Advanced geological prediction is a crucial means to ensure safety and efficiency in tunnel construction.However,diff erent advanced geological forecasting methods have their own limitations,resulting in poor detectio...Advanced geological prediction is a crucial means to ensure safety and efficiency in tunnel construction.However,diff erent advanced geological forecasting methods have their own limitations,resulting in poor detection accuracy.Using multiple methods to carry out a comprehensive evaluation can eff ectively improve the accuracy of advanced geological prediction results.In this study,geological information is combined with the detection results of geophysical methods,including transient electromagnetic,induced polarization,and tunnel seismic prediction,to establish a comprehensive analysis method of adverse geology.First,the possible main adverse geological problems are determined according to the geological information.Subsequently,various physical parameters of the rock mass in front of the tunnel face can then be derived on the basis of multisource geophysical data.Finally,based on the analysis results of geological information,the multisource data fusion algorithm is used to determine the type,location,and scale of adverse geology.The advanced geological prediction results that can provide eff ective guidance for tunnel construction can then be obtained.展开更多
Ground source heat pump systems demonstrate significant potential for northern rural heating applications;however,the effectiveness of these systems is often limited by challenging geological conditions.For instance,i...Ground source heat pump systems demonstrate significant potential for northern rural heating applications;however,the effectiveness of these systems is often limited by challenging geological conditions.For instance,in certain regions,the installation of buried pipes for heat exchangers may be complicated,and these pipes may not always serve as efficient low-temperature heat sources for the heat pumps of the system.To address this issue,the current study explored the use of solar-energy-collecting equipment to supplement buried pipes.In this design,both solar energy and geothermal energy provide low-temperature heat to the heat pump.First,a simulation model of a solar‒ground source heat pump coupling system was established using TRNSYS.The accuracy of this model was validated through experiments and simulations on various system configurations,including varying numbers of buried pipes,different areas of solar collectors,and varying volumes of water tanks.The simulations examined the coupling characteristics of these components and their influence on system performance.The results revealed that the operating parameters of the system remained consistent across the following configurations:three buried pipes,burial depth of 20 m,collector area of 6 m^(2),and water tank volume of 0.5 m^(3);four buried pipes,burial depth of 20 m,collector area of 3 m^(2),and water tank volume of 0.5 m^(3);and five buried pipes with a burial depth of 20 m.Furthermore,the heat collection capacity of the solar collectors spanning an area of 3 m^(2)was found to be equivalent to that of one buried pipe.Moreover,the findings revealed that the solar‒ground source heat pump coupling system demonstrated a lower annual cumulative energy consumption compared to the ground source heat pump system,presenting a reduction of 5.31%compared to the energy consumption of the latter.展开更多
When the expressway crosses the goafs inevitably,the design is generally to build the road on coal pillars as much as possible.However,the existing coal pillars are often unable to meet relevant requirements of highwa...When the expressway crosses the goafs inevitably,the design is generally to build the road on coal pillars as much as possible.However,the existing coal pillars are often unable to meet relevant requirements of highway construction.Combining three-dimensional physical model tests,numerical simulations and field monitoring,with the Urumqi East Second Ring Road passing through acute inclined goafs as a background,the deformation and failure mechanism of the overlying rock and coal pillars in acute inclined goafs under expressway load were studied.And in accordance with construction requirements of subgrade,comprehensive consideration of the deformation and instability mechanism of acute inclined goafs,the treatment measures and suggestions for this type of geological disasters were put forward.The research results confirmed the rationality of coal pillars in acute inclined goafs under the expressway through grouting.According to the ratio of diff erent overlying rock thickness to coal pillar height,the change trend and value of the required grouting range were summarized,which can provide reference for similar projects.展开更多
The seismic data of the Laoshan Uplift in the South Yellow Sea Basin reveal a low signal-tonoise ratio and low refl ection signal energy in the deep Mesozoic–Paleozoic strata.The main reason is that the Mesozoic-Pale...The seismic data of the Laoshan Uplift in the South Yellow Sea Basin reveal a low signal-tonoise ratio and low refl ection signal energy in the deep Mesozoic–Paleozoic strata.The main reason is that the Mesozoic-Paleozoic marine carbonate rock strata are directly covered by the Cenozoic terrestrial clastic rock strata,which form a strong shielding layer.To obtain the reflection signals of the strata below the strong shielding layer,a one-way wave equation bidirectional illumination analysis of the main observation system parameters was conducted by analyzing the mechanism of the strong shielding layer.Low-frequency seismic sources are assumed to have a high illumination intensity on the reflection layer below the strong shielding layer.Accordingly,optimized acquisition parameter suggestions were proposed,and reacquisition was performed at the existing survey line locations in the Laoshan Uplift area.The imaging of the newly acquired data in the middle and deep layers was drastically improved.It revealed the unconformity between the Sinian and Cambrian under the strong shielding layer.The study yielded new insights into the tectonic and sedimentary evolution of the Lower Paleozoic in the South Yellow Sea.展开更多
Well logging technology has accumulated a large amount of historical data through four generations of technological development,which forms the basis of well logging big data and digital assets.However,the value of th...Well logging technology has accumulated a large amount of historical data through four generations of technological development,which forms the basis of well logging big data and digital assets.However,the value of these data has not been well stored,managed and mined.With the development of cloud computing technology,it provides a rare development opportunity for logging big data private cloud.The traditional petrophysical evaluation and interpretation model has encountered great challenges in the face of new evaluation objects.The solution research of logging big data distributed storage,processing and learning functions integrated in logging big data private cloud has not been carried out yet.To establish a distributed logging big-data private cloud platform centered on a unifi ed learning model,which achieves the distributed storage and processing of logging big data and facilitates the learning of novel knowledge patterns via the unifi ed logging learning model integrating physical simulation and data models in a large-scale functional space,thus resolving the geo-engineering evaluation problem of geothermal fi elds.Based on the research idea of“logging big data cloud platform-unifi ed logging learning model-large function space-knowledge learning&discovery-application”,the theoretical foundation of unified learning model,cloud platform architecture,data storage and learning algorithm,arithmetic power allocation and platform monitoring,platform stability,data security,etc.have been carried on analysis.The designed logging big data cloud platform realizes parallel distributed storage and processing of data and learning algorithms.The feasibility of constructing a well logging big data cloud platform based on a unifi ed learning model of physics and data is analyzed in terms of the structure,ecology,management and security of the cloud platform.The case study shows that the logging big data cloud platform has obvious technical advantages over traditional logging evaluation methods in terms of knowledge discovery method,data software and results sharing,accuracy,speed and complexity.展开更多
