Geotechnical investigation method based on variable-frequency high-density electrical method and processing system thereof

Abstract

The invention discloses a geotechnical investigation method based on a variable-frequency high-density electrical method and a processing system thereof, and relates to the technical field of geotechnical investigation, and the geotechnical investigation method comprises the following steps: arranging a series of electrodes on the earth surface of a to-be-investigated area to form a high-density electrode array, the layout spacing of the electrode array is dynamically adjusted according to the geological features and the required resolution of a to-be-surveyed area, and the coverage range of current injection and potential measurement is optimized; and current with different frequencies is applied to the underground rock-soil stratum through the electrode array. Through the high-density electrode array, the dynamic adjustment of the distance between the electrodes and the optimization of current injection and measurement, the exploration precision is remarkably improved, the multi-frequency current is adopted to detect rock and soil stratums of different depths, the electrical contrast is enhanced, the geological anomalous body is effectively identified, and high-precision measurement equipment and an advanced data processing algorithm are combined. The high-resolution resistivity image is generated, the accuracy of geological analysis is improved, a scientific basis is provided for engineering design, and the construction risk is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of geotechnical exploration, and in particular to a geotechnical exploration method based on variable frequency high-density electrical method and a processing system thereof. Background Art

[0002] Geotechnical exploration based on variable frequency high-density electrical method is a method of detecting the structure and properties of underground rock and soil using resistivity measurement technology. It obtains resistivity information of rock and soil at different depths underground by arranging a series of electrodes on the surface, applying current and measuring the potential difference. The resistivity of rock and soil is affected by many factors, including the composition, water content, porosity and temperature of the rock and soil. Therefore, the distribution of underground rock and soil and its physical properties can be inferred through high-density electrical method.

[0003] In specific operations, the high-density electrical method applies current and measures the response through densely arranged electrode arrays to obtain resistivity cross-section images. These images can intuitively show the changes in the electrical characteristics of rock and soil bodies at different depths underground, helping geotechnical engineers to identify geological anomalies such as groundwater, cracks, cavities, and gas-bearing layers, and evaluate the safety and stability of projects. This method has the advantages of non-destructive testing, wide coverage, and high detection accuracy, and has been widely used in geological exploration, environmental monitoring, and engineering construction.

[0004] The prior art has the following deficiencies:

[0005] In complex geological environments, how to accurately identify and distinguish the different electrical characteristics of underground rock formations to improve the resolution and accuracy of geotechnical exploration is a key issue. In traditional high-density electrical exploration, due to the small differences in the electrical properties of rock formations and the influence of multiple factors such as groundwater, mineral composition, and pore structure, there is a large uncertainty in the resistivity measurement results. This uncertainty makes it difficult to accurately distinguish different rock formations when interpreting data, which in turn affects the reliability of the exploration results. Therefore, an improved method is needed to enhance the contrast of electrical characteristics and improve the resolution and accuracy of data in order to more effectively identify and distinguish special rock formations in complex geological environments.

[0006] The above information disclosed in this Background section is only for enhancement of understanding of the background of the present disclosure and therefore it may contain information that does not form the prior art that is already known to one of ordinary skill in the art. Summary of the invention

[0007] The purpose of the present invention is to provide a geotechnical survey method and processing system based on variable frequency high-density electrical method, which significantly improves the survey accuracy and resolution by laying out a high-density electrode array and dynamically adjusting the electrode spacing to optimize current injection and potential measurement. A multi-frequency current injection strategy is adopted to detect geotechnical layers of different depths by combining low-frequency and high-frequency currents, enhance electrical contrast, and effectively identify geological anomaly areas; high-precision potential difference measurement equipment is combined with advanced data processing algorithms to generate high-resolution underground resistivity distribution images, and comprehensive analysis is performed through multi-source data fusion to improve the accuracy of geological body analysis and the reliability of survey reports, provide a scientific basis for engineering design and decision-making, and reduce construction risks, so as to solve the problems in the above-mentioned background technology.

[0008] In order to achieve the above object, the present invention provides the following technical solution: a geotechnical exploration method based on variable frequency high-density electrical method, comprising the following steps:

[0009] A series of electrodes are laid out on the surface of the area to be surveyed to form a high-density electrode array. The spacing of the electrode array is dynamically adjusted according to the geological characteristics and required resolution of the area to be surveyed to optimize the coverage of current injection and potential measurement;

[0010] Applying currents of different frequencies to underground rock formations through an electrode array. Currents of different frequencies include low-frequency currents and high-frequency currents. Low-frequency currents are used to penetrate deep rock formations, while high-frequency currents are used to detect shallow fine structures and enhance the electrical contrast of rock formations at different depths.

[0011] While injecting current, a high-precision potential difference measuring device is used to collect the potential difference data between the electrodes. The measuring device has a real-time calibration function to eliminate the influence of environmental noise and electrode contact resistance, ensuring the accuracy and reliability of the potential difference data.

