Real-time monitoring and early warning system and method for upstream face infiltration conditions of water conservancy projects

Abstract

The application discloses a real-time monitoring and early warning system for upstream surface infiltration conditions of water conservancy projects, which comprises an alternating electric field supply system and an electric signal acquisition system. The alternating electric field supply system comprises a power supply device capable of providing an alternating electric field and upstream and downstream electrode arrays respectively floating on the surfaces of upstream and downstream water bodies. The electric signal acquisition system comprises an acquisition instrument and a signal sensing system. The signal sensing system is installed and closely attached to the upstream infiltration surface of the water conservancy project. The acquisition instrument transmits the collected voltage and current signals to a server through a wired or wireless mode. A processing system installed on a computer, a mobile phone or other user terminals can realize real-time signal receiving, processing, display and abnormal alarm. The application can realize real-time monitoring and early warning of the upstream surface infiltration conditions of the water conservancy project, can timely find and locate the leakage position and determine the leakage amount, and has the characteristics of simple structure, convenient operation, technical popularization and scientific research.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of detecting the seepage condition of water conservancy projects such as embankments, dams, cofferdams, etc., and in particular to a real-time monitoring and early warning system and method for the infiltration condition of the upstream face of a water conservancy project. BACKGROUND

[0002] Seepage state is an important characterization of embankment behavior. Due to factors such as embankment animals and construction quality, water conservancy projects such as embankments, dams and cofferdams generally have seepage phenomena. When seepage is normal, the seepage of the embankment is small within the design calculation range; when there is a leak, a seepage channel is easily formed in the embankment, and the seepage is large. Seepage damage to water conservancy projects can cause serious consequences, as the flood caused by embankment, dam and cofferdam breaches will submerge a large amount of farmland downstream, destroy civil infrastructure, and in severe cases, cause huge loss of life and bring great disaster to society.

[0003] Previous studies have shown that water conservancy projects, especially earth and rock embankment projects, usually exhibit a gradual damage phenomenon from the downstream to the upstream, and when the seepage inlet is formed in the upstream, if it is not found and plugged in time, it is likely to lead to an uncontrollable and difficult-to-control situation. When the seepage inlet is formed, it will cause a sharp change in seepage velocity and seepage volume, and if the increase process can be detected and located, it will be very helpful for the development of emergency rescue work.

[0004] The water-electric analogy method is a commonly used method for drawing seepage flow fields in the field of hydraulic engineering, which mainly relies on the similarity between seepage fields and electric fields. The relevant theory is described in "Electrical Simulation Test and Seepage Research" (Mao Changxi, 1981). For the purpose of understanding the idea of the present application, the relevant parameters of seepage fields and electric fields are listed in Table 1. As can be seen from Table 1, under the condition that the boundary conditions are as similar as possible, the parameters of the electric field can be used to represent the parameters of the seepage field. For example, when the water surface on the upstream and the water surface on the downstream of the electric field are subjected to electric potentials u and 0 electric potential respectively, the seepage velocity v can be represented by the current density i, and the seepage volume Q can be represented by the current intensity I. Conversely, the greater the seepage velocity v, the greater the current density i, and the greater the seepage volume Q, the greater the current intensity I.

[0005] Table 1 Comparison of relevant parameters of seepage fields and electric fields

[0006]

[0007]

[0008] The Hall coil or Hall current sensor is made according to the principle of the Hall effect, the Hall element is vertically placed in the magnetic field, and when the current end is connected to the current, a potential difference will be generated in the direction perpendicular to the current and the magnetic field, and the size is proportional to the magnetic flux density. The conductor around the conductor will generate a magnetic field related to the current size of the conductor. The size of the potential difference measured by the Hall coil can calculate the current size in the conductor.

[0009] The Rogowski coil is a current detection sensor made based on Faraday's law of electromagnetic induction and Ampere's law, which can detect the size of the current in the closed loop, and is suitable for alternating electric field current collection.

[0010] According to the above technical principle, a specific device is made to collect electric field distribution and current distribution signals, and then to infer the infiltration condition of the detected area to realize abnormal leakage monitoring and early warning. SUMMARY

[0011] The purpose of the present application is to provide a real-time monitoring and early warning system and method for upstream face infiltration condition of water conservancy project, which can clearly determine the upstream face infiltration condition of water conservancy project, clearly determine the leakage entrance position and determine the leakage amount, and provide guidance for emergency rescue.

