Understanding rock behavior is crucial in mine geotechnical engineering to ensure construction efficiency,mitigate rock-related hazards,and promote environmental sustainability.Coda Wave Interferometry(CWI),a non-dest...Understanding rock behavior is crucial in mine geotechnical engineering to ensure construction efficiency,mitigate rock-related hazards,and promote environmental sustainability.Coda Wave Interferometry(CWI),a non-destructive ultrasonic testing method,has been widely employed to assess micro-damage evolution in rocks induced by perturbations in scatterer position,velocity,or source location due to its exceptional sensitivity.However,challenges persist in evaluating cross-scale rock behavior influenced by nonlinear deformation and multi-field interactions under multiple coupled perturbations.A comprehensive review of the perturbation factors affecting rock damage evolution and potential failure mechanisms is essential for presenting available knowledge in a more systematic and structured manner.This review provides an in-depth analysis of the CWI technique,encompassing its origins,theoretical framework,and classical data processing methodologies.Additionally,it explores the diverse applications of CWI in assessing rock behavior under various perturbation factors,including temperature variations,fluid infiltration,and stress conditions,with a particular emphasis on nonlinear deformation and multi-field coupling effects.Furthermore,a novel method for calculating relative velocity changes in coda waves is introduced,enabling a more precise characterization of the entire rock failure process.The study also proposes a cutting-edge concept of ultra-early and refined monitoring and warning technology for mine rock disasters,leveraging the advancements in CWI.Finally,the review highlights the potential future developments of CWI in high-level intelligent mining scenarios,particularly its integration with ambient noise interferometry and microseismic coda wave analysis.This work serves as a valuable reference,contributing to the refinement of CWI applications for assessing complex rock behavior and enhancing the accuracy of rock disaster prediction and early warning systems.展开更多
The approach of evaluating the final scores of multi-criteria decision-making(MCDM)methods according to the strength of association with real-life rankings is interesting for comparing MCDM methods.This approach has r...The approach of evaluating the final scores of multi-criteria decision-making(MCDM)methods according to the strength of association with real-life rankings is interesting for comparing MCDM methods.This approach has recently been applied mostly to financial data.In these studies,where it is emphasized that some methods show more stable success,it would be useful to see the results that will emerge by testing the approach on different data structures more comprehensively.Moreover,not only the final MCDM results but also the performance of normalization techniques and data types(fuzzy or crisp),which are components of MCDM,can be compared using the same approach.These components also have the potential to affect MCDM results directly.In this direction,in our study,the economic performances of G-20(Group of 20)countries,which have different data structures,were calculated over ten different periodic decision matrices.Ten different crisp-based MCDM methods(COPRAS,CODAS,MOORA,TOPSIS,MABAC,VIKOR(S,R,Q),FUCA,and ELECTRE III)with different capabilities were used to better visualize the big picture.The relationships between two different real-life reference anchors and MCDM methods were used as a basis for comparison.The CODAS method develops a high correlation with both anchors in most periods.The most appropriate normalization technique for CODAS was identified using these two anchors.Interestingly,the maximum normalization technique was the most successful among the alternatives(max,min–max,vector,sum,and alternative ranking-based).Moreover,we compared the two main data types by comparing the correlation results of crisp-based and fuzzy-based CODAS.The results were very consistent,and the“Maximum normalization-based fuzzy integrated CODAS procedure”was proposed to decision-makers to measure the economic performance of the countries.展开更多
Coda waves are multiply scattered waves that arrive much later than the major waves. Small seismic velocity variations are observed in reservoirs because of small variations in reservoir properties, which affect the f...Coda waves are multiply scattered waves that arrive much later than the major waves. Small seismic velocity variations are observed in reservoirs because of small variations in reservoir properties, which affect the first arrivals. Hence, first arrivals cannot be used to detect small seismic velocity variations. However, small variations can be reliably detected by the coda waves because of the amplification owing to multiple scattering. We investigate the ability of coda wave interferometry to detect seismic velocity variations and monitor time-lapse reservoir characteristics using numerical simulations and experimental data. We use the Marmousi II model and finite-difference methods to build model seismic data and introduce small seismic velocity variations in the target layer. We examine the model seismic data before and after the changes and observe the coda waves. We find that velocity changes can be detected by coda wave interferometry and demonstrate that coda wave interferometry can be used in monitoring time- lapse reservoir characteristics.展开更多
Two large earthquakes(an earthquake doublet)occurred in south-central Turkey on February 6,2023,causing massive damages and casualties.The magnitudes and the relative sizes of the two mainshocks are essential informat...Two large earthquakes(an earthquake doublet)occurred in south-central Turkey on February 6,2023,causing massive damages and casualties.The magnitudes and the relative sizes of the two mainshocks are essential information for scientific research and public awareness.There are obvious discrepancies among the results that have been reported so far,which may be revised and updated later.Here we applied a novel and reliable long-period coda moment magnitude method to the two large earthquakes.The moment magnitudes(with one standard error)are 7.95±0.013 and 7.86±0.012,respectively,which are larger than all the previous reports.The first mainshock,which matches the largest recorded earthquakes in the Turkish history,is slightly larger than the second one by 0.11±0.035 in magnitude or by 0.04 to 0.18 at 95%confidence level.展开更多
基金supported by the National Key Research and Development Program of China(Fund for Young Scientists 2021YFC2900400)Chongqing Outstanding Youth Science Fund project(CSTB2023NSCQ-JQX0027).