[0012] Perform multi-dimensional data fusion processing on the collected potential difference data, use feature enhancement algorithm and inversion algorithm to generate high-resolution underground resistivity distribution images, display the changes in electrical characteristics of different rock and soil strata, and automatically identify potential geological anomaly areas;

[0013] Based on the generated resistivity distribution image, data interpretation and analysis are carried out in combination with geological background information to determine the nature, thickness and distribution of underground rock strata, and generate a detailed geotechnical investigation report to guide subsequent engineering design and decision-making.

[0014] Preferably, the electrode array is arranged in an adaptive manner, and the density and distribution of the electrodes are adjusted in real time through preliminary survey data, so as to increase the electrode density in areas with complex geological conditions or geological structures, thereby improving the resistivity measurement accuracy and resolution in the area. The adaptive arrangement can be achieved through a mobile electrode platform or a remote control electrode deployment system, ensuring that the electrode position and spacing can be quickly adjusted during the survey process to cope with different complex geological bodies and specific survey needs.

[0015] Preferably, the current application of different frequencies includes a multi-frequency current sequence that increases in sequence, from ultra-low frequency to ultra-high frequency, so as to obtain rock formation data of different depths and different electrical characteristics. The current application time of each frequency can be automatically adjusted according to specific geological conditions to ensure sufficient detection and analysis of different rock formations, maximize electrical contrast, and improve the accuracy of the overall survey.

[0016] Preferably, the high-precision potential difference measurement device further includes a synchronous measurement device of multiple channels, which can simultaneously collect the potential difference between multiple electrodes in real time. The device uses a low-noise amplifier and a high-precision analog-to-digital converter, so that the accuracy of the potential difference measurement can be ensured even when the signal is weak or there is high background noise. The device also has an automatic detection function, which can issue an alarm when the electrode contact is poor or the data is abnormal, prompting recalibration or adjustment of the measurement.

[0017] Preferably, the multi-dimensional data fusion processing includes time-space domain fusion and frequency domain fusion, which combines resistivity data of different time, space and frequency, eliminates noise and measurement errors, and improves the integrity and accuracy of the data. Time-space domain fusion realizes the coordinated processing of different data by considering the time series of current application and the spatial layout of electrode layout; frequency domain fusion removes useless high-frequency noise and retains key low-frequency features through spectrum analysis, thereby further improving the resolution of underground resistivity distribution images.

[0018] Preferably, the feature enhancement algorithm includes a deep learning neural network model, which is trained to identify the electrical characteristics of complex rock formations and potential geological anomaly areas. The model is trained based on a large amount of actual survey data, and can automatically learn the patterns and laws of different electrical characteristics to improve the accuracy and reliability of geological anomaly identification. At the same time, the model can also continue to learn and update according to new survey data to maintain efficient geological analysis capabilities.

[0019] Preferably, the inversion algorithm adopts a combination of constrained inversion and multi-layer inversion to improve the computational efficiency while ensuring the accuracy of data inversion. Constrained inversion reduces the non-uniqueness of the solution and improves the credibility of the inversion result by introducing known geological information as a priori constraints; multi-layer inversion inverts the shallow layer first and then the deep layer in a layer-by-layer progressive manner, gradually optimizing the resistivity distribution image to ensure the accuracy of the depth information.

[0020] Preferably, the generation process of the resistivity distribution image further includes noise filtering and abnormal data removal steps, and the random noise and abnormal points in the resistivity data are automatically identified and filtered out through an adaptive noise suppression algorithm and a statistical analysis method. This process can effectively reduce the influence of external interference and measurement errors, ensure the clarity and accuracy of the resistivity image, and thus improve the visualization effect of the electrical characteristics of the underground rock formation.

[0021] Preferably, the data interpretation and analysis step also includes a comprehensive analysis module based on multi-source geological information, which jointly analyzes the resistivity distribution image with geological drilling data, geophysical logging data and remote sensing image data to form a multi-dimensional geological model. Through the mutual verification and supplementation of multi-source data, the overall understanding of the structure and properties of the underground rock and soil layers is improved, and the accuracy and reliability of the survey report are enhanced.

[0022] Preferably, the geotechnical survey report further includes a three-dimensional visualization model and a virtual reality (VR) display function, which can dynamically display the resistivity distribution and geological structure changes of underground geotechnical strata on a computer or mobile device. Through this function, users can interactively view geological information at different depths and orientations in real time, conduct virtual drilling and profile analysis, and provide an intuitive and visual reference for engineering design and construction decisions.

[0023] A geotechnical investigation and processing system based on variable frequency high-density electrical method, comprising an electrode layout module, a current injection module, a data acquisition module, a data processing module, and a data analysis and report generation module;

[0024] The electrode layout module lays a series of electrodes on the surface of the area to be surveyed to form a high-density electrode array. The layout spacing of the electrode array is dynamically adjusted according to the geological characteristics and required resolution of the area to be surveyed to optimize the coverage of current injection and potential measurement;

[0025] The current injection module applies currents of different frequencies to the underground rock and soil formations through the electrode array. The currents of different frequencies include low-frequency currents and high-frequency currents. The low-frequency current is used to penetrate deep rock and soil layers, and the high-frequency current is used to detect shallow fine structures and enhance the electrical contrast of rock and soil formations at different depths.

