Multi-dimensional concrete diaphragm wall full-section defect detection method based on electrical method

Abstract

The invention provides a multi-dimensional concrete diaphragm wall full-section defect detection method based on an electrical method, and the method comprises the steps: pre-burying five columns of longitudinal electrode probes and multiple layers of transverse electrode probes when a diaphragm wall body is poured, and forming a detection network; performing electrode control on the embedded electrode probe by using terminal equipment, performing defect detection according to requirements, and determining the working performance stability of the electrode probe and the control terminal; after a joint detection requirement is received, carrying out high-density resistivity method layered detection by using a transverse electrode from bottom to top, and counting a first abnormal low-resistance region existing in the whole section, and carrying out electric perspective method segmented detection by using a longitudinal electrode from left to right, and counting a second abnormal low-resistance region existing in the whole section; and superposing the first abnormal low-resistance region and the second abnormal low-resistance region, and taking the superposed region as a finally determined defect position. Based on the scheme provided by the invention, full-section defect identification and positioning of hidden engineering of the dam foundation diaphragm wall can be realized.

Description

Technical Field

[0001] The present application relates to the field of concrete anti-seepage wall defect detection, and in particular to a multi-dimensional concrete anti-seepage wall full-section defect detection method based on electrical methods. Background Art

[0002] Concrete anti-seepage wall is a commonly used anti-seepage measure in water conservancy projects. During the construction and operation stages, because the anti-seepage wall is a typical underground hidden project, it is impossible to observe and warn in time when there are phenomena such as poor wall continuity, voids, segregation, local mud inclusions, local looseness, cracks, insufficient burial depth, etc., which leads to the decay of the strength of the anti-seepage wall and the reduction of anti-seepage performance, bringing many safety hazards. Using an efficient, fast and reliable full-section defect detection method for hidden projects to accurately grasp the spatial distribution and distribution range of internal wall defects, it can well evaluate the continuity of the internal structure of the wall and provide a basis for the subsequent directional repair of anti-seepage wall defects.

[0003] In terms of detection and identification of impermeable wall defects, due to the characteristics of hidden engineering, it is impossible to identify and locate defects through intuitive observation, and traditional detection methods such as drilling sampling detection methods have limitations such as low efficiency, high cost, discontinuous detection results, and damage to the wall itself. At present, the detection of impermeable wall defects is more borrowed from geophysical science methods, such as ground penetrating radar method, electromagnetic wave CT method, elastic wave CT method, etc. These methods mainly use the differences in the physical properties of defects and the impermeable wall, surrounding foundation and other parts of the material. By considering the application of electric fields, magnetic fields, elastic waves and other physical fields, and using the differences in the absorption or reflection of different materials to the physical fields, the inversion images of the cross-section resistivity, absorption coefficient, etc. are obtained, and the abnormal areas are calibrated as the identified defect parts. On the one hand, this requires the application of a large range of artificial physical fields, and on the other hand, it is necessary to reasonably interpret the inversion result images of the cross-section detection. Therefore, the current commonly used methods cannot quickly and efficiently realize the identification and positioning of impermeable wall defects.

[0004] The current technical shortcomings are mainly concentrated in several aspects. First, it is impossible to achieve true non-destructive testing. Drilling sampling detection technology, elastic wave CT technology, electromagnetic wave CT technology, etc. all require drilling on the continuous wall, which destroys the continuity of the anti-seepage wall structure and affects the force performance of the anti-seepage wall. In addition, the drilling technology is inefficient and costly. Secondly, the current commonly used detection technology has the problem of shallow detection depth. It is believed that the applied physical field has attenuation during the transmission process, and the detection of the physical field is also affected by the range. Therefore, various geophysical science detection methods are currently unable to identify and locate deep-level defects, and many detection methods such as transient electromagnetic methods have detection depths related to the detection range. In actual engineering, it is impossible to increase the detection range indefinitely, so effective depth measurement cannot be obtained. Furthermore, the inversion image results of these detection methods have multiple solutions. Various factors can cause abnormal areas in the detection image. It is impossible to accurately determine the defect location simply by determining the abnormal area. Summary of the invention

[0005] The present application aims to solve one of the technical problems in the related art at least to some extent.

[0006] To this end, the purpose of this application is to propose a multi-dimensional concrete anti-seepage wall full-section defect detection method based on electrical methods, so as to realize the full-section defect identification and positioning of the dam foundation anti-seepage wall, a hidden project.

