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303 results about "Transient electromagnetics" patented technology

Transient electromagnetics, (also time-domain electromagnetics / TDEM), is a geophysical exploration technique in which electric and magnetic fields are induced by transient pulses of electric current and the subsequent decay response measured. TEM / TDEM methods are generally able to determine subsurface electrical properties, but are also sensitive to subsurface magnetic properties in applications like UXO detection and characterization. TEM/TDEM surveys are a very common surface EM technique for mineral exploration, groundwater exploration, and for environmental mapping, used throughout the world in both onshore and offshore applications.

Multi-source collaborative advanced geological exploration method based on TBM construction

The invention discloses a multi-source collaborative advanced geological exploration method based on TBM construction, and belongs to the technical field of tunnel engineering geological exploration. A three-dimensional geological model is constructed through multi-scale collaborative operation of directional long exploration drilling, branch short exploration drilling and in-hole transient electromagnetic detection; the directional long exploration adopts a secondary drilling structure and a screw motor directional drilling technology to realize accurate control of a deep stratum, the branch short exploration realizes dynamic and rapid verification through a TBM integrated drilling machine, meanwhile, in-hole transient electromagnetic exploration adopts three-component measurement and an intelligent inversion algorithm to fill the blank of geological information between drill holes, and by means of mutual data correction of the three methods, the detection accuracy is improved. A three-in-one detection system of drilling, geophysical prospecting and intelligent analysis is formed, and then accurate advanced prediction is achieved, so that the problems that a traditional single detection technology is low in precision and insufficient in coverage range are effectively solved, the water inrush risk is remarkably reduced, construction safety is guaranteed, and the method is effectively suitable for deep tunnel TBM safety construction.
Owner:CHINA COAL TUNNEL ENG CO LTD +1

Goaf joint detection and identification method fusing gravity, earthquake and transient electromagnetism

The invention relates to the technical field of coal mine goaf exploration, in particular to a goaf combined detection and identification method fusing gravity, earthquake and transient electromagnetism, which comprises the following steps of: (1) arranging an earthquake, transient electromagnetism and gravity method combined observation system according to a detection geological task and a field condition of a coal goaf; (2) seismic data, transient electromagnetic data and gravity data are collected through the combined observation system; (3) performing independent inversion on the gravity data, the transient electromagnetic data and the seismic data to obtain density distribution, resistivity distribution and wave velocity distribution of the goaf; (4) carrying out a joint inversion method based on improved cross gradient seismic data, transient electromagnetic data and gravity data; (5) obtaining a joint inversion resistivity profile map, a joint inversion wave velocity profile map and a joint inversion density profile map of the goaf through joint inversion of the seismic data, the transient electromagnetic data and the gravity data of the goaf; and identifying development characteristics of the goaf.
Owner:CHINA COAL SCI & ENG ECOLOGICAL ENVIRONMENT TECH CO LTD +1

Underground anti-seepage structure leakage monitoring method and system based on discrete time

The invention discloses an underground anti-seepage structure leakage monitoring method and system based on discrete time, and relates to leakage detection. The method comprises the following steps: collecting transient electromagnetic response data generated by an excitation signal; according to the initial conductivity parameter and the electrode position parameter of the monitoring area, establishing a three-dimensional geophysical model of the monitoring area through a full waveform inversion algorithm; obtaining electromagnetic abnormal data by using a finite element forward modeling algorithm; according to the temperature data, a distributed temperature field analysis method is adopted to calculate the space gradient and the time change rate of the temperature, and temperature abnormal data are obtained; according to the pressure data and time sequence change characteristics of the pressure data, determining pressure abnormal data; fusing the electromagnetic abnormal data, the temperature abnormal data and the pressure abnormal data by using a Bayesian algorithm to obtain fused data; and inputting the fusion data into a pre-trained machine learning model to obtain a leakage detection result. Aiming at the low dynamic leakage monitoring precision of the underground anti-seepage structure, the dynamic monitoring precision is improved.
Owner:CHINA ACAD OF BUILDING RES +2

Sea water area karst cave group transient electromagnetic collaborative investigation data processing method and system