Fractures are critical control factors in volcanic reservoirs.Thus,studies on the prediction and distribution patterns of volcanic fractures are crucial for oil and gas exploration and development.Although considerabl...Fractures are critical control factors in volcanic reservoirs.Thus,studies on the prediction and distribution patterns of volcanic fractures are crucial for oil and gas exploration and development.Although considerable research has been conducted on volcanic fractures,targeted research on the spatial distribution patterns of fracture development remains limited in the literature.Two eruption modes,subaqueous eruption and subaerial eruption,have been identified in the Chaganhua subsag of the Songliao Basin,where gas resources have been discovered.Studying the differences in volcanic fracture development is highly important for understanding the law of oil and gas enrichment in volcanic reservoirs.On the basis of thin sections,cores,electrical imaging logs,and other data obtained from boreholes of subaqueous volcanic eruptions in the Songnan fault depression,we describe the characteristics of drilled fractures in detail and use 3D seismic data to extract intrinsic coherence,ant bodies,and Fourier series to extend the azimuthal anisotropic P-wave reflection coefficient,thereby predicting the spatial distribution of fractures at different scales.Moreover,through statistical analysis of quantitative evaluation indicators,such as fracture density and fracture development rate in different drilling wells,combined with the spatial distribution patterns of the predicted fractures,we compared and analyzed the relationships between the distributions of fractures and volcanic institutions,lithology,and volcanic facies.Results indicate that fractures are more developed in volcanic edifices located closer to faults.Considerable differences in fracture development are observed among lithofacies of volcanic rocks.Near faults,effusion facies,explosive facies and external clastic pyroclastic sedimentary subfacies are favorable for fracture development.This research provides a reference for investigating volcanic rock fractures of the same origins worldwide.展开更多
In this paper,we investigate the method of compensating LTS SQUID Gradiometer Systems data.By matching the attitude changes of the pod in fl ight to the anomalies of the magnetic measurement data,we find that the yaw ...In this paper,we investigate the method of compensating LTS SQUID Gradiometer Systems data.By matching the attitude changes of the pod in fl ight to the anomalies of the magnetic measurement data,we find that the yaw attitude changes most dramatically and corresponds best to the magnetic data anomaly interval.Based on this finding,we solved the compensation model using least squares fitting and Huber's parametric fitting.By comparison,we found that the Huber parametric fit not only eliminates the interference introduced by attitude changes but also retains richer anomaly source information and therefore obtains a higher signal-to-noise ratio.The experimental results show that the quality of the magnetometry data obtained by using the compensation method proposed in this paper has been significantly improved,and the mean value of its improvement ratio can reach 118.93.展开更多
The deep learning algorithm,which has been increasingly applied in the field of petroleum geophysical prospecting,has achieved good results in improving efficiency and accuracy based on test applications.To play a gre...The deep learning algorithm,which has been increasingly applied in the field of petroleum geophysical prospecting,has achieved good results in improving efficiency and accuracy based on test applications.To play a greater role in actual production,these algorithm modules must be integrated into software systems and used more often in actual production projects.Deep learning frameworks,such as TensorFlow and PyTorch,basically take Python as the core architecture,while the application program mainly uses Java,C#,and other programming languages.During integration,the seismic data read by the Java and C#data interfaces must be transferred to the Python main program module.The data exchange methods between Java,C#,and Python include shared memory,shared directory,and so on.However,these methods have the disadvantages of low transmission efficiency and unsuitability for asynchronous networks.Considering the large volume of seismic data and the need for network support for deep learning,this paper proposes a method of transmitting seismic data based on Socket.By maximizing Socket’s cross-network and efficient longdistance transmission,this approach solves the problem of inefficient transmission of underlying data while integrating the deep learning algorithm module into a software system.Furthermore,the actual production application shows that this method effectively solves the shortage of data transmission in shared memory,shared directory,and other modes while simultaneously improving the transmission efficiency of massive seismic data across modules at the bottom of the software.展开更多
The geological disasters such as collapse,mud bursting and water gushing often occur during tunnel construction.Thus,it is of great significance to detect the hidden geological disasters ahead of the tunnel face.The a...The geological disasters such as collapse,mud bursting and water gushing often occur during tunnel construction.Thus,it is of great significance to detect the hidden geological disasters ahead of the tunnel face.The audio magnetotelluric(AMT)was applied for the advanced detectionstudy during the boring process of the Tianheshan tunnel in the Taihang Mountains.Three AMT profiles were deployed above the tunnel,and the data obtained in the field were analysed in terms of electrical principal axes.From shallow to deep,the direction of the geoelectric strike angle changes,generally between 30°and 60°NE,which is consistent with similar to the direction of the Taihangshan Uplift,and the data show some 3D characteristics.Two-dimensional(2D)and three-dimensional(3D)inversion methods were adopted to jointly study the subsurface structural information,and the resistivity model was geophysically and geologically interpreted.Two sets of low resistance anomalies were found,and it was hypothesised that the near-erect low-resistivity anomalies in the east might be a fragmentation zone,while the low resistance anomalies in the west,which are inclined to the westward,might be a tectonic structure or fragmentation zone related to the regional major fault,and the results of the tunnelling confirmed the reliability of the inversion interpretation.The 3D inversion can fully reflect the development scale and morphological changes of the fracture zone,and the inversion model is more reliable.Finally,it is concluded that the audio magnetotelluric method,which adopts advanced acquisition,processing and inversion interpretation techniques,is an effective means of over-detection of tunnels.展开更多
The Jurassic Lianggaoshan Formation in eastern Sichuan Basin is a key target for shale oil exploration.It faces challenges in three-pressure prediction due to complex structural and sedimentary interactions,as well as...The Jurassic Lianggaoshan Formation in eastern Sichuan Basin is a key target for shale oil exploration.It faces challenges in three-pressure prediction due to complex structural and sedimentary interactions,as well as strong reservoir anisotropy.These issues often lead to wellbore instability and gas logging anomalies during drilling.This study presents an integrated workflow that combines residual moveout correction using correlation-based dynamic time warping(CDTW),high-resolution seismic waveform indication inversion,and three-pressure prediction of jointing well-seismic data.Applied to the LT1 well block,the workflow effectively corrects anisotropic residual moveout in image gathers,leading to a signal strength increase of over 10%in frequency bands above 30 Hz and enhancing event continuity.High-resolution rock mechanical parameters are obtained through seismic waveform inversion and regional calibration,enabling the prediction of three-dimensional pore pressure,collapse pressure and fracture pressure.The results are consistent with actual drilling gas shows and core data,confirming the method's accuracy and supporting mud weight planning and wellbore stability efforts.This cost-effective and technically robust approach proves highly reliable in complex environments with significant heterogeneity and anisotropy,assisting drilling decisions and risk management in eastern Sichuan and similar challenging geological settings.展开更多
