190 results about "Apparent resistivity" patented technology

The invention discloses a dam leakage channel detection and danger elimination quality evaluation method based on transient electromagnetism, and relates to the technical field of earth and rockfill dam danger elimination and reinforcement. The method comprises the following steps: A, leakage channel detection: A1, data acquisition: performing data acquisition on a dam by adopting pull-type small loop transient electromagnetic equipment to obtain original electromagnetic signal data; a2, forward modeling: performing forward modeling on the acquired data, and calculating a theoretical attenuation curve and apparent resistivity distribution by considering special boundary conditions of the dam; and A3, carrying out inversion calculation. According to the method, leakage signals can be accurately captured based on the high sensitivity of a transient electromagnetic method to a low-resistance body, the used pull-type small-loop transient electromagnetic equipment is convenient to operate, a dam can be comprehensively covered by combining reasonable measurement point arrangement, forward modeling and inversion calculation can comprehensively consider various factors, the position and depth of a leakage area are determined, and the detection accuracy is improved. Compared with a traditional method, the method has obvious advantages in detection depth and accuracy.

The invention discloses a coal mine tunnel shield excavation-following multi-frequency alternating current parallel advanced detection method and system, and the method comprises the steps: arranging a three-direction data observation system in a tunnel excavation direction; collecting a three-direction potential difference amplitude value and a three-direction potential difference phase value for the arranged three-direction data observation system by adopting a multi-frequency pseudo-random galvanic couple source emission mode; the obtained three-direction potential difference amplitude value and the potential difference phase value are sent to professional software based on a Cole-Cole model for inversion, and a three-dimensional apparent resistivity image and a three-dimensional apparent charging rate image are obtained; according to the method, the problems that a traditional advanced detection method is insufficient in space positioning of a geologic body and detection is carried out while excavation under the tunnel shield condition are solved, and technical support is provided for tunnel shield excavation-while-excavation water disaster detection.

The invention discloses a non-contact geomagnetic coil single-frequency and multi-frequency combined stratum exploration method. The method comprises the following steps that S1, observation parameters are calculated according to exploration requirements; s2, transmitting a single-frequency vertical coil, and moving and scanning a three-component coil; s3, the apparent resistivity and the apparent polarizability of the earth are quickly found through transverse and longitudinal table look-up; s4, quickly identifying a regional stratum, and dividing abnormal sections; s5, abnormal section multi-frequency static data acquisition; s6, multi-frequency data longitudinal underground layering inversion is carried out; and S7, performing combined output of plane quick sweeping and section layering results. According to the method, the precision of the exploration result and the data accuracy are guaranteed, the final exploration result is combined with the plane section and the longitudinal section, the exploration efficiency is guaranteed, the exploration precision can be guaranteed, and the exploration cost is greatly reduced on the premise that the exploration precision is guaranteed.

The invention belongs to the technical field of oil-gas exploration and development, and relates to a transient electromagnetic wave through casing resistivity measurement method, which comprises the following steps of: establishing a cased well stratum model by considering a borehole, a casing and a stratum and combining transient electromagnetic wave logging characteristics; in a cased well formation model, the resistivity is measured by adopting an apparent resistivity extraction method based on a late signal, and the resistivity measurement method of the apparent resistivity extraction method based on the late signal comprises the following steps: simulating different formation resistivity in the cased well formation model; a single-transmitting single-receiving coil structure is adopted to measure zz component induced electromotive force of late transient electromagnetic wave logging; the apparent resistivity is extracted according to the late transient electromagnetic wave logging zz component induced electromotive force signal, and the extracted apparent resistivity is the transient electromagnetic wave through casing resistivity. According to the method, the transient electromagnetic wave through casing logging response precision can be improved, and formation resistivity extraction under the influence of a high-conductivity casing is achieved.