[0007] To achieve the above-mentioned purpose, an embodiment of the present application proposes a multi-dimensional concrete anti-seepage wall full-section defect detection method based on electrical method, comprising:

[0008] When pouring the anti-seepage wall, five rows of longitudinal electrode probes and multiple layers of transverse electrode probes are embedded to form a detection network;

[0009] Use the terminal equipment to control the buried electrode probes, perform defect detection as required, and determine the working performance stability of the electrode probes and control terminals;

[0010] After receiving the joint detection request, the high-density resistivity method is used to perform layered detection from bottom to top using the transverse electrode, and the first abnormal low-resistance area in the whole section is counted, and the electro-perspective method is used to perform segmented detection from left to right using the longitudinal electrode, and the second abnormal low-resistance area in the whole section is counted;

[0011] The first abnormally low resistance area and the second abnormally low resistance area are superimposed, and the overlapping area thereof is taken as the final defect position.

[0012] Optionally, when pouring the anti-seepage wall, five rows of longitudinal electrode probes and multiple layers of transverse electrode probes are embedded to form a detection network, including:

[0013] S11. According to the construction sequence, use drilling and milling equipment to dig trenches and perform mud wall consolidation;

[0014] S12, according to the depth of the anti-seepage wall, the electrode probes are arranged at a first preset interval, and concrete is poured for protection first, and the electrode probes with prefabricated concrete protection blocks are gradually lowered at the designated boundary, i.e., the location of the longitudinal probes;

[0015] S13, completing the concrete pouring of the corresponding height of the middle part of the longitudinal probe;

[0016] S14, when pouring to the designated high level, according to the span of the anti-seepage wall, the electrode probes are arranged at a second preset spacing, and concrete is poured first for protection, and the electrode probes with prefabricated concrete protection blocks are lowered, and the top of the probes are provided with insulating rings and signal isolators, and the resistance value electrical signals are transmitted upward, completing the horizontal electrode probe arrangement;

[0017] S15, continue pouring the upper layer of concrete anti-seepage wall;

[0018] S16. Casting is performed according to steps S12-S15. The longitudinal electrode rows are arranged by drilling holes at intervals of half the maximum depth, and the transverse electrode layers are arranged at intervals of one quarter of the span until the anti-seepage wall casting is completed.

[0019] Optionally, the method of using the terminal device to control the buried electrode probe and perform defect detection as required to determine the working performance stability of the electrode probe and the control terminal includes:

[0020] Conduct high-density resistivity and electro-perspective testing on buried electrode probes to test their performance;

[0021] Test the sensitivity and accuracy of the supporting control terminal and detection signal processing system, and obtain the original resistivity distribution image of the anti-seepage wall section.

[0022] Optionally, the buried electrode probe is subjected to high-density resistivity and electro-perspective testing to test its performance, including:

[0023] Use the terminal equipment to perform high-density resistivity testing on the transversely arranged electrode probes, use the initial electrode spacing as the actual spacing, and perform a round of routing measurements to check whether the transversely arranged electrode probes can work normally;

[0024] Using the terminal equipment, the longitudinally arranged electrode probes are tested by electro-perspective method. The initial electrode spacing is used as the actual spacing. A round of wiring measurement is performed to check whether the longitudinally arranged electrode probes can work normally.

[0025] Perform complete measurements to verify that the entire detection system is functioning properly.

[0026] Optionally, the test supporting control terminal and the detection signal processing system sensitivity and accuracy, and obtaining the original cut-off wall section apparent resistivity distribution image, include:

[0027] Using terminal equipment, high-density resistivity method detection is performed on transversely arranged electrode probes by setting different power-on and detection modes to test the difference and consistency of the test effects of different power-on and detection modes, wherein the different power-on and detection modes include a two-pole device, a Wenner device, a dipole device, a three-pole device, a combined profile device, a differential device, a Schlumberger 1 device, and a Schlumberger 2 device;

[0028] Adjust the initial electrode spacing and examine the effect of the electrode spacing on the apparent resistivity test results.

