A non-contact groundwater level pressure sensing device and method based on magnetic coupling

Abstract

The application provides a kind of non-contact groundwater level pressure sensing device and method based on magnetic coupling, belongs to the technical field of groundwater level monitoring, device includes ground measuring device, monitoring station and underground deformation device, underground deformation device is fixed at measuring point by flange, monitoring station is fixed on the ground directly above it, ground measuring device is fixed with monitoring station, ground magnet and underground magnet repel each other by magnetic force.Piston is driven by water pressure to move underground magnet along limit rod and compress spring, ground magnet moves synchronously by magnetic repulsion, laser emitter detects ground magnet displacement amount in combination with scale and angle ruler, spring deformation is obtained by formula calculation, and water pressure is back calculated by combining spring elastic force formula and water pressure formula, finally, the water level elevation of measuring point is calculated.The application realizes full-range continuous measurement, completes non-contact signal transmission through magnetic coupling, is easy to install, has high measurement accuracy, and is suitable for various underground water level monitoring scenes.

Description

Technical Field

[0001] This invention relates to the field of groundwater level monitoring technology, and in particular to a non-contact groundwater level pressure sensing device and method based on magnetic coupling. Background Technology

[0002] In groundwater resource exploration, construction pit dewatering monitoring, dam seepage pressure monitoring, and environmental groundwater pollution tracking, high-precision groundwater level measurement is a crucial step in obtaining basic data. Currently, the most widely used method for water level measurement is the piezometer method. This method involves drilling a borehole at the measurement point and burying a guide pipe to ensure the water level inside the pipe is consistent with the surrounding groundwater level. The water level is then measured using a pressure gauge or electrical level gauge at the pipe opening. However, this method has significant technical bottlenecks: First, the piezometer is buried underground for extended periods, and the stagnant water inside allows calcium and magnesium ions to easily precipitate, forming scale and causing blockages in the inlet or pipe, resulting in the water level not reflecting the true groundwater level in real time. Second, dissolved gases in the groundwater accumulate at the top of the pipe, superimposing on the water pressure and causing errors in the pressure gauge reading, leading to an overestimation of the calculated water level. Third, when the groundwater level drops significantly below the installation elevation of the pressure gauge, the pressure gauge reads zero upon contact with air, creating a measurement blind zone and preventing continuous monitoring. Summary of the Invention

[0003] The purpose of this invention is to solve the technical problems of existing pressure measurement tube methods, such as pipe blockage, air pressure accumulation interference, and measurement blind spots, and to provide a non-contact groundwater level pressure sensing device and method based on magnetic coupling, so as to realize full-range, high-precision, non-contact continuous monitoring of groundwater level.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: A non-contact groundwater level and pressure sensing device based on magnetic coupling includes a ground measuring device, a monitoring station, and an underground deformation device. The underground deformation device is installed at the groundwater level measuring point, and the monitoring station is installed on the ground along the same vertical line as the underground deformation device. The ground measuring device and the monitoring station are fixed together. The ground magnet in the ground measuring device and the underground magnet in the underground deformation device repel each other magnetically. The piston of the underground deformation device moves longitudinally under the action of water pressure at the groundwater level measuring point, which drives the underground magnet to move longitudinally synchronously and compress the spring. The ground magnet moves longitudinally synchronously with the underground magnet under the action of magnetic repulsion. The displacement of the ground magnet is detected by the ground measuring device, and the water pressure at the underground measuring point is inferred to obtain the water level at the measuring point.

