PHC pipe pile intelligent real-time water level monitoring system and method based on hydrogel sensor
By combining a U-shaped component pre-embedded in the outer wall of the PHC pipe pile with a hydrogel sensor, the compatibility and accuracy issues of water level monitoring during the construction of PHC pipe piles were solved, achieving real-time and low-cost groundwater level monitoring.
Patent Information
- Application Number
- CN202511990148.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-26
- Publication Date
- 2026-04-17
AI Technical Summary
Existing technologies cannot achieve accurate and real-time monitoring of the groundwater level in the soft soil between piles during PHC pipe pile construction. Furthermore, traditional monitoring methods are incompatible with the PHC pipe pile structure, sensors are easily damaged, and costs are high.
A hydrogel sensor based on changes in electrical signals is used. A protective groove is formed by pre-embedding a U-shaped component on the outer wall of the PHC pipe pile to accommodate the hydrogel sensor array. The array is then encapsulated with a high-mechanical-strength protective cover and combined with a water-permeable protective medium to achieve direct and real-time monitoring of the groundwater level.
It enables accurate and real-time monitoring of groundwater levels. The sensors are not easily damaged during construction, reducing installation difficulty and cost, and extending service life.
Smart Images
Figure CN121877140A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of soft soil foundation reinforcement technology, specifically to a PHC pipe pile intelligent real-time water level monitoring system and method based on hydrogel sensors. Background Technology
[0002] PHC pipe piles (prestressed high-strength concrete pipe piles) are deep foundation piles produced in factories using standardized prefabrication techniques with high-strength concrete and prestressing technology. They are widely used in soft soil foundation reinforcement due to their advantages such as high single-pile bearing capacity, consistent and reliable quality, and efficient construction (using static pressure method, environmentally friendly and vibration-free). During soft soil foundation reinforcement construction, the groundwater level plays a crucial role. The fundamental mechanism is that the high pore water pressure generated by a high water level significantly reduces the effective stress of the soil according to the effective stress principle.
[0003] In existing technologies, groundwater level monitoring mainly relies on two core technologies: the observation well method and the pore water pressure gauge method. The observation well method involves drilling a well with a filter to directly measure the groundwater level in equilibrium with the soil within the well. This can be done manually or with automated sensors (such as pressure-type or float-type sensors). The pore water pressure gauge method (currently dominated by high-precision vibrating wire sensors) is more accurate, measuring the pore water pressure at a specific soil depth using sensors embedded in that depth. However, neither of these monitoring methods can be directly integrated with PHC pipe piles. The fundamental reason is firstly, the conflict in structural integrity: PHC pipe piles are prefabricated components that rely on prestressed and high-strength concrete sections for load-bearing capacity. Any monitoring channels or slots pre-installed within the pile will severely damage its cross-section, creating fatal structural defects and causing a sharp decrease in bearing capacity. Secondly, there is extreme incompatibility in construction processes: PHC pipe piles rely on hammer driving or static pressure driving methods. The enormous impact forces, high-frequency vibrations, or compressive friction forces during construction are sufficient to instantly destroy any precision sensors and cables embedded within the pile. Furthermore, traditional observation well methods lack real-time monitoring and are easily damaged during construction; while pore water pressure methods often have high installation requirements and costs, and their measurement of groundwater level relies on the hydraulic formula h=p / γ, measuring the total pore water pressure P, which cannot distinguish between hydrostatic pressure (determined by groundwater level elevation) and excess pore water pressure (caused by external loads such as construction, surcharge, and electroosmotic consolidation). Therefore, it is necessary to develop a new type of monitoring device that can accurately and in real-time monitor the groundwater level of the soft soil between piles during PHC pipe pile construction. Summary of the Invention
[0004] This invention provides an intelligent real-time water level monitoring system for PHC pipe piles based on hydrogel sensors, overcoming the aforementioned problems in the prior art. The system utilizes hydrogel sensors based on changes in electrical signals. During operation, the elevation of the groundwater level can be determined by analyzing the locations of abrupt changes in the sensor impedance values on the vertical array in real time, avoiding the need to measure total pore water pressure and achieving separate, direct measurement of hydrostatic pressure (i.e., groundwater level). Furthermore, this invention uses a U-shaped component pre-embedded along the longitudinal direction of the PHC pipe pile to form a protective groove on the outer wall, housing the hydrogel sensor array. Simultaneously, a protective cover with high mechanical strength and precise pore size encapsulates the sensors, providing robust physical protection and ensuring free infiltration of groundwater. In addition, the protective groove is backfilled with a permeable protective medium, providing additional buffering and mechanical protection for the signal cables and sensors, enabling them to withstand the enormous impact, high-frequency vibration, or compressive friction during pile driving, thus improving their service life. Correspondingly, the present invention also provides a method for intelligent real-time water level monitoring of PHC pipe piles based on hydrogel sensors.