Shale gas reservoirs have large burial depths,thin thickness,and low resistance,which lead to problems with weak surface observation,abnormal information,and multiple inversion solutions.The traditional electromagneti...Shale gas reservoirs have large burial depths,thin thickness,and low resistance,which lead to problems with weak surface observation,abnormal information,and multiple inversion solutions.The traditional electromagnetic method cannot effectively identify information from deep,low-resistance thin layers in terms of detection depth and accuracy.Wide field electromagnetic method(WFEM)with large depth and high precision has become the main method for deep earth exploration.This method has been widely used in the exploration of deep oil and gas energy,as well as mineral resources.However,an in-depth analysis of the various factors that affect the deep detection ability of WFEM is lacking.Therefore,the analysis of system parameters has significant theoretical importance and practical value for studying the effectiveness of WFEM in deep-layer identification.In this study,a multilayer geoelectric model is established in this study using the measured well data.The influence characteristics of different observation system parameters on the resolution of specific deep-seated targets under the WFEM_E-Ex mode are analyzed in detail through forward modeling and inversion.Results show that the resolution ability of WFEM for deep,low-resistance thin layers is affected by factors such as transceiver distance,target layer thickness,and resistivity difference between the target body and the surrounding rock,but the influence range differs.This study analyzes the influence characteristics of various system parameters.It provides targeted work scheme design and feasibility analysis for deep shale gas exploration.It also offers an important theoretical basis for optimizing construction schemes and improving the recognition ability of WFEM for deep,low-resistance targets.展开更多
The identification of igneous rock in sedimentary basins serves as the basis for the exploration of igneous oil and gas reservoirs.The implementation of magnetic exploration in the identification and delineation of ig...The identification of igneous rock in sedimentary basins serves as the basis for the exploration of igneous oil and gas reservoirs.The implementation of magnetic exploration in the identification and delineation of igneous rock can often achieve good results.However,when igneous rock and deep magnetic layers are under the influence of remanence,the reduction to the pole of magnetic anomaly and conventional magnetic inversion methods,which require clear magnetization directions,is limited,and special magnetic anomaly processing and inversion methods are necessary.We present a case study on igneous rock imaging through a strategy involving the joint use of a preferential filtering method and amplitude inversion affected by remanence in the Qikou depression in China.We first extract the weak anomalies of igneous rock from the observed total-field anomaly via preferential filtering and calculate their amplitude data.We then perform amplitude inversion to determine the underground three-dimensional magnetism distribution and propose a reasonable interpretation by combining seismic and other data.This work demonstrates the feasibility and effectiveness of the above strategy in delineating the igneous rock buried deep in sedimentary basins.展开更多
In the 3D inversion modeling of gravity and magnetic potential field data,the model weighting function is often applied to overcome the skin eff ect of inversion results.However,divergence occurs at the the deep area,...In the 3D inversion modeling of gravity and magnetic potential field data,the model weighting function is often applied to overcome the skin eff ect of inversion results.However,divergence occurs at the the deep area,and artificial weak negative anomalies form around the positive anomalies in the horizontal direction,resulting in a reduction in the overall resolution.To fully utilize the model weighting function,this study constructs a combined model weighting function.First,a new depth weighting function is constructed by adding a regulator into the conventional depth weighting function to overcome the skin eff ect and inhibit the divergence at the deep area of the inversion results.A horizontal weighting function is then constructed by extracting information from the observation data;this function can suppress the formation of artificial weak anomalies and improve the horizontal resolution of the inversion results.Finally,these two functions are coupled to obtain the combined model weighting function,which can replace the conventional depth weighting function in 3D inversion.It improves the vertical and horizontal resolution of the inversion results without increasing the algorithm complexity and calculation amount,is easy to operate,and adapts to any 3D inversion method.Two model experiments are designed to verify the effectiveness,practicability,and anti-noise of the combined model weighting function.Then the function is applied to the 3D inversion of the measured aeromagnetic data in the Jinchuan area in China.The obtained inversion results are in good agreement with the known geological data.展开更多
High temperature and high stress are critical challenges facing enhanced geothermal systems(EGS).This study investigates the physical and mechanical behavior and acoustic emission(AE)characteristics of granite subject...High temperature and high stress are critical challenges facing enhanced geothermal systems(EGS).This study investigates the physical and mechanical behavior and acoustic emission(AE)characteristics of granite subjected to heating–water cooling treatments at temperatures ranging from 25℃ to 400℃.Changes in physical properties,including volume expansion,mass loss,and P-wave velocity,were examined to quantify the extent of thermal damage.Results show that visible surface cracking occurs on granite samples treated above 300℃,with P-wave velocity being the most sensitive indicator of thermal damage.Uniaxial and triaxial compression tests were conducted to explore the effects of temperature and confining pressure on granite’s strength,deformation,failure modes,energy evolution,and brittleness.While peak strength remains largely unaffected by temperature,failure modes transition from axial splitting to shear as confining pressure increases.Thermal damage reduces the rock’s energy storage capacity and increases energy dissipation during loading.The brittleness index decreases with temperature and confining pressure,though granite still exhibits pronounced brittle behavior within the studied range.Distinct differences were observed in the AE temporal characteristics and energy evolution of granite samples under uniaxial and triaxial compression conditions.As the specimen approaches failure,the abrupt increase in AE hit rate occurs earlier than the corresponding rise in AE energy.The global b-value of the granite samples increased with treatment temperature,and the global b-value in triaxial compression tests was higher than that in uniaxial compression tests.The evolution of timedependent b-value also varied with increasing confining pressure.These findings,particularly the AE temporal characteristics and distinct b-value evolution under confinement of thermally damaged granite,provide important implications for microseismic-based stability assessment and early warning in thermally damaged rock masses.展开更多
Since April 2002,the Gravity Recovery and Climate Experiment Satellite(GRACE)has provided monthly total water storage anomalies(TWSAs)on a global scale.However,these TWSAs are discontinuous because some GRACE observat...Since April 2002,the Gravity Recovery and Climate Experiment Satellite(GRACE)has provided monthly total water storage anomalies(TWSAs)on a global scale.However,these TWSAs are discontinuous because some GRACE observation data are missing.This study presents a combined machine learning-based modeling algorithm without hydrological model data.The TWSA time-series data for 11 large regions worldwide were divided into training and test sets.Autoregressive integrated moving average(ARIMA),long short-term memory(LSTM),and an ARIMA-LSTM combined model were used.The model predictions were compared with GRACE observations,and the model accuracy was evaluated using fi ve metrics:the Nash-Sutcliff e effi ciency coeffi cient(NSE),Pearson correlation coeffi cient(CC),root mean square error(RMSE),normalized RMSE(NRMSE),and mean absolute percentage error.The results show that at the basin scale,the mean CC,NSE,and NRMSE for the ARIMA-LSTM model were 0.93,0.83,and 0.12,respectively.At the grid scale,this study compared the spatial distribution and cumulative distribution function curves of the metrics in the Amazon and Volga River basins.The ARIMA-LSTM model had mean CC and NSE values of 0.89 and 0.61 and 0.92 and 0.61 in the Amazon and Volga River basins,respectively,which are superior to those of the ARIMA model(0.86 and 0.48 and 0.88 and 0.46,respectively)and the LSTM model(0.80 and 0.41 and 0.89 and 0.31,respectively).In the ARIMA-LSTM model,the proportions of grid cells with NSE>0.50 for the two basins were 63.3%and 80.8%,while they were 54.3%and 51.3%in the ARIMA model and 53.7%and 43.2%in the LSTM model.The ARIMA-LSTM model significantly improved the NSE values of the predictions while guaranteeing high CC values in the GRACE data reconstruction at both scales,which can aid in fi lling in discontinuous data in temporal gravity fi eld models..展开更多
