Time-frequency domain combined induced polarization monitoring method and system of permeable reactive barrier
By combining time-frequency domain and time-domain joint excitation polarization monitoring method, the problems of long monitoring time and poor data quality in the existing technology are solved, realizing real-time and accurate monitoring of PRB walls and ensuring their long-term effectiveness.
Patent Information
- Application Number
- CN202511070134.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-31
- Publication Date
- 2025-11-18
AI Technical Summary
Existing induced polarization monitoring techniques for monitoring permeable reactive walls (PRBs) suffer from limitations such as long measurement times and poor data quality in the single frequency domain method and the single time domain method, making it impossible to achieve real-time feedback and accurate monitoring.
A joint time-frequency domain excitation polarization monitoring method is adopted. Representative points are measured by frequency domain excitation polarization method, and all points are measured by time domain excitation polarization method. A joint measurement system is established, and Fourier transform is used to analyze the error, thereby improving the monitoring accuracy and reliability and shortening the monitoring time.
It enables real-time reflection and precise monitoring of the PRB wall condition, reduces monitoring costs, increases monitoring frequency, and ensures the long-term effectiveness of the PRB wall.
Smart Images
Figure CN120971296A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present disclosure relates to the technical field of environmental remediation, in particular to a time-frequency domain joint induced polarization monitoring method and system for a permeable reactive wall. BACKGROUND
[0002] The statements in this section merely provide background information related to the present disclosure and do not necessarily constitute the prior art.
[0003] Hexavalent chromium pollution [Cr(Ⅵ)] is one of the important pollution problems of groundwater, which exists in the form of soluble anions in water bodies, has high pollution depth and wide diffusion range. [Cr(Ⅵ)] is a primary carcinogen and can be enriched layer by layer through the food chain, not only polluting groundwater and long-term threatening human health, but also causing serious harm to the entire ecological system. Since [Cr(Ⅵ)] has strong oxidizing property, permeable reactive wall (PRB) can effectively reduce the concentration of hexavalent chromium anions in groundwater due to its reducing property and adsorption property. However, during the use of PRB, with the passage of time, problems such as consumption of chemical reducing materials, precipitation covering the surface and blocking the pores will occur, resulting in reduced performance. Therefore, a comprehensive and accurate technical method is needed to monitor the performance of PRB buried underground to ensure that it can work with healthy performance.
[0004] Traditional PRB monitoring technologies include monitoring well method, numerical simulation method, sampling detection method, etc. These methods rely on invasive means, and the data obtained cannot represent the integrity of the PRB wall and internal changes in the structure for a long time, and the data accuracy is poor. At present, induced polarization as a gradually developed geophysical method can effectively solve the above problems. However, the existing methods still have the following problems: 1) In the induced polarization monitoring technology, although the single frequency domain induced polarization method can obtain sufficient information and relatively accurate measurement results, the measurement process needs to take a very long time, which cannot well feedback the PRB wall state and changes in real time, and the measurement frequency is limited to a certain extent; 2) The single time domain induced polarization method greatly shortens the data acquisition time, but it is greatly affected by data quality, resulting in less information obtained, which limits its effect in monitoring PRB. SUMMARY
[0005] To address the aforementioned issues, this disclosure proposes a time-frequency domain joint excitation polarization monitoring method and system for permeable reactive barrier (PRB). This method employs a joint measurement system that uses frequency domain excitation polarization to measure representative points and time domain excitation polarization to measure all points, enabling comprehensive monitoring and analysis of the overall state of the PRB. The basic parameters for time domain monitoring are determined using the frequency domain representative point measurement results, improving the accuracy of time domain monitoring. Furthermore, the use of time-frequency domain coincidence point parameters for time domain result error analysis enhances the reliability of the time domain results for overall monitoring, addressing the issue of insufficient information in time domain measurement results. Simultaneously, it shortens the overall monitoring time, providing real-time reflection of the PRB's state and changes.