The invention discloses a sea water area karst cave group transient electromagnetic collaborative investigation data processing method and system, and the method comprises the steps: transmitting a wide frequency spectrum excitation signal to the seabed through a shipborne transient electromagnetic transmitting system, and synchronously collecting a secondary field attenuation signal responded by a seabed medium through a pull-type receiving array, meanwhile, a distributed sensor network is arranged at a preset seabed node to collect background noise base data; performing motion attitude compensation on the secondary field attenuation signal to generate transient electromagnetic response data; constructing an adaptive filter based on the background noise base data, performing noise suppression processing on the transient electromagnetic response data, and outputting noise suppression data; and performing space-time alignment on the noise suppression data of the towed array and the seabed node data to form a three-dimensional space sampling data set. According to the method, high-precision fusion of deep and shallow detection data and quantitative evaluation of the stability of the karst cave are realized, and the detection reliability and the engineering risk early warning capability of the complex ocean karst area are remarkably improved.
Owner:CHINA RAILWAY INVESTMENT GRP CO LTD +3

Transient electromagnetic and magnetic method data joint inversion method

The invention discloses a transient electromagnetic and magnetic method data joint inversion method. The method comprises the following steps: acquiring transient electromagnetic observation data and magnetic method observation data; converting the transient electromagnetic observation data into transient electromagnetic moment data; based on the transient electromagnetic moment data and the magnetic method observation data, a joint inversion objective function is constructed, and the joint inversion objective function comprises a data fitting residual term and a model constraint term; performing parameter coupling on the model constraint term by using a multivariate Gaussian mixture model to obtain a coupled model constraint term; and combining the data fitting residual term and the coupled model constraint term into a final objective function, and minimizing the final objective function through an optimization algorithm to obtain an electrical parameter and a magnetic parameter of the underground medium. According to the method, transient electromagnetic and magnetic method data joint inversion is realized, the problem of low three-dimensional inversion calculation efficiency is solved by introducing transient electromagnetic moment, and electrical and magnetic parameters are coupled by utilizing rock physics constraint, so that the inversion result is more accurate, and the structure is more consistent.
Owner:INSTITUTE OF GEOLOGY AND GEOPHYSICS CHINESE ACADEMY OF SCIENCES

Method and system for monitoring migration of separation grouting slurry

ActiveCN121322104AMining devicesSlurryCoal
The invention belongs to the technical field of geological engineering monitoring and multi-physics field intelligent sensing, and discloses a separation grouting slurry migration monitoring method and system, and the method comprises the steps: constructing an acoustics-optics-electricity-electromagnetism multi-physics field coupling monitoring system; a grouting hole and a monitoring drilling hole array are arranged in a target stratum, a distributed optical fiber sensor, a drilling hole ultrasonic imager, a resistivity measuring device and a transient electromagnetic detection device are installed, and a three-dimensional monitoring network is formed; synchronously acquiring sound field, light field, electric field and magnetic field data; four-field monitoring data and overlying strata multi-parameter observation data are fused, a coal seam mining three-dimensional overlying strata separation model is constructed, and a slurry diffusion three-dimensional visualization model is generated through numerical simulation; and based on the four-field monitoring response difference of the separation space before and after grouting, in combination with a monitoring frequency domain correction model of multiple indexes of grout diffusion, the diffusion range, compactness and filling effect of the grouting grout are evaluated, and abnormal early warning is triggered.
Owner:SHANDONG UNIV OF SCI & TECH +1

Drill hole joint detection method and system capable of reducing number of advance drill holes of tunnel roadway

The invention provides a drill hole joint detection method and system capable of reducing the number of advance drill holes in a tunnel roadway, and relates to the field of roadway engineering detection, and the method comprises the steps: obtaining the depth of a measurement point and the radar data and transient electromagnetic data of a target region, and enabling the radar data and the transient electromagnetic data to be collected through an integrated detection device in a drill hole; performing feature extraction on the radar data and the transient electromagnetic data, and fusing the extracted features based on contribution weights of the radar and the transient electromagnetism to obtain a fused feature vector; based on the depth of the measuring point and the fused feature vector, utilizing the trained physical information neural network to invert the dielectric constant and the resistivity; according to the dielectric constant and the resistivity, the geological anomalous body of the target area is identified; according to the invention, the drilling radar and the drilling transient electromagnetism are combined, so that the number of advanced drilling holes is reduced, the detection cost is reduced, and the full-area coverage of the forepoling of the roadway is ensured.
Owner:SHANDONG UNIV

