A flat gate distributed corrosion monitoring system and gate strength evaluation method

Abstract

The application provides a kind of plane gate distributed corrosion monitoring system and the intensity evaluation method of gate local corrosion residual thickness, the corrosion monitoring system includes monitoring probe, signal cable, collector and industrial computer, the monitoring probe of the corrosion monitoring system is arranged at gate panel, main beam web and side beam position;In addition, the application also proposes the intensity evaluation method based on local corrosion based on distributed plane gate corrosion monitoring system, the corrosion depth of gate panel, main beam web, side beam obtained by monitoring, the gate structure model based on residual plate thickness is constructed, finite element numerical calculation is carried out, the stress and strain distribution of gate after corrosion occurs is obtained, and then the residual strength of gate is evaluated.The plane gate distributed corrosion monitoring system and the intensity evaluation method of gate local corrosion residual thickness proposed in the application can fill the lack of gate corrosion monitoring in water conservancy and hydropower engineering, and perfect the safety monitoring and evaluation system of gate structure.

Description

Technical Field

[0001] This invention relates to the field of metal structure safety technology in water conservancy and hydropower projects, and in particular to a distributed corrosion monitoring system for planar gates and a method for evaluating gate strength. Background Technology

[0002] Gates in water conservancy and hydropower projects play an irreplaceable role in water retention, discharge, and navigation. With the continuous construction of large-scale water conservancy and hydropower projects and near-shore projects, the environmental conditions of planar gates are becoming increasingly harsh, and the corrosion problem of gate structures is becoming more and more prominent.

[0003] The corrosion status of gate panels, side beams, and main beam webs, as primary load-bearing components, is closely related to structural strength. The "Technical Specification for Safety Inspection of Hydraulic Steel Gates and Hoists" stipulates that "the appearance inspection of the gate body should include the corrosion status of the main components and connecting bolts." However, in actual engineering operations, corrosion monitoring devices are almost never installed on gates. The gate's condition can only be observed manually during periodic maintenance. This method, on the one hand, cannot obtain timely and effective information on the gate's corrosion and protection status; on the other hand, it has limitations in terms of comprehensive inspection in areas difficult for humans to access.

[0004] Gate structural failure typically occurs in localized areas. However, gate design usually only considers the average corrosion level, while the degree of corrosion varies significantly depending on the environmental conditions and stress states of the gate components. Therefore, assessing the structural strength of a gate by only considering the uniform thinning of the plate thickness due to corrosion is insufficient. Generally, areas with alternating waterlines on the panel and areas with water accumulation in the main beam web are areas of severe corrosion, requiring close monitoring of localized corrosion. It is therefore essential to deploy corrosion monitoring probes in these key areas, promptly monitor the localized corrosion status, construct a gate structural model based on residual corrosion thickness, calculate structural strength, and ultimately assess the gate's safety status. Summary of the Invention

[0005] The primary objective of this invention is to provide a comprehensive and reliable corrosion monitoring system for planar gates, which is applicable to planar gates with beam grids arranged on the inflow side and a top water seal that is a rear stop.

[0006] Therefore, the above-mentioned objective of the present invention is achieved through the following technical solution:

[0007] A distributed corrosion monitoring system for planar gates includes multiple monitoring probes, signal cables, a data acquisition unit, and an industrial control computer.

[0008] Multiple monitoring probes are distributed on the planar gate panel, the web of the main beam, and the side beams; the monitoring probes are connected to the data acquisition unit via signal cables; the data acquisition unit is connected to an industrial control computer, and the data acquisition unit controls the acquisition sequence and frequency of the monitoring probes via the industrial control computer;

[0009] The monitoring probe includes a sensing element, which has a corrosion zone and a compensation zone. The corrosion zone and the compensation zone are adjacent but spatially isolated. The corrosion zone is exposed, and the compensation zone is covered by an anti-corrosion coating. The probe in the corrosion zone is exposed for direct corrosion sensing, and the probe in the compensation zone is covered by an anti-corrosion coating to eliminate the influence of temperature when calculating the corrosion depth of the corrosion zone.