[0006] According to some embodiments, the present disclosure adopts the following technical solutions: A time-frequency domain co-excitation polarization monitoring method for permeable reactive walls includes: Obtain data on the height, width, and thickness of the permeable reactive barrier; The measurement profile, measurement line length, electrode spacing, and number of measurement lines are determined based on the height, width, and thickness of the permeable reactive barrier. The measurement profile is divided into zones, and a representative measurement point is selected in each zone for frequency domain excitation polarization monitoring. The excitation polarization monitoring data is then inverted to obtain frequency domain parameters. The basic parameters for full-waveform time-domain excitation polarization monitoring are determined based on the frequency domain parameters. Time-domain excitation polarization monitoring is performed on all measuring points in each region based on the basic parameters for time-domain excitation polarization monitoring. The parameters of the time-frequency domain monitoring coincidence points are converted into frequency domain parameters through Fourier transform. The error of the time-domain excitation polarization measurement of the coincidence points relative to the frequency-domain excitation polarization measurement is calculated. Based on the error, it is determined whether the monitoring accuracy requirements are met. When the accuracy requirements are met, calculate the percentage error between the time-domain monitoring parameters of all grids and the initial excitation polarization parameters of the permeable reactive barrier, and determine the state of the permeable reactive barrier by the percentage error.
[0007] According to some embodiments, the present disclosure adopts the following technical solutions: A time-frequency domain co-excitation polarization monitoring system for permeable reactive walls includes: The data acquisition and initialization module is used to acquire the height, width, and thickness data of the permeable reactive barrier; and to determine the measurement profile, measurement line length, electrode spacing, and number of measurement lines based on the height, width, and thickness of the permeable reactive barrier. The frequency domain excitation polarization module is used to divide the measurement profile into zones, select a representative measurement point in each zone for frequency domain excitation polarization monitoring, and invert the excitation polarization monitoring data to obtain frequency domain parameters. The time-domain excitation polarization module is used to determine the basic parameters for full-waveform time-domain excitation polarization monitoring based on the frequency domain parameters. Based on the basic parameters for time-domain excitation polarization monitoring, time-domain excitation polarization monitoring is performed on all measurement points in each region. The parameters of the time-frequency domain monitoring coincidence points are converted into frequency domain parameters through Fourier transform. The error of the time-domain excitation polarization measurement of the coincidence points relative to the frequency domain excitation polarization measurement is calculated. Based on the error, it is determined whether the monitoring accuracy requirements are met. The status monitoring module is used to calculate the percentage error between the time-domain monitoring parameters of all grids and the initial excitation polarization parameters of the permeable reactive barrier when the accuracy requirements are met, and to determine the status of the permeable reactive barrier by the percentage error.
[0008] According to some embodiments, the present disclosure adopts the following technical solutions: A computer program product includes a computer program that, when executed by a processor, implements the time-frequency domain joint excitation polarization monitoring method for a permeable reactive wall.
[0009] According to some embodiments, the present disclosure adopts the following technical solutions: A non-transitory computer-readable storage medium is provided for storing computer instructions, which, when executed by a processor, implement the time-frequency domain joint excitation polarization monitoring method for a permeable reactive wall.
[0010] According to some embodiments, the present disclosure adopts the following technical solutions: An electronic device includes a processor, a memory, and a computer program; wherein the processor is connected to the memory, the computer program is stored in the memory, and when the electronic device is running, the processor executes the computer program stored in the memory to enable the electronic device to perform the time-frequency domain joint excitation polarization monitoring method for implementing the permeable reactive wall.
[0011] Compared with the prior art, the beneficial effects of this disclosure are as follows: This disclosed method for time-frequency domain combined excitation polarization monitoring of permeable reactive barrier (PRB) establishes a joint measurement system that uses frequency domain excitation polarization to measure representative points and time domain excitation polarization to measure all points, thus shortening the time required for complete and systematic monitoring of PRB. By determining the basic parameters of the time domain monitoring method through the measurement results of representative points in the frequency domain, the accuracy of the time domain monitoring method is improved. Furthermore, by using the parameters of coincident points in the time and frequency domains for error analysis of the time domain results, the reliability of the time domain for the overall monitoring results is further improved. This method solves the problem of insufficient information in the time domain measurement results while shortening the overall monitoring time, and is of great significance for reflecting the state and changes of the PRB wall in real time.