[0005] For the system, the technical solution of this application is as follows:
[0006] A PHC pipe pile intelligent real-time water level monitoring system based on hydrogel sensors includes a PHC pipe pile; the PHC pipe pile is provided with at least one U-shaped component distributed along its length, with the grooved surface of the U-shaped component facing outward, thereby forming a longitudinal mounting groove on the outer wall of the PHC pipe pile; a set of hydrogel sensors are arranged at intervals along the length of the PHC pipe pile in the mounting groove; the hydrogel sensors are connected to a data acquisition instrument outside the PHC pipe pile via signal cables; the data acquisition instrument is connected to a ground base station signal; the hydrogel sensor includes a sensing substrate and interdigitated electrodes disposed on the sensing substrate, the surface of the interdigitated electrodes being coated with a layer of hydrogel; a protective cover is provided outside the mounting groove, and the protective cover is connected to the U-shaped component; the protective cover is provided with a micropore array, and a water-permeable protective medium is filled between the protective cover and the mounting groove.
[0007] Furthermore, both the U-shaped component and the protective cover are made of stainless steel. Stainless steel possesses excellent mechanical strength and corrosion resistance, effectively resisting corrosion from salts, acids, and alkalis in groundwater, thereby extending the service life of the U-shaped component and the protective cover. The protective cover is manufactured using powder metallurgy. Thus, by selecting the powder particle size and shape, and controlling the pressing pressure, sintering temperature, and time, a porous protective structure with specific porosity, interconnected channels, and ideal pore size can be precisely designed. This allows the protective cover to function as both a robust mechanical armor and a functional permeable / ventilated window: groundwater molecules and ions can freely exchange with the hydrogel through the pores, while external soil particles and microorganisms are effectively blocked.
[0008] Furthermore, the depth of the mounting groove is 30–50 mm. This ensures sufficient installation space for the hydrogel sensor without damaging the prestressed main reinforcement of the PHC pipe pile.
[0009] Furthermore, the hydrogel is a PVA hydrogel that has undergone chemical cross-linking treatment. PVA hydrogels have advantages such as strong controllability of mechanical properties, high environmental stability, and low cost, which are conducive to large-scale applications.
[0010] Furthermore, in the aforementioned PHC pipe pile intelligent real-time water level monitoring system based on hydrogel sensors, the data acquisition instrument is a multi-channel AC impedance analyzer, and it establishes a wireless signal connection with the ground base station through a built-in ZigBee wireless transmission module.
[0011] Furthermore, the permeable protective medium can be selected from coarse sand or porous grouting material. Good permeability helps maintain good water permeability channels within the installation trench.
[0012] Furthermore, the protective cover is fixed to the U-shaped component by welding. This results in a high degree of connection strength, improving the overall rigidity and stability of the PHC pipe pile.
[0013] Furthermore, the PHC pipe pile is provided with four U-shaped components evenly spaced along the circumference and distributed along the length direction, thereby forming four longitudinally spaced installation grooves on the outer wall of the PHC pipe pile, which helps to improve monitoring accuracy.