[0005] Furthermore, the ground measuring device includes a scale, a rigid connecting rod, an angle gauge, a laser emitter, a limiting rod, a ground magnet, and a limiting hole. The two ends of the rigid connecting rod are fixedly connected to the scale and the laser emitter, respectively, ensuring that the scale and the laser incident direction of the laser emitter are parallel. The angle gauge is connected to the laser emitter and is used to detect the angle between the laser emitter and the direction perpendicular to the ground. A reflector is fixedly installed on the upper surface of the ground magnet, and the laser emission direction of the laser emitter faces the reflector on the ground magnet. The reflected laser light from the reflector is projected onto the scale surface. The limiting rod is arranged vertically, and the ground magnet is slidably fitted onto the limiting rod and can only move longitudinally along the limiting rod. The limiting hole is located at the base of the ground measuring device.

[0006] Furthermore, the ground measuring device includes a shaft end retaining ring and a shock absorber. The shaft end retaining ring is located at the top of the limiting rod, and the shock absorber is laid on the upper surface of the base of the ground measuring device. The scale, rigid connecting rod, angle ruler and laser emitter are all arranged next to the ground magnet.

[0007] Furthermore, the monitoring station includes a limiting block and a monitoring base. The monitoring base is horizontally fixed on the ground, and the limiting block protrudes from the upper surface of the monitoring base. The limiting block engages with the limiting hole of the ground measuring device to fix the ground measuring device to the monitoring station and prevent the ground measuring device from sliding horizontally.

[0008] Furthermore, the underground deformation device includes a waterproof and breathable valve, a spring, an underground magnet, a limiting post, a piston, a filter cylinder, and a flange. The limiting post is vertically arranged inside the underground deformation device. The underground magnet is slidably sleeved on the limiting post and can only move longitudinally along the limiting post. The piston is fixedly connected to the lower surface of the underground magnet. The spring is sleeved on the limiting post, and one end of the spring abuts against the underground magnet. The waterproof and breathable valve is located on the housing. The filter cylinder is located below the piston. The flange is fixedly installed at the bottom of the underground deformation device for fixing the underground deformation device.

[0009] Furthermore, the underground deformation device also includes a circular spirit level and spiral blades. The circular spirit level is embedded in the upper end face of the underground deformation device shell to calibrate the installation verticality of the underground deformation device. The spiral blades are arranged at intervals along the vertical direction of the shell to increase the contact tightness with the soil and the lateral friction force. The filter cylinder is detachably connected to the lower end of the underground deformation device shell, and a waterproof and breathable valve is installed on the top side wall of the shell.

[0010] Furthermore, when the water pressure at the underground measuring point is stable, the water pressure is equal to the elastic force of the spring, and the change in longitudinal displacement of the underground magnet along the limiting column is equal to the deformation of the spring and the change in longitudinal displacement of the ground magnet along the limiting rod.

[0011] This invention also provides a non-contact groundwater level and pressure sensing method based on magnetic coupling, implemented using the aforementioned sensing device, comprising the following steps: S1: Install the underground deformation device at the groundwater level measuring point, fix it to the ground at the measuring point through the flange or place it at the groundwater level measuring point, use the circular spirit level to calibrate the verticality of the underground deformation device, fix the monitoring platform horizontally on the ground at the same vertical line as the underground deformation device, fix the ground measuring device to the monitoring platform through the locking fit of the limiting hole and the limiting block, and complete the overall assembly of the device. S2: The water pressure at the groundwater level measuring point acts on the lower surface of the piston, pushing the piston to move longitudinally along the limiting column. The piston drives the underground magnet to move longitudinally synchronously and compress the spring. The ground magnet moves longitudinally synchronously along the limiting rod under the magnetic repulsion of the underground magnet. S3: The longitudinal displacement of the ground magnet is detected by a ground measuring device. The deformation of the spring is obtained based on the displacement. The water pressure at the underground measuring point is then calculated by combining the spring force formula. S4: The water level elevation of the underground measuring point is calculated based on the derived water pressure and water pressure formula.

[0012] Furthermore, the specific process of detecting the longitudinal displacement of the ground magnet in step S3 is as follows: a laser is emitted from a laser emitter to a reflector on the ground magnet. The reflector reflects the laser onto a scale and obtains the laser displacement x1. The angle θ between the laser emitter and the direction perpendicular to the ground is detected by an angle ruler. The vertical displacement x of the ground magnet is calculated according to the formula x=x1cosθ, where x is the deformation of the spring.