[0012] In order to solve the above technical problems, the present application discloses a real-time monitoring and early warning system for upstream face infiltration condition of water conservancy project, which comprises an alternating electric field supply system and an electric signal collection system, wherein,

[0013] The alternating electric field supply system comprises a power supply device, an upstream electrode array and a downstream electrode array, the upstream electrode array and the downstream electrode array are arranged on the upstream water surface and the downstream water surface of the water conservancy project to be detected respectively, and the power supply device is connected with the electrodes in the upstream electrode array and the downstream electrode array respectively to form a detection loop and transmit current signals to the collection instrument.

[0014] The electric signal collection system comprises a collection instrument and a signal sensing system, the signal sensing system is arranged on the upstream infiltration surface of the water conservancy project, and comprises a signal sensing electrode group and a coil group; the signal sensing electrode group is used for sensing voltage signals and transmitting the voltage signals to the collection instrument; the coil group is a Hall coil made according to the principle of the Hall effect or a Rogowski coil made according to Faraday's law of electromagnetic induction and Ampere's law, which can collect the current passing through the plane of the coil in the coil and transmit the current to the collection instrument, and the coil group covers the entire detection area.

[0015] Preferably, the monitoring and early warning system further comprises a server 4 and a processing system 5; the server is used for collecting the information collected by the collection instrument; the processing system is used for receiving the data signals of the download server (4) and performing signal processing, display and abnormal alarm.

[0016] The upstream or downstream electrode array includes a power supply positioning grid, a power transmission system, a power supply electrode group, and a float group. The power supply electrode groups of the upstream and downstream electrode arrays are connected to the output terminal and grounding terminal of the power supply equipment, respectively, through the power transmission system. The positioning grid is used to install and position the electrode group; the power supply electrode group is an array composed of a series of electrodes; the float group is an array composed of individual floats, each float positioned above an electrode for floating, ensuring the electrode group is in contact with the water surface but does not sink or submerge. The floats can be fixed to the electrodes by binding or other securing methods.

[0017] The power supply equipment provides an alternating electric field for the water conservancy project through upstream and downstream electrode arrays.

[0018] The power supply positioning grid and the float group are insulators or good conductors; the power transmission system and the power supply electrode group are both good conductors.

[0019] The purpose of the electrode array is to ensure that the upstream and downstream water surfaces have the same potential under power supply conditions. For example, when a 5V voltage is supplied, the upstream water surface is at 5V, while the downstream water surface is at 0V. The electric field attenuates in the water and within the dam body, for example, attenuating from 5V to 4V, then to 2V, and finally to 0V. Therefore, the denser the arrangement of the power supply electrodes in the electrode array, the more likely the water surfaces will be at the same potential. Hence, it is required that the power supply positioning grid and float group be insulators or good conductors, and the power transmission system and power supply electrode group be good conductors, in order to ensure that the upstream and downstream water surfaces have the same potential.

[0020] In one embodiment, the electrode group can be selected as a square arrangement with a spacing of (1 / 5 to 1 / 10)l, where l = s 0.5 , where s is the area covered by the upstream electrode array.

[0021] The signal sensing system includes a signal sensing positioning grid, a signal sensing electrode group, a signal cable, a coil group, a coil cable, and a counterweight. The signal cable serves as the voltage signal transmission medium between the signal sensing electrode group and the data acquisition instrument, and is insulated from the water. The signal sensing electrode group is in contact with the water and is used to collect voltage signals in the water. The coil cable serves as the electrical signal transmission medium between the coil group and the data acquisition instrument. The coil group is connected to the data acquisition instrument via the coil cable and is insulated from the water. The counterweight is used to submerge the signal sensing system on the bottom of the water and to ensure it is close to the upstream infiltration surface of the water conservancy project.

[0022] Specifically, each electrode collects a potential difference signal and transmits it to the acquisition instrument. The potential difference is a relative value, and the potential collected by the signal sensing electrode group is relative to the downstream electrode array. The acquisition instrument is further connected to the downstream electrode array.

[0023] Preferably, the signal sensing positioning grid, signal cable, and counterweight are insulators, and the signal sensing electrode group is a good conductor.

[0024] The coils in the coil group are arranged independently, closely, and without overlap, covering the entire area to be tested.