[0029] Using the Wenner dipole device to perform layered detection, the first full-section apparent resistivity image was obtained;

[0030] Repeat the above three steps for the longitudinal electrode to obtain a second full-section apparent resistivity image;

[0031] The first full-section apparent resistivity image using the transverse electrode probe arrangement is compared and denoised with the second full-section apparent resistivity image using the longitudinal electrode probe arrangement to obtain an initial full-section apparent resistivity map of the cut-off wall.

[0032] Optionally, before receiving the joint testing request, it also includes:

[0033] Based on the power station's seepage monitoring and pore pressure monitoring data, determine whether there is large-scale leakage and surge in pore water pressure. If so, initiate joint testing.

[0034] Optionally, the method of performing layered detection by a high-density resistivity method from bottom to top using a transverse electrode and counting the first abnormally low-resistance area existing in the entire section includes:

[0035] For each layer of transversely arranged electrode probes, high-density resistivity method layered detection is performed. The detection principle is as follows:

[0036]

[0037] J=σE

[0038]

[0039]

[0040] Where R is the resistance, ρ is the resistivity, L is the distance between the electrodes, S is the cross-sectional area, J is the current density, σ is the conductivity, and E is the electric field strength. is the gradient of the electric potential, is the divergence of the current density, is the unit volume, δ(xx s )δ(yy s )δ(zz s ) is the Dirac delta function, which indicates that the current source is located at a specific position (x z ,y z , z z ), u is the electric potential, ρI is the product of current I and resistivity, r is the distance between the measuring point and the current source, r A With r B Indicates the distance from two different electrodes to the measurement point;

[0041] The interlayer apparent resistivities obtained by layered detection are superimposed together to form a third full-section apparent resistivity image;

[0042] Based on the third full-section apparent resistivity image, all areas with abnormal apparent resistivity are marked as the first abnormally low-resistance areas.

[0043] Optionally, the electro-perspective detection is performed from left to right using longitudinal electrodes, and the second abnormal low-resistance area existing in the whole section is counted, including:

[0044] The longitudinal electrode is used to perform electro-perspective detection in the width direction to form a fourth full-section apparent resistivity image;

[0045] Based on the fourth full-section apparent resistivity image, all areas with abnormal apparent resistivity are marked as the second abnormally low-resistance areas.

[0046] Optionally, the superimposing the first abnormally low resistance area and the second abnormally low resistance area and taking the overlapping area thereof as the finally determined defect position includes:

[0047] In order to narrow the range of the abnormal apparent resistivity area, the first abnormal low-resistance area and the second abnormal low-resistance area are superimposed and analyzed to obtain the overlapping area;

[0048] The overlapping area is taken as the final defect position, and the range of the overlapping area is taken as the final defect size.

[0049] The technical solution provided by the embodiments of the present application brings at least the following beneficial effects:

[0050] First, predictive electrode layout: Based on the traditional high-density resistivity detection method, electrodes are laid on the surface, which cannot achieve effective depth measurement, and the electro-perspective method has the disadvantage of damaging the integrity of the anti-seepage wall during later drilling. This application proposes a detection electrode pre-embedding method that serves the later real-time electrical detection, which can be used for layered detection to increase the depth measurement. In addition, since the electrodes are buried during the construction process of the anti-seepage wall, the integrity of the wall is guaranteed, and the mechanical and structural properties of the wall in a complex environment are guaranteed.

[0051] Second, depth gain and full cross-section coverage: The traditional high-density resistivity method requires the deployment of electrodes on the surface of the detection body, and its effective detection depth is relatively limited, with a maximum depth of only 20-30m underground. The applicant adopts a layered deployment scheme to achieve layered segment detection based on the downward electrode layer. The bottom electrode can be used to achieve deep-level defect detection, and multi-layer electrodes can be used to achieve full cross-section coverage of the underground hidden project detection range.

[0052] Third, convenient electro-fluoroscopic detection: Traditional inter-hole DC electro-fluoroscopic method and other CT methods require on-site drilling, which not only destroys the integrity of the anti-seepage wall, but also greatly increases the workload and difficulty of the work. This application proposes a method of pre-embedded electrodes during the wall construction process. When detection is required during the operation and maintenance period, the corresponding two-hole electrodes are directly selected for terminal electrical signal control, electrical signal release and reception, and inter-hole DC electro-fluoroscopic imaging can be completed, which greatly reduces the amount of later drilling construction and construction costs.