文摘Understanding rock behavior is crucial in mine geotechnical engineering to ensure construction efficiency,mitigate rock-related hazards,and promote environmental sustainability.Coda Wave Interferometry(CWI),a non-destructive ultrasonic testing method,has been widely employed to assess micro-damage evolution in rocks induced by perturbations in scatterer position,velocity,or source location due to its exceptional sensitivity.However,challenges persist in evaluating cross-scale rock behavior influenced by nonlinear deformation and multi-field interactions under multiple coupled perturbations.A comprehensive review of the perturbation factors affecting rock damage evolution and potential failure mechanisms is essential for presenting available knowledge in a more systematic and structured manner.This review provides an in-depth analysis of the CWI technique,encompassing its origins,theoretical framework,and classical data processing methodologies.Additionally,it explores the diverse applications of CWI in assessing rock behavior under various perturbation factors,including temperature variations,fluid infiltration,and stress conditions,with a particular emphasis on nonlinear deformation and multi-field coupling effects.Furthermore,a novel method for calculating relative velocity changes in coda waves is introduced,enabling a more precise characterization of the entire rock failure process.The study also proposes a cutting-edge concept of ultra-early and refined monitoring and warning technology for mine rock disasters,leveraging the advancements in CWI.Finally,the review highlights the potential future developments of CWI in high-level intelligent mining scenarios,particularly its integration with ambient noise interferometry and microseismic coda wave analysis.This work serves as a valuable reference,contributing to the refinement of CWI applications for assessing complex rock behavior and enhancing the accuracy of rock disaster prediction and early warning systems.
文摘The approach of evaluating the final scores of multi-criteria decision-making(MCDM)methods according to the strength of association with real-life rankings is interesting for comparing MCDM methods.This approach has recently been applied mostly to financial data.In these studies,where it is emphasized that some methods show more stable success,it would be useful to see the results that will emerge by testing the approach on different data structures more comprehensively.Moreover,not only the final MCDM results but also the performance of normalization techniques and data types(fuzzy or crisp),which are components of MCDM,can be compared using the same approach.These components also have the potential to affect MCDM results directly.In this direction,in our study,the economic performances of G-20(Group of 20)countries,which have different data structures,were calculated over ten different periodic decision matrices.Ten different crisp-based MCDM methods(COPRAS,CODAS,MOORA,TOPSIS,MABAC,VIKOR(S,R,Q),FUCA,and ELECTRE III)with different capabilities were used to better visualize the big picture.The relationships between two different real-life reference anchors and MCDM methods were used as a basis for comparison.The CODAS method develops a high correlation with both anchors in most periods.The most appropriate normalization technique for CODAS was identified using these two anchors.Interestingly,the maximum normalization technique was the most successful among the alternatives(max,min–max,vector,sum,and alternative ranking-based).Moreover,we compared the two main data types by comparing the correlation results of crisp-based and fuzzy-based CODAS.The results were very consistent,and the“Maximum normalization-based fuzzy integrated CODAS procedure”was proposed to decision-makers to measure the economic performance of the countries.
基金sponsored by the 973 Program of China(No.2013CB228604)the Natural Science Foundation of Shandong Province(No.ZR2013DQ020)+1 种基金the Fundamental Research Funds for the Central Universities(No.15CX08002A)the National Natural Science Foundation of China(No.41374123)
文摘Coda waves are multiply scattered waves that arrive much later than the major waves. Small seismic velocity variations are observed in reservoirs because of small variations in reservoir properties, which affect the first arrivals. Hence, first arrivals cannot be used to detect small seismic velocity variations. However, small variations can be reliably detected by the coda waves because of the amplification owing to multiple scattering. We investigate the ability of coda wave interferometry to detect seismic velocity variations and monitor time-lapse reservoir characteristics using numerical simulations and experimental data. We use the Marmousi II model and finite-difference methods to build model seismic data and introduce small seismic velocity variations in the target layer. We examine the model seismic data before and after the changes and observe the coda waves. We find that velocity changes can be detected by coda wave interferometry and demonstrate that coda wave interferometry can be used in monitoring time- lapse reservoir characteristics.
基金the National Key R&D Program of China(No.2022YFF0800601)the National Natural Science Foundation of China(No.U1939204).
文摘Two large earthquakes(an earthquake doublet)occurred in south-central Turkey on February 6,2023,causing massive damages and casualties.The magnitudes and the relative sizes of the two mainshocks are essential information for scientific research and public awareness.There are obvious discrepancies among the results that have been reported so far,which may be revised and updated later.Here we applied a novel and reliable long-period coda moment magnitude method to the two large earthquakes.The moment magnitudes(with one standard error)are 7.95±0.013 and 7.86±0.012,respectively,which are larger than all the previous reports.The first mainshock,which matches the largest recorded earthquakes in the Turkish history,is slightly larger than the second one by 0.11±0.035 in magnitude or by 0.04 to 0.18 at 95%confidence level.