[0025] In one implementation, the data acquisition device transmits the current information, voltage signals sensed by the signal sensing electrode group, and current signals sensed by the coil group from the alternating electric field supply system circuit to the server via wireless or wired means.

[0026] This invention further proposes a method for real-time monitoring and early warning of infiltration conditions on the upstream face of a water conservancy project using the aforementioned monitoring and early warning system, comprising the following steps:

[0027] a. For water conservancy projects that need to be inspected, draw a plan based on the design or measured engineering data, and draw the area to be monitored;

[0028] b. A signal sensing system is deployed on the upstream infiltration surface of the water conservancy project in the area to be monitored, and upstream and downstream electrode arrays are set up on the upstream and downstream horizontal planes respectively. The coil group of the signal sensing group should cover the entire monitoring area, and the coverage range of the upstream electrode array should exceed the range of the signal sensing system projected on the upstream water surface. At the same time, a water measuring weir is set up downstream, which can obtain the seepage value of the dam in real time. The upstream and downstream electrode arrays are connected to the power supply equipment, and the signal sensing system is connected to the data acquisition instrument.

[0029] c. Start the power supply equipment and data acquisition instrument. The data acquisition instrument will transmit the current information, voltage signals sensed by the signal sensing electrode group, and current signals sensed by the coil group in the alternating electric field supply system circuit to the server wirelessly or via wired means. The power supply voltage is determined through experiments. Generally, large projects require large voltages and currents, while small model experiments require smaller ones.

[0030] d. The processing system downloads and analyzes the data from the server to determine the upstream infiltration status and issues an alarm when abnormal data is detected.

[0031] The data processing steps include:

[0032] Step 1: Obtain the leakage amount Q(t) at time t based on the measuring weir. This value represents the total leakage.

[0033] Step 2: Obtain the potential u of all electrodes (assuming there are n electrodes in total) at time t based on the signal sensing electrode group. i (t), find its average value according to formula (1-1) The relative potential difference is calculated using the following formula (1-2):

[0034]

[0035]

[0036] Plot the relative potential difference Δu in the monitoring area i Planar distribution diagram of (t);

[0037] Step 3: Obtain the current I collected by each coil at time t based on the coil group. j (t), combined with the total current I(t) in the alternating electric field supply system circuit collected by the data acquisition instrument, the leakage in the j-th coil is calculated according to formula (1-3), and the ratio η of the leakage in the j-th coil to the total leakage is calculated according to formula (1-4). j :

[0038]

[0039]

[0040] Plot the leakage rate Q in the monitored area j (t) and η j (t) distribution plot;

[0041] Step 4: Implement alarm procedures in stages. When the relative potential difference Δu between the electrodes... i (t) shows a clustering of negative values, or the leakage Q in this area j When (t) is large, it indicates a potential vulnerability, triggering a level two alarm. Close monitoring of data changes is crucial for emergency response preparation. When the relative potential difference Δu between the electrodes is large... i (t) shows a clustering of negative values, and the leakage rate Q in this area is also present. j When (t) is large, it indicates that the vulnerability has been penetrated, triggering a level one alarm, removing the monitoring equipment, and starting to seal the area with clay or other materials.

[0042] Step 5: After the sealing is completed, install a monitoring system to continue monitoring and early warning.

[0043] Beneficial effects: Compared with the prior art, the present invention can realize real-time monitoring and early warning of infiltration status on the upstream surface of water conservancy projects, can promptly detect and locate the location of leakage loopholes, determine the leakage amount, and provide quantitative guidance for scientifically locating, finding and sealing loopholes. It has the characteristics of simple structure, easy operation, and is conducive to technology promotion and scientific research. Attached Figure Description

[0044] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, and the advantages of the present invention in the above and / or other aspects will become clearer.

