bluuebunny/crossref_metadata_2025 huggingface dataset:
Modified Frequency-Bessel Transform Method for Dispersion Imaging of Surface Wave from Six-Component Ambient Noise Recordings
Authors: Xi Chaoqiang , Liu Ya , Wu Haibo , Ning Ling , Zhang Hao , Guan Bo
Published: December 2023

Surface wave analysis methods based on ambient noise have attracted considerable attention within the geophysical and civil engineering communities, particularly in light of the limitations associated with traditional seismic surveys in densely populated urban areas. Conventionally, translational seismic sensors have been employed for the observation of ambient noise. Nevertheless, recent advancements in rotational sensor technology have facilitated the direct measurement of ground motion induced by seismic waves in a rotational manner. Through the integration of these rotational sensors with traditional inertial seismometers, a novel six-component seismic sensor has been developed. This innovative sensor enables the local observation of six degrees of freedom pertaining to ground motion, encompassing three orthogonal components of translational motion and three orthogonal components of rotational motion. In order to demonstrate the seismological significance of rotational ground-motion data, we applied the modified frequency-Bessel transform method (MFJ) to six-component ambient noise recordings for surface wave analysis. To underscore the practical utility of the MFJ method, a real-world case study is presented, illustrating its effectiveness in quantifying Rayleigh and Love wave dispersion from six-component ambient noise recordings.
Application of Deep Learning in Rayleigh Dispersion Curves Inversion
Authors: Ye Zhihu , Xie Xiaoguo , Zhang Zhihou , Zhao Minghao , Zhang Tianyi , Wang Hu
Published: December 2023

The inversion of the Rayleigh wave dispersion curve is a fundamental step in determining the shear wave velocity profile. However, existing inversion methods, such as linear and nonlinear approaches, have inherent limitations. In order to overcome these challenges and enhance the speed and accuracy of the inversion, this paper proposes a novel deep learning-based approach. We establish a method to construct sample data that ensures ergodicity and evolutive orderliness of the near-surface velocity profile using a constrained Markov decision process to address these limitations. We then design a deep learning model to capture the nonlinear mapping relationship between the dispersion sequence data and velocity structure. Training the model on the generated sample data accurately predicts the subsurface velocity profile based on the dispersion curve. The proposed method is evaluated through theoretical model experiments, demonstrating high computational accuracy.
Application of Variational Mode decomposition in GPR Detection of Oil Contaminated Soil
Authors: Lu Qi , Guo Shilong , Zeng Zhaofa , Liu Sixin , Liu Kexin , Li Xiaolong
Published: December 2023

In this article, Ground penetrating radar (GPR) is used to investigate the contaminated soil by oil pollutants in oilfield operation area. Time frequency analysis method is applied to GPR data to reveal the changes of GPR signal frequency components with time variation, which is very important for data interpretation. We use variational mode decomposition (VMD) for time frequency analysis. It can decompose radar signal into several quasi-orthogonal intrinsic mode functions (IMFs) with limited bandwidth, and has strong robustness and local decomposition ability. We apply the VMD on field data acquired in the area with waste liquid contaminated soil in oilfield. The decomposed IMFs from GPR data shows that the signals from the contaminated soil is characterized by the strong energy and low frequency. Then the instantaneous attribute analysis of the IMF is carried out to delineate the scope and thickness of contaminated soil. The experimental results show that the limited bandwidth IMF with specific sparsity obtained by VMD method is more conducive to the processing and interpretation of GPR data.
Near-field Focusing in Ground Penetrating Radar Based on Phase Compensation Algorithm
Authors: Zhang Qifei , Guo Linyan , Chen Lianfeng , Zhang Qisheng
Published: December 2023

Underground energy intensity and electromagnetic wave penetration depth are important parameters to characterize the detection performance of Ground Penetrating Radar (GPR). Near-field focusing (NFF) is an effective means to improve the electromagnetic energy fed into the ground by the antennas. In this paper, the phase compensation algorithm considering underground media is derived. In order to verify the effectiveness of the algorithm, the NFF antenna array is proposed. By changing the phase of the NFF array, the focus distance can be adjusted in the range of 400 mm – 800 mm. The maximum field enhancement coefficient in the focal region can achieve 19.2 dB. This shows that NFF array based on phase compensation algorithm has potential application prospects in increasing GPR detection performance.
Removal of Diagonal Strip Noise in Airborne Ice Penetrating Radar Data
Authors: Luo Kun , Liu Sixin , Tang Xueyuan , Li Lin
Published: December 2023