[0053] Fourth, comprehensive verification avoids the problem of multiple solutions: After electrical detection, the apparent resistivity image of the measured section will be obtained. In engineering, the apparent resistivity image is analyzed to find the abnormal resistance area in the image and then determine the defect location. Then, the cause of the abnormal resistance area in the electrical detection has multiple solutions. This application proposes a defect location method that comprehensively utilizes high-density electrical layered detection and inter-hole DC electric perspective detection. By comparing the two detection results, the intersection is obtained as the defect location result, which greatly reduces the survey error caused by the multiple solutions of the detection results and has important engineering significance.

[0054] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0056] Figure 1 It is a flow chart of a method for detecting full-section defects of a multi-dimensional concrete anti-seepage wall based on electrical method according to an embodiment of the present application;

[0057] Figure 2 It is a flow chart of a method for detecting full-section defects of a multi-dimensional concrete anti-seepage wall based on electrical method according to an embodiment of the present application;

[0058] Figure 3 It is a flow chart of a method for detecting full-section defects of a multi-dimensional concrete anti-seepage wall based on electrical method according to an embodiment of the present application;

[0059] Figure 4 is a schematic diagram of the layout of anti-seepage wall detection electrodes according to an embodiment of the present application;

[0060] Figure 5 It is a three-dimensional model diagram of an anti-seepage wall with detection electrodes at the base of an earth-rock dam according to an embodiment of the present application;

[0061] Figure 6(a)-Figure 6(h) This is a layered electrode layout process shown in an embodiment of the present application;

[0062] Figure 7 It is a schematic diagram of an electrode probe with a concrete protective shell according to an embodiment of the present application. DETAILED DESCRIPTION

[0063] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0064] The following describes, with reference to the accompanying drawings, a multi-dimensional concrete anti-seepage wall full-section defect detection method based on electrical methods in an embodiment of the present application.

[0065] like Figure 1 , Figure 2 and Figure 3 As shown, the method comprises the following steps:

[0066] Step S1: when pouring the anti-seepage wall, five rows of longitudinal electrode probes and multiple layers of transverse electrode probes are embedded to form a detection network.

[0067] In the embodiment of the present application, the pre-buried longitudinal electrode probes and transverse electrode probes form a dense detection network, ensuring all-round coverage of the entire anti-seepage wall. This layout can maximize the coverage of the detection, reduce blind spots, and, by pre-buried electrode probes, it is convenient to locate specific detection points in subsequent detection, thereby improving the accuracy of the detection.

[0068] Specifically, step S1 also includes:

[0069] S11. According to the construction sequence, use drilling and milling equipment to dig trenches and perform mud wall consolidation;

[0070] S12, according to the depth of the anti-seepage wall, the electrode probes are arranged at a first preset interval, and concrete is poured for protection first, and the electrode probes with prefabricated concrete protection blocks are gradually lowered at the designated boundary, i.e., the location of the longitudinal probes;

[0071] S13, completing the concrete pouring of the corresponding height of the middle part of the longitudinal probe;

[0072] S14, when pouring to the designated high level, according to the span of the anti-seepage wall, the electrode probes are arranged at a second preset spacing, and concrete is poured first for protection, and the electrode probes with prefabricated concrete protection blocks are lowered, and the top of the probes are provided with insulating rings and signal isolators, and the resistance value electrical signals are transmitted upward, completing the horizontal electrode probe arrangement;

[0073] S15, continue pouring the upper layer of concrete anti-seepage wall;

[0074] S16. Casting is performed according to steps S12-S15. The longitudinal electrode rows are arranged by drilling holes at intervals of half the maximum depth, and the transverse electrode layers are arranged at intervals of one quarter of the span until the anti-seepage wall casting is completed.

[0075] In a possible embodiment, in step S12, the electrode probes are arranged at intervals of 1 m according to the depth of the anti-seepage wall.

[0076] In another possible embodiment, in step S14, the electrode probes are arranged at intervals of 4 m according to the span of the cut-off wall.

[0077] Further, the schematic diagram of the arrangement of the anti-seepage wall detection electrodes shown in the embodiment of the present application is as follows Figure 4 shown.

[0078] The three-dimensional model of the earth-rock dam foundation with detection electrode anti-seepage wall shown in the embodiment of the present application is as follows Figure 5 shown.

[0079] The layered electrode arrangement process shown in the embodiment of the present application is as follows Figure 6(a)-Figure 6(h) shown.