[0045] Figure 1 This is a cross-sectional schematic diagram of the application scenario of this invention;

[0046] Figure 2 This is a schematic diagram of the plan layout of the alternating electric field supply system of the present invention;

[0047] Figure 3 This is a typical cross-sectional schematic diagram of the alternating electric field supply system of the present invention at the upstream water surface;

[0048] Figure 4 This is a schematic diagram of the planar layout of the electrical signal acquisition system of the present invention;

[0049] Figure 5 This is a schematic cross-sectional view of the electrode section of the electrical signal acquisition system of the present invention;

[0050] Figure 6 This is a schematic diagram illustrating the connection logic between the signal sensing electrode group and the data acquisition instrument of this invention;

[0051] Figure 7 This is a schematic diagram illustrating the connection logic between the coil group and the data acquisition instrument of this invention;

[0052] Figure 8 This is a schematic diagram of the earth dam test model structure of the present invention;

[0053] Figure 9 This is a planar distribution diagram of the relative potential difference of the earth dam test model of the present invention;

[0054] Figure 10 This is a planar distribution diagram of the leakage volume and leakage ratio of the earth dam test model of the present invention;

[0055] In the diagram, 1. Dam; 11. Dam body; 12. Upstream water surface; 13. Downstream water surface; 14. Upstream infiltration surface; 15. Infiltrated surface; 16. Measuring weir; 17. Seepage channel; 2. Alternating electric field supply system; 21. Power supply equipment; 22. Upstream electrode array; 23. Downstream electrode array; 221. Power supply positioning grid; 222. Power transmission system; 223. Power supply electrode group; 224. Float group; 3. Electrical signal acquisition system; 31. Acquisition instrument; 32. Signal sensing system; 321. Signal sensing positioning grid; 322. Signal sensing electrode group; 323. Signal cable; 324. Coil group; 325. Coil cable; 326. Counterweight; 4. Server; 5. Processing system. Detailed Implementation

[0056] Specific embodiments of the invention will now be described in more detail. While specific embodiments of the invention are shown in the accompanying drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the invention and to fully convey the scope of the invention to those skilled in the art.

[0057] As used throughout the specification and claims, the terms "comprising" or "including" are open-ended and should be interpreted as "including but not limited to". The following descriptions are preferred embodiments for carrying out the invention; however, these descriptions are for the purpose of understanding the general principles of the specification and are not intended to limit the scope of the invention. The scope of protection of this invention is determined by the appended claims.

[0058] This application provides a real-time monitoring and early warning system for infiltration conditions on the upstream face of a water conservancy project, including an alternating electric field supply system 2, an electrical signal acquisition system 3, a server 4, and a processing system 5.

[0059] The alternating electric field supply system 2 includes a power supply device 21, an upstream electrode array 22, and a downstream electrode array 23. The power supply device 21 can generate an alternating electric field; the upstream electrode array 22 includes a power supply positioning grid 221, a power transmission system 222, a power supply electrode group 223, and a group of floats 224; the power supply positioning grid 221 can be an insulator or a good conductor; the power transmission system 222 and the power supply electrode group 223 are both good conductors; the group of floats 224 can be an insulator or a good conductor, and it provides buoyancy, so that the upstream electrode array 22 and the downstream electrode array 23 float on the upstream water surface 12 and the downstream water surface 13, respectively.

[0060] The upstream electrode array 22 and the downstream electrode array 23 are connected to the output terminal and ground terminal of the power supply equipment 21 through the power transmission system 222, respectively.

[0061] The downstream electrode array 23 is configured to be the same as the upstream electrode array 22.

[0062] After the alternating electric field supply system 2 is turned on, the power supply equipment 21 provides an alternating electric field to the dam through the upstream electrode array 22 and the downstream electrode array 23.

[0063] The electrical signal acquisition system 3 includes an acquisition instrument 31 and a signal sensing system 32. The acquisition instrument 31 can acquire current information in the circuit of the alternating electric field supply system 2 in real time using either a series contact method or a non-contact method such as a Hall coil or Rogowski coil. The signal sensing system 32 includes a signal sensing positioning grid 321, a signal sensing electrode group 322, a signal cable 323, a coil group 324, a coil cable 325, and a counterweight 326. The signal sensing positioning grid 321 and counterweight 326 are insulators; the signal sensing electrode group 322 is a good conductor used to acquire voltage signals in the water; the signal cable 323 serves as the electrical signal transmission medium between the signal sensing electrode group 322 and the acquisition instrument 31, and is insulated from the water. The acquisition instrument 31 has the function of acquiring current information in the circuit of the alternating electric field supply system 2, voltage signals sensed by the signal sensing electrode group 322, and current signals sensed by the coil group 324.