Enhancing the mining speed of a working face has become the primary approach to achieve high production and efficiency in coal mines,thereby further improving the production capacity.However,the problem of rock bursts...Enhancing the mining speed of a working face has become the primary approach to achieve high production and efficiency in coal mines,thereby further improving the production capacity.However,the problem of rock bursts resulting from this approach has become increasingly serious.Therefore,to implement coal mine safety and efficient extraction,the impact of deformation pressure caused by different mining speeds should be considered,and a reasonable mining speed of the working face should be determined.The influence of mining speed on overlying rock breaking in the stope is analyzed by establishing a key layer block rotation and subsidence model.Results show that with the increasing mining speed,the compression amount of gangue in the goaf decreases,and the rotation and subsidence amount of rock block B above goaf decreases,forcing the rotation and subsidence amount of rock block A above roadway to increase.Consequently,the contact mode between rock block A and rock block B changes from line contact to point contact,and the horizontal thrust and shear force between blocks increase.The increase in rotation and subsidence of rock block A intensifies the compression degree of coal and rock mass below the key layer,thereby increasing the stress concentration degree of coal and rock mass as well as the total energy accumulation.In addition,due to the insufficient compression of gangue in the goaf,the bending and subsidence space of the far-field key layer are limited,the length of the suspended roof increases,and the influence range of mining stress and the energy accumulation range expand.Numerical test results and underground microseismic monitoring results verify the correlation between mining speed and stope energy,and high-energy events generally appear 1-2 d after the change in mining speed.On this basis,the statistical principle confirms that the maximum mining speed of the working face at 6 m/d is reasonable.展开更多
Absorption compensation is a process involving the exponential amplification of reflection amplitudes.This process amplifies the seismic signal and noise,thereby substantially reducing the signal-tonoise ratio of seis...Absorption compensation is a process involving the exponential amplification of reflection amplitudes.This process amplifies the seismic signal and noise,thereby substantially reducing the signal-tonoise ratio of seismic data.Therefore,this paper proposes a multichannel inversion absorption compensation method based on structure tensor regularization.First,the structure tensor is utilized to extract the spatial inclination of seismic signals,and the spatial prediction filter is designed along the inclination direction.The spatial prediction filter is then introduced into the regularization condition of multichannel inversion absorption compensation,and the absorption compensation is realized under the framework of multichannel inversion theory.The spatial predictability of seismic signals is also introduced into the objective function of absorption compensation inversion.Thus,the inversion system can effectively suppress the noise amplification effect during absorption compensation and improve the recovery accuracy of high-frequency signals.Synthetic and field data tests are conducted to demonstrate the accuracy and effectiveness of the proposed method.展开更多
This study compares the performance of a quantum absolute gravimeter(QAG)and a gPhone relative gravimeter(RG)installed at the same site in Zhangjiakou.The comparison focuses on their capabilities in recording seismic ...This study compares the performance of a quantum absolute gravimeter(QAG)and a gPhone relative gravimeter(RG)installed at the same site in Zhangjiakou.The comparison focuses on their capabilities in recording seismic waveforms and detecting Earth's free oscillation signals following the Myanmar Ms7.9 earthquake.Both instruments exhibit unique advantages in their observation capabilities.The QAG demonstrates high sensitivity to the initial arrival of seismic waves,producing distinct peak waveforms,while the RG maintains a stable waveform suitable for analyzing seismic wave propagation and energy dissipation mechanisms.In terms of time-frequency analysis,the QAG excels in surface wave frequency resolution but experiences rapid signal attenuation.Conversely,the RG offers superior stability in sustained gravity disturbances with slower signal decay.Regarding spherical Earth free oscillation signals,the RG generally detects more pronounced signals with minimal deviation from the Preliminary Reference Earth Model(PREM)theoretical values.However,the QAG exhibits high sensitivity and a wide dynamic range in higher frequency bands.Combining data from both instruments provides comprehensive seismic monitoring data,facilitating a deeper understanding of Earth's internal mass distribution and dynamic processes.展开更多
Earthquakes not only release the long-term accumulated stress on the seismogenic fault but may also increase the stress on some surrounding faults or other segments of the seismogenic fault,thereby raising the seismic...Earthquakes not only release the long-term accumulated stress on the seismogenic fault but may also increase the stress on some surrounding faults or other segments of the seismogenic fault,thereby raising the seismic risk on these faults.This study investigates the impact of the April 2,2024,Mw 7.4 earthquake in Hualien,Taiwan,China,on the surrounding faults and aftershocks.We analyze stress-triggering effects by calculating Coulomb stress changes(ΔCFS)using rupture models and focal mechanism data.Historical focal mechanism nodal planes serve as receiver fault parameters forΔCFS calculations.Our findings indicate signifi cant Coulomb stress loading on the Longitudinal Valley fault and Central Range structure due to the mainshock,promoting their seismic activity.Loading effects vary by fault type,with thrust and strike-slip faults experiencing more stress loading than normal and odd faults.Conversely,the rupture’s coseismic slip concentration area shows predominant stress unloading,inhibiting seismic activity in the region.Aftershocks mainly experience increasedΔCFS,suggesting that the stress-triggering induced by the mainshock considerably influences the earthquake sequence evolution.These insights are crucial for understanding aftershock patterns and enhancing seismic hazard assessments.展开更多
The stratum lithology and geological structure of the highway tunnel in the mountainous areas of western China are complex,and the engineering geological conditions are complicated.When the highway tunnel passes throu...The stratum lithology and geological structure of the highway tunnel in the mountainous areas of western China are complex,and the engineering geological conditions are complicated.When the highway tunnel passes through different lithological strata,its structural design and construction technology are completely diff erent.Therefore,in order to support the tunnel design and construction,the tunnel survey Among them,the identification of the contact boundary between magmatic rock and metamorphic rock and the grade of surrounding rock is very important.Through magnetotelluric survey of the Mupi tunnel of Jiuzhaigou-Mianyang highway on G8513 line,2D forward numerical simulation,1D,2D,3D inversion,and engineering geological analysis,it is revealed that the electrical characteristics of each layer,focusing on the identification of the contact boundary between magmatic rock and metamorphic rock.This study provides the electrical characteristics of the magmatic rock and metamorphic rock contact boundary of the Mupi Tunnel.It is speculated that the boundary is revealed by the tunnel construction excavation,which verifies the correctness of the geophysical inversion model and provides a more detailed design basis for the tunnel design.I believe that taking the Mupi Tunnel survey as an example,through this research,it can provide detailed geophysical evidence for highway tunnels to distinguish between magmatic rock and metamorphic rock.展开更多
基金National Natural Science Foundation of China(grant numbers 42293351,41877239,51422904 and 51379112).
文摘Advanced geological prediction is a crucial means to ensure safety and efficiency in tunnel construction.However,diff erent advanced geological forecasting methods have their own limitations,resulting in poor detection accuracy.Using multiple methods to carry out a comprehensive evaluation can eff ectively improve the accuracy of advanced geological prediction results.In this study,geological information is combined with the detection results of geophysical methods,including transient electromagnetic,induced polarization,and tunnel seismic prediction,to establish a comprehensive analysis method of adverse geology.First,the possible main adverse geological problems are determined according to the geological information.Subsequently,various physical parameters of the rock mass in front of the tunnel face can then be derived on the basis of multisource geophysical data.Finally,based on the analysis results of geological information,the multisource data fusion algorithm is used to determine the type,location,and scale of adverse geology.The advanced geological prediction results that can provide eff ective guidance for tunnel construction can then be obtained.