[0010] The sensing element is connected to a current signal line at each end, and the corrosion zone and the compensation zone are connected to a voltage signal line at each end; the connection points of the current signal line, the voltage signal line and the sensing element are covered with an anti-corrosion coating.

[0011] The surface of the sensing element, except for the corrosion area and the compensation area, is also covered with an anti-corrosion coating.

[0012] The corrosion zone and the compensation zone are made of the same material, have the same initial specifications, and the spacing between the voltage signal lines in their respective areas is also the same. Both the corrosion zone and the compensation zone of the sensing element on the monitoring probe are cuboid in shape; that is, the exposed sensing surface of the corrosion zone is rectangular, and the cross-sections of the corrosion zone and the compensation zone are also rectangular. Furthermore, the sensing elements in the corrosion zone and the compensation zone have the same initial voltage signal line spacing, cross-sectional width, and thickness.

[0013] While adopting the above technical solutions, the present invention may also adopt or combine the following technical solutions:

[0014] As a preferred technical solution of the present invention: the monitoring probe further includes a fixing plate, on which a sensing element is disposed, and the fixing plate is fixed to the planar gate panel, the web of the main beam or the side beam by fixing bolts.

[0015] As a preferred embodiment of the present invention, the material of the sensing element is the same as that of the gate, so that the sensing element and the gate have the same resistivity at the same temperature.

[0016] As a preferred embodiment of the present invention, the monitoring probe measures the corrosion depth using the following method:

[0017] The excitation current is input to the current signal lines at both ends of the sensing element on the monitoring probe by the acquisition device. The voltage value of the corrosion zone is obtained through the voltage signal lines at both ends of the corrosion zone on the sensing element. The voltage value of the compensation zone is obtained through the voltage signal lines at both ends of the compensation zone on the sensing element. Then, the resistance values ​​of the two regions are obtained through Ohm's law.

[0018] As a preferred embodiment of the present invention, the method further includes:

[0019] If the corrosion depth of the corrosion zone on the sensing element is x, its resistance value R cor for:

[0020]

[0021] Where ρ(T) is the resistivity of the sensing element on the monitoring probe, l is the distance between the two voltage signal lines at both ends of the corrosion zone on the sensing element, w is the cross-sectional width of the sensing element, and d is the thickness of the sensing element.

[0022] No corrosion occurred in the compensation zone, and its resistance value R ref It can be represented as:

[0023]

[0024] By calculating the resistance ratio of the etched region and the compensation region on the sensing element, the corrosion depth x can be obtained as follows:

[0025]

[0026] As a preferred embodiment of the present invention, the signal cable passes through the drainage opening in the web of the main beam and / or the groove in the flange of the side beam to avoid interference between the signal cable and the gate beam grid.

[0027] As a preferred technical solution of the present invention: the signal cable is set on a cable winding and unwinding device arranged at the maintenance platform, and the cable winding and unwinding device has the same opening and closing speed as the fixed winch, so as to avoid interference between the signal cable and the winch wire rope, the pull rod box and the beam grid during the opening and closing process.

[0028] As a preferred technical solution of the present invention: the number of monitoring probes distributed on the planar gate panel, the web of the main beam and the side beam is not less than three;

[0029] Monitoring probes are placed in the upper, middle and bottom areas of the incoming flow side panel, and preferably in the mid-span area; monitoring probes are placed in the upper, middle and bottom areas of one side beam; monitoring probes are placed in the upper, middle and bottom areas of the main beam web.

[0030] If the gate height is large, the number of monitoring probes on the panel, main beam web and side beam in the vertical direction can be increased, and the probes should be arranged at equal intervals.

[0031] If the gate span is large, the number of monitoring probes on the web of the main beam in the horizontal direction can be increased, and the probes should be arranged at equal intervals.

[0032] Another objective of this invention is to provide a method for strength assessment of the local corrosion thickness of a gate based on the distributed corrosion monitoring system for planar gates described above.

[0033] Therefore, the above-mentioned objective of the present invention is achieved through the following technical solution:

[0034] The strength assessment method for the local corrosion thickness of a gate based on the distributed corrosion monitoring system for planar gates described above includes the following steps:

[0035] S1. Based on the water pressure distribution characteristics corresponding to the plane gate panel, main beam web, and side beam, select the measurement points for the corrosion monitoring probe sensor.