Airborne ice-penetrating radar (IPR) is a powerful geophysical method for detecting ice thickness, subglacial topography and internal layers in the vast and frigid Antarctic ice sheet. Data processing is an essential step in improving the signal-to-noise ratio (SNR). In order to eliminate the diagonal strip noise mainly present in airborne IPR data of the Amery ice shelf and Grove Mountain regions, traditional ground penetrating radar processing methods such as F-K (frequency-wavenumber domain) filtering and F-K migration are applied. The validity of the data processing methods is proved by the quantitative index of image quality evaluation. It provides a reference for subsequent airborne radar data processing and application.
Research on GPR Response Recognition of Levee Hazards Based on Convolutional Neural Network
Authors: Zhao Wenxue , Ma Changying , Yan Lingling , Ding Wenqiang , Zhong Weichen , Xie Song
Published: December 2023

As a key part of water conservancy and flood control, the safe service of levee is a matter of national importance. Since the construction of early levee showing the disease phenomena such as breakage, leakage and hollowness, it has seriously threatened the safety of people’s lives and properties, and became one of the important livelihood problems that need to be solved imminently. In this paper, the network model for automatic classification of levee hazards is constructed using convolutional neural network algorithm. The data set of the ground-penetrating radar responses of different hazards types required for training is constructed by forward modeling. Then, the network model is used to predict the hazards types from the actual measured data of a levee in Jiangxi Province. The results show that the good recognition accuracy and effect of the convolutional neural network model established in this paper.
Application Research of 3D Geological Radar Detection Technology in Urban Road Disease Survey
Authors: Tan Shunjia , Qian Peng , RuixueWang
Published: December 2023

With the comprehensive detection and risk assessment industry of urban road underground diseases taking shape and the long-term development of new technologies, new methods and new equipment, this paper introduces the important breakthrough of 3D geological radar detection technology. Such nondestructive testing site acquisition can achieve high-density seamless detection, qualitative accuracy of data interpretation, accurate determination of road disease scope, detection data has long-term preservation and application research value.
Breakthrough and Practice of Ground Penetrating Radar Detection Technology in Baiyangdian Lake
Authors: Wang Chunhui , Pu Yuantian , Guo Shujun , Sun Sheng
Published: December 2023

In order to investigate the stratum structure of the lake bottom in the Baiyangdian Lake area, implement the test of the water-based ground penetrating radar detection system, explore the working mode of the water-based radar detection, compare the water exploration capabilities of different hardware devices, analyze the electromagnetic wave propagation characteristics in the Baiyangdian Lake area, and interpret the geophysical response of the native strata at the bottom of the lake. The stratum structure data in the 15m depth range of the bottom of the lake was obtained to provide a basis for the establishment of a three-dimensional geological model of the Dian District. This technical achievement can strongly promote the construction of a lake and wetland water-land integrated technical method system.
AVO Attribute Characteristics of Ground Penetrating Radar
Authors: Yuan Lei , Jiang Zhihai , Liu Shucai , Li Maofei
Published: December 2023

As a non-destructive and high-efficiency electromagnetic wave exploration method, the conventional fixed-offset GPR detection has been able to solve some practical problems. However, in the case of complex formation conditions and variable physical parameters, the effect is not too ideal. In reference to earthquakes, AVO processing technology can be used to enhance the detection of lithologic parameters. This paper introduces the application of AVO in GPR by numerical simulation. By controlling variables and changing the parameters of the model, the response characteristics under different offsets and different relative dielectric constants are analyzed, and the application of AVO technology in radar processing and the identification of lithologic parameters of the lower interface are verified.
Effect Analysis of Random-weighted Equipoise Multi-channel Adaptive Matched Filtering on Regular Interference Removal
Authors: Li Yongxin , Li Zhongsheng , Xiao Weiguo , Lu Qiang , Wang Zhongsheng , Su Wuque , Ren Quanchao , Li Xingwang , Hu Jing
Published: December 2023

Equipoise multi-channel adaptive matched filtering is an effective method to remove regular interference signals from the original seismic records. In order to weaken the dependence of data on orthogonality restrictions, some channels around the target are usually selected as equipoise channels. In order to accurately extract the wavelet shape, the selected equipoise channels need to be as few as possible. The fewer equipoise channels, however, will lead to unsatisfactory filtering effect because of data non-orthogonality. In view of this defect, we develop conventional equipoise multi-channel adaptive matching via randomly selecting channels away from the target as the equipoise channels and assigning different weight factors to different equipoise channels simultaneously. This method may weaken the data non-orthogonality and reduce the influence related to the number of equipoise channels. In order to verify the effectiveness of this method, numerical experiments and analysis of different models have been carried out. The results show that in the case of a small number of matching channels, the effects of the random or random-weighted equipoise multi-channel adaptive matched filtering are better than the conventional one. The random-weighted has the best effect.
The Strain State Analysis of 4-component Borehole Strainmeter Observations in Sichuan-Yunnan Region
Authors: Tang Lei , Ye Qing , Fan Junyi
Published: December 2023

Analysis of nearly a decade of crustal strain changes state after the Ms8.0 Wenchuan earthquake by using 4-component borehole strain observation data, and combined with the tectonic stress field, this paper studied the regional stress and strain variation characteristics and dynamics. The results show that the main compressive strain direction of the 4-component borehole strain observation is approximately the same as that of tectonic stress field. However, there are also some regional inconsistencies, which should be related to regional structural features.
MTAINV3D: A Three-dimensional Adaptive Magnetotelluric Inversion Tool Using Unstructured Grids
Authors: Chen Huang , Ren Zhengyong , Tang Jingtian
Published: December 2023