[0013] Furthermore, in step S4, according to the formula... The water level elevation H at the measuring point is calculated; where h1 is the installation elevation of the underground deformation device, k is the spring constant, ρ is the water density, g is the gravitational acceleration, and A is the effective area of ​​the piston subjected to water pressure.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. The traditional pressure measuring pipe's guide pipe has been eliminated, and only a compact, sealed measuring unit is set up. The flow path of groundwater is short, which eliminates the problem of pipe scaling and blockage at the source and avoids measurement system failure.

[0015] 2. During the measurement process, there is no free interface between water and air, and the gas released from the groundwater cannot accumulate to form an air cushion, thus completely avoiding measurement errors caused by air pressure accumulation and ensuring the authenticity and accuracy of the measurement results.

[0016] 3. The measurement method using a water pressure-driven spring means that as long as the water level is higher than the measuring point, the water pressure will continue to act on the spring and drive the magnet to move, achieving continuous and uninterrupted measurement across the entire range from low to high water levels, greatly expanding the applicable working conditions of the device.

[0017] 4. Non-contact ground transmission of underground physical displacement signals is achieved through magnetic coupling, eliminating the need for wires or pipes that penetrate the strata. This ensures the sealing performance of the underground unit, simplifies the installation process of the ground measurement section, reduces manpower input, and improves the efficiency of monitoring operations.

[0018] 5. The device has a compact overall structure, stable component connections, and a simple process for detecting and calculating measurement data. It can achieve real-time and accurate monitoring of groundwater levels and is suitable for various groundwater level monitoring scenarios. Attached Figure Description

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 This is a schematic diagram of the ground measuring device according to an embodiment of the present invention; Figure 2 This is a diagram showing the displacement of the ground magnet in an embodiment of the present invention; Figure 3 This is a schematic diagram of the monitoring station structure according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the underground deformation device according to an embodiment of the present invention.

[0020] In the diagram: 1. Scale; 2. Rigid connecting rod; 3. Angle gauge; 4. Laser emitter; 5. Shaft end retaining ring; 6. Limiting rod; 7. Ground magnet; 8. Shock absorber; 9. Limiting hole; 10. Limiting block; 11. Monitoring base; 12. Waterproof and breathable valve; 13. Circular spirit level; 14. Spring; 15. Ground magnet; 16. Spiral blade; 17. Limiting post; 18. Piston; 19. Filter cartridge; 20. Flange. Detailed Implementation

[0021] The technical solutions of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0022] like Figure 1 , 3 As shown in Figure 4, a non-contact groundwater level and pressure sensing device based on magnetic coupling includes, as shown in Figure 4. Figure 1 The ground measuring device shown, such as Figure 3 The monitoring station shown and as Figure 4 The underground deformation device shown; such as Figure 4 The underground deformation device shown is installed at the groundwater level measuring point, such as... Figure 3 The monitoring station shown is installed in the same location as... Figure 4The underground deformation device shown is on the ground at the same vertical line as the ground, such as Figure 1 The ground measuring device shown is similar to... Figure 3 The monitoring station shown is fixed in place, such as Figure 1 The ground magnet 7 in the ground measuring device shown and as Figure 4 The underground magnets 15 in the underground deformation device shown repel each other magnetically. For example... Figure 4 The piston 18 of the underground deformation device shown is moved longitudinally by the water pressure at the groundwater level measuring point, which drives the underground magnet 15 to move longitudinally synchronously and compress the spring 14. The ground magnet 7 is subjected to magnetic repulsion and moves longitudinally synchronously with the underground magnet 15, through... Figure 1 The ground measuring device shown detects the displacement of the ground magnet 7, which can then be used to infer the water pressure at the underground measuring point and thus calculate the water level at the measuring point.