Earth and rockfill dam leakage detection method based on combination of transient electromagnetic method and single-hole dilution method

The invention mainly relates to the related technical field of earth and rockfill dam leakage detection, in particular to an earth and rockfill dam leakage detection method based on combination of a transient electromagnetic method and a single-hole dilution method. A leakage hidden danger area is rapidly scanned and positioned through a transient electromagnetic method, a single-hole dilution method is guided to conduct drilling in a key area, and invalid drilling is reduced; on the basis of a traditional dilution curve model, a drilling radius correction factor and a non-Darcy effect correction term are introduced, and the output precision of a vertical seepage profile is remarkably improved; a quantitative mapping model of the resistivity inversion image and the seepage velocity is established, and quantitative conversion from physical detection data to hydraulic parameters is achieved; leakage channel space distribution is automatically extracted based on the image recognition technology, and rapid calculation of the total dam leakage amount is achieved.
Owner:CHONGQING YUFA WATER CONSERVANCY RES INST CO LTD

Double-top umbrella type multi-angle adjustable transient electromagnetic transmitting coil array detection device

The invention relates to the technical field of geophysical exploration equipment, and particularly discloses a double-top umbrella type multi-angle adjustable transient electromagnetic transmitting coil array detection device which comprises a main supporting system, a framework supporting system, a coil system, a multi-angle adjusting mechanism and a rapid storage system. The device has the beneficial effects that accurate adjustment in a continuous angle range is realized, and the adaptability of the device to different exploration environments is improved; a double-coil system design is adopted, so that two typical working modes are realized; in structural design, a double-top umbrella type folding structure is combined with a light-weight material, so that the weight of equipment is reduced. According to the device, conversion of multiple detection modes is achieved, traditional multiple fixed angle devices are replaced, the equipment investment cost is reduced, and the equipment operation efficiency is improved.
Owner:JILIN UNIVERSITY

Transient electromagnetism-based grounding grid corrosion defect evaluation method and system

The invention is suitable for the technical field of grounding grid defect evaluation, and provides a transient electromagnetism-based grounding grid corrosion defect evaluation method and system, and the method comprises the steps: placing a sensor of a transient electromagnetic detection device above a to-be-detected region of a grounding grid, injecting a pulse current excitation signal into a conical focusing excitation coil, and carrying out the detection of the to-be-detected region of the grounding grid; acquiring an induced voltage time sequence signal through a receiving coil; extracting at least one characteristic parameter from the induced voltage time sequence signal, wherein the characteristic parameter comprises a signal peak value, peak value time, an attenuation rate or a signal integral quantity; inputting the characteristic parameters into a preset corrosion evaluation model, and performing inversion to obtain a residual thickness value or a corrosion depth value of the grounding grid in the to-be-detected area; generating and outputting a quantitative evaluation result containing the residual thickness value or the corrosion depth value; the method can be implemented in a non-stop state of the grounding grid, and an efficient and reliable decision basis is provided for safe operation and state maintenance of a power system.
Owner:ELECTRIC POWER RES INST OF GUANGXI POWER GRID CO LTD

Transient electromagnetic and seismic wave multi-mode joint inversion imaging method based on physical information Transformer

The invention relates to a transient electromagnetic and seismic wave multi-mode joint inversion imaging method based on physical information Transform, and belongs to the crossing field of geophysical exploration and artificial intelligence. Comprising the following steps: carrying out anomaly detection, interpolation, filtering and normalization preprocessing on transient electromagnetic and seismic wave original data; extracting features representing electrical property, elasticity and cross physical significance; serializing the spatial data through a gridding and alternating fusion strategy, and constructing an enhanced code fusing absolute and relative positions and physical attributes; a physically constrained encoder-decoder architecture is designed to carry out multi-scale forward modeling-inversion; and quantizing the uncertainty of an inversion result by adopting a Bayesian Monte Carlo method, and generating a confidence map. According to the method, through physical rule driving and multi-modal depth complementary fusion, the fine recognition capability and interpretation reliability of hidden disaster-causing geologic bodies such as underground goaf and collapse columns are effectively improved while the physical consistency of data is kept.
Owner:CHONGQING UNIV +2