[0080] Specifically, Figure 6(a) shows the excavation of the anti-seepage wall trench section, Figure 6(b) shows the pouring of part of the concrete, Figure 6(c) shows the embedded protective probe, Figure 6(d) shows the completion of the casting of the trench section, Figure 6(e) shows the excavation of the next trench section, Figure 6(f) shows the pouring of concrete and the embedded probe, Figure 6(g) shows the completion of the casting of the trench section, and Figure 6(h) shows the completion of the casting of the anti-seepage wall.

[0081] The schematic diagram of the electrode probe with a concrete protective shell shown in the embodiment of the present application is as follows Figure 7 shown.

[0082] Step S2: Use the terminal equipment to control the buried electrode probes, perform defect detection as required, and determine the working performance stability of the electrode probes and the control terminal.

[0083] This step is used to determine the working performance stability of the electrode probe and the control terminal. Performing this round of testing before the formal test can detect and eliminate potential hardware or software failures in advance, ensuring the smooth progress of subsequent tests.

[0084] It should be noted that the embodiment of the present application controls and monitors the status of the electrode probe in real time through the terminal device, can promptly respond to and handle problems found during the detection process, and the terminal device can remotely control the power-on status of the electrode probe, select a suitable detection method and detection area according to actual needs, thereby improving the flexibility and efficiency of the detection, and using the terminal device to automatically control the electrode probe, reducing the need for manual intervention, improving the degree of automation of the detection, and reducing the possibility of human error.

[0085] Specifically, step S2 also includes:

[0086] S21. Conduct high-density resistivity and electro-perspective testing on the buried electrode probes to test their performance.

[0087] Specifically, step S21 also includes:

[0088] S211. Use the terminal equipment to perform high-density resistivity detection on the transversely arranged electrode probes, use the initial electrode spacing as the actual spacing, and perform a round of routing measurement to check whether the transversely arranged electrode probes can work normally.

[0089] In the embodiment of the present application, by performing high-density resistivity testing, it is possible to verify whether the horizontally arranged electrodes can work properly. This includes checking whether the electrodes can correctly transmit current and receive voltage signals and confirming whether the connection between the electrodes and the terminal equipment is intact to ensure that there is no disconnection or poor contact.

[0090] Furthermore, using the initial electrode spacing for testing can verify whether the electrode spacing is appropriate and meets the design requirements. If the spacing is not appropriate, it may need to be adjusted. Through a round of routing measurements, the effectiveness of the data acquisition system can be preliminarily verified to ensure the accuracy and reliability of the data.

[0091] S212. Using the terminal equipment, perform electro-perspective detection on the longitudinally arranged electrode probes, use the initial electrode spacing as the actual spacing, perform a round of routing measurement, and check whether the longitudinally arranged electrode probes can work normally.

[0092] Similar to step S211, by performing electrofluoroscopic detection on the longitudinally arranged electrodes, it is possible to verify whether the longitudinal electrodes can operate normally, including current transmission and voltage reception, and confirm whether the connection between the longitudinal electrodes and the terminal device is intact to ensure that there is no disconnection or poor contact.

[0093] Furthermore, using the initial electrode spacing for testing can verify whether the electrode spacing is appropriate and meets the design requirements. If the spacing is not appropriate, it may need to be adjusted. Through a round of routing measurements, the effectiveness of the data acquisition system can be preliminarily verified to ensure the accuracy and reliability of the data.

[0094] S213. Perform complete measurement to check whether the entire detection system can work normally.

[0095] It should be noted that the entire detection system refers to the entire system used to detect anti-seepage wall defects, including terminal equipment, electrode probes and their connections and control systems. By conducting complete measurements, it is possible to fully test whether the various components of this system can work together normally, ensuring that the detection process can proceed smoothly and the data is accurate and reliable.

[0096] S22. Test the sensitivity and accuracy of the supporting control terminal and the detection signal processing system to obtain the apparent resistivity distribution image of the original anti-seepage wall section.

[0097] Specifically, step S22 also includes:

[0098] S221. Using the terminal equipment, perform high-density resistivity testing on the transversely arranged electrode probes by setting different energization and detection modes, and test the difference and consistency of the test results of the different energization and detection modes;

[0099] S222. Adjust the initial electrode spacing and examine the effect of the electrode spacing on the apparent resistivity test results.