基金supported by 2024 Central Guidance Local Science and Technology Development Fund Project"Study on the mechanism and evaluation method of thermal pollution in water bodies,as well as research on thermal carrying capacity".(Grant 246Z4506G)Key Research and Development Project in Hebei Province:"Key Technologies and Equipment Research and Demonstration of Multiple Energy Complementary(Electricity,Heat,Cold System)for Solar Energy,Geothermal Energy,Phase Change Energy"(Grant 236Z4310G)the Hebei Academy of Sciences Key Research and Development Program"Research on Heat Transfer Mechanisms and Efficient Applications of Intermediate and Deep Geothermal Energy"(22702)。
文摘Ground source heat pump systems demonstrate significant potential for northern rural heating applications;however,the effectiveness of these systems is often limited by challenging geological conditions.For instance,in certain regions,the installation of buried pipes for heat exchangers may be complicated,and these pipes may not always serve as efficient low-temperature heat sources for the heat pumps of the system.To address this issue,the current study explored the use of solar-energy-collecting equipment to supplement buried pipes.In this design,both solar energy and geothermal energy provide low-temperature heat to the heat pump.First,a simulation model of a solar‒ground source heat pump coupling system was established using TRNSYS.The accuracy of this model was validated through experiments and simulations on various system configurations,including varying numbers of buried pipes,different areas of solar collectors,and varying volumes of water tanks.The simulations examined the coupling characteristics of these components and their influence on system performance.The results revealed that the operating parameters of the system remained consistent across the following configurations:three buried pipes,burial depth of 20 m,collector area of 6 m^(2),and water tank volume of 0.5 m^(3);four buried pipes,burial depth of 20 m,collector area of 3 m^(2),and water tank volume of 0.5 m^(3);and five buried pipes with a burial depth of 20 m.Furthermore,the heat collection capacity of the solar collectors spanning an area of 3 m^(2)was found to be equivalent to that of one buried pipe.Moreover,the findings revealed that the solar‒ground source heat pump coupling system demonstrated a lower annual cumulative energy consumption compared to the ground source heat pump system,presenting a reduction of 5.31%compared to the energy consumption of the latter.
基金Science and Technology Major Project of Xinjiang Uygur Autonomous Region(2020A03003-7)Fundamental Research on Natural Science Program of Shaanxi Province(2021JM-180)+2 种基金Fundamental Research Funds for the Central Universities,CHD(Project for Leading Talents)(300102211302)Tianshan Cedar Plan of Science and Technology Department of Xinjiang Uygur Autonomous Region(2017XS13)Shaanxi Province Young Talent Lifting Program(CLGC202219).
文摘When the expressway crosses the goafs inevitably,the design is generally to build the road on coal pillars as much as possible.However,the existing coal pillars are often unable to meet relevant requirements of highway construction.Combining three-dimensional physical model tests,numerical simulations and field monitoring,with the Urumqi East Second Ring Road passing through acute inclined goafs as a background,the deformation and failure mechanism of the overlying rock and coal pillars in acute inclined goafs under expressway load were studied.And in accordance with construction requirements of subgrade,comprehensive consideration of the deformation and instability mechanism of acute inclined goafs,the treatment measures and suggestions for this type of geological disasters were put forward.The research results confirmed the rationality of coal pillars in acute inclined goafs under the expressway through grouting.According to the ratio of diff erent overlying rock thickness to coal pillar height,the change trend and value of the required grouting range were summarized,which can provide reference for similar projects.
基金“High precision prestack reverse time depth migration imaging of long array seismic data in the East China Sea Shelf Basin”of the National Natural Science Foundation of China(No.42106207)“Seismic acquisition technology for deep strata under strong shielding layers in the sea and rugged seabed”of Laoshan Laboratory Science and Technology Innovation Project(No.LSKJ202203404)“Research on the compensation methods of the middledeep weak seismic reflections in the South Yellow Sea based on multi-resolution HHT time-frequency analysis”of the National Natural Science Foundation of China(No.42106208).
文摘The seismic data of the Laoshan Uplift in the South Yellow Sea Basin reveal a low signal-tonoise ratio and low refl ection signal energy in the deep Mesozoic–Paleozoic strata.The main reason is that the Mesozoic-Paleozoic marine carbonate rock strata are directly covered by the Cenozoic terrestrial clastic rock strata,which form a strong shielding layer.To obtain the reflection signals of the strata below the strong shielding layer,a one-way wave equation bidirectional illumination analysis of the main observation system parameters was conducted by analyzing the mechanism of the strong shielding layer.Low-frequency seismic sources are assumed to have a high illumination intensity on the reflection layer below the strong shielding layer.Accordingly,optimized acquisition parameter suggestions were proposed,and reacquisition was performed at the existing survey line locations in the Laoshan Uplift area.The imaging of the newly acquired data in the middle and deep layers was drastically improved.It revealed the unconformity between the Sinian and Cambrian under the strong shielding layer.The study yielded new insights into the tectonic and sedimentary evolution of the Lower Paleozoic in the South Yellow Sea.
基金supported By Grant (PLN2022-14) of State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation (Southwest Petroleum University)。
文摘Well logging technology has accumulated a large amount of historical data through four generations of technological development,which forms the basis of well logging big data and digital assets.However,the value of these data has not been well stored,managed and mined.With the development of cloud computing technology,it provides a rare development opportunity for logging big data private cloud.The traditional petrophysical evaluation and interpretation model has encountered great challenges in the face of new evaluation objects.The solution research of logging big data distributed storage,processing and learning functions integrated in logging big data private cloud has not been carried out yet.To establish a distributed logging big-data private cloud platform centered on a unifi ed learning model,which achieves the distributed storage and processing of logging big data and facilitates the learning of novel knowledge patterns via the unifi ed logging learning model integrating physical simulation and data models in a large-scale functional space,thus resolving the geo-engineering evaluation problem of geothermal fi elds.Based on the research idea of“logging big data cloud platform-unifi ed logging learning model-large function space-knowledge learning&discovery-application”,the theoretical foundation of unified learning model,cloud platform architecture,data storage and learning algorithm,arithmetic power allocation and platform monitoring,platform stability,data security,etc.have been carried on analysis.The designed logging big data cloud platform realizes parallel distributed storage and processing of data and learning algorithms.The feasibility of constructing a well logging big data cloud platform based on a unifi ed learning model of physics and data is analyzed in terms of the structure,ecology,management and security of the cloud platform.The case study shows that the logging big data cloud platform has obvious technical advantages over traditional logging evaluation methods in terms of knowledge discovery method,data software and results sharing,accuracy,speed and complexity.