[0023] In this embodiment, spring 14 is a cylindrical helical compression spring with a stiffness coefficient of 500-2000 N / m, which can be selected according to the groundwater level measurement range. The laser emitter is a high-precision laser displacement emitter. Both the ground magnet 7 and the underground magnet 15 are neodymium iron boron permanent magnets. The filter cartridge is a 304 stainless steel filter cartridge with a mesh diameter of 0.5-1 mm. The waterproof and breathable valve 12 is a diaphragm-type waterproof and breathable valve. The angle ruler 3 is a high-precision digital angle ruler. The limiting rod 6 and the limiting post 17 are stainless steel optical shaft rods to ensure the smooth sliding of the magnet and the structural strength.

[0024] This device includes, for example Figure 1 The ground measuring device shown, such as Figure 3 The monitoring station shown and as Figure 4 The underground deformation device shown includes a ground measuring device comprising a ruler 1, a rigid connecting rod 2, an angle ruler 3, a laser emitter 4, a limiting rod 6, a ground magnet 7, and a limiting hole 9, and is also equipped with a shaft end retaining ring 5 and a shock absorber 8; the monitoring platform consists of a limiting block 10 and a monitoring base 11; the underground deformation device includes a waterproof and breathable valve 12, a spring 14, an underground magnet 15, a limiting column 17, a piston 18, a filter cylinder 19, and a flange 20, and is also equipped with a circular spirit level 13 and a spiral blade 16.

[0025] like Figure 4As shown, the underground deformation device is installed at the groundwater level measuring point. Its flange 20 is fixedly installed at the bottom of the underground deformation device shell. It can be fixedly connected to the foundation ground at the measuring point through the flange 20, or the underground deformation device can be directly placed at the preset position of the groundwater level measuring point through the flange 20 to achieve rapid deployment of the device. The spiral blades 16 are arranged at intervals on the outside of the shell along the vertical direction of the underground deformation device shell, which can increase the contact tightness and lateral friction between the device and the surrounding soil, and prevent the underground deformation device from shifting or tilting in the soil. The circular level bubble 13 is embedded in the upper end face of the underground deformation device shell. The operator can calibrate the groundwater level by observing the position of the bubble in the circular level bubble 13. The verticality of the lower deformation device ensures that the piston 18 and underground magnet 15 inside the device can only move longitudinally. The filter cylinder 19 is detachably connected to the lower end of the housing of the underground deformation device. The filter cylinder 19 is located below the piston 18 and can statically intercept large particles of sand and gravel and impurities in the groundwater, while allowing groundwater to seep smoothly into the piston 18, avoiding sand and gravel wear on the piston 18 and affecting the measurement accuracy. The detachable structure also facilitates the cleaning and replacement of the filter cylinder 19 in the later stage. The waterproof and breathable valve 12 is installed through the top side wall of the housing, which can balance the air pressure inside the underground deformation device and the outside in real time, preventing changes in air pressure inside the device from interfering with the movement of the underground magnet 15 and ensuring the accuracy of the measurement.

[0026] like Figure 4 As shown, the limiting post 17 of the underground deformation device is vertically fixed inside its shell. The underground magnet 15 is slidably sleeved on the limiting post 17 and can only move longitudinally along the limiting post 17. The piston 18 is fixedly connected to the lower surface of the underground magnet 15. The spring 14 is sleeved on the limiting post 17, with one end of the spring 14 abutting against the underground magnet 15 and the other end fixedly connected to the inner shell of the underground deformation device. When the groundwater pressure acts on the piston 18, it can push the piston 18 to move upward along the limiting post 17. The piston 18 drives the underground magnet 15 to move longitudinally synchronously and compress the spring 14. The spring 14 generates a deformation that matches the water pressure.