[0100] S223, performing layered detection using a Wenner dipole device to obtain a first full-section apparent resistivity image;

[0101] S224, repeat the above three steps for the longitudinal electrode to obtain a second full-section apparent resistivity image;

[0102] S225. Compare and reduce noise on the first full-section apparent resistivity image using the transverse electrode probe arrangement and the second full-section apparent resistivity image using the longitudinal electrode probe arrangement to obtain an initial apparent resistivity map of the full section of the cut-off wall.

[0103] It should be noted that the different power-on and detection methods mentioned here refer to the different electrode arrangements used in the high-density resistivity detection process. Each arrangement has its own characteristics and is suitable for different detection purposes and environmental conditions, including two-pole device, Wenner device, dipole device, three-pole device, combined profile device, differential device, Schlumberger 1 device, and Schlumberger 2 device.

[0104] Among them, the two-electrode device refers to the use of two electrodes, one for power supply and the other for receiving current signals. It is simple but has low resolution.

[0105] The Wenner device refers to the use of four electrodes, arranged in sequence, with the middle two used for power supply and the outer two for voltage measurement. It is characterized by providing higher resolution and better stability.

[0106] The dipole device refers to the use of four electrodes, two adjacent electrodes are powered, and the other two adjacent electrodes are used to measure the voltage difference. The characteristic is that it can eliminate the influence of the uniform background field and is suitable for detecting local anomalies.

[0107] The three-pole device refers to the use of three electrodes, one of which is powered and the other two adjacent electrodes are used for voltage measurement. The characteristic is that it can take into account both resolution and detection depth;

[0108] Combined profile device refers to a device that combines the advantages of different devices and obtains more comprehensive information by combining multiple electrode arrangements. Its characteristic is that it can obtain richer geological information.

[0109] Differential devices use three electrodes, two for power supply and one in the center to measure voltage, and are suitable for detecting subtle changes.

[0110] The Schlumberger 1 device refers to four electrodes arranged in a symmetrical manner, with two power supply electrodes located in the center and two measuring electrodes located on both sides. The distance between the power supply electrodes is equal to the distance between the measuring electrodes. It is suitable for deep detection.

[0111] The Schlumberger 2 device refers to a device in which four electrodes are also arranged in a row, but the distances between the two power supply electrodes and the two measuring electrodes are not equal. Usually, the distance between the power supply electrodes is greater than the distance between the measuring electrodes. The characteristic of the device is that it can detect deeper geological structures.

[0112] Step S3, after receiving the joint detection request, use the transverse electrodes to perform layered detection by the high-density resistivity method from bottom to top, and count the first abnormal low-resistance area in the entire section, and use the longitudinal electrodes to perform segmented detection by the electro-perspective method from left to right, and count the second abnormal low-resistance area in the entire section.

[0113] It can be understood that by using the high-density resistivity method to detect the resistivity changes in the wall in layers, the abnormal areas in the vertical direction can be found. By using the electro-perspective method to detect the longitudinal electrodes, the resistivity distribution inside the wall can be observed in sections, and the abnormal areas in the horizontal direction can be found.

[0114] like Figure 2 and Figure 3 As shown, the conditions for receiving the joint detection request are:

[0115] Based on the power station's seepage monitoring and pore pressure monitoring data, determine whether there is large-scale leakage and surge in pore water pressure. If so, initiate joint testing.

[0116] As a possible implementation method, the process of using the lateral electrode to perform high-density resistivity layered detection from bottom to top and counting the first abnormal low-resistance area in the entire section is as follows:

[0117] For each layer of transversely arranged electrode probes, high-density resistivity method layered detection is performed. The detection principle is as follows:

[0118]

[0119] J=σE

[0120]

[0121] Where R is the resistance, ρ is the resistivity, L is the distance between the electrodes, S is the cross-sectional area, J is the current density, σ is the conductivity, and E is the electric field strength. is the gradient of the electric potential, is the divergence of the current density, is the unit volume, δ(xx s )δ(yy s )δ(zz s ) is the Dirac delta function, which indicates that the current source is located at a specific position (x z ,y z , z z ), u is the electric potential, ρI is the product of current I and resistivity, r is the distance between the measuring point and the current source, r A With r B Indicates the distance from two different electrodes to the measurement point.