[0012] The time-frequency domain combined excitation polarization monitoring method for permeable reactive walls disclosed herein is a non-invasive monitoring method. Compared with traditional sampling monitoring methods, the method disclosed herein will not damage the permeable reactive wall during operation. Compared with the frequency domain excitation polarization method alone, it takes less time and can increase the monitoring frequency, thereby achieving more real-time monitoring of the permeable reactive wall status and reflecting its changes. Compared with the time domain excitation polarization method alone, the method disclosed herein provides more accurate measurement data, making up for the problem of insufficient accuracy of measurement results due to the limited information content of the time domain excitation polarization method.
[0013] The time-frequency domain joint excitation polarization monitoring method for permeable reactive walls disclosed herein can determine the specific layout requirements of the measuring lines and electrodes based on the parameters of the permeable reactive wall without the need to excavate monitoring wells. After a one-time deployment, long-term cyclic monitoring can be carried out, which reduces monitoring costs and can better reflect the changes in its internal state. This provides reliable technical support for the subsequent aging law of permeable reactive walls and the optimization of permeable reactive wall repair schemes. Attached Figure Description
[0014] The accompanying drawings, which form part of this disclosure, are used to provide a further understanding of this disclosure. The illustrative embodiments of this disclosure and their descriptions are used to explain this disclosure and do not constitute an undue limitation of this disclosure.
[0015] Figure 1 This is a schematic diagram of the time-frequency domain joint excitation polarization monitoring method for a permeable reactive wall according to an embodiment of this disclosure; Figure 2 This is a diagram showing the arrangement of excitation polarization measurement lines according to an embodiment of this disclosure; Figure 3 This is a top view of the arrangement of excitation polarization measuring lines according to an embodiment of this disclosure; Figure 4 This is a monitoring profile view corresponding to a certain measuring line in an embodiment of this disclosure; Figure 5 This is a diagram illustrating the division of the measurement point region for a dipole-dipole array according to an embodiment of this disclosure. Detailed Implementation
[0016] The present disclosure will be further described below with reference to the accompanying drawings and embodiments.
[0017] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this disclosure. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.
[0018] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this disclosure. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms “comprising” and / or “including” are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.
[0019] Terminology Explanation A permeable reactive barrier (PRB) is a passive engineering technology used for in-situ remediation of contaminated groundwater. Essentially, it is a "wall" or "reaction zone" installed within an aquifer. This wall is filled with a mixture of highly permeable materials (such as gravel) and key active reactive media (or reactive materials), and is positioned downstream of the contaminated groundwater flow path. The contaminated groundwater flows naturally through this permeable reactive barrier under the influence of the natural hydraulic gradient. As the contamination plume (a contamination belt formed by pollutants carried by groundwater) flows through the wall, the active reactive media within the wall undergo physical, chemical, or biological reactions with the pollutants. These reactions aim to degrade, adsorb, precipitate, or transform the pollutants in the groundwater into non-toxic or low-toxic, insoluble or poorly soluble forms, thereby purifying the groundwater.
[0020] Example 1 One embodiment of this disclosure provides a time-frequency domain joint excitation polarization monitoring method for a permeable reactive barrier, the method comprising the following steps: Step 1: Obtain the height, width, and thickness data of the permeable reactive barrier; determine the measurement profile, measurement line length, electrode spacing, and number of measurement lines based on the height, width, and thickness of the permeable reactive barrier; Step 2: Divide the measurement profile into zones, select a representative measurement point in each zone for frequency domain excitation polarization monitoring, and invert the excitation polarization monitoring data to obtain frequency domain parameters; Step 3: Determine the basic parameters for full waveform time-domain excitation polarization monitoring based on the frequency domain parameters. Perform time-domain excitation polarization monitoring on all measurement points in each region based on the basic parameters for time-domain excitation polarization monitoring. Convert the parameters of the time-frequency domain monitoring coincidence points into frequency domain parameters through Fourier transform. Calculate the error of the time-domain excitation polarization measurement of the coincidence measurement points relative to the frequency-domain excitation polarization measurement. Determine whether the monitoring accuracy requirements are met based on the error. Step 4: When the accuracy requirements are met, calculate the percentage error between the time-domain monitoring parameters of all grids and the initial excitation polarization parameters of the permeable reactive barrier, and determine the state of the permeable reactive barrier by the percentage error.