[0026] The data acquisition module uses a high-precision potential difference measuring device to collect the potential difference data between the electrodes while injecting current. The measuring device has a real-time calibration function to eliminate the influence of environmental noise and electrode contact resistance, ensuring the accuracy and reliability of the potential difference data;

[0027] The data processing module performs multi-dimensional data fusion processing on the collected potential difference data, uses feature enhancement algorithm and inversion algorithm to generate high-resolution underground resistivity distribution images, displays the changes in electrical characteristics of different rock and soil strata, and automatically identifies potential geological anomaly areas;

[0028] The data analysis and report generation module interprets and analyzes the data based on the generated resistivity distribution image and the geological background information, determines the nature, thickness and distribution of the underground rock and soil strata, and generates a detailed geotechnical investigation report to guide subsequent engineering design and decision-making.

[0029] In the above technical solution, the technical effects and advantages provided by the present invention are:

[0030] The present invention deploys a high-density electrode array and adopts a method of dynamically adjusting the electrode spacing to optimize the configuration according to geological characteristics and exploration needs, thereby improving exploration accuracy and resolution. In complex geological environments, traditional fixed electrode deployment methods are difficult to fully capture geological details, resulting in insufficient data quality and difficulty in accurately distinguishing the electrical characteristics of different rock and soil formations. The present invention increases the electrode density and optimizes the deployment method, especially in areas with complex geological structures, such as faults, abundant groundwater, and gas-bearing areas, to enhance the sensitivity to resistivity changes, and can more accurately reflect rock and soil layers of different depths and with small electrical differences. This method can improve the accuracy of exploration data and provide more reliable data support for subsequent geological analysis and engineering design.

[0031] The present invention realizes multi-frequency detection of rock and soil strata by applying electric currents of different frequencies, significantly enhancing the electrical contrast of rock and soil strata at different depths. Low-frequency current is used to detect deep rock and soil strata, while high-frequency current is used to obtain shallow microstructures. The combination of the two can provide more comprehensive underground electrical information. This multi-frequency current injection strategy can not only penetrate rock and soil strata at different depths, but also effectively distinguish geological bodies with slight differences in electrical characteristics, thereby improving the ability to identify geological anomalies. Whether it is deep fault zones, groundwater distribution or shallow cavities, fissures and gas-bearing strata, the present invention can clearly detect and present them, providing high-resolution resistivity distribution images for geological surveys, helping geotechnical engineers to better understand the underground geological environment.

[0032] The present invention generates high-resolution underground resistivity distribution images through high-precision potential difference measurement equipment and advanced data processing algorithms, and combines multi-source geological information for comprehensive analysis, greatly enhancing the scientificity and reliability of the survey report. Through the deep learning neural network model, the resistivity image is automatically analyzed, combined with existing drilling data, logging data, remote sensing images and other geological background information, a multi-dimensional geological model is formed, which can more accurately describe the properties, thickness and distribution of underground rock formations. This comprehensive analysis method helps to identify potential geological risks, reduce uncertainties and risks during project implementation, and ensure project safety and maximize economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0034] Figure 1 The present invention is a method flow chart of a geotechnical exploration method based on variable frequency high-density electrical method.

[0035] Figure 2 The module schematic diagram of a geotechnical exploration and processing system based on variable frequency high-density electrical method of the present invention. DETAILED DESCRIPTION

[0036] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these example embodiments are provided so that the description of the present disclosure will be more comprehensive and complete, and the concept of the example embodiments will be fully conveyed to those skilled in the art.

[0037] The present invention provides Figure 1 A geotechnical investigation method based on variable frequency high-density electrical method is shown, comprising the following steps:

[0038] A series of electrodes are laid out on the surface of the area to be surveyed to form a high-density electrode array. The spacing of the electrode array is dynamically adjusted according to the geological characteristics and required resolution of the area to be surveyed to optimize the coverage of current injection and potential measurement;

[0039] Applying currents of different frequencies to underground rock and soil formations through an electrode array. Currents of different frequencies include low-frequency currents and high-frequency currents. Low-frequency currents are used to penetrate deep rock and soil formations, while high-frequency currents are used to detect shallow fine structures and enhance the electrical contrast of rock and soil formations at different depths.

[0040] While injecting current, a high-precision potential difference measuring device is used to collect the potential difference data between the electrodes. The measuring device has a real-time calibration function to eliminate the influence of environmental noise and electrode contact resistance, ensuring the accuracy and reliability of the potential difference data.

[0041] Perform multi-dimensional data fusion processing on the collected potential difference data, use feature enhancement algorithm and inversion algorithm to generate high-resolution underground resistivity distribution images, display the changes in electrical characteristics of different rock and soil strata, and automatically identify potential geological anomaly areas;

[0042] Based on the generated resistivity distribution image, combined with the geological background information, data interpretation and analysis are carried out to determine the nature, thickness and distribution of the underground rock strata, and generate a detailed survey report to guide subsequent engineering design and decision-making.