Currently, 3D magnetotelluric inversion often uses a fixed inversion grid. Too sparse inversion grids cannot approximate the complex subsurface conductivity distribution, and may also lead to inversion results failing to converge. Too dense inversion grids will increase not only the computational cost, but also the non-uniqueness of the inversion. Aiming at the above problems, we have developed a three-dimensional magnetotelluric adaptive inversion strategy with unstructured finite element and limited memory BFGS (L-BFGS) algorithms. Firstly, based on the unstructured finite element method, the high accuracy forward responses of the 3D geo-electric model with arbitrary complex terrain and conductivity distributions can be obtained. Then, the forward and inversion meshes are decoupled by using the nested forward and inversion tetrahedral meshes. The Thikhonov regularization objective function with smooth constraints is established and minimized by L-BFGS optimization algorithm with inexact line search procedure, where the gradient of the objective function is solved by using the adjoint principle. Most importantly, an inversion grid adjustment strategy based on the dual constraints of sensitivity matrix and model gradient is proposed, which are used to guide the automatic refinement of inversion grid in the optimization process. Finally, a topographic model is used to validate and test the performance of the proposed adaptive inversion algorithm.
Using High-speed Train Induced Signal to Estimate High-Speed Train Acceleration
Authors: Wang Hailin , Wang Xiaokai , Chen Wenchao , Liu Zhaodan
Published: December 2023

A moving high-speed train (HST) stimulates various seismic waves near a high-speed railroad (HSR). Thus, the HST has been treated as a combined and moving seismic source. Moreover, the speed and acceleration of HST are typical moving parameters for this HST seismic source. Certain devices, such as GPS, Doppler radar, and cameras, can be used to estimate the HST’s speed. However, they are inconvenient or can be affected by the obstacles. The geophone near an HSR continuously receives the seismic signal induced by the moving HST. This work focuses on the HST acceleration estimation using only one geophone near the HSR and proposes an acceleration estimation method based on the time-frequency spectrum. The experimental field result for a viaduct situation shows the proposed method’s ability to estimate a passing HST’s acceleration, which is verified by acceleration estimation results based on a 14-geophones array along the HSR.
A Rapid Forward for Grounded Long Wire Source Transient Electromagnetic Method
Authors: Yang Yunjian , Sun Weibin , Mi Xiaoli , Zhu Yongshan , Chai Yanning
Published: December 2023

Aiming at enhancing the forward and inversion efficiency of grounded long wire source TEM (Transient ElectroMagnetic method), a new rapid layered medium forward method is proposed in the paper. This forward method is based on two points, one is to approximate the vertical magnetic component in frequency domain of a grounded long wire source by the response of several circular loops, and the other is to introduce the technique of "flow through" into the digital filtering calculation of sinusoidal transformation. The result of model tests shows that the calculation efficiency of proposed method is improved greatly (dozens of times) compared with that of the conventional method.
Application of Electromagnetic Wave Computerized Tomography in Metro Tunnel Detection in Karst Area
Authors: Sun Jianxin , Wang Hui
Published: December 2023

When tunnelling in karst areas, a series of geological hazards caused by karst are often encountered, resulting in huge economic losses as well as human casualties. In order to ensure the safety of tunnel construction, risk assessment and early warning of karst-related geological hazards, it is necessary to use geophysical methods to find out the location, size, shape and filling of karst, and to provide necessary reference information for traffic route planning and tunnel construction planning. Based on theoretical model research, the construction plan of electromagnetic wave CT method was designed for data acquisition in an underground tunnel detection project in a city of Jiangsu province based on existing geological data, and the inverse interpretation of the measured data was carried out in combination with borehole core data to study the feasibility, effectiveness and accuracy of the electromagnetic wave CT method for karst detection in urban underground space.
3D Forward and Inversion Research on Frequency Domain Electromagnetic Tipper Data
Authors: Gao Wenlong , Wang Xuben , Mao Lifeng , Luo Wei
Published: December 2023

The tipper is one of the main parameters of the electromagnetic exploration data in the frequency domain and has an important role and significant advantage in the exploration under complex geological conditions. In this paper, the 3D forward modeling is carried out based on the staggered grid finite difference method, and the analytical solution of the layered medium is used to verify its correctness; the L-BFGS algorithm is used to perform the 3D inversion of the tipper data. Through the three-dimensional complex model, the forward response characteristics and spatial distribution of the tipper are analyzed. The inversion results show that the inversion using the inversion data has less influence on static displacement and better inversion results.
Research on the Capacity of Shale Fracture Network based on Fractal Dimension
Authors: Wu Xiang , Wang Fei
Published: December 2023

