in a borehole of geotechnical engineering exploration includes a bracket. A main machine is arranged at the top of the bracket, and a measuring assembly is arranged below the main machine. The measuring assembly includes a cylinder, a second connecting wire, and a measuring device. The top of the cylinder is set as an opening, and an inner tube is arranged inside. The top of the inner tube is connected to the bracket. The second connecting wire is wound on the inner tube, and one end is connected to the measuring device, and the other end is electrically connected to the main machine; the measuring device includes a pressure sensor.

[0009] Preferably, the top of the inner tube protrudes from the cylinder, and the lower end is inserted into the cylinder through a bearing connection; the difference between the outer diameter of the inner tube and the inner diameter of the cylinder is greater than or equal to the diameter of the second connecting wire.

[0010] Preferably, a plurality of through holes are arranged at the top of the inner tube, and the plurality of through holes are distributed along the height direction of the inner tube. One end of the second connecting wire connected to the main machine penetrates through a certain through hole.

[0011] Preferably, a threaded rod is arranged on the outer side of the cylinder, and an extrusion plate is arranged on the inner side of the cylinder. The extrusion plate is sleeved on the inner tube, and the part protruding from the cylinder is threadedly sleeved on the threaded rod; the extrusion plate is located below the part where the second connecting wire is wound.

[0012] Preferably, a top plate is fixedly arranged at the top end of the inner tube, and a second bolt is threadedly sleeved on the top of the cylinder. The top of the second bolt can press against the lower side of the top plate.

[0013] Preferably, the measuring device further includes a bottom cylinder and a sealing cover. The sealing cover is detachably arranged on the top of the bottom cylinder. The second connecting wire penetrates through the sealing cover in a sealed manner; a threaded hole is arranged at the bottom of the bottom cylinder, and the end of the pressure sensor is threadedly inserted at the threaded hole, and the other end is electrically connected to the second connecting wire.

[0014] Preferably, a filtering device is arranged below the measuring device. The filtering device includes a frame and a filter net. A disc net is arranged at the bottom of the frame, and a jack is arranged on the upper side. The central angle of the jack is less than 180°. The filter net penetrates through the jack, and the bottom is inserted into the slot.

[0015] Preferably, the bracket includes a top rod and a plurality of legs. The plurality of legs are evenly distributed on the outer side of the top rod and are hinged to the top rod at the top; a diagonal support plate is hinged to the side of each leg, and the end of the diagonal support plate away from the leg is arranged below the top rod.

[0016] Preferably, a first bolt is threadedly penetrated through the bottom of the ejector rod, and a bottom pipe is inserted at the bottom of the ejector rod. A plurality of limit holes are provided on the bottom pipe, and the end of the first bolt is inserted into a certain limit hole; a plurality of diagonal support plates are hinged to the bottom of the bottom pipe; the top end of the inner pipe is fixedly provided with an external threaded pipe, and the external threaded pipe is threadedly inserted into the bottom pipe.

[0017] Preferably, a battery pack is provided; the battery pack includes a support frame, a socket and a storage battery, and the storage battery and the socket are installed on the support frame; a threaded connection hole is provided at the top of the support frame, a threaded column is threadedly penetrated through the threaded connection hole, and the top of the threaded column is hinged with an inclined connection plate, and the top of the inclined connection plate can be connected to the leg through a pin.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0019] 1. The present invention is provided with a retractable bracket, and a main unit is provided at the top of the bracket, and a measuring component is provided inside the bracket, realizing a small-size setting of the device, facilitating the adjustment of the position of the device according to needs, and changing the current situation that the existing measuring device is inconvenient to transfer.

[0020] 2. The present invention is provided with a column cylinder, and the column cylinder is connected to the outside of the inner pipe through a bearing. At the same time, the second connecting wire is wound on the inner pipe, and the length of the second connecting wire output from the column cylinder can be adjusted by rotating the column cylinder, realizing the adjustment of the height of the measuring device, and providing support for submerging it into the groundwater for measurement.