[0014] Compared with the prior art, the PHC pipe pile intelligent real-time water level monitoring system based on hydrogel sensor of the present invention has the following advantages: (1) The monitoring system of the present invention adopts a hydrogel sensor based on the change of electrical signal. Since the conductivity of hydrogel changes significantly, it is insoluble in water and has reversible water absorption-dehydration characteristics, when the hydrogel sensor is below the groundwater level, the hydrogel on its surface absorbs water and swells, and the impedance value drops sharply. When it is above the groundwater level, the hydrogel on its surface remains dry and the impedance value remains high. Thus, by collecting the impedance values of each sensor in real time through the data acquisition instrument and comparing and analyzing the abrupt change position of the impedance value on the vertical array, the elevation of the groundwater level can be accurately and dynamically reflected, realizing the separate and direct measurement of hydrostatic pressure (i.e., groundwater level), and solving the problem of traditional The problem that pore water pressure gauges cannot distinguish between hydrostatic pressure and excess pore water pressure; (2) This invention pre-embeds U-shaped components along the longitudinal direction of PHC pipe piles to form a protective groove (i.e., installation groove) on the outer side wall and accommodates the hydrogel sensor array therein, which reduces the difficulty and cost of installation. At the same time, a protective cover with high mechanical strength and precision aperture is used to encapsulate the sensor, which provides robust physical protection and allows groundwater to freely infiltrate and fully contact the sensor. In addition, the protective groove is backfilled with a permeable protective medium, which provides additional buffer and mechanical protection for the signal cable and sensor, thereby enabling the signal cable and sensor to withstand the huge impact force, high frequency vibration or squeezing friction during the pile driving process, improve their service life, and ensure the high survival rate of the sensing system in harsh construction conditions.
[0015] Regarding the method, the technical solution of this application is as follows:
[0016] A method for intelligent real-time water level monitoring of PHC pipe piles based on hydrogel sensors includes the following steps: Step 1, at least one U-shaped component is pre-embedded along the length of the PHC pipe pile, with the grooved surface of the U-shaped component facing outwards, and at least one longitudinal mounting groove is prefabricated on the outer side wall of the PHC pipe pile; then, multiple hydrogel sensors are fixed in the mounting groove of the PHC pipe pile at predetermined intervals; then, the hydrogel sensors are connected to signal cables; the signal cables are laid along the length of the mounting groove, and the ends are led out from the top of the PHC pipe pile; Step 2, a protective cover is installed on the U-shaped component; the surface of the protective cover is provided with a micropore array and covers the outside of the mounting groove; then, the hydrogel sensors are connected to the mounting groove. Step 3: Backfill the trench with a permeable protective medium to obtain the intelligent PHC pipe pile; Step 4: Transport the intelligent PHC pipe pile to the construction site and use static pressure or hammering method to sink it into the soil until the design elevation is reached; Step 5: Connect the signal cable lead-out line at the top of the PHC pipe pile to the data acquisition instrument; The data acquisition instrument applies a low-amplitude AC excitation signal to the hydrogel sensor at regular intervals and collects the impedance response value of each hydrogel sensor. Then, it analyzes the abrupt change position of the impedance value of the hydrogel sensor located in the same installation trench and sends it to the ground base station; The ground base station determines the elevation of the groundwater level based on the abrupt change position information, thereby realizing the automated real-time monitoring of the groundwater level.
[0017] Furthermore, the preparation method of the hydrogel sensor is as follows: First, interdigitated electrodes are fabricated on the surface of the sensing substrate; then, a small amount of crosslinking agent is added to the PVA solution and stirred evenly, and the mixed solution is coated on the surface of the interdigitated electrodes; after standing for several hours, the mixed solution is cured into a PVA hydrogel coating, and the hydrogel sensor is prepared.
[0018] Compared with existing technologies, the intelligent real-time water level monitoring method for PHC pipe piles based on hydrogel sensors in this application involves setting hydrogel sensors on PHC pipe piles and connecting them to a data acquisition instrument via signal cables. The data acquisition instrument periodically applies low-amplitude AC excitation signals to each sensor and collects impedance response values. When a hydrogel sensor at a certain depth is submerged below the groundwater level, the hydrogel absorbs water and swells, and its internal ionic conductivity increases significantly, causing the impedance value to drop sharply. For sensors located above the groundwater level, the hydrogel is in a dry or shrunken state, exhibiting a high impedance (insulation) state. By analyzing the abrupt changes in impedance of each sensor on the same vertical array and transmitting the data to a ground base station, the data acquisition instrument can determine the elevation of the groundwater level, thereby achieving real-time monitoring of the groundwater level with a high degree of automation. Attached Figure Description
[0019] Figure 1 This is a structural schematic diagram of the intelligent PHC pipe pile in this application;
[0020] Figure 2 yes Figure 1 A top view of the intelligent PHC pipe pile in the project;
[0021] Figure 3 This is a flowchart of the intelligent real-time water level monitoring method for PHC pipe piles based on hydrogel sensors according to this application.