[0043] Specific implementation 1: In this specific implementation, first, a high-density electrode array containing 100 electrodes is arranged according to the geological characteristics and requirements of the area to be surveyed. In actual operation, in order to ensure the accuracy and efficiency of the survey, the spacing of the electrodes is no longer fixed, but is dynamically adjusted according to the results of the preliminary geological survey and the site conditions. Specifically, the spacing of the electrodes can vary between 0.5m and 2m. By dynamically adjusting the strategy of the electrode spacing, it is possible to appropriately increase the electrode density in some areas with more drastic geological changes, such as faults, fracture zones, or areas with abundant groundwater and shallow gas distribution, according to the complexity of the geological structure or specific survey needs, that is, to reduce the electrode spacing to 0.5m, so as to improve the resolution and measurement accuracy of the area. At the same time, in areas where the geological conditions are relatively simple or the changes are small, the electrode spacing can be increased to 2m to save equipment and time costs and optimize the configuration of survey resources. This adaptive electrode layout method can not only improve the survey accuracy in complex geological environments, but also improve work efficiency when the survey conditions permit.

[0044] In order to further optimize the coverage of current injection and potential measurement, the electrode layout adopts a high-density and regional strategy. This strategy requires the layout of a higher density of electrode arrays in areas with complex geological conditions, such as underground faults, fracture zones, gas-bearing layers, and areas with obvious changes in geological interfaces, so that current injection is more uniform and potential measurement is more accurate. During the implementation process, the material of the electrode is selected from metal materials with excellent corrosion resistance, such as copper or stainless steel, and is specially treated to ensure the long-term stable conductivity and durability of the electrode. In addition, the depth of electrode burial has also been carefully designed. Usually, the top of the electrode is buried at a depth of between 0.3m and 0.5m, which can effectively avoid interference from surface vegetation and soil, and ensure good contact between the electrode and the underground rock and soil layer, reducing the impact of contact resistance on the measurement results. Through this layout strategy, it can be ensured that current injection and potential difference measurement can be effectively carried out in various geological environments, providing accurate and reliable resistivity data.

[0045] After the high-density electrode array is laid out, current injection and potential difference measurement become the next key operations. Through the electrode array, currents of different frequencies are applied to the underground rock and soil layers, mainly including low-frequency currents and high-frequency currents, which are used to detect deeper and shallower rock and soil structures, respectively. Specifically, low-frequency currents are usually below 10Hz, suitable for penetrating deep rock and soil layers, and the detection depth can reach more than 50m; while high-frequency currents are above 1kHz, mainly used to detect shallow fine structures, with a detection depth of about 10m. This multi-frequency current injection method makes the electrical characteristics of rock and soil layers at different depths more obvious, thereby enhancing the electrical contrast and improving the identification accuracy of different rock and soil layers. During the current injection process, in order to ensure the accuracy and reliability of the data, a high-precision potential difference measurement device is also equipped. The device has a real-time calibration function, which can automatically eliminate the influence of environmental noise and electrode contact resistance to ensure the accuracy of the measurement data. Through these measures, the potential difference data obtained has high resolution and high precision, laying a solid foundation for subsequent data processing and analysis. This method can not only effectively distinguish rock and soil layers with slight electrical differences, but also accurately identify potential geological anomaly areas, providing a scientific and reliable basis for geotechnical exploration.

[0046] The strategy of adaptively deploying high-density electrode arrays and dynamically adjusting the electrode spacing can effectively improve the survey accuracy in complex geological environments. This deployment method reduces the electrode spacing (to 0.5m) in areas with complex geological conditions to increase resolution, and increases the spacing (to 2m) in areas with simple geological conditions to optimize resources. Combined with corrosion-resistant materials and appropriate electrode burial depth, the electrodes can maintain stable conductivity for a long time and reduce the impact of contact resistance on measurement. At the same time, the multi-frequency injection method of applying low-frequency and high-frequency currents enhances the electrical contrast of rock formations at different depths, so that both shallow and deep structures can be accurately detected and identified, thereby providing high-resolution potential difference data, improving the reliability and accuracy of the overall survey, and ultimately providing a scientific and reliable basis for engineering design.

[0047] In geotechnical survey, optimizing electrode layout is not limited to dynamically adjusting the electrode spacing, but can also be used in a variety of ways to further improve survey accuracy and results. The core purpose of optimizing layout is to flexibly configure the electrode array according to the complexity of the geological environment and survey requirements to ensure uniform current injection, accurate potential measurement, and capture the subtle electrical differences of underground rock and soil layers.

[0048] First, the diversification of electrode arrangement patterns is an important strategy for optimizing layout. For example, traditional electrode array layout methods usually adopt linear, grid-type or equally spaced arrangements, while in complex geological environments, eccentric arrangements or non-uniform arrangements can be selected according to actual conditions. For areas with large geological changes (such as faults and fracture zones), the electrical contrast of the area can be enhanced by concentrating the electrodes in these key areas. This layout method can effectively improve the resolution of areas with large local electrical differences and ensure the collection of important geological information. In other areas with smaller geological changes, the electrode spacing can be appropriately increased to reduce redundant measurements and optimize exploration efficiency.