[0021] 3. The present invention is provided with a pressing plate, the pressing plate is sleeved on the inner pipe, and a threaded rod is provided on the outside of the column cylinder. The position of the pressing plate can be adjusted by rotating the threaded rod, and the second connecting wire wound is pressed by the pressing plate, increasing the resistance of the second connecting wire in contact with each other, so that the second connecting wire maintains a corresponding output length, and further enabling the measuring device to be stably placed. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic structural diagram of the whole of the present invention;

[0023] Figure 2 is a schematic structural diagram of the bracket of the present invention;

[0024] Figure 3 is a schematic structural diagram of the ejector rod and the bottom pipe of the present invention;

[0025] Figure 4 is a schematic structural diagram of the main unit of the present invention;

[0026] Figure 5 is a schematic structural diagram of the measuring component of the present invention;

[0027] Figure 6It is a schematic structural diagram of the column cylinder, inner tube, and extrusion plate of the present invention;

[0028] Figure 7 It is a schematic structural diagram of the inner tube of the present invention;

[0029] Figure 8 It is a schematic structural diagram of the column cylinder of the present invention;

[0030] Figure 9 It is a schematic structural diagram of the measuring device and filtering device of the present invention;

[0031] Figure 10 It is a schematic structural diagram of the measuring device of the present invention;

[0032] Figure 11 It is a schematic structural diagram of the pressure sensor of the present invention;

[0033] Figure 12 It is a schematic structural diagram of the filtering device of the present invention;

[0034] Figure 13 It is a schematic structural diagram of the battery pack of the present invention.

[0035] In the figure:

[0036] 1. Bracket;

[0037] 11. Thumb rod; 12. Diagonal brace plate; 13. Leg; 14. First bolt; 15. Bottom tube; 16. Limit hole;

[0038] 2. Mainframe;

[0039] 21. Housing; 22. Top cover; 23. Industrial control mainboard; 24. Power cord; 25. First connecting wire;

[0040] 3. Measuring assembly;

[0041] 31. Column cylinder; 311. Threaded rod; 312. Second bolt;

[0042] 32. Second connecting wire;

[0043] 33. Measuring device; 331. Bottom cylinder; 332. Threaded hole; 333. Pressure sensor; 334. Sealing cover;

[0044] 34. Inner tube; 341. Through hole; 342. Top plate; 343. External threaded tube

[0045] 35. Extrusion plate;

[0046] 36. Filtering device; 361. Frame; 362. Jack; 363. Filter screen;

[0047] 4. Battery pack;

[0048] 41. Battery; 42. Support frame; 43. Threaded connection hole; 44. Socket; 45. Threaded post; 46. Inclined connecting plate. Detailed implementation manner

[0049] In the present invention, unless otherwise clearly specified and defined, terms such as "installation", "connection", "connection", "fixation", etc. shall be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components or the interaction relationship between two components.

[0050] For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0051] The following is further described in conjunction with the accompanying drawings and specific embodiments:

[0052] Embodiment 1

[0053] As Figure 1 shown, in the embodiment of the present application, in order to be able to facilitate the transfer of the water level measuring device and realize the measurement of the water levels in multiple drill holes, this embodiment provides a new, small-sized and foldable and storable water level measuring instrument. The water level measuring instrument includes a bracket 1, a measuring component 3, a main unit 2, a battery pack 4, etc. The main unit 2 is installed on the top of the bracket 1, the measuring component 3 is arranged inside the bracket 1 and is electrically connected to the main unit 2, and a battery pack 4 is provided. The main unit 2 is a prior art device, which measures the water level through the connected measuring component 3 and uses a sensor for water level measurement. Its measurement principle is the prior art and will not be elaborated in the present application.