The invention discloses a method for dividing an electric dipole source CSAMT field region, and the method comprises the steps: defining a last coincidence point of an apparent resistivity curve of a whole region and a far region of an electric field Ex component as a far region separation point from a high-frequency end to a low-frequency end, and recording a corresponding induction number as B = crifar-tran; in the direction from the low-frequency end to the high-frequency end, the last coincidence point of the whole area of the electric field Ex component and the near area apparent resistivity curve is defined as a near area separation point, and the corresponding induction number is recorded as B = critra-new. The method for dividing the field by the determined induction number can adapt to various geoelectric structures, and provides a universally applicable and non-empirical standard for defining the field.

The invention provides a grouting diffusion three-dimensional monitoring system and method and a medium, and relates to the technical field of railway roadbeds, and the system comprises an acquisition module and a data processing module; the acquisition module is used for acquiring apparent resistivity corresponding to a grouting diffusion area in a railway roadbed in parallel; and the data processing module is connected with the acquisition module and is used for performing forward modeling and inversion according to a preset geoelectric model and the apparent resistivity to obtain a three-dimensional apparent resistivity map representing the grouting diffusion range. Thus, on one hand, the collection efficiency of apparent resistivity is improved, on the other hand, a three-dimensional apparent resistivity map can be obtained, three-dimensional real-time monitoring of the slurry flow path, the flow range, the spatial and temporal distribution and the occurrence state in the grouting process is achieved, the slurry diffusion condition is accurately and visually reflected, and the grouting quality is improved. And a basis is provided for grouting reinforcement mechanism research, technical development and scheme optimization.

The invention relates to the technical field of geophysical exploration, and provides a three-dimensional electromagnetic method fracturing monitoring method which comprises the following steps: collecting parameter data of a target well; establishing a target well work area geoelectric model, and performing forward modeling through the target well work area geoelectric model to select reasonable acquisition parameters; arranging a three-dimensional measuring net according to a fracturing construction scheme; collecting data of a natural field source and an artificial field source in the fracturing monitoring process; processing to obtain natural potential data before and after fracturing, induced polarization method data before and after fracturing, time-frequency electromagnetic method data before and after fracturing, and controllable source magnetotelluric method apparent resistivity data and controllable source magnetotelluric method phase data before and after fracturing; differential abnormal data are obtained through calculation, all the differential abnormal data are comprehensively analyzed, and fracturing fluid and fracture distribution form data in the complete fracturing process are obtained. According to the invention, multiplicity of solutions is reduced, precision and monitoring accuracy are improved, and construction cost is reduced.

The invention belongs to the technical field of earth and rockfill dam deep burying disease identification and positioning, and discloses an earth and rockfill dam leakage channel comprehensive detection method and system, and the method comprises the steps: determining the distribution of detection points detected by an electrical method, and collecting the apparent resistivity data and the apparent polarizability data of the detection points; inverting apparent resistivity and apparent polarizability data to obtain a resistivity profile and a polarizability profile, and obtaining a normalized polarizability profile based on the resistivity profile and the polarizability profile; performing stratum zoning on the to-be-detected area based on the section, determining the soil cation exchange capacity and the cementation index of the zoned stratum, and calculating the soil water content and the permeability of the measured section according to the normalized polarizability, the soil cation exchange capacity and the cementation index; and determining an earth and rockfill dam leakage channel according to a water content and permeability judgment mechanism. According to the method, the uncertainty of a single physical property threshold value method is overcome, and the accuracy and precision of the leakage hidden danger of the earth and rockfill dam are improved.

The invention relates to the technical field of data processing, discloses an earth and rockfill dam leakage positioning method based on joint inversion and data fusion, and aims to solve the problems of limitation and non-uniqueness of an existing single geophysical prospecting method in leakage hidden danger positioning. Converting the first apparent resistivity into a first apparent resistivity; second apparent resistivity distribution of the earth-rock dam is obtained through a high-density electrical method; acquiring electromagnetic wave velocity distribution by adopting a ground penetrating radar method, and converting the electromagnetic wave velocity distribution into third apparent resistivity; performing data standardization processing on the apparent resistivity to obtain standardized apparent resistivity data; performing dimension reduction fusion on the standardized apparent resistivity data corresponding to each apparent resistivity by adopting a principal component analysis method to obtain simulated apparent resistivity distribution; and determining the position of the leakage hidden danger channel in the earth-rock dam based on the pseudo-apparent resistivity distribution. The method improves objectivity, accuracy and reliability of leakage positioning, and is particularly suitable for danger removal and reinforcement of earth and rockfill dams.