Differential transient electromagnetic method device and unexploded ordnance detection method thereof

The invention belongs to the technical field of geophysical exploration, and particularly discloses a differential transient electromagnetic method device and an unexploded ordnance detection method thereof.The differential transient electromagnetic method device is characterized in that a transmitter injects emission current into an emission loop, and the emission loop generates a primary field excitation signal; the underground anomalous body target generates a secondary field excitation signal under the action of the primary field excitation signal; the receiving coil assembly is based on the structure of a differential coil, synchronously counteracts a primary field excitation signal and a uniform background signal in an induced voltage, and expands a local asymmetric differential signal generated by an underground anomalous body target; and the receiver carries out time sequence analysis on the local asymmetric differential signals and extracts differential signal features so as to realize positioning and identification of an underground anomalous body target. The device is suitable for detection of shallow-buried small bodies such as UXO, the overall arrangement range of the device is small, and rapid arrangement and mobile observation in the field are facilitated.
Owner:CHINA UNIV OF GEOSCIENCES (WUHAN)

Karst cave group detection method and device in shield construction

The invention provides a karst cave group detection method and device in shield construction, and the method achieves the comprehensive detection of karst caves through a transient electromagnetic and sound wave array composite wave field detection mode, and improves the detection accuracy and detection efficiency of the karst cave group. And feature extraction is performed on the composite wave field detection data through a cross-physical coupling model, a karst cave probability model is established, and quantitative evaluation of a karst cave detection result is realized. When the karst cave possibly exists in the construction direction of the shield tunneling machine, the distribution prediction direction of the karst cave is further determined, and the shield tunneling machine is prevented from entering the karst cave area blindly in the tunneling process. Through the multi-source sensing array carried on the shield tunneling machine, equipment parameters during operation of the shield tunneling machine are collected in real time, potential construction anomalies can be found easily, and the accuracy and timeliness of karst cave detection are improved. Combined analysis is carried out on the composite wave field detection data and the operation parameters of the shield tunneling machine through the risk assessment model, a karst cave risk prediction value is determined, and the accuracy of karst cave risk assessment is improved.
Owner:CHINA RAILWAY INVESTMENT GRP CO LTD +3

Fast ground-air transient electromagnetic inversion method based on FiLM-U-net

The invention discloses a fast air-ground transient electromagnetic inversion method based on FiLM-U-net, and belongs to the field of electromagnetic signal data processing, and the method comprises the steps: obtaining geological data and air-ground transient electromagnetic detection data, carrying out the preprocessing, and constructing a data set; dividing a training set, a verification set and a test set; the method comprises the following steps: constructing a FiLM-U-net network model in combination with a FiLM structure and a U-net structure; adopting the training set to select a proper training strategy to train the FiLM-U-net network model, and adopting the test set to evaluate the inversion effect of the model; and the trained FiLM-U-net network model is used to carry out inversion on ground-air transient electromagnetic measured data, transmit-receive positions and ground-air transient electromagnetic response are inputted, and an underground model resistivity value is outputted. According to the invention, the space information can be effectively utilized to carry out efficient and rapid inversion on the ground-air transient electromagnetic signal.
Owner:JILIN UNIVERSITY

Method for rapidly and efficiently extracting coal mine gas in broken and soft coal seam

The invention discloses a method for rapidly and efficiently extracting coal mine gas in a broken and soft coal seam, and belongs to the technical field of coal seam gas development and coal mine gas prevention and control. According to the method, geological features of a coal mining planning area are determined, a ground U-shaped well and underground bottom-pumped rock drift layer-crossing drilling combined treatment system is deployed, and regional large-scale treatment is achieved in a well factory mode; the fracturing transformation range and the fracturing fluid distribution characteristics are detected by using a ground and underground combined micro-seismic monitoring and underground transient electromagnetic method, and the arrangement of layer-crossing drill holes is optimized; dividing the cross-layer drill holes into drainage holes and air exhaust holes, and formulating a collaborative extraction system in combination with different drainage and extraction stages; the method solves the problems that broken soft coal seam gas extraction is low in efficiency and long in period, and treatment blind areas exist, treatment time is remarkably shortened, cost is reduced, and safe and efficient production of a coal mine is guaranteed.
Owner:CHANGJIANG THREE GORGES SURVEY INST CO LTD (WUHAN) +1