[0022] The labels in the attached diagram are: 1-PHC pipe pile; 2-U-shaped component; 3-hydrogel sensor; 4-signal cable; 5-data acquisition instrument; 6-protective cover; 7-water-permeable protective medium. Detailed Implementation
[0023] The present application will be further described below with reference to the accompanying drawings and embodiments, but this should not be construed as limiting the present application. Contents not described in detail in the following embodiments are all common knowledge in the art.
[0024] To address the problems of incompatibility between existing monitoring equipment and PHC pipe pile driving, low sensor survival rate, and inability to achieve real-time and accurate measurement of water levels around the pile, this invention employs a PVA hydrogel sensor based on changes in electrical signals. During use, a data acquisition instrument analyzes the locations of abrupt changes in the impedance values of sensors on the same vertical array in real time to determine the elevation of the groundwater level, thus resolving the "ambiguity" problem in traditional pore water pressure gauge measurements. Furthermore, this invention integrates the sensor onto the PHC pipe pile body and employs a multi-layered integrated protective structure. A U-shaped steel channel is pre-embedded along the longitudinal direction of the PHC pipe pile to form a protective groove on the outer wall. The sensor is encapsulated with a sintered stainless steel protective cover with high mechanical strength and precise aperture. Simultaneously, coarse sand is backfilled into the groove as a permeable protective medium, enabling the sensor to withstand the enormous impact, high-frequency vibration, or compressive friction during pile driving, thus resolving the "incompatibility" problem between traditional monitoring equipment and PHC pipe pile driving.
[0025] Example 1:
[0026] See Figure 1 and Figure 2The PHC pipe pile intelligent real-time water level monitoring system based on hydrogel sensors in this embodiment includes a PHC pipe pile 1. Four U-shaped components 2 are evenly spaced along the circumference and distributed along the length direction on the PHC pipe pile 1, with the grooved surfaces of the U-shaped components 2 facing outwards, thus forming four spaced longitudinal mounting grooves on the outer wall of the PHC pipe pile 1. The depth of the mounting grooves is 40mm. A set of hydrogel sensors 3 is spaced along the length direction of the PHC pipe pile 1 within the mounting grooves (the number of hydrogel sensors 3 is set according to the actual length of the PHC pipe pile 1; in this embodiment, the spacing between two adjacent hydrogel sensors 3 is 1m). The hydrogel sensors 3 are connected to the PHC pipe pile 1 via signal cables 4. The data acquisition instrument 5 is connected to the outside of the HC pipe pile 1; the data acquisition instrument 5 is connected to the ground base station signal; the hydrogel sensor 3 includes a sensing substrate (a ceramic substrate is used in this embodiment) and interdigital electrodes disposed on the sensing substrate, the surface of the interdigital electrodes is coated with a layer of PVA hydrogel treated by chemical crosslinking; a protective cover 6 is provided outside the mounting groove, and the protective cover 6 is connected to the U-shaped component 2; a micropore array is provided on the protective cover 6, and a water-permeable protective medium 7 (coarse sand is used in this embodiment) is filled between the protective cover 6 and the mounting groove; the data acquisition instrument 5 is a multi-channel AC impedance analyzer, and establishes a wireless signal connection with the ground base station through a built-in ZigBee wireless transmission module.
[0027] In this embodiment, both the U-shaped component 2 and the protective cover 6 are made of stainless steel. Stainless steel has good mechanical strength and corrosion resistance, and can effectively resist corrosion from salt, acid, and alkali substances in groundwater, thereby improving the service life of the U-shaped component 2 and the protective cover 6.
[0028] Furthermore, the protective cover 2 and the U-shaped component 2 are fixed together by welding. This ensures a high degree of connection strength, improving the overall rigidity and stability of the PHC pipe pile 1.
[0029] Furthermore, the protective cover 6 is manufactured using a powder metallurgy process.
[0030] Example 2:
[0031] See Figure 3 The intelligent real-time water level monitoring method for PHC pipe piles based on hydrogel sensors in this embodiment includes the following steps.
[0032] Step 1, preparation of hydrogel sensor: First, interdigitated electrodes are fabricated on the surface of a sensing substrate (such as a ceramic substrate); then, a small amount (such as 5%) of crosslinking agent (such as borax) is added to a PVA (polyvinyl alcohol) solution and stirred evenly, and then the mixed solution is coated on the surface of the interdigitated electrodes; after standing for several hours, the mixed solution is cured into a PVA hydrogel coating, and the preparation of hydrogel sensor 3 is completed.