The invention relates to the field of geophysical electromagnetic exploration, and provides a time-frequency electromagnetic data processing method, device, equipment and medium, and the method comprises the steps: calculating the similarity offset ratio of each measuring point on a measuring line, and determining a static displacement measuring point on the measuring line based on the similarity offset ratio; calculating equivalent apparent resistivity ratio of static displacement measurement point based on equivalent apparent resistivity of electric field component and corrected equivalent apparent resistivity of magnetic field component corresponding to adjacent measurement points on left and right sides of static displacement measurement point, and updating equivalence of electric field component of static displacement measurement point based on equivalent apparent resistivity ratio and corrected equivalent apparent resistivity of magnetic field component apparent resistivity; and completing static displacement correction in response to the static displacement measuring points on the measuring line, and performing inversion calculation on the magnetic field component amplitude and the electric field component amplitude of each measuring point on the measuring line to obtain resistivity distribution of a preset depth below the measuring line. The scheme disclosed by the invention is beneficial to improving the exploration and prediction precision of the time-frequency electromagnetic oil and gas target.

The invention discloses a tunnel shield interval boulder prediction method, medium and equipment, and the method comprises the steps: S1, obtaining the high-density electrical method apparent resistivity data of a detection region, and carrying out the inversion to obtain an apparent resistivity two-dimensional profile; s2, integrating the two-dimensional profile into a three-dimensional space, and constructing a continuous three-dimensional resistivity data volume; s3, extracting a threshold value abnormal region according to a preset threshold value A, and determining a boulder suspicious region A; s4, background signal propagation characteristics of the boulder-free area are measured through ultrasonic waves, a threshold value B is set, and if the background signal propagation characteristics exceed the threshold value B in the actual measurement process, the boulder-free area is marked as a boulder suspicious area B; and S5, obtaining an intersection of the abnormal coordinates of the boulder suspicious area A and the boulder suspicious area B, generating a closed three-dimensional boulder suspicious area, and outputting a result in a three-dimensional visualization manner. According to the method, the problems of high false anomaly rate, insufficient spatial information, strong subjective dependence and the like of a traditional single geophysical prospecting method are systematically solved, and the accuracy, the reliability and the engineering applicability of boulder detection are remarkably improved.

The invention relates to the technical field of open hole well logging in petroleum and natural gas exploration and development, in particular to an ultra-thin layer resistivity logging variable K value interpretation method and device, equipment and a medium. The method comprises the steps that stratum parameters are set, forward modeling is carried out to measure five parameters, the theoretical K value and the Rd4-Rs18 value of each layer are calculated according to the five parameters, and the Rd4-Rs18 value of each layer is calculated according to the theoretical K value and the Rd4-Rs18 value; the neural network is trained through set parameters and measurement and calculation parameters, an interpretation model is obtained, resistivity and invasion influence correction is carried out on the variable K value, and three stratum parameters of the variable K value of each layer, the specific value of the stratum and the resistivity of the invasion zone and the radius of the invasion zone can be explained through the interpretation model; the error between the variable K value and the theoretical K value is the quantitative interpretation error of the true resistivity of the stratum; the method is used for solving the problem that the stratum true resistivity value cannot be quantitatively explained due to the fact that the resistivity of the corresponding layer thickness cannot be developed and an invasion influence correction chart cannot be developed due to the fact that the obtained apparent resistivity value of the ultrathin layer is too low and the change range is too small by an original fixed K value explaining method.