[0021] As one embodiment, this disclosure discloses a time-frequency domain joint excitation polarization monitoring method for permeable reactive barrier (PRB). By establishing a joint measurement system where representative points are measured using the frequency domain excitation polarization method and all points are measured using the time domain excitation polarization method, the basic parameters of the time domain monitoring method are determined using the measurement results of the representative points in the frequency domain, thus improving the accuracy of the time domain monitoring method. Furthermore, by using the time-frequency domain coincidence point parameters for time domain result error analysis, the reliability of the time domain for the overall monitoring results is further improved. This solves the problem of insufficient information in the time domain measurement results while shortening the overall monitoring time, which is of great significance for reflecting the state and changes of the PRB in real time. The specific implementation process is as follows: Step 1: Determine the measurement profile, measurement line length, electrode spacing, and number of measurement lines based on the height, width, and thickness of the permeable reactive barrier; Specifically, taking an abandoned industrial site as an example, the groundwater there is contaminated with chlorinated solvents. The contamination plume flows from west to east along the groundwater flow direction. A permeable reactive barrier is vertically arranged downstream of the contamination plume. The permeable reactive barrier is 1.5m thick, 10m deep, and 20m wide. The site survey lines and electrodes are arranged based on the height, width, and thickness of the permeable reactive barrier. The specific determination method includes: (1) Length of survey line x The height of the permeable reactive wall h Sure:
[0022] in, This is the length coefficient. n =1.2~1.5, determined by the depth resolution requirements; ξ For array coefficients, ξ =3~6, determined by the number of measurement points in the array and their arrangement.
[0023] (2) Spacing of electrodes d The thickness of the permeable reactive wall a Sure:
[0024] in, The polar moment coefficient, β =1 / 4 to 1 / 2, determined by the horizontal resolution requirements.
[0025] (3) Number of survey lines N The width of the permeable reactive wall b and electrode spacing d Sure:
[0026] As one embodiment, due to the high depth resolution requirement and the large number of measurement points, a "Compare R" array is selected, and the length coefficient is taken. n =1.4, array coefficient ξ =4, polar moment coefficient β =1 / 3, therefore the length of the survey line x The electrode spacing is 56m. d The length is 0.5m, and the number of measuring lines N is 20.
[0027] Furthermore, such as Figure 2 and Figure 3 As shown, the test lines should be evenly distributed along the width of the permeable reactive barrier (PRB), with the length of the test lines perpendicular to the width of the PRB. Electrodes should be evenly distributed along the test lines according to the electrode spacing. If periodic monitoring is required subsequently, the positions of the test lines and electrodes should remain consistent with those at the time of the initial monitoring. The purpose of evenly distributing the test lines along the width of the PRB is to fully probe the performance of each part of the PRB. The perpendicularity of the length of the test lines to the width of the PRB is to reduce the influence of three-dimensional effects during electrical resistivity tomography (EPT).
[0028] Step 2: Divide the measurement profile into zones, select a representative measurement point in each zone for frequency domain excitation polarization monitoring, and invert the excitation polarization monitoring data to obtain frequency domain parameters; Specifically, in this embodiment, the required survey line length for the permeable reactive wall is 56m, the electrode spacing is 0.5m, and the required number of electrodes is 111.
[0029] like Figure 4 As shown, the measurement point position of the measurement line profile is the intersection of the midpoints of the two pairs of electrodes tilted downwards at 45°. The monitoring array is selected as a dipole-dipole array, and the measurement point as a whole presents an isosceles trapezoidal shape with a base angle of 45°.