[0064] Coil group 324 consists of Hall coils based on the Hall effect principle or Rogowski coils based on Faraday's law of electromagnetic induction and Abe's circuital law. Insulated from water, these coils can collect the current passing through their plane. The coils in coil group 324 are arranged independently, closely, and without overlap, covering the entire area to be measured.

[0065] The coil cable 325 serves as the electrical signal transmission medium between the coil group 324 and the data acquisition instrument 31, and is insulated from the water.

[0066] The ballast block 326 provides gravity, causing the signal sensing system 32 to sink to the bottom of the water and adhere closely to the upstream infiltration surface 14 of the water conservancy project.

[0067] Under the action of the alternating electric field provided by the upstream electrode array 22, the signal sensing electrode group 322 can sense the alternating voltage signal and transmit it to the acquisition instrument 31 through the signal cable 323. The other end of the acquisition instrument 31 is connected to the downstream electrode array 23, so that the voltage signal sensed by the signal sensing system 32 is a relative value.

[0068] Under the influence of the alternating electric field provided by the upstream electrode array 22, the coil group 324 can generate an induced current according to the principle of electromagnetic induction. The induced current is transmitted to the data acquisition instrument 31 through the coil cable 325.

[0069] Server 4 can collect signals emitted by acquisition device 31 via wireless or wired transmission.

[0070] The processing system 5 is installed on user terminals such as computers and mobile phones to receive, process, display, and alarm for abnormalities.

[0071] In practical use, firstly, for the dam project that needs to be monitored, draw a plan based on the design or measured engineering data, and draw the area to be monitored. The signal sensing system 32 should cover the entire monitoring area, and the coverage of the upstream electrode array 22 should exceed the range of the signal sensing system 32 projected on the upstream water surface 12.

[0072] Secondly, upstream and downstream electrode arrays 22 and 23 and signal sensing system 32 are manufactured. The arrangement of power supply electrode group 223 and signal sensing electrode group 322 is arranged according to the monitoring accuracy and requirements. Coil group 324 should cover the entire monitoring area.

[0073] Then, the signal sensing system 32 is submerged in water, close to the upstream infiltration surface 14 of the water conservancy project, and connected to the data acquisition instrument 31. The upstream and downstream electrode arrays 22 and 23 are placed on the upstream and downstream horizontal surfaces 12 and 13, respectively, and connected to the power supply equipment 21.

[0074] Then, power supply equipment 21 and data acquisition device 31 are started. Data acquisition device 31 transmits the current information, voltage signal sensed by signal sensing electrode group 322 and current signal sensed by coil group 324 in the circuit of alternating electric field supply system 2 to server 4 in a wireless or wired manner.

[0075] Finally, after the data is downloaded to user devices such as laptops and mobile phones, it is analyzed using processing system 5 to clarify the upstream infiltration status and trigger alarms when abnormal data is detected. The data processing steps include:

[0076] Step 1: Obtain the leakage amount Q(t) at time t based on the water measuring weir 16. This value represents the total leakage amount.

[0077] Step 2: Obtain the potential u of all electrodes (assuming a total of n) at time t based on the signal sensing electrode group 322. i (t), find its average value according to formula (1-1) The relative potential difference is calculated using the following formula (1-2):

[0078]

[0079]

[0080] Plot the relative potential difference Δu in the monitoring area i Planar distribution diagram of (t);

[0081] Step 3: Obtain the current I collected by each coil at time t based on coil group 324. j (t), combined with the total current I(t) in the alternating electric field supply system 2 circuit collected by the data acquisition instrument, the leakage in the j-th coil is calculated according to formula (1-3), and the ratio η of the leakage in the j-th coil to the total leakage is calculated according to formula (1-4). j :

[0082]

[0083]

[0084] Plot the leakage rate Q in the monitored area j (t) and η j (t) distribution plot;

[0085] Step 4: Implement alarm procedures in stages. When the relative potential difference Δu between the electrodes... i (t) shows a clustering of negative values, or the leakage Q in this area j When (t) is large, it indicates a potential vulnerability, triggering a level two alarm. Close monitoring of data changes is crucial for emergency response preparation. When the relative potential difference Δu between the electrodes is large... i(t) shows a clustering of negative values, and the leakage rate Q in this area is also present. j When (t) is large, it indicates that the vulnerability has been penetrated, triggering a level one alarm, removing the monitoring equipment, and starting to seal the area with clay or other materials.