The invention discloses a global apparent resistivity iteration initial value setting method and device, a medium and a product, and relates to the technical field of electromagnetic detection, and the method comprises the steps: selecting a plurality of roughly estimated resistivity values in a preset resistivity range according to logarithm equal intervals, and constructing a corresponding roughly estimated resistivity model according to the values; and then calculating the transient electromagnetic response of each roughly estimated model on different time channels, and comparing the transient electromagnetic response with the actually measured transient electromagnetic response to obtain a response deviation value of the model. Therefore, an initial resistivity initial value is selected. Then, transient electromagnetic response fitting is carried out on a plurality of time channels of the shallow layer, and a more accurate resistivity estimation value is obtained. Based on the finely-estimated resistivity values, the finely-estimated initial resistivity value of each time channel is further calculated. And finally, aiming at any time channel, fitting transient electromagnetic response of the time channel, and by taking the difference between the minimum actual measurement value and the predicted value as a target, determining a final resistivity initial value of the time channel.

The invention discloses a method for identifying logging interpretation electrical standard parameters, and solves the problems of inaccurate difference and low efficiency caused by the influence of subjective factors on the manual identification result of the logging interpretation electrical standard parameters in the prior art. The method comprises the following steps: S1, establishing a benchmarking array for a well section to be identified; s2, matching the target well data on the apparent resistivity curve A based on the established benchmarking array; obtaining optimal matching data; s3, determining a reference layer identified by the electrical standard; s4, identifying a microsphere standard, a sound wave calcium judgment standard and a deep three lateral standard; s5, identifying a microelectrode standard; and S6, identifying a micro-gradient calcium judgment standard. The device for realizing the automatic identification of the logging interpretation electrical standard parameters comprises an establishing unit; a matching unit; a determination unit; a first identification unit; a second identification unit; and a third identification unit. According to the method, logging interpretation electrical standard parameters can be rapidly identified, and quality improvement and efficiency improvement of logging interpretation reservoir thickness division work are assisted.

The invention provides a deep and large fracture depicting method based on low-frequency electromagnetic information recovery enhancement, and the method comprises the steps: S1, collecting electromagnetic data, and carrying out the preprocessing of the electromagnetic data, and obtaining the preprocessed electromagnetic data; s2, obtaining frequency domain apparent resistivity and phase according to the preprocessed electromagnetic data; s3, establishing a shallow stratum electrical model; s4, acquiring a depth domain apparent resistivity profile according to the shallow stratum electrical model; and S5, depicting deep and large fracture distribution based on the depth domain apparent resistivity profile. According to the invention, enhancement of low-frequency electromagnetic signals is realized, the inversion precision of electromagnetic data is improved, low-frequency geological information is effectively recovered, and deep and large fractures can be effectively described.

The application provides a three-dimensional geological modeling method and system for ductile shear zone type gold exploration, and relates to the technical field of gold exploration modeling. The application extracts a plurality of alteration anomaly zones related to gold mineralization hydrothermal alteration by acquiring multispectral remote sensing data of an exploration area; superimposes the anomaly zones to identify a prospecting target area and acquire electrical parameter data such as apparent resistivity and apparent polarization rate; determines the structural geological distribution in combination with surface geological mapping, divides a prospecting unit in space superposition with the target area, sets the electrical parameter range to establish a three-dimensional prospecting unit framework; and obtains the three-dimensional distribution of electrical parameters and the geological unit boundary by jointly inverting the electrical parameters as measured data, the framework and the parameter range, generates a three-dimensional geological model reflecting the spatial distribution of the gold mineralization body, and can accurately depict the spatial distribution of the ductile shear zone type gold mineralization body, thereby supporting efficient exploration.

The application discloses a global apparent resistivity iterative initial value setting method, device, medium and product, relates to the electromagnetic detection technical field, and the method comprises the following steps: firstly, a plurality of rough estimated resistivity values are selected in a predetermined resistivity range according to logarithmic equal intervals, and a corresponding rough estimation resistivity model is constructed accordingly. Then, the transient electromagnetic response of each rough estimation model on different time channels is calculated, and compared with the actually measured transient electromagnetic response, so that the response deviation value of the model is obtained. According to this, the preliminary resistivity initial value is selected. Subsequently, the transient electromagnetic response of several time channels of the shallow layer is fitted, and a more accurate resistivity estimation value is obtained. Based on these fine estimation resistivity values, the fine estimation resistivity initial value of each time channel is further calculated. Finally, for any one time channel, the transient electromagnetic response thereof is fitted, and the final resistivity initial value of the time channel is determined by taking minimizing the difference between the actual measured value and the predicted value as the target.