The quantitative evaluation method of fracture network capacity after shale fracturing is crucial for optimizing hydraulic fracturing of shale gas reservoirs and improving shale gas recovery. In order to quantitatively evaluate the shape of the shale fracture network after fracturing, the mud shale cores from the Longmaxi Formation were taken to carry out the constant-rate strain method fracturing pressure experiment. The fracture information of the two-dimensional lateral development surface after the core is compressed, and the surface fracture rate, concentrative value and fractal dimension of the fractures after compression are calculated. Through multiple linear regression, it is found that the fractal dimension is positively correlated with the surface fracture rate, which describes the number of fractures, and the concentrative value, which describes the spatial distribution of fractures, and the former has a greater impact on the size of the fractal dimension. Considering the above parameters comprehensively, a fracture network capacity evaluation model is established, which is in good agreement with the rock mechanical characteristics reflected by the strain-stress curve and the reconstructed three-dimensional fracture morphological characteristics. It has a certain guiding significance for shale brittleness research and fractability evaluation.
Numerical Modeling of Anisotropic Magnetic Field for High Susceptibility in Undulating Topography
Authors: Zhang Ying , Dai Shikun , Zhang Qianjiang , Chen Qingrui , Ling Jiaxuan
Published: December 2023

Most minerals with high magnetism have anisotropic characteristics, and the magnetic field distribution will be affected by topography. Based on the numerical modeling of magnetic field of anisotropic ferromagnetic body, this paper introduces the undulating topographic surface, sets up multiple horizontal planes with different depths between the highest point and the lowest point of the undulating terrain, calculates the magnetic field of these horizontal planes, and finally obtains the distribution of magnetic anomaly field on undulating topographic surface through interpolation. The correctness of undulating topography calculation is verified by comparison with the analytical solution. It is of great significance for inversion imaging of strong magnetic bodies in undulating topography.
Study on The Influence Law of Side Effect of Two-dimensional ERT
Authors: Li Sai , Zhang Guoqiang , Sun Zhen , Du Lizhi
Published: December 2023

As a traditional exploration method, two-dimensional high density resistivity method has been widely used in various projects. However, when using this method for exploration, three-dimensional geological bodies often affect the two-dimensional detection results, which is the side effect of two-dimensional high density resistivity method. Although the three-dimensional high density resistivity method can effectively remove the side effect of the two-dimensional high density resistivity method, the application of the three-dimensional high density resistivity method is often limited by the performance and cost of the instrument. Therefore, it is of great significance to explore the influence law of the side effect of the two-dimensional high density resistivity method. In this paper, through the method of numerical simulation, by comparing the data of different inversion arrays, the influence of abnormal body size, type, different arrays and other factors on the side effect is discussed.
Application of Elastic Wave CT in Geotechnical Investigation of Suning Square
Authors: Li Zhengcai , Du Lizhi , Du Jindu , Zhang Guoqiang , Wang Yong
Published: December 2023

Elastic wave CT technology, also known as elastic wave tomography technology. It is on the premise of not destroying the internal structure of the rock and soil medium in the test area, according to the basic principle that elastic waves propagate at different speeds in different rock and soil media, the travel time and wave velocity of the elastic wave in the rock and soil between two points are obtained through the experiment, and through a special inversion method, a large amount of elastic wave velocity information is used to obtain the distribution law and the elastic wave velocity chromatogram of the medium in the test area, in this way, the lithology, structural development and velocity parameters of the rock-soil medium in the test area can be inferred. This article briefly introduces the basic theory of elastic wave CT, including Radon transform and inverse transform, forward ray tracing method and inversion iterative image reconstruction technology. Then combined with the engineering survey example of the Suning Plaza project, it briefly introduced the field work method, data parameter collection, geological interpretation and result analysis. The analysis shows that the results of the three-dimensional velocity map obtained by the elastic wave CT method are intuitive, the test accuracy is high, and the development state, size and location of the karst in the survey area can be clearly seen. It can describe the spatial distribution characteristics of karst in detail, has outstanding advantages in karst exploration, and has good application prospects.
Application of Regional Gravity and Magnetic Data in Yambajan and Gudui Geothermal Fields, Tibet
Authors: Ming Yuanyuan , Zeng Zhaofa , Li Qiuchen , Guo Shujun , Xie Xinglong , Niu Xue
Published: December 2023

Yambajan geothermal field is the first wet steam field developed in the Chinese mainland. It is also the geothermal power station with the highest elevation in the world. It is rich in geothermal resources and its exploration and development level is relatively high. The Gudui geothermal field is the second largest geothermal display area in Tibet. It is rich in geothermal resources, second only to Yambajan Geothermal field, but its energy construction is relatively backward. In this paper, satellite gravity and aeromagnetic data are used to make a comprehensive comparative analysis of the two regions. The results show that they are both low gravity value areas and weak magnetic, and both of which are located on the fault zone. There is a very obvious relationship between the regional tectonic characteristics and the distribution law of hydrothermal activities, and the tectonic activities provide favorable conditions for the formation of hydrothermal activities. The fault depth in the south of the study area is deeper than that in the north, which is inferred to be caused by plate movement.
Application Comparison of Different Transient Electromagnetic Devices in Water Exploration of Tunnel Advanced Geological Prediction
Authors: Zhen Dayong , Liu Kang , Zhao Siwei , Zhou Chao
Published: December 2023