[0030] like Figure 5 As shown, the measurement points of the measurement profile are divided into zones, including: using the isosceles right triangle zoning method, that is, firstly, the 45° isosceles trapezoidal measurement area is divided into two equal parts. When the number of measurement points along the hypotenuse is even, the number of measurement points along the hypotenuse is the same in both the upper and lower parts; when the number of measurement points is odd, one more measurement point is added to one of the upper or lower parts along the hypotenuse. Then, using the number of measurement points along the hypotenuse as the right-angled side, isosceles right triangles are constructed, and the upper and lower parts are further divided along the horizontal direction in an alternating forward and reverse manner. Finally, the zoning of the monitoring profile for a certain measurement line is completed, and each isosceles right triangle region is used as the unit region for subsequent excitation polarization measurement and error calculation.
[0031] As one example, this instance is divided into 20 regions.
[0032] Furthermore, a representative measurement point is selected within each region for frequency domain excitation polarization monitoring, and the excitation polarization monitoring data is inverted to obtain frequency domain parameters, specifically including: First, representative measurement points need to be selected in each partition area for frequency-domain excited polarization monitoring. Then, frequency domain parameters, including resistivity, are obtained by inverting the frequency-domain excited polarization monitoring parameters using commercial software. ρ Polarizability m Relaxation time τ.
[0033] Step 3: Determine the basic parameters for full waveform time-domain excitation polarization monitoring based on the frequency domain parameters. Perform time-domain excitation polarization monitoring on all measurement points in each region based on the basic parameters for time-domain excitation polarization monitoring. Convert the parameters of the time-frequency domain monitoring coincidence points into frequency domain parameters through Fourier transform. Calculate the error of the time-domain excitation polarization measurement of the coincidence measurement points relative to the frequency-domain excitation polarization measurement. Determine whether the monitoring accuracy requirements are met based on the error. Specifically, the basic parameters for full-waveform time-domain excitation polarization monitoring, determined based on frequency domain parameters, must meet the following conditions: (1) Full waveform sampling frequency Must meet f t ≥2 αf max ,in
[0034] Where frequency coefficient α The value ranges from 1.2 to 1.4. f max To obtain the maximum characteristic frequency at the representative measurement point, τ min The minimum relaxation time is the frequency domain result; in this embodiment, the minimum relaxation time is... τ min Given a time interval of 0.0026 seconds, and a frequency coefficient α = 1.3, the sampling frequency is calculated. f t ≥999Hz, therefore the sampling rate is set to 1000Hz; (2) Single test duration Must meet T ≥3 τ max in τ max The maximum relaxation time is the frequency domain result; in this embodiment, the maximum relaxation time is 0.43 seconds, and the single measurement time is calculated. T ≥1.29 seconds, therefore the single measurement and supply time is taken as 2 seconds; (3) Current intensity
[0035] in, U al This refers to the allowable accuracy of the instrument's measuring voltage. K max This represents the maximum value of the device coefficient on the cross-section. m min This represents the minimum value of the frequency polarizability among all the resulting parameters. ρ min This represents the minimum resistivity in the frequency domain results. In this embodiment, the minimum polarizability is... m min The resistivity is 0.003, the minimum value. ρ min The allowable accuracy of the instrument's measuring voltage is 10 Ω·m. U al The maximum value of the device coefficient is 0.0001V. K max The value is 27143, and the calculated current intensity is... I ≥90.477mA, therefore the constant current supply current intensity is taken as 100mA.