The present invention discloses a multi-scale electromagnetic exploration method based on single-electrode potential detection, which relates to the field of exploration geophysical technology. The method includes: determining the measurement area, clarifying the exploration target, and determining the measurement area and measurement point density based on the depth of the exploration target; deploying a number of transmitting sources and receiving arrays in the measurement area to collect surface potential data of the measurement area in real time, and processing the data frequency by frequency according to a preset frequency sequence; generating a surface potential distribution surface based on the single-electrode potential data, constraining and suppressing the field source effect, obtaining electric field distribution information of the measurement surface, and calculating apparent resistivity parameters in combination with magnetic field measurement data; using a multi-directional excitation mode and a multi-source emission scheme to suppress the field source effect, and constructing a three-dimensional resistivity profile to identify low-resistance or high-resistance bodies. The present invention solves the static effect and volume effect, breaking through the limitations of existing electromagnetic instruments on detection accuracy and depth.

The application discloses a kind of based on the combination of detection and simulation's structural feature analysis method, belongs to fault structural feature analysis field, comprising the following steps: first, by combining early part drilling and known data to predict possible results, and establish numerical model for each possibility to carry out electrical method analysis, obtain apparent resistivity spatial distribution model by analysis calculation;Then, the actual apparent resistivity spatial distribution model is obtained by carrying out electrical measurement in the field;The result figure obtained by numerical simulation is compared with the actual result, and is corrected, to determine more accurate geological structure.The application adopts the above-mentioned structural feature analysis method based on the combination of detection and simulation, realizes the combination of detection and simulation, based on the result of numerical analysis is constantly corrected, so as to obtain exact fault structural feature.

The invention provides an apparent resistance correction method and system based on a resistivity method, a medium and equipment, and relates to the technical field of electric field detection. According to the technical scheme provided by the invention, the intra-group control scheme is generated by matching the preset optimization target corresponding to the attribute tag, adjustment is performed according to the inter-group influence factors to form the target control scheme, and the measurement strategy can be adaptively adjusted according to the geologic features. After the vector receiving voltage is acquired, vector synthesis is performed on the initial apparent resistance according to the horizontal included angle to obtain the target apparent resistance, so that the problem that a single component signal is weak and is easily interfered by noise in a traditional resistivity method is effectively solved. When component signals in a certain direction are particularly weak or abnormal, negative apparent resistivity can be avoided by adopting a vector synthesis mechanism, and the data stability is improved. The convergence of the inversion algorithm and the stability of the solution are obviously improved by improving the quality of the final input data and fully utilizing the vector information, vector synthesis can be carried out on component signals, and the inversion effect of the resistivity method is improved.

The invention belongs to the technical field of geophysical exploration, and discloses a mine transient electromagnetic anomaly boundary identification method based on DBSCAN clustering. The method comprises the following steps: step 1, establishing a three-dimensional geophysical model; 2, calculating apparent resistivity data by using a small loop transient electromagnetic method; 3, drawing a k-distance map, and obtaining an optimal neighborhood radius according to the k-distance map; step 4, performing DBSCAN clustering on the apparent resistivity data to obtain a clustering result; 5, replacing the intra-cluster apparent resistivity value with a cluster center value to obtain replaced apparent resistivity data; step 6, imaging the replaced apparent resistivity data and identifying an abnormal body; 7, comparing the anomalous body boundary with the anomalous body boundary in the model, and if the difference is too large, adjusting the optimal neighborhood radius and returning to the step 4; and otherwise, taking the current abnormal body as a final identified abnormal body. The method can effectively identify irregular anomalous body boundaries of non-uniform complex stratums, and can adapt to real-time identification requirements of underground anomalous bodies.