[0122] Then, the interlayer apparent resistivities obtained by the layered detection are superimposed together to form a third full-section apparent resistivity image; and based on the third full-section apparent resistivity image, all abnormal apparent resistivity areas are marked as first abnormal low-resistance areas.

[0123] Furthermore, the process of using the longitudinal electrode to perform segmented detection from left to right using the electro-perspective method and counting the second abnormal low-resistance area in the entire section is as follows:

[0124] The electro-perspective method using longitudinal electrodes is used to perform segmented detection along the width direction to form a fourth full-section apparent resistivity image; based on the fourth full-section apparent resistivity image, all abnormal apparent resistivity areas are marked as second abnormal low-resistance areas.

[0125] It should be noted that in this step, by counting the first abnormal low-resistance area and the second abnormal low-resistance area in the entire section, the abnormal conditions inside the wall can be fully recorded, providing detailed data support for subsequent analysis, and through two different detection methods (high-density resistivity method and electro-perspective method), cross-verification can be carried out from different angles to improve the accuracy of the detection results.

[0126] Step S4, superimposing the first abnormally low resistance area and the second abnormally low resistance area, and taking the overlapping area as the final defect position.

[0127] In the embodiment of the present application, in order to narrow the range of the abnormal apparent resistivity zone, the first abnormal low-resistance zone and the second abnormal low-resistance zone are superimposed and analyzed to obtain the overlapping area.

[0128] It should be noted that by superimposing the results of transverse and longitudinal inspections, the defect position inside the wall can be accurately located, especially the overlapping area, indicating that there are abnormalities in this area in both directions, which is very likely to be the real defect position.

[0129] Furthermore, the overlapping area is used as the final defect position, and the size of the overlapping area is used as the final defect size, thereby reducing false positives or false negatives caused by a single detection method and improving the reliability of the detection result.

[0130] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps recorded in this application can be executed in parallel, sequentially or in different orders, as long as the expected results of the technical solution of this application can be achieved, and this document is not limited here.

[0131] The above specific implementations do not constitute a limitation on the protection scope of this application. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principles of this application should be included in the protection scope of this application.

Claims

1. A multi-dimensional concrete anti-seepage wall full-section defect detection method based on electrical method, characterized in that: include: When pouring the anti-seepage wall, five rows of longitudinal electrode probes and multiple layers of transverse electrode probes are pre-buried to form a comprehensive detection network; Use terminal equipment to accurately control the buried electrode probes and perform defect detection as required to ensure stable and reliable working performance of the electrode probes and control terminals; After receiving the joint detection request, the high-density resistivity method is used to perform layered detection from bottom to top using the transverse electrode to count the first abnormal low-resistance area of ​​the entire section; at the same time, the electro-perspective method is used to perform segmented detection from left to right using the longitudinal electrode to count the second abnormal low-resistance area of ​​the entire section; The first abnormally low resistance area and the second abnormally low resistance area are superimposed and compared, and the overlapping area of ​​the two is determined as the final defect position.

2. The method according to claim 1, characterized in that The five rows of longitudinal electrode probes and the multiple layers of transverse electrode probes are embedded in advance when pouring the anti-seepage wall to form a detection network. The specific steps include: S11. According to the construction sequence, use drilling and milling equipment to dig trenches and perform mud wall consolidation; S12, according to the depth of the anti-seepage wall, the electrode probes are arranged according to the first preset spacing, concrete is poured for protection first, and the electrode probes with prefabricated concrete protection blocks are gradually lowered at the designated boundary, i.e., the location of the longitudinal probes; S13, completing the concrete pouring of the corresponding height of the middle part of the longitudinal probe; S14, when pouring to the designated high level, according to the span of the anti-seepage wall, the electrode probes are arranged at a second preset spacing, concrete is poured first for protection, and the electrode probes with prefabricated concrete protection blocks are lowered, and the top of the probes are provided with insulating rings and signal isolators, so that the resistance value electrical signals are transmitted upward, and the lateral electrode probe arrangement is completed; S15, continue pouring the upper layer of concrete anti-seepage wall; S16. Casting is performed according to steps S12-S15. The longitudinal electrode rows are arranged by drilling holes at intervals of half the maximum depth, and the transverse electrode layers are arranged at intervals of one quarter of the span until the anti-seepage wall casting is completed.