[0036] Furthermore, based on the fundamental parameters of time-domain induced polarization monitoring, time-domain induced polarization monitoring is performed on all measuring points in each region. The advantage of the second measurement in the time domain is its short measurement time, but its accuracy is poor. In order to compare with the first frequency domain results, it is necessary to convert the time domain to the frequency domain so that comparison can be made in the same dimension. Therefore, the parameters of the time-frequency domain monitoring coincidence points are converted into frequency domain parameters through Fourier transform, and then the error of the time-domain induced polarization measurement of the coincidence points relative to the frequency-domain induced polarization measurement is calculated. During the calculation, the error of each partition needs to be calculated according to the following method: With the first i Taking the polarizability error analysis of a region as an example:
[0037] in, m ti For the first i Time-domain measurement of polarization at overlapping measurement points in each partition m pi For the first i Frequency domain measurement of polarization at overlapping measurement points in each partition; E ≤5%.
[0038] The calculated error of the time-domain excited polarization measurement relative to the frequency-domain excited polarization measurement must meet the following requirements: It is necessary to ensure that more than 80% of the data meets the error requirements. If the requirements are not met, the time domain measurement parameters need to be readjusted.
[0039] As one example, this embodiment has 20 partitions, and the error of 19 partitions was calculated. E If the value is less than 5%, the polarizability measurement results meet the error requirements.
[0040] Step 4: When the accuracy requirements are met, calculate the percentage error between the time domain monitoring parameters of all grids and the initial excitation polarization parameters of the permeable reactive barrier, and determine the state of the permeable reactive barrier by the percentage error.
[0041] Specifically, when conducting a condition assessment of a permeable reactive barrier, it is necessary to collect the time-domain induced polarization monitoring parameters of all grids and calculate the percentage error between these parameters and the induced polarization parameters of the barrier in its initial state. η : Taking the calculation of the percentage error in polarizability as an example:
[0042] in n The number of sections in the cross-section. For the first t The average value of the time-domain polarizability measurement results at all measurement points in each partition. m 0 represents the measured polarizability of the wall in its initial state.
[0043] Furthermore, the process of determining the state of the permeable reactive barrier based on the percentage error in polarizability includes: when η When the percentage is 85%~100%, it indicates that the permeable reactive barrier is in good condition. when η When the percentage is 70%~85%, it indicates that the condition of the permeable reactive barrier is generally normal. when η When the percentage is 60%~70%, it indicates that the condition of the permeable reactive barrier is poor. when η When the percentage is less than 60%, it indicates that the condition of the permeable reactive barrier is very poor.
[0044] In this embodiment, the final calculated η If the percentage is 87%, then the conclusion is that the permeable reactive wall is currently in good condition and can continue to be used.
[0045] As an example, when the target PRB requires repeated cyclic monitoring, it is necessary to ensure that the arrangement of measuring lines and electrodes, the array type of measuring points, the zoning method of measuring points, and the selection of initial excitation polarization parameters remain consistent with the initial monitoring in subsequent monitoring processes. During the monitoring process, a remote geophysical electrical resistivity tomography (PRB) equipment control and dynamic data acquisition platform can be built using existing wireless network technology to conduct remote periodic monitoring of the permeable reactive barrier.
[0046] Example 2 One embodiment of this disclosure provides a time-frequency domain co-excitation polarization monitoring system for a permeable reactive wall, comprising: The data acquisition and initialization module is used to acquire the height, width, and thickness data of the permeable reactive barrier; and to determine the measurement profile, measurement line length, electrode spacing, and number of measurement lines based on the height, width, and thickness of the permeable reactive barrier. The frequency domain excitation polarization module is used to divide the measurement profile into zones, select a representative measurement point in each zone for frequency domain excitation polarization monitoring, and invert the excitation polarization monitoring data to obtain frequency domain parameters. The time-domain excitation polarization module is used to determine the basic parameters for full-waveform time-domain excitation polarization monitoring based on the frequency domain parameters. Based on the basic parameters for time-domain excitation polarization monitoring, time-domain excitation polarization monitoring is performed on all measurement points in each region. The parameters of the time-frequency domain monitoring coincidence points are converted into frequency domain parameters through Fourier transform. The error of the time-domain excitation polarization measurement of the coincidence points relative to the frequency domain excitation polarization measurement is calculated. Based on the error, it is determined whether the monitoring accuracy requirements are met. The status monitoring module is used to calculate the percentage error between the time-domain monitoring parameters of all grids and the initial excitation polarization parameters of the permeable reactive barrier when the accuracy requirements are met, and to determine the status of the permeable reactive barrier by the percentage error.