[0054] The innovation of the present application is to utilize the existing measurement main unit chip or the configured measurement sensor (the sensors and industrial control computers involved are all prior art) to provide a small-sized measurement device, in order to facilitate adjusting the position of the device according to requirements, so as to change the problem that the existing measurement device is inconvenient to transfer, facilitate use, and improve the stability of the device during the measurement process.

[0055] When using this water level measuring instrument to complete the water level measurement in the drill hole, open the bracket 1 to make it stably placed in a triangular state above the drill hole, and adjust the state of the measuring component 3 according to requirements, so that its measuring probe extends into the drill hole and is immersed in the groundwater. Through the actual work of the probe, measure the liquid pressure at its position, and use the relationship formula between pressure and depth (P = ρgh, where P is the pressure, ρ is the density of water, g is the acceleration due to gravity, and h is the water level depth) to calculate the distance between the probe and the liquid surface, which facilitates obtaining the groundwater level.

[0056] The battery pack 4 here provides electrical energy for the operation of the host 2 and the measurement component 3, and because it is arranged at the top of the bracket 1, the stability of the bracket 1 can be enhanced.

[0057] As Figure 5 、 Figure 6 shown, in the embodiment of the present application, in order to measure the groundwater level through the measurement component 3, the measurement component 3 includes a column tube 31, a second connecting wire 32, a measuring device 33, an inner tube 34, etc.

[0058] As Figures 6 - 8 shown, in the embodiment of the present application, the top of the column tube 31 is set to be open, and the inner diameter is greater than the outer diameter of the inner tube 34. At the same time, the bottom of the inner tube 34 is connected through a bearing and penetrates through the bottom of the column tube 31, and the top of the inner tube 34 protrudes from the column tube 31 and is connected to the bracket 1. While realizing the stable connection between the measurement component 3 and the bracket 1, the stable connection between the column tube 31 and the inner tube 34 is realized, and it provides convenience for rotating the inner tube 34 and the column tube 31 according to requirements.

[0059] As Figure 1 、 Figure 5 shown, in the embodiment of the present application, a scale is provided on the outer side wall of the second connecting wire 32, and the zero end point of the scale is arranged adjacent to the measuring device 33. The second connecting wire 32 is wound on the inner tube 34. One end of the second connecting wire 32 is connected to the measuring device 33, and the other end is electrically connected to the host 2. On the premise of stably supporting the measuring device 33, the second connecting wire 32 can be wound and unwound by relatively rotating the column tube 31 and the inner tube 34, and then the length of the second connecting wire 32 protruding from the column tube 31 can be adjusted, providing support for the measuring device 33 to lift and immerse into the groundwater for measurement.

[0060] As Figure 7 shown, in the embodiment of the present application, in order to wind the second connecting wire 32 on the inner tube 34 and be able to realize the winding of the second connecting wire 32, a plurality of through holes 341 are provided at the top of the inner tube 34, and the plurality of through holes 341 are distributed along the height direction of the inner tube 34. One end of the second connecting wire 32 connected to the host 2 penetrates through a certain through hole 341. Therefore, one end of the second connecting wire 32 is restricted to remain stationary relative to the inner tube 34, providing support for the column tube 31 to rotate relative to the inner tube 34 to realize the winding and unwinding of the second connecting wire 32.

[0061] As Figure 6 、 Figure 8 shown, in the embodiment of the present application, in order to keep the second connecting wire 32 with adjusted length at a corresponding length and make the measuring device 33 stably at a certain height, a threaded rod 311 is provided on the outer side of the column tube 31, and the end of the threaded rod 311 is connected through a bearing and penetrates through the top of the column tube 31, realizing the stable installation of the threaded rod 311 relative to the column tube 31.