[0036] First, since the water pressure on the gate is proportional to the water depth, monitoring probes should be arranged at equal intervals in the vertical direction of the gate panel and side beams, and should be arranged in the middle of the beam grid as much as possible.

[0037] Second, in the vertical direction of the main beam web, the number of monitoring probes is equal to the number of webs, and the probes are placed on the upward side of the webs.

[0038] Third, monitoring probes should be arranged at equal intervals in the horizontal direction of the gate panel and the web of the main beam, and should be arranged in the middle of the beam grid as much as possible.

[0039] S2. The data acquisition unit is controlled by an industrial control computer to monitor the voltage signal of the corrosion monitoring system;

[0040] S3. Calculate the corrosion depth at each measuring point based on the voltage signal;

[0041] To improve the accuracy of corrosion depth measurement, a high-precision voltage testing module was selected. Furthermore, to eliminate the influence of thermoelectric potential and additional potential, a square-wave alternating excitation current was applied to both the corrosion zone and the compensation zone. During one measurement cycle, the forward excitation current (V) was measured separately. + ) and reverse excitation current (V - The potential signal generated is used, and the average value (U) of the two is used as the voltage signal for calculating the corrosion depth. The voltage signal satisfies the following equation:

[0042]

[0043] S4. Based on the calculated corrosion depth of each local area of ​​the gate, assess the corrosion risk zone of the gate; that is, based on the corrosion depth, the degree of local corrosion of the gate can be preliminarily determined according to the "Technical Specification for Safety Inspection of Hydraulic Steel Gates and Hoists" and the "Technical Specification for Inspection and Evaluation of Hydraulic Structures in Water Transport Engineering".

[0044] S5. Based on the corrosion depth results of each local area, calculate the residual thickness D of each plate of the gate:

[0045] D = D0 - x

[0046] Where D0 is the initial plate thickness; since the monitoring probes are arranged at equal intervals, the plate thickness can be defined as the plate thickness with half the distance between the two sides of the monitoring probe arrangement point.

[0047] If the corrosion depth of the corrosion zone on the sensing element is x, its resistance value R cor for:

[0048]

[0049] Where ρ(T) is the resistivity of the sensing element on the monitoring probe, l is the distance between the two voltage signal lines at both ends of the corrosion zone on the sensing element, w is the cross-sectional width of the sensing element, and d is the thickness of the sensing element.

[0050] No corrosion occurred in the compensation zone, and its resistance value R ref It can be represented as:

[0051]

[0052] By calculating the resistance ratio of the etched region and the compensation region on the sensing element, the corrosion depth x can be obtained as follows:

[0053]

[0054] S6. Based on the thickness of the etched plate, construct a finite element model of the gate;

[0055] S7. Conduct finite element numerical calculations of the erosion gate;

[0056] S8. Based on the finite element calculation results, evaluate the remaining strength of the gate; if the remaining strength σ of the local structure satisfies the following formula, the structure is safe; otherwise, the structure is unsafe.

[0057] σ<[σ]

[0058] Where σ is the residual strength of the local structure, and [σ] is the allowable stress of the structural material.

[0059] This invention provides a distributed corrosion monitoring system for planar gates and a method for strength assessment of local corrosion thickness in gates. The distributed corrosion monitoring system includes monitoring probes, signal cables, a data acquisition unit, and an industrial control computer. The system is suitable for planar gates with a beam grid arrangement on the upstream side of the flow and a rear-sealed top water seal. The monitoring probes are positioned on the gate panel, main beam web, and side beams. Furthermore, this invention proposes a strength assessment method based on localized corrosion using the distributed planar gate corrosion monitoring system. By monitoring the corrosion depth of the gate panel, main beam web, and side beams, a gate structural model based on the remaining plate thickness is constructed. Finite element numerical calculations are then performed to obtain the stress-strain distribution of the gate after corrosion occurs, thereby assessing the remaining strength of the gate. The distributed corrosion monitoring system for planar gates and the strength assessment method for local corrosion thickness proposed in this invention can fill the gap in corrosion monitoring of gates in water conservancy and hydropower projects, and improve the safety monitoring and assessment system for gate structures. This invention considers the non-uniform corrosion distribution characteristics of gate structures, and the structural assessment fully integrates the corrosion status of major components such as gate panels, side beams, and main beam webs. This invention proposes a corrosion monitoring method based on resistance temperature compensation, which has high measurement accuracy and is not limited by environmental conditions. Corrosion data can be monitored in humid atmospheres, immersed solutions, or alternating wet and dry areas. Attached Figure Description