Semi-aviation transient electromagnetic signal adaptive gain method and system

The invention discloses a semi-aviation transient electromagnetic signal adaptive gain method and system, and relates to the technical field of geophysical exploration, and the method comprises the steps: obtaining a differential signal of a receiving coil, and carrying out the chopping self-stabilization zero amplification processing of the differential signal; the method comprises the following steps: dividing a total time window of a differential signal into a plurality of time channels under a set time reference, adjusting the length of each time channel according to a signal attenuation characteristic, calculating the time length and data point number of each time channel according to a sampling rate and the total time window, and calculating the time length and data point number of each time channel; the data points are distributed to an early time channel, a middle time channel and a late time channel, so that different gain multiples are switched, and adaptive gain amplification is carried out; and the differential signal subjected to adaptive gain amplification is transmitted to a receiver after being collected by an ADC (Analog to Digital Converter). By dynamically adjusting the gain coefficient in different time channels, the technical problems of large dynamic range of transient electromagnetic signals and low signal-to-noise ratio of weak signals are solved, and high-fidelity acquisition of full-time-domain signals is realized.
Owner:SHANDONG UNIV

Three-dimensional transient electromagnetic detection method for tunnel advanced geological forecast

The invention discloses a three-dimensional transient electromagnetic detection method for tunnel advanced geological forecast. The transient electromagnetic exploration method has the advantages of low construction cost, high safety coefficient, reliable detection result and the like. The method comprises the following steps: installing a plurality of loop sources in an area nearby a tunnel face in a set mode, and obtaining stratum information data of the area nearby the tunnel face; and analyzing the data by adopting a three-dimensional transient electromagnetic forward and reverse modeling method to obtain related information of the unfavorable geologic body in front of the tunnel face. According to the method, the efficiency and the accuracy of transient electromagnetic tunnel advanced prediction are improved.
Owner:CHINA RAILWAY FIRST SURVEY & DESIGN INST GRP

Earthquake forecasting and tsunami early warning method and system

The invention discloses an earthquake forecasting and tsunami early warning method and system, and the method comprises the steps: monitoring the earth electromagnetic field data in real time, and recognizing and extracting a regional transient electromagnetic signal which accords with a preset abnormal feature as an earthquake precursor signal; taking the position of the precursor signal as a reference, and predicting the earthquake generation time, the magnitude and the potential influence area based on an earth crust stress wave propagation model; when the early warning condition is met, earthquake early warning information containing risk avoiding guidance is generated and issued, and if the prediction area relates to the coastal area and the earthquake magnitude reaches a threshold value, tsunami early warning information is synchronously generated and issued. The corresponding system comprises a geomagnetic monitoring module, a forecast analysis module and an early warning issuing module. According to the method, pre-earthquake prediction based on the physical precursor is realized, the prediction time is remarkably prolonged, the problems that earthquake and tsunami early warning information is separated and published lags are solved, and the disaster response capability is improved.
Owner:ZHEJIANG NANSHENG TECHNOLOGY CO LTD

Transient electromagnetic vertical component detection data one-dimensional real-time accurate inversion method and system

The invention belongs to the technical field of geophysical exploration, and discloses a transient electromagnetic vertical component detection data one-dimensional real-time accurate inversion method and system. Processing the established stratum model, training the constructed Seq2seq network by using a back propagation algorithm, and training transient electromagnetic optimal inversion models with different numbers of layers; performing background field extraction on all measurement points of the actually measured data, constructing simulated background field data, and extracting pure abnormal field ratio data; multiplying the obtained actually measured pure abnormal field ratio data by the obtained simulated background curve to reconstruct brand new total field data; the reconstructed brand-new total field data is corrected to be consistent with the time domain of the sample library; an inversion model of the corresponding layer number is selected, and the resistivity-thickness of the stratum is calculated in real time; and carrying out visual display on an inversion result. According to the invention, inversion precision is improved, and real-time inversion of transient electromagnetic detection data is realized.
Owner:XIAN COAL SCI TRANSPARENT GEOLOGICAL TECH CO LTD

Electromagnetic wave logging detection depth determination method and device, medium and program product