[0049] Secondly, the layered layout method is also an optimization strategy. In some survey areas, the depth and electrical characteristics of the underground rock and soil layers vary greatly. The combination of deep and shallow electrode layout, that is, using denser electrode layout in shallow areas and increasing the electrode spacing in deep areas, can effectively carry out fine detection of geological information at different levels. This method helps to reduce unnecessary measurements and costs while ensuring survey accuracy.

[0050] In addition, the azimuth adjustment of electrode layout is also one of the important strategies for optimizing layout. In some complex geological environments, the electrical characteristics of underground rock and soil layers may show obvious directional differences. For example, in areas with transverse faults, stratification or obvious water flow directions, appropriate adjustment of the azimuth angle of electrode layout to match the current injection with the direction of the geological structure can significantly improve the accuracy of capturing the electrical characteristics of the geological body. By adjusting the azimuth of the electrode array, the electrical response of the geological body can be simulated more effectively, and higher resolution and accuracy can be obtained.

[0051] In addition, automated layout and real-time adjustment is also a cutting-edge optimization method. In actual operation, the electrode layout can be automatically optimized through intelligent algorithms in combination with real-time data from the geological survey site. For example, the system can adjust the electrode density and layout mode in real time according to the changes in data obtained during the survey to cope with different geological changes and survey needs. This method can not only improve the flexibility of the survey, but also greatly improve the efficiency and accuracy of the survey.

[0052] In summary, optimizing the electrode layout method is not only to enhance the accuracy by dynamically adjusting the electrode spacing, but also to adopt strategies such as diversified arrangement modes, layered layout, orientation adjustment and automated real-time optimization. It can achieve more precise and efficient geotechnical surveys for different geological environments and survey needs, greatly improving the quality and reliability of survey data.

[0053] Specific implementation method 2: Applying currents of different frequencies to underground rock and soil strata through an electrode array is one of the key steps to improve the accuracy of identifying the electrical characteristics of underground rock and soil strata. In order to effectively detect rock and soil structures at different depths, the frequency range of current injection is designed to be from ultra-low frequency to ultra-high frequency, specifically including a low-frequency current of 10Hz and a high-frequency current of 1kHz. Low-frequency current has a strong penetrating ability and can penetrate deep rock and soil strata to obtain structural information of rock and soil strata with a depth of more than 50m. High-frequency current is mainly used to detect shallow fine structures, and the effective detection depth is usually about 10m. By injecting multi-frequency currents, the electrical characteristics of rock and soil strata at different depths can be effectively distinguished, and the electrical contrast of rock and soil strata at different depths can be enhanced. This method is particularly suitable for surveys under complex geological conditions, such as multi-layered rock and soil structures or areas with abundant groundwater, and helps to accurately identify and distinguish subtle changes and geological anomalies in rock and soil strata.

[0054] In order to ensure the effect of current injection and measurement accuracy, a multi-frequency current sequence injection technology that increases in sequence is introduced in the specific implementation. When the current is applied, it starts from low frequency and gradually increases to high frequency, which can maximize the electrical characteristic information that each frequency can provide while detecting the rock and soil layer by layer. The current application time of each frequency is automatically controlled by a computer and adjusted in real time according to the geological conditions. For areas with large electrical differences, the low-frequency current application time is longer in order to obtain more detailed deep information; while in areas with small electrical changes, the high-frequency current application time is longer in order to obtain shallow fine structures. This method of dynamically adjusting the current application time can better adapt to different geological conditions, improve electrical contrast, and thus effectively enhance the ability to identify geological anomalies.

[0055] In addition, during the current injection process, the high-precision potential difference measurement equipment is the key technical support, which is directly related to the quality and accuracy of the data. The equipment adopts a multi-channel synchronous measurement device, which can simultaneously collect the potential difference between multiple electrodes in real time, effectively reducing the measurement error caused by time delay. The low-noise amplifier and high-precision analog-to-digital converter are integrated in the equipment, so that it can maintain high-precision data acquisition capabilities in complex geological environments even when the signal is weak or there is high background noise. To further ensure the accuracy of the data, the equipment must also have a real-time calibration function, which can automatically detect changes in electrode contact resistance and eliminate the influence of environmental noise through correction algorithms. This high-precision, automatically calibrated potential difference measurement technology can greatly improve the reliability of measurement data and provide a solid foundation for subsequent data processing and analysis. Finally, by combining multi-frequency current injection and high-precision measurement, a high-resolution underground resistivity distribution image is generated, which accurately displays the changes in the electrical characteristics of different rock formations and automatically identifies potential geological anomaly areas, providing a scientific basis for geotechnical survey reports and guiding subsequent engineering design and decision-making.

[0056] Through the multi-frequency current sequence injection technology that increases in sequence, detailed detection of rock and soil strata at different depths is achieved, effectively enhancing the electrical contrast, which is particularly suitable for surveys under complex geological conditions. Low-frequency current is used to detect deep structures, providing detailed information with a penetration depth of more than 50m, while high-frequency current focuses on the detection of shallow fine structures, making the electrical characteristics clearer. Combined with high-precision potential difference measurement equipment with real-time control, this method, supported by multi-channel synchronous acquisition and low-noise amplification technology, can still maintain high data accuracy even in the presence of environmental noise. This efficient, multi-level data acquisition and processing strategy ensures that the generated resistivity images can accurately display the changes in different underground rock and soil layers, improve the ability to identify abnormal geology, and provide a reliable scientific basis for engineering design.