[0086] Step 5: After the sealing is completed, install a monitoring system to continue monitoring and early warning.

[0087] The application scenarios of this application are illustrated below through detailed embodiments.

[0088] Example 1

[0089] A test model of an earth dam has an axis length of approximately 0.45m, a maximum height of 0.5m, a crest width of 5cm, and slope ratios of 1:1 for both the upstream and downstream slopes. The maximum water depth in front of the dam is 0.3m. The base of the earth dam is a concrete structure, while the dam body is made of clay with a maximum dry density of 1.78g / cm³. 3 The optimum moisture content was 15.5%, and the compaction degree was controlled at 0.95. A seepage channel was simulated by wrapping coarse sand and clay with geotextile, with a mass ratio of coarse sand to clay of 1:1, and the mixture was homogeneous. The seepage channel had a diameter of 1 cm and was buried in the earthen dam. The upstream elevation of the seepage channel was 0.15 m above the riverbed, and the downstream elevation was 0.1 m above the riverbed. A 0.05 m high measuring weir was placed downstream of the dam to measure the seepage volume. A schematic diagram of the earthen dam test model layout is shown below. Figure 8 .

[0090] The upstream infiltration surface 14 of the earth dam test model has a length of 0.45m, the same as the dam axis, and a width of 0.42m. The upstream infiltration surface 14 is divided into rectangles 0.15m long and 0.14m wide. Sixteen signal sensing electrodes are arranged at the corners of the rectangles, numbered as follows: Figure 6 As shown, the electrodes of the signal sensing electrode group 322 are copper pillars, 1 cm long and 0.5 cm in diameter. The coil group 324 consists of nine flexible coils, each 0.15 m long and 0.14 m wide, numbered as shown in the diagram. Figure 7 As shown, the upstream infiltration surface 14 is covered. The flexible coil is a high-precision Rogowski coil with a coil diameter of 2mm, a bandwidth of 10MHz, and a measurement accuracy of mA level.

[0091] Power is supplied to the upstream electrode array 22 located on the upstream water surface 12 and the downstream electrode array 23 located on the downstream water surface 13 via power supply equipment 21. The upstream electrode array 22 has a length of 0.45m along the dam axis and a width of 0.45m, satisfying the requirement that "the coverage area of ​​the upstream electrode array 22 should exceed the projection range of the signal sensing system 32 on the upstream water surface 12". The power supply electrodes of the power supply electrode group 223 are copper columns with a length of 1cm and a diameter of 0.5cm, arranged in a square with a spacing of 5cm. Plastic foam boards are used as floats. The supplied electric field waveform is a sine wave with a frequency of 1kHz.max =30V, V p =5V.

[0092] After one day of water storage, water flow was observed in the canal behind the dike. The flow rate measured by the measuring weir was 36 ml / s, and the maximum current of the circuit was 0.822 A at this time. After three days of water storage, the flow rate of the measuring weir increased to 52 ml / s, and the maximum current of the circuit was 1.193 A at this time. Real-time monitoring was performed using the system described in this paper, and the maximum voltage u sensed by the signal sensing electrodes was statistically analyzed. i (i = 1, 2, ..., 16), calculate the relative potential difference Δu. i (t), see the relative potential difference distribution plane diagrams for 1 day and 3 days. Figure 9 The figures in the graph are in units of V, showing the distribution of leakage volume and percentage across the nine monitoring areas. Figure 10 .

[0093] from Figure 9 It can be seen from the relative potential difference distribution diagram that when a leakage channel exists, the monitoring results from 1d and 3d show that there is a relatively obvious leakage in the area enclosed by A22, A32, A33, and A23, which is close to the leakage inlet location set in the experiment. At the same time, the monitoring from 1d to 3d also shows that the leakage is intensifying.

[0094] from Figure 10 It can be seen that at day 1, the total leakage measured by the coil group was 34.96 ml / s, accounting for 97.1% of the total leakage. The largest leakage was observed in the O5 region, at 7.15 ml / s, accounting for 19.9% ​​of the total leakage. At day 3, the total leakage measured by the coil group was 49.33 ml / s, accounting for 94.9% of the total leakage. The largest leakage was still observed in the O5 region, at 12.50 ml / s, accounting for 24.0% of the total leakage. This percentage increased compared to day 1, indicating that the leakage had intensified. Figure 10 The statistical results show that although the coil group is tightly arranged, there are still some currents that cannot be captured, but the current loss is small and does not affect the overall leakage situation analysis.