[0027] like Figure 3 As shown, the monitoring base 11 of the monitoring station is horizontally fixed to the ground on the same vertical line as the underground deformation device by expansion bolts. The limiting block 10 protrudes from the upper surface of the monitoring base 11, and the limiting hole 9 of the ground measuring device is opened at its base. The limiting block 10 and the limiting hole 9 are engaged to achieve a firm fixation between the ground measuring device and the monitoring station, effectively preventing the ground measuring device from sliding horizontally during the monitoring process, ensuring that the ground measuring device and the underground deformation device are always on the same vertical line, and ensuring the accuracy of magnetic coupling transmission.

[0028] like Figure 1As shown, the limiting rod 6 of the ground measuring device is arranged vertically. The ground magnet 7 is slidably sleeved on the limiting rod 6 and can only move longitudinally along the limiting rod 6. The shaft end retaining ring 5 is set at the top of the limiting rod 6 to prevent the ground magnet 7 from detaching from the limiting rod 6 during upward movement. The shock-absorbing sheet 8 is laid on the upper surface of the base of the ground measuring device to prevent the ground magnet 7 from having a hard collision when it moves downward to the base, thus preventing damage to the magnet. A reflector is fixedly installed on the upper surface of the ground magnet 7. The two ends of the rigid connecting rod 2 are respectively connected to the scale 1. The laser emitter 4 is fixedly connected so that the scale 1 and the laser incident direction of the laser emitter 4 are parallel. The scale 1, rigid connecting rod 2, angle ruler 3 and laser emitter 4 are all arranged next to the ground magnet 7. The angle ruler 3 is connected to the laser emitter 4 and can detect the angle between the laser emitter 4 and the vertical direction of the ground in real time. The laser emission direction of the laser emitter 4 is towards the reflector on the ground magnet 7. The reflector can reflect the laser and make the reflected laser accurately projected onto the surface of the scale 1, which makes it easy for the staff to read the laser displacement.

[0029] The ground magnet 7 and the underground magnet 15 are arranged with the same pole facing each other, forming a non-contact connection with magnetic coupling. Under the action of magnetic repulsion, the longitudinal movement of the underground magnet 15 along the limiting post 17 will drive the ground magnet 7 to move synchronously longitudinally along its limiting rod 6. When the water pressure at the underground measuring point is stable, the water pressure is equal to the elastic force of the spring 14, and the change in longitudinal displacement of the underground magnet 15 along the limiting post 17 is equal to the deformation of the spring 14 and the change in longitudinal displacement of the ground magnet 7 along the limiting rod 6.

[0030] The groundwater level pressure sensing method of this device is as follows: S1: The underground deformation device is installed at the groundwater level measuring point. It can be fixedly connected to the ground at the measuring point through the flange 20, or the underground deformation device can be directly placed at the groundwater level measuring point through the flange 20. The installation verticality of the underground deformation device is calibrated using the circular bubble 13 on the upper end face of the shell to ensure its vertical layout. The monitoring platform is horizontally fixed to the ground on the same vertical line as the underground deformation device using expansion bolts. The ground measuring device is engaged with the limiting block 10 of the monitoring platform through the limiting hole 9 of its base to fix the ground measuring device and the monitoring platform, thus completing the overall assembly and layout of the device; S2: The water pressure at the groundwater level measuring point acts on the lower surface of the piston 18. When the water pressure is greater than the initial elastic force of the spring 14, The piston 18 is pushed to move longitudinally upward along the limiting column 17 of the underground deformation device. The piston 18 drives the underground magnet 15 to move longitudinally synchronously and compress the spring 14. The ground magnet 7 is subjected to the magnetic repulsion force of the underground magnet 15 and moves longitudinally upward synchronously along the limiting rod 6 of the ground measuring device. When the groundwater level drops, the water pressure decreases, and the elastic force of the spring 14 pushes the underground magnet 15 and the piston 18 to move longitudinally downward. The ground magnet 7 also moves longitudinally downward synchronously. S3: The longitudinal displacement of the ground magnet 7 is detected by the ground measuring device. The specific process is as follows: the laser emitter 4 emits a laser to the reflector on the ground magnet 7. The reflector reflects the laser to the scale 1 and reads the laser displacement x1. The angle θ between the laser emitter 4 and the direction perpendicular to the ground is detected by the angle scale 3. Figure 2 As shown, the vertical displacement x of the ground magnet 7 is calculated according to the principle of displacement change and the formula x=x1cosθ. This displacement x is the deformation of the spring 14. The water pressure at the underground measuring point is calculated by combining the spring force formula F=kx, where k is the spring constant of the spring 14. S4: Based on the derived water pressure and the water pressure strength formula F=ρghA, the formula for calculating the water level elevation at the measuring point is derived as H=h1+(kx1cosθ) / (ρgA). The water level elevation H at the underground measuring point is calculated by substituting the relevant parameters into the formula. Where h1 is the installation elevation of the underground deformation device, ρ is the water density, taken as 1000kg / m³, g is the gravitational acceleration, taken as 9.8N / kg, and A is the effective area of ​​the piston 18 subjected to water pressure.