The invention provides a joint inversion method and device based on a cross gradient term weight factor, and the method comprises the steps: endowing each grid unit in an underground grid with an initial parameter value of a uniform half space, enabling the initial parameter value to serve as an initial model of joint inversion, enabling the underground grid to be obtained through the grid division of a research region, and enabling the initial model to serve as an initial model of joint inversion; the data range of the research area is determined according to the data range of the observation area; an objective function of joint inversion is constructed, the objective function comprises a cross gradient term and a first weight factor, the first weight factor comprises a coefficient matrix and a weight constant, and each matrix element in the coefficient matrix corresponds to each grid unit in the underground grid; the matrix element values corresponding to the grid units of the underground grid in different areas are different; and utilizing the apparent resistivity data and the apparent polarizability data to perform minimization calculation on the target function so as to update the initial model and obtain a resistivity model and a polarizability model. The precision of the inversion result can be improved.

The application provides a resistivity-based apparent resistivity correction method, system, medium and equipment, and relates to the technical field of electric field detection. The technical scheme provided by the application generates an in-group control scheme by matching a preset optimization target corresponding to an attribute label, adjusts a target control scheme according to inter-group influencing factors, and can adaptively adjust a measurement strategy according to geological characteristics. After collecting a vector receiving voltage, the initial apparent resistivity is vector synthesized according to a horizontal angle to obtain a target apparent resistivity, effectively solving the problem that a single component signal is weak and susceptible to noise interference in the traditional resistivity method. When a certain direction component signal is particularly weak or abnormal, the vector synthesis mechanism can avoid the appearance of negative apparent resistivity, improving data stability. The improvement of the final input data quality and the full use of vector information significantly improve the convergence of the inversion algorithm and the stability of the solution, can perform vector synthesis on the component signal, and improve the inversion effect of the resistivity method.

The invention discloses a multi-scale electromagnetic exploration method based on single-electrode potential detection, and relates to the technical field of exploration geophysics, and the method comprises the steps: determining a measurement region, determining an exploration target, and determining the area of the measurement region and the density of measurement points according to the depth of the exploration target; arranging a plurality of emission sources and receiving arrays in a measurement area, collecting surface potential data of the measurement area in real time, and processing the data frequency point by frequency point according to a preset frequency sequence; on the basis of the single-electrode potential data, generating a surface potential distribution surface, constraining and suppressing a field source effect, obtaining electric field distribution information of a measurement surface, and calculating apparent resistivity parameters in combination with magnetic field measurement data; a multi-azimuth excitation mode and a multi-source emission scheme are adopted, a field source effect is inhibited, a three-dimensional resistivity profile is constructed, and a low-resistance body or a high-resistance body is identified. According to the invention, the static effect and the volume effect are solved, and the limitation of the existing electromagnetic instrument on the detection accuracy and depth is broken through.

The invention discloses an anomalous body positioning method and system combining borehole transient electromagnetic and geological radar, and relates to the technical field of mine safety detection, and the method comprises the steps: synchronously collecting the borehole transient electromagnetic data and geological radar data of an ore body to be analyzed, and generating a borehole transient electromagnetic imaging graph and a borehole geological radar imaging graph; two-dimensional coordinates of a target abnormal point in the borehole geological radar imaging graph are extracted, and the corresponding target apparent resistivity is determined; drawing an apparent resistivity contour map based on the target apparent resistivity in a target radial sectioning map of the borehole transient electromagnetic imaging map, and determining a plurality of candidate three-dimensional coordinates of a target abnormal point; at least one target feature point is selected from the borehole geological radar imaging graph, and the feature apparent resistivity corresponding to the target feature point is determined; and drawing a feature circle based on the target feature points, and screening the plurality of candidate three-dimensional coordinates to obtain coordinates of the geological anomalous body. According to the invention, the technical problem of insufficient positioning precision and reliability in the prior art is solved.

The present application relates to the engineering geophysical exploration technical field, specifically to a kind of complex terrain direct current resistivity three-dimensional forward and inversion method and system based on octree;Method includes: establishing target information sequence;Three-dimensional geoelectric model based on octree grid is constructed using target information sequence, and local encryption is carried out in the surface near the detection area and electrode neighborhood, and the modeling result is output;Based on the modeling result, the underground active unit located below the terrain surface and the air unit located above the terrain surface are distinguished, the finite volume method is used to discretize and solve the direct current resistivity method potential field control equation of underground active unit, the theoretical potential response corresponding to electrode device is obtained, and the theoretical apparent resistivity response is obtained;Construct inversion objective function, and iteratively update resistivity parameters of three-dimensional geoelectric model using inversion strategy;The three-dimensional resistivity imaging result of underground medium in detection area is output through updated three-dimensional geoelectric model, and adverse geological body is identified.