Detecting the possibility of water inrush in front of tunnel face is always the key of tunnel advanced geological prediction. Because of its sensitivity to groundwater, transient electromagnetic method is gradually being used in water exploration of tunnel advanced geological prediction. However, the current transient electromagnetic theory is established based on the half-space environment. In order to adapt to the detection work in the full-space environment such as tunnels, different transient electromagnetic devices have been improved. The effectiveness of these improved devices still need to be tested in actual engineering projects. In this paper, a tunnel under construction is used as the engineering background, and different transient electromagnetic devices are placed in front of the same tunnel face for detection. The detection results are compared and analyzed with the actual situation of tunnel excavation, which can provide reference for water exploration of tunnel advanced geological prediction.
Inversion of Self-potential Generated from Biogeobattery Model by Particle Filter Based on Particle Swarm Optimization Algorithm
Authors: Lu Heshunzi , Cui Yian , Luo Yijian , Xie Jing
Published: December 2023

Organic pollution has been exacerbated by industrial activity. How to quickly and effectively delineate the pollutant distribution and carry out targeted treatment has become an urgent matter. In order to improve the reliability of observation data inversion and interpretation, we propose a new particle filter algorithm based on particle swarm optimization, which does not only improves the accuracy of the particle filter algorithm but also inherits the advantages of fast convergence speed of particle swarm optimization algorithm. This method is tested and verified in a numerical model and sandbox experiments. The results show that this method can accurately estimate the parameters of anomaly sources and has good anti-noise ability. It is suitable for the inversion of pollution monitoring data which are easily disturbed by noise.
Image-guided Structure-constrained Inversion of Electrical Resistivity Data for Improving Contaminations Characterization
Authors: Ma Xinmin , Han Jingjing , Chao Chen , Li Jing , Zhou Jieyi , Xia Teng , Mao Deqiang
Published: December 2023

Electrical resistivity tomography often has high uncertainty in contamination characterization due to the complex subsurface structure. Utilizing available prior information is crucial for enhancing geological plausibility. We propose an improved structure-constrained method that updates the smooth weights of all eight elements surrounding a boundary element using three different magnitudes. The methodology is tested on seven synthetic models and a field case covering four different types of structural boundaries. Structural constraints are vital to increasing boundary contrast. With the increase of data points from an optimized array, the influence of structural constraint is reduced. Correct structural constraints can tighten the abnormal contamination resistivity. However, misplaced structural constraints in the proximity of the contamination can lead to worse characterization. Without knowing exactly the boundary information, we propose a method to obtain local constraints from borehole logging, which is verified by both numerical and field data. This method reduces the interference of uncertain structural boundaries and enhances the robustness of the IIGSC method in contamination surveys. In the end, we conclude that correct boundary information even with limited constraints from borehole logging can increase the identification of the abnormal contamination resistivity.
Heat Flow Prediction in Songliao Basin Based on Deep Neural Network
Authors: Bai Lige , Li Jing , Zeng Zhaofa
Published: December 2023

The heat flow is the key data for accurately predicting the contribution of underground heat, but due to the high cost of measurement, the spatial difference is huge, and the heat flow information in some areas is little known. This paper uses deep neural network technology to perform machine learning on a large number of relevant geological and geophysical features and heat flow measurements on a global scale. In addition, the model uncertainty quantification process is introduced, and the reliability of the prediction results is discussed based on the global sensitivity analysis and correlation calculation of the deep learning method. Finally, for the distribution map of heat flow and absolute difference in the Songliao Basin in the study area, the measured data error is less than 11%, and the predicted absolute difference is less than ±20 mW/m2. The results prove the accuracy of the method and the abnormal high heat flow in the central region of the basin. The existence of, further combined with the results of geophysical surveys, provides evidence for the analysis of regional thermal causes.
Study on Three-dimensional Water-Bearing Response Characteristics of Surface-to-Underground NMR Traversal
Authors: Wang Wenchuang , Jiang Zhihai , Miao Bin , Liu Shucai , Li Maofei
Published: December 2023

Nuclear magnetic resonance (NMR) is the only geophysical method that can directly detect groundwater. However, the response signal collected by nuclear magnetic resonance method is very weak, and it is difficult to detect reliable results by conventional ground nuclear magnetic resonance when the water-bearing anomaly is located deeper underground. In order to increase the detection depth, the surface-to-underground nuclear magnetic resonance device received in the ground launch roadway can be used. In this paper, the basic principle and working method of surface-to-underground NMR are introduced. The three-dimensional numerical simulation of different water-bearing structures and different device forms is carried out, and the response law and advantage range of surface-to-underground NMR to underground water are summarized.
Research on The Source Parameters and Scaling Relations of Earthquakes in Weihe Basin and Its Adjacent Area
Authors: Wang Weidong , Dou Chen , Zhang Yucheng
Published: December 2023