3. The method according to claim 1, characterized in that The method of using the terminal equipment to control the buried electrode probe and perform defect detection as required to determine the working performance stability of the electrode probe and the control terminal specifically includes: Conduct high-density resistivity and electro-perspective testing on buried electrode probes to evaluate their performance; Test the sensitivity and accuracy of the supporting control terminal and detection signal processing system to obtain the original resistivity distribution image of the cut-off wall section.

4. The method according to claim 3, characterized in that The buried electrode probe is tested by high-density resistivity method and electro-perspective method to test its performance, including: Use the terminal equipment to perform high-density resistivity testing on the transversely arranged electrode probes, use the initial electrode spacing as the actual spacing, and perform a round of routing measurements to check whether the transversely arranged electrode probes can work normally; Using the terminal equipment, the longitudinally arranged electrode probes are tested by electro-perspective method. The initial electrode spacing is used as the actual spacing. A round of wiring measurement is performed to check whether the longitudinally arranged electrode probes can work normally. Carry out a complete set of measurement processes to verify the working performance of the entire detection system.

5. The method according to claim 3, characterized in that: The test supporting control terminal and the detection signal processing system sensitivity and accuracy, and obtaining the original cut-off wall section apparent resistivity distribution image, include: Using terminal equipment, high-density resistivity method detection is performed on transversely arranged electrode probes by setting different power-on and detection modes, and the difference and consistency of the inspection effects of different power-on and detection modes are evaluated, wherein the different power-on and detection modes include a two-pole device, a Wenner device, a dipole device, a three-pole device, a combined profile device, a differential device, a Schlumberger 1 device, and a Schlumberger 2 device; Adjust the initial electrode spacing and examine the effect of the electrode spacing on the apparent resistivity test results. Using the Wenner device and the dipole device to perform layered detection, the first full-section apparent resistivity image was obtained; Repeat steps 1 to 3 for the longitudinal electrode to obtain a second full-section apparent resistivity image; The first full-section apparent resistivity image using the transverse electrode probe arrangement is compared and denoised with the second full-section apparent resistivity image using the longitudinal electrode probe arrangement to obtain an initial full-section apparent resistivity map of the cut-off wall.

6. The method according to claim 1, characterized in that Before receiving the joint testing request, it also includes: Based on the power station's seepage monitoring and pore pressure monitoring data, determine whether there is large-scale leakage and surge in pore water pressure. If so, initiate joint testing.

7. The method according to claim 1, characterized in that The method of using the lateral electrodes to perform layered detection using the high-density resistivity method from bottom to top and counting the first abnormal low-resistance area existing in the entire section includes: For each layer of transversely arranged electrode probes, high-density resistivity method layered detection is performed. The detection principle is as follows: J=σE Where R is the resistance, ρ is the resistivity, L is the distance between the electrodes, S is the cross-sectional area, J is the current density, σ is the conductivity, and E is the electric field strength. is the gradient of the electric potential, is the divergence of the current density, is the unit volume, δ(xx s )δ(yy s )δ(zz s ) is the Dirac delta function, which indicates that the current source is located at a specific position (x z ,y z , z z ), u is the electric potential, ρI is the product of current I and resistivity, r is the distance between the measuring point and the current source, r A With r B Indicates the distance from two different electrodes to the measurement point; The interlayer apparent resistivities obtained by layered detection are superimposed together to form a third full-section apparent resistivity image; Based on the third full-section apparent resistivity image, all areas with abnormal apparent resistivity are marked as the first abnormally low-resistance areas.

8. The method according to claim 1, characterized in that: The electro-perspective detection is performed from left to right using longitudinal electrodes, and the second abnormal low-resistance area existing in the whole section is counted, including: The longitudinal electrode is used to perform electro-perspective detection in the width direction to form a fourth full-section apparent resistivity image; Based on the fourth full-section apparent resistivity image, all areas with abnormal apparent resistivity are marked as the second abnormally low-resistance areas.

9. The method according to any one of claims 7-8, characterized in that: The step of superimposing the first abnormally low resistance area and the second abnormally low resistance area and taking the overlapping area thereof as the finally determined defect position includes: In order to narrow the range of the abnormal apparent resistivity area, the first abnormal low-resistance area and the second abnormal low-resistance area are superimposed and analyzed to obtain the overlapping area; The overlapping area is taken as the final defect position, and the size of the overlapping area is taken as the final defect size.

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