The embodiment of the invention discloses an electromagnetic wave logging detection depth determination method and device, a medium and a program product. The method comprises the steps that a conductivity disturbance stratum model under the homogeneous medium background condition is established, a multi-component transmitting and receiving antenna combination mode is simulated, a lower step signal source serves as an excitation source of transient electromagnetic wave logging, and a homogeneous medium transient electromagnetic wave logging response model is determined; according to the electromagnetic wave logging response perturbation model and the uniform medium transient electromagnetic wave logging response model, a sensitivity function of induced electromotive force is determined; determining a radial integral sensitivity function under a cylindrical coordinate system according to the sensitivity function of the induced electromotive force; and determining the detection depth of transient electromagnetic wave logging in the target time range according to the radial integral sensitivity function. According to the scheme, specific analysis can be carried out in combination with instrument parameters and signal definition, the detection performance evaluation problem of time domain signals measured in a well is solved, and the detection depth of transient electromagnetic wave logging equipment is accurately determined.
Owner:GUANGZHOU MARINE GEOLOGICAL SURVEY

Ultra-wide coal face roof electrical tomography system and method

The invention belongs to the technical field of geophysical exploration transient electromagnetic detection, particularly relates to an ultra-wide coal face roof electrical tomography system and method, and is suitable for high-precision detection of a hidden geological structure of a working face roof with the width exceeding 300 meters and the depth within 100 meters in an underground coal mine. A transient electromagnetic perspective detection technology is adopted, and full-coverage imaging of an electrical structure of a working face roof is realized through alternate arrangement of transmitting-receiving roadways and dynamic data fusion; a time-space mapping relation is established in combination with a smoke ring effect diffusion model, and omnibearing imaging of the top plate is achieved; aiming at the refined detection of the hidden geologic structure of the top plate of the ultra-wide coal face (the width is greater than or equal to 300 meters), bidirectional detection and grid subdivision are adopted, and a single-side detection blind area is eliminated through roadway transposition of a transmitting end and a receiving end, so that grid full-coverage imaging in a detection range is realized.
Owner:BEIJING EXPLORATION RESOURCES TECH CO LTD +1

Quick tunneling surrounding rock drilling geophysical prospecting device and method for weakly cemented rock stratum coal mine tunnel

The invention discloses a quick tunneling surrounding rock drilling geophysical prospecting device and method for a weakly cemented rock stratum coal mine tunnel. The device comprises a tunneling machine, a drilling device, a while-drilling transient electromagnetic device, a while-drilling impact seismic source device, an equipment cable and a field host. The while-drilling transient electromagnetic device, the while-drilling impact seismic source device and the drill bit are sequentially connected, the while-drilling transient electromagnetic device is used for collecting data of electromagnetic detection, and the while-drilling impact seismic source device is used for exciting seismic waves; the on-site host is connected with the while-drilling transient electromagnetic device, the while-drilling impact seismic source device and the drill bit. According to the invention, drilling, seismic wave detection and transient electromagnetic detection are organically fused, real-time identification and dynamic analysis of a surrounding rock structure are realized, seamless connection of real-time exploration and construction, synchronous exploration and tunneling and integration of fused drilling geophysical prospecting data are realized; the method is especially suitable for geological detection requirements of weak cemented surrounding rock strata in coal mine tunnel excavation, and can effectively improve detection precision and operation efficiency under complex and weak surrounding rock conditions.
Owner:CHINA UNIV OF MINING & TECH +1

Submarine dipole-dipole electromagnetic detection system and method carried on remote control underwater robot

The invention discloses a seabed dipole-dipole electromagnetic detection system and method carried on a remote control underwater robot, and belongs to the technical field of seabed metal mineral resource fine exploration. The system comprises a remote control underwater robot (ROV), a retractable receiving coil extension bracket, a transient electromagnetic transmitting coil, a transient electromagnetic receiving coil, a transient electromagnetic main engine room and an instrument fixing bracket. The extension bracket is controlled through the hydraulic retraction device, so that the receiving coil is arranged away from the ROV body, and the interference of the equipment body on electromagnetic signals is obviously reduced. The ROV performs low-altitude cruising on the seabed along a preset fine measuring line to acquire transient electromagnetic data, and the actually measured data is corrected in real time by using the full-space seawater environment response in the diving process, so that the system interference is effectively inhibited. According to the method, the high-resolution electromagnetic detection capability of ore bodies such as seabed polymetallic sulfide is improved, and the method is suitable for mineral resource investigation of complex terrains and small-scale regions.
Owner:SECOND INST OF OCEANOGRAPHY MNR +1