[0060] Figure 1 This is a schematic diagram of the composition of the distributed corrosion monitoring system for planar gates provided by the present invention.

[0061] Figure 2 The diagram shows the direction of the incoming flow and the layout of the gate monitoring probes (the positions of the monitoring probes are shown by the black triangles, and the direction of the incoming flow is shown by the arrows).

[0062] Figure 3 This is a diagram showing the arrangement of corrosion monitoring probes on a flat gate panel.

[0063] Figure 4 This is a diagram showing the arrangement of corrosion monitoring probes on the web of the main beam.

[0064] Figure 5 The corrosion monitoring probe structure provided by this invention;

[0065] Figure 6 This is a schematic diagram of the sensing element on the corrosion monitoring probe provided by the present invention;

[0066] Figure 7 This is a top view of the sensing element on the corrosion monitoring probe provided by the present invention;

[0067] Figure 8 This is a longitudinal sectional view of the sensing element on the corrosion monitoring probe provided by the present invention;

[0068] Figure 9 A flowchart illustrating the strength assessment method for local erosion thickness of a gate provided by the present invention;

[0069] In the diagram: 1-Monitoring probe; 2-Signal cable; 3-Data acquisition unit; 4-Industrial control computer; 11-Corrosion zone; 12-Compensation zone; 13-Epoxy coating layer; 14-Fixing bolt; 15-Fixing pad; 16-Current signal line; 17-Voltage signal line. Detailed Implementation

[0070] The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

[0071] like Figure 1 As shown, a distributed planar gate corrosion monitoring system includes a monitoring probe 1, a signal cable 2, a data acquisition unit 3, and an industrial control computer 4. Figure 2 , Figure 3 and Figure 4 The diagrams shown depict a planar gate with a beam grid arrangement on the inflow-facing side and a top water seal that acts as a rear stop, along with the arrangement of monitoring probes. S represents the inflow direction, and monitoring probe 1 is arranged in a distributed manner, i.e., on the panel (N). i ), main beam web (L) i ) and edge beam (M) i Three types of locations; the distributed monitoring probes are connected to the data acquisition unit via signal cables; the data acquisition unit controls the acquisition sequence and frequency of the monitoring probes via an industrial control computer.

[0072] The number of monitoring probes should be no less than three at each of the panel, main beam web, and side beams. Specifically, monitoring probes should be placed in the upper, middle, and bottom areas of the incoming flow side panel, preferably in the mid-span area; monitoring probes should be placed in the upper, middle, and bottom areas of one side beam; and monitoring probes should be placed in the upper, middle, and bottom areas of the main beam web. If the gate height is large, the number of monitoring probes in the vertical direction on the panel, main beam web, and side beams can be increased, ensuring equal spacing. If the gate span is large, the number of monitoring probes in the horizontal direction on the main beam web can be increased, ensuring equal spacing.

[0073] like Figure 5 The diagram shows the structure of a corrosion monitoring probe. The probe includes a corrosion zone 11, a compensation zone 12, an epoxy coating (i.e., an anti-corrosion coating) 13, fixing bolts 14, a fixing pad 15, a current signal line 16, and a voltage signal line 17. The corrosion zone 11 and the compensation zone 12 are adjacent areas of the probe, meaning they belong to the same sensing element. The sensing element of the probe is made of the same material as the gate's plate, meaning it has the same resistivity at the same temperature.

[0074] like Figure 6As shown, the monitoring probe 1 is connected to a total of 6 monitoring signal lines, including 1 voltage signal line 17 welded to each end of the corrosion zone and the compensation zone, and 1 current signal line 16 at each end of the monitoring probe.