[0095] from Figure 9 and Figure 10 It can be seen that when the relative potential difference between the electrodes is Δu i (t) shows a clustering of negative values, and the leakage rate Q in this area is also present. j If (t) is large, it indicates that the vulnerability has been penetrated, and a level one alarm should be triggered.

[0096] The relative potential difference calculation method and leakage calculation method involved in this paper are only commonly used statistical calculation methods. Modifications or improvements to parameters such as potential, current, current density, resistivity / conductivity or their statistical calculation methods based on the ideas in this paper are within the scope of protection of this invention.

[0097] When the number of coils is small and cannot fully cover the surface to be tested, the current can be continuously measured by moving the coils. The leakage in the coil measurement area can be calculated in real time by combining the total current information and the total leakage. This allows for the location of abnormal leakage areas and the analysis of their development trends.

[0098] The rectangular coil used in this paper, and any modifications or improvements to the coil's shape, fall within the scope of protection claimed by this invention.

[0099] This article relates to real-time monitoring and early warning of seepage at the upstream face of water conservancy projects. It is worth noting that applying it to the downstream face or the body of the dam does not deviate from the spirit of this invention.

[0100] The electrode array used in this paper is placed upstream and downstream. Modifications or improvements to the electrode array form or the number of electrodes are within the scope of protection claimed by this invention.

[0101] The field covered in this article is water conservancy engineering such as dams. Research and applications in other fields involving seepage analysis of infiltration surfaces, such as groundwater, tailings ponds, and waste liquid pools, which are carried out based on the ideas in this article, have not deviated from the spirit of this invention.

[0102] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A real-time monitoring and early warning system for upstream face infiltration conditions in hydraulic engineering, characterized in that, The alternating electric field supply system (2) and the electric signal acquisition system (3); wherein, The alternating electric field supply system (2) includes a power supply device (21) and an upstream electrode array (22) and a downstream electrode array (23), the upstream electrode array (22) and the downstream electrode array (23) are arranged on the upstream water surface (12) and the downstream water surface (13) of the water conservancy project to be detected respectively, and the power supply device (21) is connected with the electrodes in the upstream electrode array (22) and the downstream electrode array (23) to form a detection loop and transmit a current signal to the acquisition instrument (31). The electric signal acquisition system (3) includes an acquisition instrument (31) and a signal sensing system (32), the signal sensing system (32) is arranged on the upstream infiltration surface (14) of the water conservancy project and includes a signal sensing electrode group (322) and a coil group (324); the signal sensing electrode group (322) is used for sensing a voltage signal and transmitting the voltage signal to the acquisition instrument (31); the coil group (324) is a Hall coil made according to the Hall effect principle or a Rogowski coil made according to the Faraday's law of electromagnetic induction and the Ampere's circuital law, can acquire a current passing through the coil plane in the coil and transmit the current to the acquisition instrument (31), and the coil group (324) covers the entire detection area.

2. The monitoring and warning system of claim 1, wherein, Further comprising a server (4) and a processing system (5), the server (4) collects information acquired by the acquisition instrument (31) through wired or wireless transmission; the processing system (5) is used for receiving data signals downloaded from the server (4) and performing signal processing, display and abnormality alarm.

3. The monitoring and warning system of claim 1, wherein, The upstream electrode array (22) or the downstream electrode array (23) includes a power supply positioning grid (221), a power transmission system (222), a power supply electrode group (223) and a float group (224); the positioning grid (221) is used for installing and positioning the electrodes; the power supply electrode group (223) is an array composed of a plurality of electrodes; the float group (224) is an array composed of a plurality of floats, and a single float is arranged above an electrode and is used for floating, so that the electrode group is located in water contact; the power supply electrode group (223) of the upstream electrode array (22) and the downstream electrode array (23) is connected to the output end and the grounding end of the power supply device (21) through the power transmission system (222) respectively.

4. The monitoring and warning system of claim 3, wherein, The power supply device (21) provides an alternating electric field for the water conservancy project through the upstream electrode array (22) and the downstream electrode array (23).