[0062] In the embodiment of the present application, a pressing plate 35 is arranged inside the column barrel 31. The pressing plate 35 is sleeved on the inner tube 34 and is located below the winding part of the second connecting line 32. At the same time, the part of the pressing plate 35 protruding from the column barrel 31 is threadedly sleeved on the threaded rod 311. Therefore, the position of the pressing plate 35 can be adjusted by rotating the threaded rod 311, providing support for rising to press the second connecting line 32 to force the second connecting line 32 to maintain a corresponding length, and also facilitating the release of the restriction on the second connecting line 32 by the lowering of the pressing plate 35 to realize the winding and unwinding of the second connecting line 32.

[0063] As Figure 7 , Figure 8 shown, in the embodiment of the present application, a top plate 342 is fixedly arranged at the top end of the inner tube 34. A second bolt 312 is threadedly sleeved on the top of the column barrel 31. The second bolt 312 can be rotated so that the top of the second bolt 312 presses against the lower side of the top plate 342, increasing the resistance to relative rotation between the inner tube 34 and the column barrel 31. Furthermore, after adjusting the length of the second connecting line 32, the column barrel 31 and the inner tube 34 can be kept relatively stationary.

[0064] As Figures 9 - 11 shown, in the embodiment of the present application, in order to realize pressure measurement after the measuring device 33 is immersed in groundwater, the measuring device 33 includes a pressure sensor 333, a bottom barrel 331, and a sealing cover 334. The sealing cover 334 is detachably arranged at the top of the bottom barrel 331 through bolts, and the second connecting line 32 is hermetically penetrated through the sealing cover 334. A threaded hole 332 is arranged at the bottom of the bottom barrel 331. One end of the pressure sensor 333 is electrically connected to the second connecting line 32, and the other end is threadedly inserted at the threaded hole 332. There is a pressure-sensitive element inside the pressure sensor 333, usually a thin film made of a semiconductor material (such as silicon).

[0065] When an external pressure acts on this thin film, the thin film will deform, resulting in a change in its internal resistance. By measuring the change in resistance and using circuits such as a Wheatstone bridge, the pressure signal can be converted into an electrical signal. Since the bottom of the pressure sensor 333 is installed at the bottom of the bottom barrel 331, it can be directly in contact with the liquid and bear the pressure exerted by the liquid, thereby realizing the measurement of the pressure at this place.

[0066] As Figure 4As shown in the figure, in the embodiment of the present application, in order to cooperate with the measurement component 3 to measure the water pressure, the host 2 includes a housing 21, a top cover 22 and an industrial control main board 23. The top cover 22 is installed on the top of the housing 21, and the industrial control main board 23 is installed inside the housing 21 and is electrically connected to the operation screen installed outside the housing 21. The power line 24 is connected to the battery pack 4, and at the same time, a first connecting line 25 and a power line 24 are connected below. The first connecting line 25 is plugged into the second connecting line 32. Both the first connecting line 25 and the second connecting line 32 include a power line and a data line. Therefore, the pressure sensor 333 can be controlled by the industrial control main board 23 to work, and at the same time, the monitored information is transmitted to the industrial control main board 23 in real time and displayed through the operation screen.

[0067] In addition, in the embodiment of the present application, the industrial control main board 23 is an existing processor or chip for measurement, and its internal integrates a memory module (such as DRAM, SRAM), or is additionally configured with a memory module. A driver program adapted to the pressure sensor 333 is pre-installed in the industrial control main board 23, and a signal conditioning and adaptation circuit (signal amplification, signal filtering, level conversion) can be equipped. In short, to realize the normal operation of the pressure sensor 333 and the industrial control main board 23, which is the prior art and will not be elaborated here.

[0068] As Figure 2 、 Figure 3 shown in the figure, in the embodiment of the present application, in order to stably install the device under the action of the bracket 1, the bracket 1 includes a top rod 11, a bottom tube 15 and multiple legs 13. The multiple legs 13 are evenly distributed on the outside of the top rod 11 and are hinged to the top rod 11 at the top. A first bolt 14 is threadedly penetrated through the bottom of the top rod 11. Multiple limiting holes 16 are provided on the bottom tube 15, and the top is inserted into the top rod 11. The end of the first bolt 14 is inserted into a certain limiting hole 16, which provides convenience for adjusting the relative positions of the top rod 11 and the bottom tube 15 as required while realizing the stable connection of the top rod 11 and the bottom tube 15.