[0031] Through the above steps, real-time and continuous monitoring of groundwater levels can be achieved. Staff can quickly calculate the water level elevation at the measuring point based on the laser displacement of scale 1 and the angle data of angle scale 3, without complicated operating procedures, thus greatly improving monitoring efficiency.

[0032] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A non-contact groundwater level and pressure sensing device based on magnetic coupling, characterized in that, Includes ground measuring devices, monitoring stations, and underground deformation devices; The underground deformation device is installed at the groundwater level measuring point. The monitoring station is installed on the ground at the same vertical line as the underground deformation device. The ground measuring device is fixed in conjunction with the monitoring station. The ground magnet in the ground measuring device and the underground magnet in the underground deformation device repel each other. The piston of the underground deformation device moves longitudinally under the action of the water pressure at the groundwater level measuring point, which drives the underground magnet to move longitudinally synchronously and compress the spring. The ground magnet moves longitudinally synchronously with the underground magnet under the action of magnetic repulsion. The displacement of the ground magnet is detected by the ground measuring device, and the water pressure at the underground measuring point is calculated to obtain the water level at the measuring point.

2. The non-contact groundwater level and pressure sensing device based on magnetic coupling as described in claim 1, characterized in that, The ground measuring device includes a scale, a rigid connecting rod, an angle gauge, a laser emitter, a limiting rod, a ground magnet, and a limiting hole. The two ends of the rigid connecting rod are fixedly connected to the scale and the laser emitter, respectively, ensuring that the scale and the laser incident direction of the laser emitter are parallel. The angle gauge is connected to the laser emitter and is used to detect the angle between the laser emitter and the direction perpendicular to the ground. A reflector is fixedly installed on the upper surface of the ground magnet, and the laser emission direction of the laser emitter faces the reflector on the ground magnet. The reflected laser light from the reflector is projected onto the scale surface. The limiting rod is arranged vertically, and the ground magnet is slidably fitted onto the limiting rod and can only move longitudinally along the limiting rod. The limiting hole is located at the base of the ground measuring device.

3. The non-contact groundwater level and pressure sensing device based on magnetic coupling as described in claim 2, characterized in that, The ground measuring device includes a shaft end retaining ring and a shock absorber. The shaft end retaining ring is set at the top of the limiting rod, and the shock absorber is laid on the upper surface of the base of the ground measuring device. The scale, rigid connecting rod, angle ruler and laser emitter are all arranged next to the ground magnet.

4. The non-contact groundwater level and pressure sensing device based on magnetic coupling as described in claim 1, characterized in that, The monitoring station includes a limiting block and a monitoring base. The monitoring base is horizontally fixed on the ground, and the limiting block protrudes from the upper surface of the monitoring base. The limiting block engages with the limiting hole of the ground measuring device to fix the ground measuring device to the monitoring station and prevent the ground measuring device from sliding horizontally.