[0057] Specific implementation 3: High-precision potential difference measurement equipment plays a vital role in the current injection process. These devices are equipped with multi-channel synchronous measurement devices, which can simultaneously collect potential difference data between multiple electrodes. This design not only improves the measurement efficiency, but also significantly reduces the data error caused by time delay. The measuring equipment converts the potential difference signal into a digital signal for storage and analysis through a low-noise amplifier and a high-precision analog-to-digital converter. The multi-channel design of the equipment can process data from up to 32 channels in real time, thereby ensuring measurement accuracy under complex geological conditions. In addition, the built-in real-time calibration function of the equipment can automatically detect and compensate for changes in electrode contact resistance, eliminate the influence of environmental noise and interference on the measurement results, and thus ensure the accuracy and stability of the potential difference data. This high-precision measurement capability provides high-quality basic data for subsequent data analysis and geotechnical structure interpretation.

[0058] In order to further improve the accuracy and reliability of the data, multi-dimensional data fusion processing technology is introduced in this embodiment. After the collected potential difference data is processed, a high-resolution underground resistivity distribution image is generated through a feature enhancement algorithm and an inversion algorithm. The feature enhancement algorithm eliminates random noise and measurement errors in the data by weighted processing of measurement data of different electrodes, thereby highlighting the geological feature information. In the inversion algorithm, a combination of constrained inversion and multi-layer inversion is adopted. By introducing a priori geological information constraints, the non-uniqueness of the solution is reduced, and the underground resistivity distribution is inverted layer by layer. First, the shallow data is inverted to obtain a shallow resistivity distribution map, and then the depth information is gradually increased to finally generate a complete high-resolution resistivity distribution image. This layer-by-layer inversion method can not only improve the efficiency of data processing, but also ensure the accuracy and reliability of depth information, and can better reflect the true electrical characteristics of underground rock and soil layers.

[0059] After the data processing generates resistivity distribution images, the system combines these images with geological background information to carry out data interpretation and analysis. In this process, the data interpretation module uses a deep learning neural network model to analyze and interpret the generated resistivity images. The neural network model is trained based on a large amount of actual survey data, and can automatically learn the patterns and laws of different electrical characteristics, and identify and classify the features in the resistivity image according to the geological background information. By jointly analyzing multi-source geological information (such as drilling data, logging data, remote sensing images, etc.) with resistivity distribution images, a multi-dimensional geological model is formed. This multi-source data fusion method can effectively verify and complement each other, providing an overall understanding of the structure and properties of underground rock and soil layers. During the interpretation process, the system can automatically identify potential geological anomaly areas, such as groundwater zones, cavities, faults, gas-bearing layers, etc., laying the foundation for generating detailed geotechnical survey reports. These reports describe the properties, thickness and distribution of underground rock and soil layers in detail, providing a scientific basis for subsequent engineering design and decision-making, thereby effectively guiding the construction process and avoiding potential engineering risks.

[0060] The accuracy and reliability of geotechnical surveys are significantly improved through the combination of high-precision potential difference measurement equipment and multi-dimensional data fusion processing technology. The multi-channel synchronous acquisition function of the equipment, as well as the built-in low-noise amplifier and high-precision analog-to-digital converter, ensure stable and high-precision data acquisition under complex geological conditions. The real-time calibration function further eliminates the influence of environmental noise and contact resistance to ensure the stability of the measured data. Combined with feature enhancement and constrained inversion algorithms, the high-resolution resistivity images processed and generated layer by layer provide detailed and deeply progressive underground geotechnical layer information, enhancing the clarity and analysis capabilities of geological features. Through joint analysis with multi-source geological information, the system can automatically identify geological anomaly areas, provide a reliable basis for geotechnical survey reports, and assist in engineering design and risk management.

[0061] The present invention can greatly improve the survey accuracy and resolution by deploying a high-density electrode array and dynamically adjusting the electrode spacing to optimize the configuration according to geological characteristics and survey needs. In complex geological environments, the traditional fixed electrode deployment method is difficult to fully capture geological details, resulting in insufficient data quality and difficulty in accurately distinguishing the electrical characteristics of different rock and soil layers. The present invention increases the electrode density and optimizes the deployment method, especially in areas with complex geological structures, such as faults and areas with abundant groundwater, to enhance the sensitivity to resistivity changes, and can more accurately reflect rock and soil layers of different depths and with small electrical differences.

[0062] The present invention realizes multi-frequency detection of rock and soil strata by applying electric currents of different frequencies, significantly enhancing the electrical contrast of rock and soil strata at different depths. Low-frequency current is used to detect deep rock and soil layers, while high-frequency current is used to obtain shallow microstructures. The combination of the two can provide more comprehensive underground electrical information. This multi-frequency current injection strategy can not only penetrate rock and soil layers of different depths, but also effectively distinguish geological bodies with slight differences in electrical characteristics, thereby improving the ability to identify geological anomalies. Whether it is deep fault zones, groundwater distribution or shallow cavities, fissures and gas-bearing areas, the present invention can clearly detect and present them, providing high-resolution resistivity distribution images for geological surveys, helping geotechnical engineers better understand the underground geological environment.