[0069] In the embodiment of the present application, the legs 13 are controlled to be stably inclined relative to the top rod 11. A diagonal support plate 12 is hingedly arranged on the side of each leg 13 through cooperation of an axis, a bearing, etc. The multiple diagonal support plates 12 are all hingedly connected to the bottom of the bottom tube 15. Therefore, by adjusting the position of the bottom tube 15 relative to the top rod 11, the inclination angle of the legs 13 can be adjusted so that the bracket 1 maintains a stable shape and provides support for the operation of the device.

[0070] In the embodiment of the present application, in order to realize the connection between the inner tube 34 and the bracket 1, an external threaded tube 343 is fixedly arranged at the top end of the inner tube 34, and the external threaded tube 343 is threadedly inserted into the bottom tube 15.

[0071] As Figure 13As shown in the figure, in the embodiment of the present application, in order to detachably arrange the battery pack 4 below the bracket 1, the battery pack 4 includes a support frame 42, a socket 44 and a storage battery 41. The storage battery 41 and the socket 44 are installed on the support frame 42. A threaded connection hole 43 is provided at the top of the support frame 42, and a threaded post 45 is threaded through the threaded connection hole 43. The top of the threaded post 45 is inserted into the top post through a bearing connection. The top post is hinged below the inclined connecting plate 46. The top of the inclined connecting plate 46 is connected to the leg 13 through a pin. Therefore, after the bracket 1 is erected, the threaded post 45 is installed on the side of the leg 13 through the inclined connecting plate 46, and the bottom is threaded into the threaded connection hole 43. Then, the staff holds a wrench to clamp the top of the threaded post 45, aligns the wrench with the keyway, and controls the rotation of the threaded post 45 to achieve the stable connection between the leg 13 and the battery pack 4. The center of gravity of the bracket 1 is reduced by the battery pack 4, enhancing the stability of the device.

[0072] Embodiment 2

[0073] As Figure 9 , Figure 12 As shown in the figure, in the embodiment of the present application, on the basis of Embodiment 1, in order to prevent sundries from contacting the pressure sensor 333 and affecting the measurement accuracy, a filtering device 36 is provided below the measuring device 33. The filtering device 36 includes a frame 361 and a filter screen 363. The frame 361 is installed below the bottom cylinder 331 through bolt connection, set as an annular structure, and has a jack 362 on the top surface. At the same time, a slot is provided at the bottom. The slot is aligned with the jack 362, and the central angles are all less than 180°. The filter screen 363 is set as an arc structure and is installed in the space formed by the jack 362 and the slot to filter the liquid on the side wall of the frame 361. A disc screen is provided at the bottom of the frame 361 to filter the liquid at the bottom of the frame 361.

[0074] The above is only the preferred embodiment of the present invention and is not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A geotechnical engineering exploration borehole water level measuring instrument, including a bracket (1), and a main machine (2) is arranged at the top of the bracket (1), characterized in that, A measuring component (3) is arranged below the host (2); the measuring component (3) includes a column cylinder (31), a second connecting wire (32) and a measuring device (33), the top of the column cylinder (31) is provided with an opening, and an inner tube (34) is arranged inside, the top of the inner tube (34) is connected to the bracket (1), the second connecting wire (32) is wound on the inner tube (34), one end is connected to the measuring device (33), and the other end is electrically connected to the host (2); the measuring device (33) includes a pressure sensor (333).

2. The groundwater level measuring instrument for geotechnical engineering investigation according to claim 1, characterized in that, The top of the inner tube (34) protrudes from the column cylinder (31), and the lower end is inserted into the column cylinder (31) through a bearing connection; the difference between the outer diameter of the inner tube (34) and the inner diameter of the column cylinder (31) is greater than or equal to the diameter of the second connecting wire (32).