[0033] Step 2, PHC pipe pile prefabrication and sensor array integration: First, at least one U-shaped component 2 (such as a U-shaped steel channel) is pre-embedded along the length of the PHC pipe pile 1, with the groove surface of the U-shaped component 2 facing outwards, forming at least one longitudinal installation groove on the outer side wall of the PHC pipe pile 1; then, according to the monitoring design requirements, multiple hydrogel sensors 3 prepared in Step 1 are fixed in the installation groove of the PHC pipe pile 1 at predetermined intervals (e.g., 1 meter); then, the hydrogel sensors 3 are connected to the signal cable 4 (e.g., welded and subjected to strict waterproof insulation treatment); the signal cable 4 is laid along the length of the installation groove, and its end is led out from the top of the PHC pipe pile 1 (a terminal block can be set at the top to gather all the leads on the terminal block).
[0034] Step 3, Protective Treatment: A sintered stainless steel protective cover 6 is welded onto the U-shaped component 2 and placed over the installation trench. The protective cover 6 has a precise porous structure (pore size approximately 20µm; prepared using powder metallurgy by controlling powder particle size and sintering pressure). Its function is to allow groundwater and dissolved ions to freely infiltrate and contact the hydrogel; simultaneously, its high mechanical strength and small pore size effectively block soil particles, gravel, and other impurities from entering, preventing the hydrogel from being worn, scratched, or blocked during pile driving and long-term use. Then, a permeable protective medium 7 (such as coarse sand) is backfilled into the installation trench to obtain the intelligent PHC pipe pile. The function of the permeable protective medium 7 is to provide additional buffering and mechanical protection for the cables and sensors during pile driving, preventing them from being damaged under pressure; at the same time, its permeability ensures that groundwater around the pile can pass through the permeable protective medium 7 and reach the hydrogel sensor 3.
[0035] Step 4, PHC pipe pile driving construction: The intelligent PHC pipe piles produced in Step 3 are transported to the construction site and driven into the soil using the static pressure method until the design elevation is reached. Since the sensors and cables are all housed within the robust pre-embedded U-shaped component 2, and are protected by a sintered stainless steel protective cover 6 and a permeable protective medium 7, they can effectively resist high-frequency vibrations, huge impacts, or compressive friction during the pile driving process, ensuring a high survival rate of the sensing system.
[0036] Step 5, System Connection and Monitoring Startup: After the PHC pipe pile 1 is driven and stabilized, connect the signal cable 4 at its top to the data acquisition instrument 5 (such as a multi-channel AC impedance analyzer; installed in a protective box on the ground or pile top); the data acquisition instrument 5 applies a low-amplitude AC excitation signal (such as 100mV @ 1kHz) to the hydrogel sensor 3 according to a preset program (such as every hour), and collects the impedance response value of each hydrogel sensor 3. Then, it analyzes the abrupt change location of the impedance value of the hydrogel sensors 3 located on the same vertical array (i.e., in the same mounting slot) (when the hydrogel sensor 3 is submerged below the groundwater level, the hydrogel absorbs water and swells, and its internal ionic conductivity increases significantly, resulting in a decrease in impedance value; when the hydrogel sensor 3 is above the groundwater level, the hydrogel is in a dry or shrinking state, exhibiting a high impedance value), and sends the data to the ground base station (or remote monitoring center) through the built-in ZigBee wireless transmission module; the ground base station determines the elevation of the groundwater level based on the abrupt change location information, thereby realizing automated real-time monitoring of the groundwater level.
[0037] The foregoing general description of the invention and its specific embodiments should not be construed as a limitation on the technical solution of the invention. Those skilled in the art, based on the disclosure of this application, can add, reduce, or combine the disclosed technical features in the foregoing general description and / or specific embodiments (including examples) without departing from the constituent elements of the invention, to form other technical solutions within the scope of protection of this application.