[0047] Example 3 One embodiment of this disclosure provides a computer program product, including a computer program that, when executed by a processor, implements the time-frequency domain joint excitation polarization monitoring method for the permeable reactive wall.
[0048] Example 4 One embodiment of this disclosure provides a non-transitory computer-readable storage medium for storing computer instructions. When executed by a processor, the computer instructions implement the time-frequency domain joint excitation polarization monitoring method for the permeable reactive wall.
[0049] Example 5 One embodiment of this disclosure provides an electronic device, including a processor, a memory, and a computer program; wherein the processor is connected to the memory, and the computer program is stored in the memory. When the electronic device is running, the processor executes the computer program stored in the memory to enable the electronic device to perform the time-frequency domain joint excitation polarization monitoring method for implementing the permeable reactive wall.
[0050] This disclosure is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this disclosure. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create a machine for implementing the flowchart illustrations and / or block diagrams. Figure One One or more processes and / or boxes Figure One A device that provides the functions specified in one or more boxes.
[0051] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure One One or more processes and / or boxes Figure One The steps of the function specified in one or more boxes.
[0052] While the specific embodiments of this disclosure have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of this disclosure. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of this disclosure are still within the scope of protection of this disclosure.
Claims
1. A time-frequency domain joint excitation polarization monitoring method for permeable reactive walls, characterized in that, include: Obtain data on the height, width, and thickness of the permeable reactive barrier; The measurement profile, measurement line length, electrode spacing, and number of measurement lines are determined based on the height, width, and thickness of the permeable reactive barrier. The measurement profile is divided into zones, and a representative measurement point is selected in each zone for frequency domain excitation polarization monitoring. The excitation polarization monitoring data is then inverted to obtain frequency domain parameters. The basic parameters for full-waveform time-domain excitation polarization monitoring are determined based on the frequency domain parameters. Time-domain excitation polarization monitoring is performed on all measuring points in each region based on the basic parameters for time-domain excitation polarization monitoring. The parameters of the time-frequency domain monitoring coincidence points are converted into frequency domain parameters through Fourier transform. The error of the time-domain excitation polarization measurement of the coincidence points relative to the frequency-domain excitation polarization measurement is calculated. Based on the error, it is determined whether the monitoring accuracy requirements are met. When the accuracy requirements are met, calculate the percentage error between the time-domain monitoring parameters of all grids and the initial excitation polarization parameters of the permeable reactive barrier, and determine the state of the permeable reactive barrier by the percentage error.
2. The time-frequency domain joint excitation polarization monitoring method for permeable reactive walls as described in claim 1, characterized in that, The length of the measuring line is determined by the height of the permeable reactive wall, the electrode spacing is determined by the thickness of the permeable reactive wall, the number of measuring lines is determined by the width of the permeable reactive wall and the electrode spacing, the measuring lines are evenly arranged along the width direction of the permeable reactive wall, and the length direction of the measuring line is perpendicular to the width direction of the permeable reactive wall, thereby determining the measurement profile.
3. The time-frequency domain joint excitation polarization monitoring method for permeable reactive walls as described in claim 1, characterized in that, The measurement profile is divided into zones, and a representative measurement point is selected in each zone for frequency-domain excited polarization monitoring. The monitoring data is then inverted to obtain multiple frequency-domain parameters, including resistivity, polarizability, and relaxation time. When determining the basic parameters for full-waveform time-domain excited polarization monitoring using these frequency-domain parameters, the following conditions must be met: full-waveform sampling frequency. f t Must meet f t ≥2 αf max Single test duration T Must meet T ≥3 τ max Current intensity Must meet ,in, U al This refers to the allowable accuracy of the instrument's measuring voltage. K max This represents the maximum value of the device coefficient on the cross-section. m min This represents the minimum value of the frequency polarizability among all the resulting parameters. ρ min This represents the minimum resistivity value in the frequency domain results. τ max The maximum relaxation time of the frequency domain result. f max The maximum characteristic frequency representing the measurement point, τ min The minimum relaxation time of the frequency domain result. α is Frequency coefficient.