3. The water level measuring instrument for geotechnical engineering exploration boreholes according to claim 2, characterized in that, A plurality of through holes (341) are arranged at the top of the inner tube (34), and the plurality of through holes (341) are distributed along the height direction of the inner tube (34), and one end of the second connecting wire (32) connected to the host (2) penetrates through a certain through hole (341).

4. The geotechnical engineering exploration borehole water level measuring instrument according to claim 2, characterized in that, A threaded rod (311) is arranged on the outer side of the column cylinder (31), and an extrusion plate (35) is arranged on the inner side of the column cylinder (31), the extrusion plate (35) is sleeved on the inner tube (34), and the part protruding from the column cylinder (31) is threadedly sleeved on the threaded rod (311); the extrusion plate (35) is located below the winding part of the second connecting wire (32).

5. The water level measuring instrument for geotechnical engineering exploration boreholes according to claim 4, characterized in that, A top plate (342) is fixedly arranged at the top end of the inner tube (34), and a second bolt (312) is threadedly sleeved on the top of the column cylinder (31), and the top of the second bolt (312) can press against the lower side of the top plate (342).

6. The water level measuring instrument for geotechnical engineering investigation boreholes according to claim 1, characterized in that, The measuring device (33) further includes a bottom cylinder (331) and a sealing cover (334), the sealing cover (334) is detachably arranged on the top of the bottom cylinder (331), and the second connecting wire (32) is hermetically penetrated through the sealing cover (334); a threaded hole (332) is arranged at the bottom of the bottom cylinder (331), and the end of the pressure sensor (333) is threadedly inserted at the threaded hole (332), and the other end is electrically connected to the second connecting wire (32).

7. The water level measuring instrument for geotechnical engineering investigation boreholes according to claim 1, characterized in that, A filtering device (36) is arranged below the measuring device (33), the filtering device (36) includes a frame (361) and a filter net (363), the bottom of the frame (361) is provided with a disc net, and the upper side is provided with a jack (362), the central angle of the jack (362) is less than 180°, the filter net (363) penetrates through the jack (362), and the bottom is inserted into the slot.

8. The water level measuring instrument for geotechnical engineering investigation boreholes according to claim 1, characterized in that, The bracket (1) includes a top rod (11) and a plurality of legs (13), the plurality of legs (13) are evenly distributed on the outer side of the top rod (11), and the top is hinged to the top rod (11); a diagonal support plate (12) is hinged to the side of each leg (13), and the end of the diagonal support plate (12) away from the leg (13) is arranged below the top rod (11).

9. The water level measuring instrument for geotechnical engineering exploration boreholes according to claim 8, characterized in that, A first bolt (14) is threadedly penetrated through the bottom of the ejector rod (11), and a bottom pipe (15) is inserted into the bottom of the ejector rod (11). A plurality of limit holes (16) are provided on the bottom pipe (15), and the end of the first bolt (14) is inserted into a certain limit hole (16); a plurality of the stay plates (12) are hinged to the bottom of the bottom pipe (15); the top end of the inner pipe (34) is fixedly provided with an external thread pipe (343), and the external thread pipe (343) is threadedly inserted into the bottom pipe (15).

10. The water level measuring instrument for geotechnical engineering exploration boreholes according to claim 8, characterized in that, A battery pack (4) is provided. The battery pack (4) includes a placement rack (42), a socket (44), and a storage battery (41). The storage battery (41) and the socket (44) are installed on the placement rack (42); a threaded connection hole (43) is provided at the top of the placement rack (42), a threaded column (45) is threadedly penetrated through the threaded connection hole (43), the top of the threaded column (45) is hingedly provided with an inclined connection plate (46), and the top of the inclined connection plate (46) can be connected to the leg (13) through a pin.

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