Method and system for extracting transient electromagnetic signal through ground nuclear magnetic resonance

The invention belongs to the technical field of geophysical methods, and particularly discloses a method and system for extracting transient electromagnetic signals through ground nuclear magnetic resonance. The method comprises the following steps: periodically transmitting nuclear magnetic resonance excitation pulses to an underground medium, and extracting nuclear magnetic resonance turn-off pulses as transient electromagnetic excitation signals at the turn-off stage of each nuclear magnetic resonance excitation pulse; after each nuclear magnetic resonance excitation pulse is turned off, detecting a transient electromagnetic response signal; and when the last nuclear magnetic resonance excitation pulse is turned off, collecting a nuclear magnetic resonance response signal. According to the invention, the high-energy turn-off pulse is directly extracted as the transient electromagnetic excitation signal in the turn-off stage of the nuclear magnetic resonance excitation pulse, so that the overall signal utilization efficiency and excitation capability of the system are remarkably improved.
Owner:CHINA UNIV OF GEOSCIENCES (WUHAN)

Dynamic regulation and control method and control system for tunneling and grouting reinforcement of water-rich layered surrounding rock tunnel

The invention discloses a dynamic regulation and control method and a control system for tunneling and grouting reinforcement of a water-rich layered surrounding rock tunnel. The method comprises the following steps: acquiring bedding surface occurrence, water pressure, fault fracture zone, water seepage area distribution and other data by adopting advanced geological detection; in a layered surrounding rock section, grouting areas are divided according to a bedding dip angle, high-pressure splitting grouting is adopted in a bedding area, and permeation grouting is adopted in a cutting area; in the fault fracture section, fault fracture zone grouting areas are divided according to the fault width and the stratum condition, and anchor rods with different depths are adopted for grouting; the ratio of the nano-composite grout is dynamically adjusted based on the real-time water pressure of each grouting area; the grouting pressure and flow are dynamically adjusted through the intelligent adjusting and controlling system; and a transient electromagnetic method is adopted to evaluate the grouting effect, and secondary grouting is carried out to achieve reinforcement. The grouting parameters can be dynamically adjusted and controlled according to the bedding surface condition during grouting.
Owner:CHINA INTERNATIONAL WATER & ELECTRIC CORPORATION

Semi-aviation transient electromagnetic detection system based on cooperation of robot dog and unmanned aerial vehicle

The invention relates to the technical field of geophysical exploration, in particular to a semi-aviation transient electromagnetic detection system based on cooperation of a robot dog and an unmanned aerial vehicle, and the system consists of a robot dog platform, an unmanned aerial vehicle platform and a ground control station. The robot dog platform comprises a high-power transient electromagnetic transmitter, a line source laying module, a voice warning module and a mobile positioning module, and can automatically lay a line source and inject pulse current to the ground; the unmanned aerial vehicle platform comprises a visual field auxiliary module, a flight driving module and a receiving coil, and the coil can be dragged according to a preset route to collect electromagnetic data; the ground control station is used for job scheduling and data processing. Wiring-transmitting-receiving integrated collaborative operation is realized through the robot dog and the unmanned aerial vehicle, and the robot is suitable for detection of a complex mountain environment.
Owner:ZHEJIANG HUADONG CONSTR ENG

Seismic-electromagnetic joint inversion method based on bidirectional cross gradient constraint

The invention discloses a seismic-electromagnetic joint inversion method based on bidirectional cross gradient constraint. The method comprises the following steps: firstly, establishing three physical field initial models; taking a seismic grid as a main grid, and mapping respective models of a direct current method and a transient electromagnetic method to the main grid through interpolation; constructing a joint inversion objective function containing data fitting terms of the three physical fields, model constraint terms and cross gradient constraint terms between every two of the three physical fields; decomposing the joint inversion objective function into three inversion objective functions which are coupled with one another, and respectively carrying out iterative updating on the seismic velocity model, the direct current method resistivity model and the transient electromagnetic method resistivity model by adopting a collaborative alternative iteration strategy; each iteration update of any model is constrained by the cross gradient exported by the last iteration result of the other two models, so that the structural consistency between the models is forcibly realized; and after completion, outputting a geologic structure model fusing the three-field information, thereby effectively improving the detection precision and interpretation reliability of the geologic structure under the complex geological condition.
Owner:YUNLONG LAKE LAB OF DEEP UNDERGROUND SCI & ENG +1