4. The time-frequency domain joint excitation polarization monitoring method for permeable reactive walls as described in claim 1, characterized in that, Fourier transform is used to convert the time-frequency domain monitoring coincidence point parameters into frequency domain parameters. The error of the time-domain excitation polarization measurement of the coincidence point relative to the frequency-domain excitation polarization measurement is calculated. When calculating the error of the time-domain excitation polarization measurement of the coincidence point relative to the frequency-domain excitation polarization measurement, the error of each partition needs to be calculated. i Taking the polarizability error analysis of a region as an example, the error analysis expression is as follows: in, m ti For the first i Time-domain measurement of polarization at overlapping measurement points in each partition m pi For the first i Frequency domain measurement of polarization at overlapping measurement points in each partition; E ≤5%.
5. The time-frequency domain joint excitation polarization monitoring method for permeable reactive walls as described in claim 1, characterized in that, The calculated error of time-domain excitation polarization measurement relative to frequency-domain excitation polarization measurement must meet the following requirements: more than 80% of the parameters must meet the error requirements. If the requirements are not met, the time-domain monitoring parameters must be readjusted.
6. The time-frequency domain joint excitation polarization monitoring method for permeable reactive walls as described in claim 1, characterized in that, Once the results meet the error requirements, the time-domain excitation polarization parameters of all grids at the permeable reactive wall are taken, and the percentage error between the parameters and the excitation polarization parameters of the wall in the initial state is calculated as follows: in, n The number of sections in the cross-section. For the first t The average value of the time-domain polarizability measurement results at all measurement points in each partition. m 0 represents the measured polarizability of the wall in its initial state.
7. A time-frequency domain co-excitation polarization monitoring system for permeable reactive walls, characterized in that, include: The data acquisition and initialization module is used to acquire the height, width, and thickness data of the permeable reactive barrier; and to determine the measurement profile, measurement line length, electrode spacing, and number of measurement lines based on the height, width, and thickness of the permeable reactive barrier. The frequency domain excitation polarization module is used to divide the measurement profile into zones, select a representative measurement point in each zone for frequency domain excitation polarization monitoring, and invert the excitation polarization monitoring data to obtain frequency domain parameters. The time-domain excitation polarization module is used to determine the basic parameters for full-waveform time-domain excitation polarization monitoring based on the frequency domain parameters. Based on the basic parameters for time-domain excitation polarization monitoring, time-domain excitation polarization monitoring is performed on all measurement points in each region. The parameters of the time-frequency domain monitoring coincidence points are converted into frequency domain parameters through Fourier transform. The error of the time-domain excitation polarization measurement of the coincidence points relative to the frequency domain excitation polarization measurement is calculated. Based on the error, it is determined whether the monitoring accuracy requirements are met. The status monitoring module is used to calculate the percentage error between the time-domain monitoring parameters of all grids and the initial excitation polarization parameters of the permeable reactive barrier when the accuracy requirements are met, and to determine the status of the permeable reactive barrier by the percentage error.
8. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the time-frequency domain joint excitation polarization monitoring method for the permeable reactive wall as described in any one of claims 1-6.
9. A non-transitory computer-readable storage medium, characterized in that, The non-transitory computer-readable storage medium is used to store computer instructions, which, when executed by a processor, implement the time-frequency domain joint excitation polarization monitoring method for a permeable reactive wall as described in any one of claims 1-6.
10. An electronic device, characterized in that, include: The device includes a processor, a memory, and a computer program; wherein the processor is connected to the memory, the computer program is stored in the memory, and when the electronic device is running, the processor executes the computer program stored in the memory to enable the electronic device to perform the time-frequency domain joint excitation polarization monitoring method for permeable reactive walls as described in any one of claims 1-6.