[0075] The sensing elements of the corrosion zone 11 and the compensation zone 12 of the monitoring probe 1 are both in the form of cuboids, that is, the exposed sensing surface of the corrosion zone 11 is rectangular, the cross-section of the corrosion zone 11 and the compensation zone 12 is also rectangular, and the sensing elements of the corrosion zone 11 and the compensation zone 12 have the same initial voltage signal line distance, cross-sectional width and thickness.

[0076] Corrosion zone 11 is exposed for direct corrosion sensing, while compensation zone 12 is covered by an anti-corrosion coating to eliminate the influence of temperature when calculating the corrosion depth of the corrosion zone.

[0077] The epoxy coating (anti-corrosion coating) 13 covers the welding points of the voltage signal line 17 and the current signal line 16 with the sensing element, forming a support structure for the monitoring probe; on the other hand, it also covers all surfaces of the compensation area to isolate the compensation area 12 from the corrosive medium and thus prevent corrosion of the compensation area 12.

[0078] The four voltage signal lines 17 and two current signal lines 16 on the monitoring probe together form the signal cable 2, which meets the requirements of waterproof and pressure resistant.

[0079] Signal cable 2 passes through drainage openings in the main beam web and slots in the side beam flanges on the gate, avoiding interference with the gate beam grid. During opening and closing, the monitoring probe signal cable passes through a cable retraction device arranged at the maintenance platform, achieving the same opening and closing speed as the fixed winch, thus avoiding interference between the signal cable and the winch wire rope, tie rod box, and beam grid during the opening and closing process.

[0080] The data acquisition unit 3 and the industrial control computer 4 are placed in the gate opening and closing machine room or the metal structure safety monitoring and control room.

[0081] like Figure 7 and Figure 8 As shown, a represents the corrosion zone, and b represents the compensation zone. The method for measuring the corrosion depth of the monitoring probe is to input an excitation current (I0) into the current signal lines at both ends of the monitoring probe 1 through the data acquisition unit 3. in / I out The voltage value (U1) of the corrosion zone is obtained through the voltage signal lines at both ends of the corrosion zone, and the voltage value (U2) of the compensation zone is obtained through the voltage signal lines at both ends of the compensation zone. Then, the resistance values ​​of the two zones are obtained through Ohm's law.

[0082] If the corrosion depth in the corrosion zone is x, its resistance value R cor for:

[0083]

[0084] Where ρ(T) is the resistivity of the monitoring probe, l is the distance between the two voltage signal lines of the sensing element, w is the cross-sectional width of the sensing element, and d is the thickness of the sensing element. No corrosion occurred in the compensation zone, and its resistance value R... ref It can be represented as:

[0085]

[0086] By calculating the resistance ratio of the corroded zone and the compensation zone, the corrosion depth x can be obtained as:

[0087]

[0088] like Figure 9 As shown, a strength assessment method based on the local corrosion thickness of a gate, according to the gate corrosion monitoring results, comprises the following steps:

[0089] S1. Based on the water pressure distribution characteristics corresponding to the gate panel, main beam web, and side beams, select the measurement points for the corrosion monitoring probe sensors. The principles for probe placement are as follows: First, since the water pressure on the gate is proportional to the water depth, the probes should be evenly spaced in the vertical direction of the gate panel and side beams, and should ideally be placed in the middle of their respective beam grids. Second, in the vertical direction of the main beam web, the number of probes should be equal to the number of webs, and the probes should be placed on the upward side of the web. Third, in the horizontal direction of the gate panel and main beam web, the probes should be evenly spaced, and should ideally be placed in the middle of their respective beam grids.

[0090] S2. The industrial control computer controls the data acquisition device to monitor the voltage signals at both ends of the corrosion zone and the compensation zone in the corrosion monitoring system.