By using the data recorded in Shaanxi seismic network, seismic source parameters were determined through spectrum analyzing basing on Brune’s source model for 125 small to moderate earthquakes (1.1 ≤ ML
≤ 4.8) from 1997 to 2016 in Weihe basin and its adjacent area. Seismic radiated energies were also obtained through integral of observed velocity spectra. The relations between stress drop, scaled energy E

s
/ M
0 and Zúñiga parameter ε with seismic moment are analyzed. The results show that the earthquakes are with low stress drop in this area, the mean value is 0.16 MPa. More than 90% of the events in the region observed the ε value is less than 1. The low stress drop and low ε value indicate that earthquakes in this area can be explained by fractional stress drop mechanism or low effective stress model. These may be the result of mature fault activity, however, it cannot be ruled out effect of underground fluid. The scaled energy of earthquakes (1.3 ≤ MW
≤ 3.6) in this area is less than that of larger earthquakes (3.6 ≤ MW
≤ 6.0) in other areas. The earthquakes in this area are fairly small, so the heat energy generated in the rupture process is small, which is not enough to produce melting along the fault plane. With large dynamic friction force, it is not easy to produce rapid brittle rupture, resulting in low scalsed energy.
Application of WFEM in Geothermal Resource Exploration
Authors: Sun Hailong , Hu Ren , Lin Xuguang , Xu Mengge , Zhou Tianhao
Published: December 2023

Geothermal resources are a kind of ecological energy with great market potential. In order to promote the development and utilization of geothermal resources in Dunhua area and promote economic and social development, the advanced WFEM is used to delineate the hidden fault zone and fracture zone, determine the basement depth and the spatial distribution of hidden faults, find out the geological conditions of geothermal resources in this area, and make a preliminary evaluation of geothermal resources, analyze the exploitation potential of geothermal resources.
Weighted Laterally Constrained Inversion of Airborne Transient Electromagnetic Data with IP Effects
Authors: Lu Juntao , Wang Xuben , Xu Zhengwei , Guo Ming
Published: December 2023

Due to the induced polarization (IP) effects, abnormal fast decay and sign reversals are often observed in the field airborne transient electromagnetic (ATEM) responses, this phenomenon can well be explained by introducing the four-parameter Cole-Cole resistivity model. However, the introduction of multiple parameters makes the non-uniqueness of inversion more serious. To improve this problem, a weighted 1D laterally constrained inversion is proposed to recover the four IP parameters and thickness via adding different weighted factors chosen by lateral constraint conditions, in this paper, a synthetic polarization model is developed and 1D forward modeling with synthetic natural noise is conducted to imitate the field response. The proposed inversion is employed on the synthetic data and the results demonstrate that the method can improve the inversion stability and obtain more reliable result.
Three-dimensional Forward Modeling of Semi-airborne Frequency-domain tipper Sounding Method with Complex Arbitrary-source Geometry
Authors: Feng Min , Deng Juzhi , Chen Hui , Yin Min , Yu Hui , Su Kejia
Published: December 2023

In this study, we propose a three-dimensional forward modeling algorithm for the Semi-airborne frequency-domain tipper sounding method (SAFTSM) based on the finite volume method to analyze the characteristics of SAFTSM responses with complex arbitary source geometry. We the used QMR algorithm preconditioned by the Jacobi method to solve the coupled symmetric equations of magnetic vector potential
A
and scalar potential ϕ under the Lorenz criterion. In these numerical experiments, we used grounded wire as a transmitting source. The accuracy of the algorithm is verified by comparing the three-dimensional results with the one dimensional results. We first calculate the low resistance model tipper response of a single source. After that, a reverse source is added on the basis of a single source, calculating the tipper response with an inverse parallel double source system. Finally, by comparing different emission source systems, we analyze the influence of the multiple sources on SAFTSM, so that we can provide a theoretical basis for practical detection.
Extraction of Elemental Information of Slope Steps in Open Pit Mine Based on UAV
Authors: Lu Hengxiao , Liang Peng , Yao Xulong , Zhang Lingyun
Published: December 2023