基金supported by General Projects of the Natural Science Foundation of China(41972313)major projects of the Natural Science Foundation of China(41790453)。
文摘Fractures are critical control factors in volcanic reservoirs.Thus,studies on the prediction and distribution patterns of volcanic fractures are crucial for oil and gas exploration and development.Although considerable research has been conducted on volcanic fractures,targeted research on the spatial distribution patterns of fracture development remains limited in the literature.Two eruption modes,subaqueous eruption and subaerial eruption,have been identified in the Chaganhua subsag of the Songliao Basin,where gas resources have been discovered.Studying the differences in volcanic fracture development is highly important for understanding the law of oil and gas enrichment in volcanic reservoirs.On the basis of thin sections,cores,electrical imaging logs,and other data obtained from boreholes of subaqueous volcanic eruptions in the Songnan fault depression,we describe the characteristics of drilled fractures in detail and use 3D seismic data to extract intrinsic coherence,ant bodies,and Fourier series to extend the azimuthal anisotropic P-wave reflection coefficient,thereby predicting the spatial distribution of fractures at different scales.Moreover,through statistical analysis of quantitative evaluation indicators,such as fracture density and fracture development rate in different drilling wells,combined with the spatial distribution patterns of the predicted fractures,we compared and analyzed the relationships between the distributions of fractures and volcanic institutions,lithology,and volcanic facies.Results indicate that fractures are more developed in volcanic edifices located closer to faults.Considerable differences in fracture development are observed among lithofacies of volcanic rocks.Near faults,effusion facies,explosive facies and external clastic pyroclastic sedimentary subfacies are favorable for fracture development.This research provides a reference for investigating volcanic rock fractures of the same origins worldwide.
基金Earth Observation and Navigation Special,Research on Low Temperature Superconducting Aeromagnetic Vector Gradient Observation Technology(2021YFB3900201)projectState Key Laboratory of Remote Sensing Science project.
文摘In this paper,we investigate the method of compensating LTS SQUID Gradiometer Systems data.By matching the attitude changes of the pod in fl ight to the anomalies of the magnetic measurement data,we find that the yaw attitude changes most dramatically and corresponds best to the magnetic data anomaly interval.Based on this finding,we solved the compensation model using least squares fitting and Huber's parametric fitting.By comparison,we found that the Huber parametric fit not only eliminates the interference introduced by attitude changes but also retains richer anomaly source information and therefore obtains a higher signal-to-noise ratio.The experimental results show that the quality of the magnetometry data obtained by using the compensation method proposed in this paper has been significantly improved,and the mean value of its improvement ratio can reach 118.93.
基金supported by the PetroChina Prospective,Basic,and Strategic Technology Research Project(No.2021ZG03-02 and No.2023DJ8402)。
文摘The deep learning algorithm,which has been increasingly applied in the field of petroleum geophysical prospecting,has achieved good results in improving efficiency and accuracy based on test applications.To play a greater role in actual production,these algorithm modules must be integrated into software systems and used more often in actual production projects.Deep learning frameworks,such as TensorFlow and PyTorch,basically take Python as the core architecture,while the application program mainly uses Java,C#,and other programming languages.During integration,the seismic data read by the Java and C#data interfaces must be transferred to the Python main program module.The data exchange methods between Java,C#,and Python include shared memory,shared directory,and so on.However,these methods have the disadvantages of low transmission efficiency and unsuitability for asynchronous networks.Considering the large volume of seismic data and the need for network support for deep learning,this paper proposes a method of transmitting seismic data based on Socket.By maximizing Socket’s cross-network and efficient longdistance transmission,this approach solves the problem of inefficient transmission of underlying data while integrating the deep learning algorithm module into a software system.Furthermore,the actual production application shows that this method effectively solves the shortage of data transmission in shared memory,shared directory,and other modes while simultaneously improving the transmission efficiency of massive seismic data across modules at the bottom of the software.
基金projects of China Railway Beijing Group Company Limited.(No.2016CG23)for funding this research。
文摘The geological disasters such as collapse,mud bursting and water gushing often occur during tunnel construction.Thus,it is of great significance to detect the hidden geological disasters ahead of the tunnel face.The audio magnetotelluric(AMT)was applied for the advanced detectionstudy during the boring process of the Tianheshan tunnel in the Taihang Mountains.Three AMT profiles were deployed above the tunnel,and the data obtained in the field were analysed in terms of electrical principal axes.From shallow to deep,the direction of the geoelectric strike angle changes,generally between 30°and 60°NE,which is consistent with similar to the direction of the Taihangshan Uplift,and the data show some 3D characteristics.Two-dimensional(2D)and three-dimensional(3D)inversion methods were adopted to jointly study the subsurface structural information,and the resistivity model was geophysically and geologically interpreted.Two sets of low resistance anomalies were found,and it was hypothesised that the near-erect low-resistivity anomalies in the east might be a fragmentation zone,while the low resistance anomalies in the west,which are inclined to the westward,might be a tectonic structure or fragmentation zone related to the regional major fault,and the results of the tunnelling confirmed the reliability of the inversion interpretation.The 3D inversion can fully reflect the development scale and morphological changes of the fracture zone,and the inversion model is more reliable.Finally,it is concluded that the audio magnetotelluric method,which adopts advanced acquisition,processing and inversion interpretation techniques,is an effective means of over-detection of tunnels.
基金supported by Science and Technology Cooperation Project of the CNPC-SWPU Innovation Alliance(No.2020CX010202).
文摘The Jurassic Lianggaoshan Formation in eastern Sichuan Basin is a key target for shale oil exploration.It faces challenges in three-pressure prediction due to complex structural and sedimentary interactions,as well as strong reservoir anisotropy.These issues often lead to wellbore instability and gas logging anomalies during drilling.This study presents an integrated workflow that combines residual moveout correction using correlation-based dynamic time warping(CDTW),high-resolution seismic waveform indication inversion,and three-pressure prediction of jointing well-seismic data.Applied to the LT1 well block,the workflow effectively corrects anisotropic residual moveout in image gathers,leading to a signal strength increase of over 10%in frequency bands above 30 Hz and enhancing event continuity.High-resolution rock mechanical parameters are obtained through seismic waveform inversion and regional calibration,enabling the prediction of three-dimensional pore pressure,collapse pressure and fracture pressure.The results are consistent with actual drilling gas shows and core data,confirming the method's accuracy and supporting mud weight planning and wellbore stability efforts.This cost-effective and technically robust approach proves highly reliable in complex environments with significant heterogeneity and anisotropy,assisting drilling decisions and risk management in eastern Sichuan and similar challenging geological settings.
基金supported by the Jingdezhen Science and Technology Plan Project(No.20234SF005)the Jingdezhen University Science and Technology Project(No.2023xjkt-02).