[0063] The present invention generates high-resolution underground resistivity distribution images through high-precision potential difference measurement equipment and advanced data processing algorithms, and combines multi-source geological information for comprehensive analysis, greatly enhancing the scientificity and reliability of the survey report. Through the deep learning neural network model, the resistivity image is automatically analyzed, combined with existing drilling data, logging data, remote sensing images and other geological background information, to form a multi-dimensional geological model to more accurately describe the properties, thickness and distribution of underground rock and soil layers. This comprehensive analysis method provides a scientific basis for engineering design and decision-making, helps to identify potential geological risks, and formulate more reasonable engineering plans, thereby reducing uncertainties and risks in the construction process and ensuring engineering safety and maximizing economic benefits.

[0064] The present invention provides Figure 2 A geotechnical investigation and processing system based on variable frequency high-density electrical method is shown, comprising an electrode layout module, a current injection module, a data acquisition module, a data processing module, and a data analysis and report generation module;

[0065] The electrode layout module lays a series of electrodes on the surface of the area to be surveyed to form a high-density electrode array. The layout spacing of the electrode array is dynamically adjusted according to the geological characteristics and required resolution of the area to be surveyed to optimize the coverage of current injection and potential measurement;

[0066] The current injection module applies currents of different frequencies to the underground rock and soil formations through the electrode array. The currents of different frequencies include low-frequency currents and high-frequency currents. The low-frequency current is used to penetrate deep rock and soil layers, and the high-frequency current is used to detect shallow fine structures and enhance the electrical contrast of rock and soil formations at different depths.

[0067] The data acquisition module uses a high-precision potential difference measuring device to collect the potential difference data between the electrodes while injecting current. The measuring device has a real-time calibration function to eliminate the influence of environmental noise and electrode contact resistance, ensuring the accuracy and reliability of the potential difference data;

[0068] The data processing module performs multi-dimensional data fusion processing on the collected potential difference data, uses feature enhancement algorithm and inversion algorithm to generate high-resolution underground resistivity distribution images, displays the changes in electrical characteristics of different rock and soil strata, and automatically identifies potential geological anomaly areas;

[0069] The data analysis and report generation module interprets and analyzes the data based on the generated resistivity distribution image and the geological background information to determine the nature, thickness and distribution of the underground rock and soil strata and generate a detailed geotechnical investigation report to guide subsequent engineering design and decision-making;

[0070] A geotechnical exploration method based on variable frequency high-density electrical method provided in an embodiment of the present invention is realized by the above-mentioned geotechnical exploration processing system based on variable frequency high-density electrical method. The specific method and process of a geotechnical exploration processing system based on variable frequency high-density electrical method are detailed in the embodiment of the above-mentioned geotechnical exploration method based on variable frequency high-density electrical method, which will not be repeated here.

[0071] The above description is only by way of illustration of certain exemplary embodiments of the present invention. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A geotechnical exploration method based on variable frequency high-density electrical method, characterized in that: The following steps are involved: A series of electrodes are laid out on the surface of the area to be surveyed to form a high-density electrode array. The spacing of the electrode array is dynamically adjusted according to the geological characteristics and required resolution of the area to be surveyed to optimize the coverage of current injection and potential measurement; Applying currents of different frequencies to underground rock and soil formations through an electrode array. Currents of different frequencies include low-frequency currents and high-frequency currents. Low-frequency currents are used to penetrate deep rock and soil formations, while high-frequency currents are used to detect shallow fine structures and enhance the electrical contrast of rock and soil formations at different depths. While injecting current, a high-precision potential difference measuring device is used to collect the potential difference data between the electrodes. The measuring device has a real-time calibration function to eliminate the influence of environmental noise and electrode contact resistance, ensuring the accuracy and reliability of the potential difference data. Perform multi-dimensional data fusion processing on the collected potential difference data, use feature enhancement algorithm and inversion algorithm to generate high-resolution underground resistivity distribution images, display the changes in electrical characteristics of different rock and soil strata, and automatically identify potential geological anomaly areas; Based on the generated resistivity distribution image, data interpretation and analysis are carried out in combination with geological background information to determine the nature, thickness and distribution of underground rock strata, and generate a detailed geotechnical investigation report to guide subsequent engineering design and decision-making.

2. A geotechnical exploration method based on variable frequency high-density electrical method according to claim 1, characterized in that: The electrode array is laid out in an adaptive manner, and the density and distribution of the electrodes are adjusted in real time based on preliminary survey data. The electrode density is increased in areas with complex geological conditions or geological structures to improve the resistivity measurement accuracy and resolution in the area.

3. A geotechnical investigation method based on variable frequency high-density electrical method according to claim 1, characterized in that: The application of currents of different frequencies includes a multi-frequency current sequence that increases in sequence, from ultra-low frequency to ultra-high frequency, so as to obtain data on rock and soil layers of different depths and with different electrical characteristics. The current application time of each frequency is automatically adjusted according to the specific geological conditions to ensure sufficient detection and analysis of different rock and soil layers, maximize the electrical contrast, and improve the overall survey accuracy.