[0091] S3. Calculate the corrosion depth at each measuring point based on the voltage signal. To improve the measurement accuracy of corrosion depth, a high-precision voltage testing module is selected. Furthermore, to eliminate the influence of thermoelectric potential and additional potential, a square-wave alternating excitation current is applied to the corrosion zone and the compensation zone. During one measurement cycle, the forward excitation current (V) is measured separately. + ) and reverse excitation current (V - The potential signal generated is used, and the average value (U) of the two is used as the voltage signal for calculating the corrosion depth. The voltage signal satisfies the following equation:

[0092]

[0093] S4. Based on the calculated corrosion depth of each local area of ​​the gate, assess the corrosion risk zone of the gate. That is, based on the corrosion depth, the degree of local corrosion of the gate can be preliminarily determined according to the "Technical Specification for Safety Inspection of Hydraulic Steel Gates and Hoists" and the "Technical Specification for Inspection and Evaluation of Hydraulic Structures in Water Transport Engineering".

[0094] S5. Based on the corrosion depth results of each local area, calculate the residual thickness (D) of each plate of the gate, i.e.

[0095] D = D0 - x

[0096] Where D0 is the initial plate thickness. Since the monitoring probes are arranged at equal intervals, the plate thickness can be defined as the plate thickness with a length equal to half the distance between the two sides of the monitoring probe placement point.

[0097] S6. Based on the thickness of the etched plate, construct a finite element model of the gate.

[0098] S7. Conduct finite element numerical calculations of the erosion gate.

[0099] S8. Based on the finite element calculation results, evaluate the remaining strength of the gate. If the remaining strength of the local structure satisfies the following formula, the structure is safe; otherwise, the structure is unsafe.

[0100] σ<[σ]

[0101] Where σ is the residual strength of the local structure, and [σ] is the allowable stress of the structural material.

[0102] The above specific embodiments are used to explain and illustrate the present invention, and are only preferred embodiments of the present invention, not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made to the present invention within the spirit and scope of the claims shall fall within the protection scope of the present invention.

Claims

1. A distributed corrosion monitoring system for planar gates, characterized in that: The distributed corrosion monitoring system for planar gates includes multiple monitoring probes, signal cables, a data acquisition unit, and an industrial control computer. Multiple monitoring probes are distributed on the planar gate panel, the web of the main beam, and the side beams; the monitoring probes are connected to the data acquisition unit via signal cables; the data acquisition unit is connected to an industrial control computer, and the data acquisition unit controls the acquisition sequence and frequency of the monitoring probes via the industrial control computer; The monitoring probe includes a sensing element, which has a corrosion zone and a compensation zone, and the corrosion zone and the compensation zone are in adjacent areas; the corrosion zone is exposed, and the compensation zone is covered by an anti-corrosion coating; The sensing element is connected to a current signal line at each end, and the corrosion zone and the compensation zone are connected to a voltage signal line at each end; the connection points of the current signal line, the voltage signal line and the sensing element are covered with an anti-corrosion coating. The surface of the sensing element, except for the corrosion area and the compensation area, is also covered with an anti-corrosion coating. The corrosion zone and the compensation zone are made of the same material, have the same initial specifications, and the spacing between the voltage signal lines in their respective zones is also the same. The number of monitoring probes distributed on the planar gate panel, the main beam web, and the side beam shall not be less than three; Monitoring probes are placed in the upper, middle and bottom areas of the incoming flow side panel, and preferably in the mid-span area; monitoring probes are placed in the upper, middle and bottom areas of one side beam; monitoring probes are placed in the upper, middle and bottom areas of the main beam web. If the gate is too high, increase the number of monitoring probes on the panel, main beam web and side beam in the vertical direction, and ensure that they are arranged at equal intervals. If the gate span is large, increase the number of monitoring probes on the web of the main beam in the horizontal direction, and ensure that they are arranged at equal intervals.

2. The distributed corrosion monitoring system for planar gates according to claim 1, characterized in that: The monitoring probe also includes a fixing plate, on which a sensing element is disposed. The fixing plate is fixed to the planar gate panel, the web of the main beam, or the side beam by fixing bolts.

3. The distributed corrosion monitoring system for planar gates according to claim 1, characterized in that: The sensing element is made of the same material as the gate.