文摘Shale gas reservoirs have large burial depths,thin thickness,and low resistance,which lead to problems with weak surface observation,abnormal information,and multiple inversion solutions.The traditional electromagnetic method cannot effectively identify information from deep,low-resistance thin layers in terms of detection depth and accuracy.Wide field electromagnetic method(WFEM)with large depth and high precision has become the main method for deep earth exploration.This method has been widely used in the exploration of deep oil and gas energy,as well as mineral resources.However,an in-depth analysis of the various factors that affect the deep detection ability of WFEM is lacking.Therefore,the analysis of system parameters has significant theoretical importance and practical value for studying the effectiveness of WFEM in deep-layer identification.In this study,a multilayer geoelectric model is established in this study using the measured well data.The influence characteristics of different observation system parameters on the resolution of specific deep-seated targets under the WFEM_E-Ex mode are analyzed in detail through forward modeling and inversion.Results show that the resolution ability of WFEM for deep,low-resistance thin layers is affected by factors such as transceiver distance,target layer thickness,and resistivity difference between the target body and the surrounding rock,but the influence range differs.This study analyzes the influence characteristics of various system parameters.It provides targeted work scheme design and feasibility analysis for deep shale gas exploration.It also offers an important theoretical basis for optimizing construction schemes and improving the recognition ability of WFEM for deep,low-resistance targets.
基金supported by the National Natural Science Foundation of China(No.41074095)the Scientific Research Foundation of China University of Petroleum(Beijing)at Karamay(NO:XQZX20230005).
文摘The identification of igneous rock in sedimentary basins serves as the basis for the exploration of igneous oil and gas reservoirs.The implementation of magnetic exploration in the identification and delineation of igneous rock can often achieve good results.However,when igneous rock and deep magnetic layers are under the influence of remanence,the reduction to the pole of magnetic anomaly and conventional magnetic inversion methods,which require clear magnetization directions,is limited,and special magnetic anomaly processing and inversion methods are necessary.We present a case study on igneous rock imaging through a strategy involving the joint use of a preferential filtering method and amplitude inversion affected by remanence in the Qikou depression in China.We first extract the weak anomalies of igneous rock from the observed total-field anomaly via preferential filtering and calculate their amplitude data.We then perform amplitude inversion to determine the underground three-dimensional magnetism distribution and propose a reasonable interpretation by combining seismic and other data.This work demonstrates the feasibility and effectiveness of the above strategy in delineating the igneous rock buried deep in sedimentary basins.
基金jointly funded by the National Natural Science Foundation of China(No.U2244220,No.42004125)the China Geological Survey Projects(No.DD20240119,No.DD20243245,No.DD20230114,No.DD20243244)the China Postdoctoral Science Foundation(No.2020M670601)。
文摘In the 3D inversion modeling of gravity and magnetic potential field data,the model weighting function is often applied to overcome the skin eff ect of inversion results.However,divergence occurs at the the deep area,and artificial weak negative anomalies form around the positive anomalies in the horizontal direction,resulting in a reduction in the overall resolution.To fully utilize the model weighting function,this study constructs a combined model weighting function.First,a new depth weighting function is constructed by adding a regulator into the conventional depth weighting function to overcome the skin eff ect and inhibit the divergence at the deep area of the inversion results.A horizontal weighting function is then constructed by extracting information from the observation data;this function can suppress the formation of artificial weak anomalies and improve the horizontal resolution of the inversion results.Finally,these two functions are coupled to obtain the combined model weighting function,which can replace the conventional depth weighting function in 3D inversion.It improves the vertical and horizontal resolution of the inversion results without increasing the algorithm complexity and calculation amount,is easy to operate,and adapts to any 3D inversion method.Two model experiments are designed to verify the effectiveness,practicability,and anti-noise of the combined model weighting function.Then the function is applied to the 3D inversion of the measured aeromagnetic data in the Jinchuan area in China.The obtained inversion results are in good agreement with the known geological data.
基金supported by the CHN Energy Investment Group,grant numbers GJNY-23-86 and GJNY-23-92.
文摘High temperature and high stress are critical challenges facing enhanced geothermal systems(EGS).This study investigates the physical and mechanical behavior and acoustic emission(AE)characteristics of granite subjected to heating–water cooling treatments at temperatures ranging from 25℃ to 400℃.Changes in physical properties,including volume expansion,mass loss,and P-wave velocity,were examined to quantify the extent of thermal damage.Results show that visible surface cracking occurs on granite samples treated above 300℃,with P-wave velocity being the most sensitive indicator of thermal damage.Uniaxial and triaxial compression tests were conducted to explore the effects of temperature and confining pressure on granite’s strength,deformation,failure modes,energy evolution,and brittleness.While peak strength remains largely unaffected by temperature,failure modes transition from axial splitting to shear as confining pressure increases.Thermal damage reduces the rock’s energy storage capacity and increases energy dissipation during loading.The brittleness index decreases with temperature and confining pressure,though granite still exhibits pronounced brittle behavior within the studied range.Distinct differences were observed in the AE temporal characteristics and energy evolution of granite samples under uniaxial and triaxial compression conditions.As the specimen approaches failure,the abrupt increase in AE hit rate occurs earlier than the corresponding rise in AE energy.The global b-value of the granite samples increased with treatment temperature,and the global b-value in triaxial compression tests was higher than that in uniaxial compression tests.The evolution of timedependent b-value also varied with increasing confining pressure.These findings,particularly the AE temporal characteristics and distinct b-value evolution under confinement of thermally damaged granite,provide important implications for microseismic-based stability assessment and early warning in thermally damaged rock masses.
基金financially supported by The National Natural Science Foundation of China (42374004)the Open Fund of Hubei Luojia Laboratory (220100045)the Natural Science Foundation of Sichuan Province (2022NSFSC1047)。
文摘Since April 2002,the Gravity Recovery and Climate Experiment Satellite(GRACE)has provided monthly total water storage anomalies(TWSAs)on a global scale.However,these TWSAs are discontinuous because some GRACE observation data are missing.This study presents a combined machine learning-based modeling algorithm without hydrological model data.The TWSA time-series data for 11 large regions worldwide were divided into training and test sets.Autoregressive integrated moving average(ARIMA),long short-term memory(LSTM),and an ARIMA-LSTM combined model were used.The model predictions were compared with GRACE observations,and the model accuracy was evaluated using fi ve metrics:the Nash-Sutcliff e effi ciency coeffi cient(NSE),Pearson correlation coeffi cient(CC),root mean square error(RMSE),normalized RMSE(NRMSE),and mean absolute percentage error.The results show that at the basin scale,the mean CC,NSE,and NRMSE for the ARIMA-LSTM model were 0.93,0.83,and 0.12,respectively.At the grid scale,this study compared the spatial distribution and cumulative distribution function curves of the metrics in the Amazon and Volga River basins.The ARIMA-LSTM model had mean CC and NSE values of 0.89 and 0.61 and 0.92 and 0.61 in the Amazon and Volga River basins,respectively,which are superior to those of the ARIMA model(0.86 and 0.48 and 0.88 and 0.46,respectively)and the LSTM model(0.80 and 0.41 and 0.89 and 0.31,respectively).In the ARIMA-LSTM model,the proportions of grid cells with NSE>0.50 for the two basins were 63.3%and 80.8%,while they were 54.3%and 51.3%in the ARIMA model and 53.7%and 43.2%in the LSTM model.The ARIMA-LSTM model significantly improved the NSE values of the predictions while guaranteeing high CC values in the GRACE data reconstruction at both scales,which can aid in fi lling in discontinuous data in temporal gravity fi eld models..