The application relates to an exploration method based on frequency division electrical method of variable frequency signals and belongs to the technical field of electrical exploration, which comprises the following steps: determining the frequency value and the frequency quantity of each channel of a multi-channel frequency division electrical method transmitter based on an exploration purpose and exploration requirements; transmitting variable frequency signals to the underground by each channel of the multi-channel frequency division electrical method transmitter; obtaining the current value of each frequency transmitted by each channel of the multi-channel frequency division electrical method transmitter at a mobile power supply point; obtaining the potential difference of different frequencies measured by a multi-channel frequency division electrical method receiver at a measuring electrode pair and the phase difference of the potential difference of the corresponding frequency relative to the current of the same frequency power supply; determining the device coefficient based on the coordinates of the measuring electrode pair and all the mobile power supply points; calculating the apparent resistivity based on the apparent resistivity parameter formula corresponding to the electrode device; and obtaining the exploration interpretation result based on the apparent resistivity and the phase difference. The application has the effect of comprehensively and accurately collecting geoelectric information.

The present invention discloses a method for advanced detection of tunnel geological anomalies based on an omnidirectional toroidal electrode arrangement. First, an omnidirectional toroidal electrode observation system is arranged in the tunnel behind the shield machine, and an advanced detection observation coordinate system is established. Advanced detection is carried out through the omnidirectional toroidal electrode observation system to obtain corresponding excitation current and potential data. Then, through multi-directional toroidal electrode synchronous coupling measurement and enhanced superposition processing, a virtual electrode coordinate is formed, and the electrode arrangements generated by the virtual electrodes are screened. The electrode arrangements that meet the requirements are selected to obtain their corresponding data for subsequent calculation of apparent resistivity, so as to realize the detection of geological anomaly bodies in front of the subway tunnel excavation. Compared with the existing conventional resistivity advanced detection, the present invention effectively improves the accuracy and coverage of advanced detection.

The invention belongs to the technical field of geophysical exploration, and provides a tunnel geological disaster advanced prediction method and system based on an orthogonal field source, and the method comprises the steps: constructing two groups of high-order pseudo-random signals, laying the orthogonal field source, and enabling the field source to transmit different groups of high-order pseudo-random signals; two groups of orthogonal observation points are arranged on a tunnel face and a tunnel bottom plate within a set distance, two field sources are excited at the same time, the two groups of observation points observe and collect received signals within set duration respectively, and electromagnetic field data of the corresponding field sources are extracted according to frequency components of emitted high-order pseudo-random signals; and according to the electromagnetic field data, calculating the single-component electric field apparent resistivity and the Kania apparent resistivity to obtain a detection result. According to the invention, the geological condition of the tunnel construction site can be detected.

The present application relates to the technical field of electromagnetic sounding, in particular to a multi-step variation AB-Hy encoding electromagnetic sounding one-dimensional inversion method and device, for the measured AB-Hy encoding electromagnetic sounding full area apparent resistivity observation value, the method presets the feasible solution space of one-dimensional horizontal layered model, randomly generates a population, forward calculation of the full area apparent resistivity of each individual in the population, calculates the fitness value of each individual in the population according to the full area apparent resistivity calculation value and observation value of each individual;Select the individual with the highest current fitness value as the optimal individual, and perform iterative calculation of multi-step differential evolution with the optimal individual participating in the population individual;The individual with the highest fitness value obtained is taken as the inversion result of the observation data. AB-Hy electromagnetic sounding one-dimensional inversion based on multi-step differential evolution algorithm is realized, the geoelectric model parameters corresponding to the observation data are obtained, and the basis for geological interpretation is provided. The method has fast optimization convergence speed and high accuracy of inversion result.