Treatment method for building door tunnel penetrating karst underground river section

The invention belongs to the technical field of tunnels, and particularly relates to a treatment method for a building door tunnel penetrating a karst underground river reach, which comprises the following steps: step 1, multi-source geophysical prospecting fusion investigation: aiming at the tunnel karst underground river reach and the range of 500m around the tunnel karst underground river reach; the method comprises the following steps of: delineating a karst abnormal area by adopting semi-aviation transient electromagnetism; screening a strong corrosion area by adopting a depression analysis method; verifying parameters of the abnormal area through surface drilling and coring; identifying surface hydrology, lithology and seepage data characteristics through unmanned aerial vehicle-mounted high-resolution multispectral and thermal infrared cooperative remote sensing; karst water dynamic conditions including underground water flow velocity, flow direction and permeability coefficient, corrosion evolution characteristics including cavern forming time and expansion rate, and key physical and mechanical parameters including cavern filler porosity, permeability coefficient, surrounding rock integrity coefficient, uniaxial compressive strength, elastic modulus and Poisson's ratio are obtained. According to the treatment method for the building door tunnel to penetrate through the karst underground river section, the karst space characteristics are clearly presented through the arrangement of the treatment method for the building door tunnel to penetrate through the karst underground river section.
Owner:CCCC SECOND PUBLIC BUREAU FOURTH ENG CO LTD

Method and system for analyzing transient electromagnetic detection signal of oil and gas pipeline based on LSTM (Long Short Term Memory) and storage medium

The invention discloses an LSTM-based oil and gas pipeline transient electromagnetic detection signal analysis method and system and a storage medium, and relates to the field of pipeline defect nondestructive detection. Acquiring electromagnetic signals at a plurality of different preset frequency points and different directions corresponding to the different preset frequency points according to a preset time interval to form electromagnetic signal array data; according to the time domain waveform, the frequency spectrum curve and the signal amplitude in the electromagnetic signal array data, abnormal electromagnetic signals are screened; the resistivity of the position, corresponding to the oil and gas pipeline, of the abnormal electromagnetic signal is collected and compared with the standard resistivity, and if the comparison result exceeds a preset range, multi-dimensional features of the abnormal electromagnetic signal are extracted to construct a feature vector; and inputting the feature vector into an LSTM signal detection network model, outputting a mapping relation between the feature vector and the oil and gas pipeline defect, and obtaining an oil and gas pipeline defect condition corresponding to the current electromagnetic signal. The pipeline fault risk can be reduced, and safe and stable operation of the oil and gas pipeline is guaranteed.
Owner:ZHENGZHOU UNIVERSITY OF AERONAUTICS

Ground well transient electromagnetic data inversion method, device, equipment, medium and product

The invention discloses a ground well transient electromagnetic data inversion method, device and equipment, a medium and a product, and relates to the field of electromagnetic detection, and the method comprises the steps: obtaining the actual measurement transient electromagnetic response data of different measurement points of a single drill hole; performing grid division on the underground medium of the measuring area by taking the drill hole as the center, and constructing a plurality of electrical layers; initializing the earth electrical parameters of each electrical hierarchy to obtain an initialized model; fitting transient electromagnetic data after the peak moment of the first measuring point by using a first target function according to the actually measured transient electromagnetic response data and the initialization model to obtain an estimated geodetic electrical parameter; and according to the actually measured transient electromagnetic response data and the estimated geodetic electrical parameters, fitting transient electromagnetic data after peak moments of all measuring points by using a second objective function to obtain inversion geodetic electrical parameters. According to the invention, the geodetic electrical parameter distribution can be accurately reconstructed.
Owner:INST OF GEOPHYSICAL & GEOCHEMICAL EXPLORATION CHINESE ACAD OF GEOLOGICAL SCI