The information of step width, height and angle of open-pit slope is of great value for open-pit mining. However, the existing methods of obtaining step element information are inefficient, and are greatly affected by staff and environmental factors, this reduces the production efficiency and acceptance accuracy of the mine. Therefore, this paper proposes a method to extract step element information based on UAV tilt photogrammetry technology. The method firstly acquires the dense point cloud data of the slope steps of the open pit based on the UAV inclined photogrammetry, preprocesses the point cloud data by using the bilateral filtering algorithm, then extracts the edge feature points of the point cloud based on the normal and curvature estimation method, and fits the step lines using the moving least squares method, and builds a step model based on the step lines, so that the profile lines at any position of the steps can be extracted on the model and obtains the step element information. The experiments show that the feature extraction method can extract the step element information efficiently and accurately, which has important application value for the production and safety of open pit mine.
3D Simulation and Leakage Detection Technique for Deep Foundation Pits Based on Electric Field
Authors: Chen Hui , Chen Yufeng , Deng Juzhi , Gao Jianglin , Wang Suo , Yu Hui , Zhang Guokun
Published: December 2023

To solve the problems of poor accuracy, poor anti-interference ability and unclear distribution of leakage electric field response characteristics of the traditional ground DC method for leakage detection of underground diaphragm walls in foundation pits, this paper proposes a deep foundation pit leakage detection technology based on the electric field. Secondly, it constructed the multi-field coupling equations and boundary conditions of the leakage electric field coupled with the leakage flow field and ion diffusion field, and then realized the three-dimensional forward evolution of the leakage electric field of the pit using the nonstructural mesh dissection method and the finite-element-infinite-element discretization method. Finally, physical model experiments and numerical simulations are used to confirm the reliability and accuracy of the foundation pit leakage detection technology and system. The results shows that monitoring the continuous change of the electric field for a period of time, the electric field detection technology for foundation pit leakage can effectively identify the location of hidden leakage and overcome the site’s strong industrial interference, resulting in a new technical solution for foundation pit leakage detection.
2D Source Inversion of Self-potential Data Based on Particle Swarm Optimization and Gradient Method
Authors: Luo Yijian , Cui Yi’an , Zhang Lijuan , Guo Youjun
Published: December 2023

The difficulty of accurately inverting the self-potential (SP) source has always been a major factor hindering the wide application of the SP method. Considering that particle swarm optimization has poor accuracy when in the face of high-dimensional SP inversion, while the gradient method depends on the selection of the initial solution, we try to combine these two algorithms to prompt the inversion result to jump out of local optimum.
Joint Inversion of Rayleigh Wave Dispersion and Ellipticity Based on Deep Learning
Authors: Zhao Minghao , Zhang Zhihou , Zhang Tianyi , Ma Ning
Published: December 2023

The joint inversion of Rayleigh wave dispersion curves and ellipticity curves is an important method to obtain information about the velocity structure of the stratum, which has the advantages of high resolution and speed. However, there are problems in the application of this technique, such as complicated data, low inversion efficiency, and large influence factors of nonlinear inversion. Deep learning has excellent nonlinear approximation capability, which can compensate for most of the above defects, and has higher efficiency and accuracy compared with traditional methods. In this paper, in order to obtain the near-surface stratigraphic structure quickly and accurately, we propose to introduce the deep learning method into the joint inversion, use the CNN-LSTM network to perform the joint inversion of Rayleigh wave dispersion curves and ellipticity curves. And in order to expand the variety of data set, we propose to add noise to the sample data set, through which the empirical risk can be reduced, and the generalization performance of the network can be increased. Model experiments show that the deep learning network can effectively and accurately perform the joint inversion of Rayleigh waves, and adding noise to the training set is an effective way to improve the generalization and stability of the network.
Research on Transient Electromagnetic Positioning Method of Underwater Towed Array Source for Moving Small Target on the Seabed
Authors: Zhou Chunkai
Published: December 2023

Different from the large-scale delineation and exploration of oil and gas resources and deep-sea hydrothermal sulfide deposits, small targets moving on the seabed require fine and accurate trace detection and higher positioning accuracy. Although the towed single source transient electromagnetic (TEM) device can detect the poisition of the static target body, but cannot determine the poisition of the moving target, the array source TEM device can effectively solve the problem of fine detection and accurate positioning of moving small targets on the seabed, and improve the signal-to-noise ratio and resolution. In this paper, an array source transient electromagnetic positioning method based on underwater towed platform is proposed for moving small targets on the seabed. At the same time, in view of the underwater towed body and array source transient electromagnetic coil, its attitude changes cause the problem of target body positioning error. Through the simulation calculation and error analysis, the results show that the calculation error of attitude angle had a great influence on positioning accuracy. In practical engineering application, attitude correction is necessary to eliminate positioning error.
Analysis on The Status of Deep-well Geo-electrical Resistivity Observation in China Geoelectric Network
Authors: Wang Xiao , Ye Qing , Liu Gaochuan , Fan Ye
Published: December 2023

With the deterioration of the observation environment and the increasing interference of surface stray currents, the commonly used surface resistivity observation is facing severe challenges. China began to experiment and develop deep-well geo-electrical resistivity observation. In this paper, the characteristics of the observation system of each resistivity station are counted and analyzed, and the data quality of the deep-well geo-electrical resistivity observation and the ground resistivity observation at the same site is compared in terms of relative standard deviation and annual variation. The results show that the operation of deep-well geo-electrical resistivity observation stations is in good condition, and its data quality and anti-interference ability are superior to ground resistivity observations. The results provide support for the popularization and application of deep-well geo-electrical resistivity observation technology, which can better serve seismic analysis and prediction.
Study on Resistivity Imaging of Urban Landfill Leachate Channel Using 3D Electrical Resistivity Tomography with Annular Electrode Configuration
Authors: Cheng Jiulong , Zhang Yuqi , Shen Yifan , Li Yao , Huang Jiaxin
Published: December 2023