Claims
1. A PHC pile intelligent real-time water level monitoring system based on a hydrogel sensor, characterized in that: The system includes a PHC pipe pile (1); the PHC pipe pile (1) is provided with at least one U-shaped component (2) distributed along the length direction, and the groove surface of the U-shaped component (2) faces outward, thereby forming a longitudinal installation groove on the outer side wall of the PHC pipe pile (1); a set of hydrogel sensors (3) are provided at intervals along the length direction of the PHC pipe pile (1) in the installation groove; the hydrogel sensors (3) are connected to a data acquisition instrument (5) outside the PHC pipe pile (1) through a signal cable (4); the data acquisition instrument (5) is connected to a ground base station signal; the hydrogel sensor (3) includes a sensing substrate and interdigitated electrodes provided on the sensing substrate, and the surface of the interdigitated electrodes is coated with a layer of hydrogel; a protective cover (6) is provided outside the installation groove, and the protective cover (6) is connected to the U-shaped component (2); the protective cover (6) is provided with a micropore array, and a water-permeable protective medium (7) is filled between the protective cover (6) and the installation groove.
2. The hydrogel sensor-based PHC pile intelligent real-time water level monitoring system according to claim 1, characterized in that: Both the U-shaped component (2) and the protective cover (6) are made of stainless steel, and the protective cover (6) is made by powder metallurgy.
3. The hydrogel sensor-based PHC pile intelligent real-time water level monitoring system according to claim 1, characterized in that: The depth of the mounting groove is 30-50mm.
4. The hydrogel sensor-based PHC pile intelligent real-time water level monitoring system according to claim 1, characterized in that: The hydrogel is a PVA hydrogel that has been chemically crosslinked.
5. The hydrogel sensor-based PHC pile intelligent real-time water level monitoring system according to claim 1, characterized in that: The data acquisition instrument (5) is a multi-channel AC impedance analyzer, and it establishes a wireless signal connection with the ground base station through the built-in ZigBee wireless transmission module.
6. The hydrogel sensor-based PHC pile intelligent real-time water level monitoring system according to claim 1, characterized in that: The permeable protective medium (7) is coarse sand or porous grouting material.
7. The intelligent real-time water level monitoring system for PHC pipe piles based on hydrogel sensors according to claim 2, characterized in that: The protective cover (2) is fixed to the U-shaped component (2) by welding.
8. The intelligent real-time water level monitoring system for PHC pipe piles based on hydrogel sensors according to claim 1, characterized in that: The PHC pipe pile (1) is provided with four U-shaped components (2) evenly spaced along the circumference and distributed along the length direction, thereby forming four longitudinally spaced installation grooves on the outer side wall of the PHC pipe pile (1).
9. A method for intelligent real-time water level monitoring of PHC pipe piles based on hydrogel sensors, characterized in that, Includes the following steps: Step 1: At least one U-shaped component (2) is pre-embedded along the length of the PHC pipe pile (1), with the groove surface of the U-shaped component (2) facing outwards, and at least one longitudinal mounting groove is prefabricated on the outer side wall of the PHC pipe pile (1); then, multiple hydrogel sensors (3) are fixed in the mounting groove of the PHC pipe pile (1) at predetermined intervals; then, the hydrogel sensors (3) are connected to the signal cable (4); the signal cable (4) is laid along the length of the mounting groove, and its end is led out from the top of the PHC pipe pile (1); Step 2: Install a protective cover (6) on the U-shaped component (2); the surface of the protective cover (6) is provided with a micropore array and covers the outside of the installation groove; then, backfill the installation groove with a permeable protective medium (7) to obtain the intelligent PHC pipe pile; Step 3: Transport the intelligent PHC pipe piles to the construction site and use static pressure or hammering methods to sink them into the soil until they reach the design elevation. Step 4: Connect the signal cable lead-out line at the top of the PHC pipe pile (1) to the data acquisition instrument (5); the data acquisition instrument (5) applies a low-amplitude AC excitation signal to the hydrogel sensor (3) at regular intervals, and collects the impedance response value of each hydrogel sensor (3). Then, it analyzes the abrupt change position of the impedance value of the hydrogel sensor (3) located in the same installation trench and sends it to the ground base station; the ground base station determines the elevation of the groundwater level based on the abrupt change position information, thereby realizing the automated real-time monitoring of the groundwater level.
10. The intelligent real-time water level monitoring method for PHC pipe piles based on hydrogel sensors according to claim 9, characterized in that, The preparation method of the hydrogel sensor (3) is as follows: First, interdigitated electrodes are made on the surface of the sensing substrate; then, a small amount of crosslinking agent is added to the PVA solution and stirred evenly, and then the mixed solution is coated on the surface of the interdigitated electrodes; after standing for several hours, the mixed solution is cured into a PVA hydrogel coating, and the hydrogel sensor (3) is prepared.