4. A geotechnical investigation method based on variable frequency high-density electrical method according to claim 1, characterized in that: The high-precision potential difference measurement equipment further includes a synchronous measurement device with multiple channels, which can simultaneously collect the potential difference between multiple electrodes in real time. Secondly, the high-precision potential difference measurement equipment adopts a low-noise amplifier and a high-precision analog-to-digital converter to ensure the accuracy of the potential difference measurement. Finally, the high-precision potential difference measurement equipment also has an automatic detection function, which can issue an alarm when the electrode contact is poor or the data is abnormal, prompting recalibration or adjustment of the measurement.

5. A geotechnical investigation method based on variable frequency high-density electrical method according to claim 1, characterized in that: Multidimensional data fusion processing includes time-space fusion and frequency-domain fusion, which combines resistivity data of different time, space and frequency to eliminate noise and measurement errors and improve data integrity and accuracy. Time-space fusion realizes the coordinated processing of different data by considering the time series of current application and the spatial layout of electrode layout. Frequency domain fusion uses spectrum analysis to remove useless high-frequency noise, retain key low-frequency features, and further improve the resolution of underground resistivity distribution images.

6. A geotechnical investigation method based on variable frequency high-density electrical method according to claim 1, characterized in that: The feature enhancement algorithm includes a deep learning neural network model, which is trained to identify the electrical characteristics of complex rock formations and potential geological anomaly areas. The training model is based on a large amount of actual survey data and can automatically learn the patterns and laws of different electrical characteristics to improve the accuracy and reliability of geological anomaly identification. At the same time, the training model can also continue to learn and update according to new survey data to maintain efficient geological analysis capabilities.

7. A geotechnical investigation method based on variable frequency high-density electrical method according to claim 1, characterized in that: The inversion algorithm adopts a combination of constrained inversion and multi-layer inversion to improve computing efficiency while ensuring data inversion accuracy. Constrained inversion introduces known geological information as a priori constraints to reduce the non-uniqueness of the solution and improve the credibility of the inversion results; multi-layer inversion uses a progressive approach to first invert the shallow layer and then the deep layer, gradually optimizing the resistivity distribution image to ensure the accuracy of the depth information.

8. A geotechnical investigation method based on variable frequency high-density electrical method according to claim 1, characterized in that: The generation process of the resistivity distribution image further includes noise filtering and abnormal data removal steps. Through adaptive noise suppression algorithms and statistical analysis methods, random noise and abnormal points in the resistivity data are automatically identified and filtered out, thereby improving the visualization effect of the electrical characteristics of underground rock formations.

9. A geotechnical investigation method based on variable frequency high-density electrical method according to claim 1, characterized in that: The data interpretation and analysis steps also include a comprehensive analysis module based on multi-source geological information. The comprehensive analysis module combines resistivity distribution images with geological drilling data, geophysical logging data and remote sensing image data to form a multi-dimensional geological model. Through the mutual verification and supplementation of multi-source data, the overall understanding of the structure and properties of underground rock formations is improved, and the accuracy and reliability of the survey report are enhanced. The geotechnical investigation report further includes three-dimensional visualization models and virtual reality display functions, which can dynamically display the resistivity distribution and geological structure changes of underground rock formations on a computer or mobile device, interactively view geological information at different depths and orientations in real time, and conduct virtual drilling and profile analysis, providing an intuitive and visual reference for engineering design and construction decisions.

10. A geotechnical exploration processing system based on variable frequency high-density electrical method, used to implement a geotechnical exploration method based on variable frequency high-density electrical method as described in any one of claims 1 to 9, characterized in that: include: Electrode layout module, current injection module, data acquisition module, data processing module, and data analysis and report generation module; The electrode layout module lays a series of electrodes on the surface of the area to be surveyed to form a high-density electrode array. The layout spacing of the electrode array is dynamically adjusted according to the geological characteristics and required resolution of the area to be surveyed to optimize the coverage of current injection and potential measurement; The current injection module applies currents of different frequencies to the underground rock and soil formations through the electrode array. The currents of different frequencies include low-frequency currents and high-frequency currents. The low-frequency current is used to penetrate deep rock and soil layers, and the high-frequency current is used to detect shallow fine structures and enhance the electrical contrast of rock and soil formations at different depths. The data acquisition module uses a high-precision potential difference measuring device to collect the potential difference data between the electrodes while injecting current. The measuring device has a real-time calibration function to eliminate the influence of environmental noise and electrode contact resistance, ensuring the accuracy and reliability of the potential difference data; The data processing module performs multi-dimensional data fusion processing on the collected potential difference data, uses feature enhancement algorithm and inversion algorithm to generate high-resolution underground resistivity distribution images, displays the changes in electrical characteristics of different rock and soil strata, and automatically identifies potential geological anomaly areas; The data analysis and report generation module interprets and analyzes the data based on the generated resistivity distribution image and the geological background information, determines the nature, thickness and distribution of the underground rock and soil strata, and generates a detailed geotechnical investigation report to guide subsequent engineering design and decision-making.

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