5. The non-contact groundwater level and pressure sensing device based on magnetic coupling as described in claim 1, characterized in that, The underground deformation device includes a waterproof and breathable valve, a spring, an underground magnet, a limiting post, a piston, a filter cylinder, and a flange. The limiting post is vertically arranged inside the underground deformation device. The underground magnet is slidably sleeved on the limiting post and can only move longitudinally along the limiting post. The piston is fixedly connected to the lower surface of the underground magnet. The spring is sleeved on the limiting post, and one end of the spring abuts against the underground magnet. The waterproof and breathable valve is located on the housing. The filter cylinder is located below the piston. The flange is fixedly located at the bottom of the underground deformation device for fixing the underground deformation device.

6. The non-contact groundwater level and pressure sensing device based on magnetic coupling as described in claim 5, characterized in that, The underground deformation device also includes a circular spirit level and spiral blades. The circular spirit level is embedded in the upper end face of the underground deformation device shell and is used to calibrate the installation verticality of the underground deformation device. The spiral blades are arranged at intervals along the vertical direction of the shell to increase the contact tightness with the soil and the lateral friction force. The filter cartridge is detachably connected to the lower end of the underground deformation device shell, and a waterproof and breathable valve is installed on the top side wall of the shell.

7. The non-contact groundwater level and pressure sensing device based on magnetic coupling as described in claim 1, characterized in that, When the water pressure at the underground measuring point is stable, the water pressure is equal to the elastic force of the spring. The change in longitudinal displacement of the underground magnet along the limiting post is equal to the deformation of the spring and the change in longitudinal displacement of the ground magnet along the limiting rod.

8. A non-contact groundwater level and pressure sensing method based on magnetic coupling, implemented using the sensing device described in any one of claims 1-7, characterized in that, Includes the following steps: S1: Install the underground deformation device at the groundwater level measuring point, fix it to the ground at the measuring point through the flange or place it at the groundwater level measuring point, use the circular spirit level to calibrate the verticality of the underground deformation device, fix the monitoring platform horizontally on the ground at the same vertical line as the underground deformation device, fix the ground measuring device to the monitoring platform through the locking fit of the limiting hole and the limiting block, and complete the overall assembly of the device. S2: The water pressure at the groundwater level measuring point acts on the lower surface of the piston, pushing the piston to move longitudinally along the limiting column. The piston drives the underground magnet to move longitudinally synchronously and compress the spring. The ground magnet moves longitudinally synchronously along the limiting rod under the magnetic repulsion of the underground magnet. S3: The longitudinal displacement of the ground magnet is detected by a ground measuring device. The deformation of the spring is obtained based on the displacement, and the water pressure at the underground measuring point is calculated by combining the spring force formula. S4: The water level elevation of the underground measuring point is calculated based on the derived water pressure and water pressure formula.

9. The non-contact groundwater level and pressure sensing device and method based on magnetic coupling as described in claim 8, characterized in that, The specific process of detecting the longitudinal displacement of the ground magnet in step S3 is as follows: a laser is emitted from the laser emitter to the reflector on the ground magnet. The reflector reflects the laser onto the scale and obtains the laser displacement x1. The angle θ between the laser emitter and the direction perpendicular to the ground is detected by the angle ruler. The vertical displacement x of the ground magnet is calculated according to the formula x=x1cosθ, where x is the deformation of the spring.

10. The non-contact groundwater level and pressure sensing device and method based on magnetic coupling as described in claim 8, characterized in that, In step S4, according to the formula The water level elevation H at the measuring point is calculated; where h1 is the installation elevation of the underground deformation device, k is the spring constant, ρ is the water density, g is the gravitational acceleration, and A is the effective area of ​​the piston subjected to water pressure.

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