Urban garbage landfills are distributed mostly in a nearly circular shape with complex internal and external environments. The conditions on the top of the landfills are not conducive to the layout of electrical measuring lines and electrodes, resulting in difficulties in using the conventional linear or rectangular mesh high density electrical surveying system to achieve good results for the detection of leachate channel under the garbage body. This paper proposed 3D electrical resistivity tomography (ERT) method by annular electrode configuration with electrodes placed around the landfill. Through numerical simulation and indoor physical simulation experiments, we have discussed the feasibility and effectiveness of this method for circling the pollution range and channel location of landfill leachate. The study shows that the 3D ERT method with annular electrode configuration can effectively detect the spatial location and extension of garbage leachate channel, reflect the leakage of garbage leachate in landfills, and thus provide technical support for the fine detection of garbage leachate channel.
Numerical Simulation and Characteristics Analysis of VSP Seismic Data in Complex Loess Plateau Area
Authors: Fu Jiawei , Sun Zhangqing , Han Fuxing , Wang Ruihu , Liu Yaguang , Lu Jipu , Cen Wenpan , Gao Zhenghui
Published: December 2023

The numerical simulation and characteristic analysis of VSP seismic data in the complex Loess Plateau area is of great significance to the design of seismic acquisition systems and the velocity modeling in near-surface areas. In this paper, we establish a velocity model of complex Loess Plateau and design three VSP acquisition systems in this model. Then, a finite difference method (FDM) for seismic modeling in the complex topographical condition is used to simulate the VSP data in this model with the above acquisition systems. Finally, based on the analysis to these data, some basic characteristics of VSP data in the complex Loess Plateau area are obtained and their significances to seismic exploration in this area are given.
Application of Horizontal-to-vertical Spectral Ratio with a Dense Linear Array on Prospecting Urban Underground Active Faults: a Case in The Mingguang City, Anhui Province
Authors: Ni Hongyu , Zhang Ruohan , Huang Xianliang , Zheng Haigang , Li Junhui , Hong Dequan , Bao Ziwen
Published: December 2023

Reliable knowledge of sedimentary structures is beneficial for the study of active faults covered by sediments and can also provide important information for seismic hazard assessment, earthquake emergency response and urban planning. Based on the dense seismic array with a spacing of ∼ 60 m between stations and a length of ∼ 8 km, the horizontal-to-vertical spectral ratio (HVSR) curves were obtained at 133 stations with the ambient noise, and the two-dimensional sedimentary structures of the Quaternary and Neogene strata were imaged over two main faults of the Tanlu fault zone in the eastern Jiashan Basin by frequency-depth conversion. The variations (∼ 130 m) in the depth of the Quaternary and Neogene sedimentary basement directly beneath the fault zone agree well with the spatial characteristics of the fault revealed by the shallow seismic reflection profile with active sources at the same locations.
Analyze the Difference Between Rotational and Translational Motions Produced by High-speed Train
Authors: Rong Chao , Zhang Dingfan , Cao Yuwen , Li Zhengbin
Published: December 2023

The development of fiber optic gyroscope technology makes it possible to directly measure the rotational ground-motion. The joint observation of the three-component rotational seismometer and the traditional three-component translational seismometer is a trend of future. In this paper, the translational and rotational signals generated during the high-speed trainway are studied, and the three-component translational and rotational seismometers are fixed together to realize the joint recording of the high-speed trainway signal. Comparing the translational and rotational three-component data, we find that only one component waveforms and the spectrum have certain consistency. However, the difference between them indicates that the rotation and translation signals generated by the shallow surface wave signal have different frequency bands.
Seismic Velocity Response to the Ocean Waves Based on Borehole Array
Authors: Meng Yi , Guo Pan , Wang Liwei , Liu Zhikun
Published: December 2023

The ambient noise correlation in recent years has been widely used to study the seismic velocity temporal variation related to volcanoes, geothermal fields, earthquake source regions. However, in some regions and times, seasonal seismic velocity changes which could be attributed to environmental factors, including temperature, atmospheric pressure and groundwater, can also be observed. Eliminating the influence of these environmental factors in the temporal variation monitoring results of subsurface media will be helpful to obtain the clear changes of shallow media due to tectonic activities. We used the ambient noise correlation technique of multi-component and multi-frequent-band to obtain the seismic velocity variation of crustal media in Hailing Island, Guangdong Province, China. The results show that the seismic velocity variation of crustal medium in the study area has a strong correlation with the ocean wave height