5. The monitoring and warning system of claim 3, wherein, The power supply positioning grid (221) and the float group (224) are insulators or good conductors; the power transmission system (222) and the power supply electrode group (223) are good conductors.

6. The monitoring and warning system of claim 1, wherein, The signal sensing system (32) comprises a signal sensing positioning grid (321), a signal sensing electrode group (322), a signal cable (323), a coil group (324), a coil cable (325) and a weight block (326), wherein the signal sensing electrode group (322) is connected to the acquisition instrument (31) through the signal cable (323); the coil group (324) is connected to the acquisition instrument (31) through the coil cable (325), the coils in the coil group (324) are independently, closely and non-overlapping arranged, and cover the whole area to be detected; the weight block (326) is used for sinking the signal sensing system (32) to the bottom of water and closely adhering to the upstream infiltration surface (14) of the water conservancy project.

7. The monitoring and warning system of claim 6, wherein, The signal sensing positioning grid (321), the signal cable (323) and the weight block (326) are insulators, and the signal sensing electrode group (322) is a good conductor.

8. The monitoring and warning system of claim 1, wherein, The signals collected by the acquisition instrument (31) include current information in the circuit of the alternating electric field supply system (2), voltage signals sensed by the signal sensing electrode group (322) and current signals sensed by the coil group (324).

9. A real-time monitoring and early warning method for the infiltration conditions of the upstream face of a hydraulic structure using the monitoring and early warning system according to any one of claims 1 to 8, characterized in that, The method comprises the following steps: a. For the water conservancy project to be detected, a plan is drawn according to design or measured engineering data, and the area to be monitored is drawn; b. The signal sensing system (32) is arranged at the upstream infiltration surface (14) of the water conservancy project in the area to be detected, and the upstream electrode array (22) and the downstream electrode array (23) are arranged at the upstream horizontal plane and the downstream horizontal plane respectively, the coil group (324) of the signal sensing group (32) should cover the whole monitoring area, the coverage range of the upstream electrode array (22) should exceed the range of the projection of the signal sensing system (32) on the upstream water surface (12), and a water measuring weir (16) is arranged downstream, which can obtain the dam leakage value in real time; the upstream electrode array (22) and the downstream electrode array (23) are connected with the power supply device (21), and the signal sensing system (32) is connected with the acquisition instrument (31); c. The power supply device (21) and the acquisition instrument (31) are started, and the acquisition instrument (31) transmits the collected current information in the circuit of the alternating electric field supply system (2), the voltage signals sensed by the signal sensing electrode group (322) and the current signals sensed by the coil group (324) to the server (4) in a wireless or wired manner; d. The processing system (5) downloads and analyzes the data in the server (4), and determines the upstream infiltration condition, and alarms when abnormal data is found.

10. The method of claim 9, wherein, The data processing steps comprise: Step one: obtain the leakage amount at time t according to the water measuring weir (16), which is the total leakage amount; Step two: Obtain the potential of all electrodes at time t (assuming a total of n electrodes) from the signal sensing electrode group (322), and calculate the average value according to formula (1-1) and the relative potential difference value according to formula (1-2): （1-1） （1-2） Draw a planar distribution map of the relative potential difference of the monitoring area; Step three: obtain the leakage of the first coil according to the coil group (324) t the current collected by each coil at the moment, combined with the total current collected by the acquisition instrument in the alternating electric field supply system (2) circuit, the leakage in the first coil is calculated according to formula (1-3), and the ratio of the leakage in the first coil to the total leakage is calculated according to formula (1-4): j j the current collected by each coil at the moment, combined with the total current collected by the acquisition instrument in the alternating electric field supply system (2) circuit, the leakage in the first coil is calculated according to formula (1-3), and the ratio of the leakage in the first coil to the total leakage is calculated according to formula (1-4): j （1-3） （1-4） Draw a leakage amount and distribution map of the monitoring area; Step four: grading alarm, when the electrode relative potential difference appears negative value aggregation phenomenon, or the area leakage is larger, which means that there may be a leak, the second level alarm, close attention to the monitoring data changes, for emergency preparedness; when the electrode relative potential difference appears negative value aggregation phenomenon, and the area leakage is larger, which means that the leak has been through, the first level alarm, evacuation of monitoring equipment, start to seal the area with clay or other materials; Step five: after the completion of the sealing, install the monitoring system to continue monitoring and early warning.

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