基金supported by Technology Innovation Fund of China Coal Research Institute(2022CX-I-04)Science and Technology Innovation Venture Capital Project of China Coal Technology Engineering Group(2020-2-TD-CXY005)。
文摘Enhancing the mining speed of a working face has become the primary approach to achieve high production and efficiency in coal mines,thereby further improving the production capacity.However,the problem of rock bursts resulting from this approach has become increasingly serious.Therefore,to implement coal mine safety and efficient extraction,the impact of deformation pressure caused by different mining speeds should be considered,and a reasonable mining speed of the working face should be determined.The influence of mining speed on overlying rock breaking in the stope is analyzed by establishing a key layer block rotation and subsidence model.Results show that with the increasing mining speed,the compression amount of gangue in the goaf decreases,and the rotation and subsidence amount of rock block B above goaf decreases,forcing the rotation and subsidence amount of rock block A above roadway to increase.Consequently,the contact mode between rock block A and rock block B changes from line contact to point contact,and the horizontal thrust and shear force between blocks increase.The increase in rotation and subsidence of rock block A intensifies the compression degree of coal and rock mass below the key layer,thereby increasing the stress concentration degree of coal and rock mass as well as the total energy accumulation.In addition,due to the insufficient compression of gangue in the goaf,the bending and subsidence space of the far-field key layer are limited,the length of the suspended roof increases,and the influence range of mining stress and the energy accumulation range expand.Numerical test results and underground microseismic monitoring results verify the correlation between mining speed and stope energy,and high-energy events generally appear 1-2 d after the change in mining speed.On this basis,the statistical principle confirms that the maximum mining speed of the working face at 6 m/d is reasonable.
基金funded by the National Key R&D Program of China(Grant no.2018YFA0702504)the Sinopec research project(P22162).
文摘Absorption compensation is a process involving the exponential amplification of reflection amplitudes.This process amplifies the seismic signal and noise,thereby substantially reducing the signal-tonoise ratio of seismic data.Therefore,this paper proposes a multichannel inversion absorption compensation method based on structure tensor regularization.First,the structure tensor is utilized to extract the spatial inclination of seismic signals,and the spatial prediction filter is designed along the inclination direction.The spatial prediction filter is then introduced into the regularization condition of multichannel inversion absorption compensation,and the absorption compensation is realized under the framework of multichannel inversion theory.The spatial predictability of seismic signals is also introduced into the objective function of absorption compensation inversion.Thus,the inversion system can effectively suppress the noise amplification effect during absorption compensation and improve the recovery accuracy of high-frequency signals.Synthetic and field data tests are conducted to demonstrate the accuracy and effectiveness of the proposed method.
基金supported by National Natural Science Foundation of China(No.42274014,42574075)Tianshan Talent Science and Technology Innovation Team of Xinjiang Uygur Autonomous Region(No.2024TSYCTD0014)+3 种基金Key Research and Development Program of Xinjiang Uygur Autonomous Region(No.2020B03006-2,2024B03018-3)The Third Scientific Expedition to Xinjiang(No.2022XJKK1305)Natural Science Foundation of Xinjiang Uygur Autonomous Region(No.2022D01A106,2023D01A105)Hebei Earthquake Science and Technology Spark Program Project(No.DZ2025082000001).
文摘This study compares the performance of a quantum absolute gravimeter(QAG)and a gPhone relative gravimeter(RG)installed at the same site in Zhangjiakou.The comparison focuses on their capabilities in recording seismic waveforms and detecting Earth's free oscillation signals following the Myanmar Ms7.9 earthquake.Both instruments exhibit unique advantages in their observation capabilities.The QAG demonstrates high sensitivity to the initial arrival of seismic waves,producing distinct peak waveforms,while the RG maintains a stable waveform suitable for analyzing seismic wave propagation and energy dissipation mechanisms.In terms of time-frequency analysis,the QAG excels in surface wave frequency resolution but experiences rapid signal attenuation.Conversely,the RG offers superior stability in sustained gravity disturbances with slower signal decay.Regarding spherical Earth free oscillation signals,the RG generally detects more pronounced signals with minimal deviation from the Preliminary Reference Earth Model(PREM)theoretical values.However,the QAG exhibits high sensitivity and a wide dynamic range in higher frequency bands.Combining data from both instruments provides comprehensive seismic monitoring data,facilitating a deeper understanding of Earth's internal mass distribution and dynamic processes.
基金supported by the National Natural Science Foundation of China(42364005,42174074,42064008 and 41704053)Science&Technology Fundamental Resources Investigation Program(Grant No.2023FY201500)+1 种基金Science and Technology Plan Project of Jiangxi Province(20212BCJ23002,20232ACB213013)the East China University of Technology Research Foundation for Advanced Talents(ECUT)(DHBK2019084)。
文摘Earthquakes not only release the long-term accumulated stress on the seismogenic fault but may also increase the stress on some surrounding faults or other segments of the seismogenic fault,thereby raising the seismic risk on these faults.This study investigates the impact of the April 2,2024,Mw 7.4 earthquake in Hualien,Taiwan,China,on the surrounding faults and aftershocks.We analyze stress-triggering effects by calculating Coulomb stress changes(ΔCFS)using rupture models and focal mechanism data.Historical focal mechanism nodal planes serve as receiver fault parameters forΔCFS calculations.Our findings indicate signifi cant Coulomb stress loading on the Longitudinal Valley fault and Central Range structure due to the mainshock,promoting their seismic activity.Loading effects vary by fault type,with thrust and strike-slip faults experiencing more stress loading than normal and odd faults.Conversely,the rupture’s coseismic slip concentration area shows predominant stress unloading,inhibiting seismic activity in the region.Aftershocks mainly experience increasedΔCFS,suggesting that the stress-triggering induced by the mainshock considerably influences the earthquake sequence evolution.These insights are crucial for understanding aftershock patterns and enhancing seismic hazard assessments.
基金National Natural Science Foundation of China(41630640)National Science Foundation of Innovation Research Group(41521002)+1 种基金National Natural Science Foundation of China(41790445)Construction S&T Project of Department of Transportation of Sichuan Province(Grant No.2020A01).
文摘The stratum lithology and geological structure of the highway tunnel in the mountainous areas of western China are complex,and the engineering geological conditions are complicated.When the highway tunnel passes through different lithological strata,its structural design and construction technology are completely diff erent.Therefore,in order to support the tunnel design and construction,the tunnel survey Among them,the identification of the contact boundary between magmatic rock and metamorphic rock and the grade of surrounding rock is very important.Through magnetotelluric survey of the Mupi tunnel of Jiuzhaigou-Mianyang highway on G8513 line,2D forward numerical simulation,1D,2D,3D inversion,and engineering geological analysis,it is revealed that the electrical characteristics of each layer,focusing on the identification of the contact boundary between magmatic rock and metamorphic rock.This study provides the electrical characteristics of the magmatic rock and metamorphic rock contact boundary of the Mupi Tunnel.It is speculated that the boundary is revealed by the tunnel construction excavation,which verifies the correctness of the geophysical inversion model and provides a more detailed design basis for the tunnel design.I believe that taking the Mupi Tunnel survey as an example,through this research,it can provide detailed geophysical evidence for highway tunnels to distinguish between magmatic rock and metamorphic rock.