4. The distributed corrosion monitoring system for planar gates according to claim 1, characterized in that: The monitoring probe measures the corrosion depth using the following method: The excitation current is input to the current signal lines at both ends of the sensing element on the monitoring probe by the acquisition device. The voltage value of the corrosion zone is obtained through the voltage signal lines at both ends of the corrosion zone on the sensing element. The voltage value of the compensation zone is obtained through the voltage signal lines at both ends of the compensation zone on the sensing element. Then, the resistance values ​​of the two regions are obtained through Ohm's law.

5. The distributed corrosion monitoring system for planar gates according to claim 4, characterized in that: The method further includes: If the corrosion depth of the corrosion zone on the sensing element is... x When, its resistance value R cor for: in, ρ(T) It monitors the resistivity of the sensing element on the probe. l The distance between the two voltage signal lines at both ends of the etched area on the sensing element. w The cross-sectional width of the sensing element. d For the thickness of the sensing element; No corrosion occurred in the compensation zone, and its resistance value was [missing value]. R ref Represented as: The corrosion depth is obtained by calculating the resistance ratio between the corroded area and the compensation area on the sensing element. x for: 。 6. The distributed corrosion monitoring system for planar gates according to claim 1, characterized in that: The signal cable passes through drainage openings in the web of the main beam and / or slots in the flanges of the side beams.

7. The distributed corrosion monitoring system for planar gates according to claim 1, characterized in that: The signal cable is mounted on a cable winding and unwinding device located at the maintenance platform, and the cable winding and unwinding device has the same opening and closing speed as the fixed winch.

8. A method for evaluating the gate strength of a distributed corrosion monitoring system for planar gates according to any one of claims 1-7, characterized in that: The method for evaluating the strength of the gate includes the following steps: S1. Based on the water pressure distribution characteristics corresponding to the plane gate panel, main beam web, and side beam, select the measurement points for the corrosion monitoring probe sensor. First, since the water pressure on the gate is proportional to the water depth, monitoring probes should be arranged at equal intervals in the vertical direction of the gate panel and side beams, and should be arranged in the middle of the beam grid as much as possible. Second, in the vertical direction of the main beam web, the number of monitoring probes is equal to the number of webs, and the probes are placed on the upward side of the webs. Third, monitoring probes should be arranged at equal intervals in the horizontal direction of the gate panel and the web of the main beam, and should be arranged in the middle of the beam grid as much as possible. S2. The data acquisition unit is controlled by an industrial control computer to monitor the voltage signal of the corrosion monitoring system; S3. Calculate the corrosion depth at each measuring point based on the voltage signal; To improve the accuracy of corrosion depth measurement, a high-precision voltage testing module was selected. Furthermore, to eliminate the influence of thermoelectric potential and additional potential, a square-wave alternating excitation current was applied to both the corrosion zone and the compensation zone. During one measurement cycle, the forward excitation current was measured separately. V + and reverse excitation current V - The generated potential signal is then averaged with the two values. U As the voltage signal used in corrosion depth calculation, the voltage signal satisfies the following equation: S4. Based on the calculated corrosion depth of each local area of ​​the gate, assess the corrosion risk zone of the gate; S5. Based on the corrosion depth results of each local area, calculate the residual thickness of each plate of the gate. D : in, D 0 The initial plate thickness is defined as the plate thickness with half the distance between the two sides of the monitoring probe placement point, since the monitoring probes are arranged at equal intervals. If the corrosion depth of the corrosion zone on the sensing element is... x When, its resistance value R cor for: in, ρ(T) It monitors the resistivity of the sensing element on the probe. l The distance between the two voltage signal lines at both ends of the etched area on the sensing element. w The cross-sectional width of the sensing element. d For the thickness of the sensing element; No corrosion occurred in the compensation zone, and its resistance value was [missing value]. R ref Represented as: The corrosion depth is obtained by calculating the resistance ratio between the corroded area and the compensation area on the sensing element. x for: S6. Based on the thickness of the etched plate, construct a finite element model of the gate; S7. Conduct finite element numerical calculations of the erosion gate; S8. Based on the finite element analysis results, evaluate the remaining strength of the gate; the remaining strength of the local structure. If the following formula is satisfied, the structure is safe; otherwise, the structure is unsafe. in, For the residual strength of the local structure, This represents the allowable stress of the structural material.

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