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Research of seismic events waveform in deep copper mine
Yang Zhiguo,Yu Runcang,Guo Ran
Strategic Study of CAE 2008, Volume 10, Issue 8, Pages 69-72
In order to better understand the regularities of rockburst occurrence,Dongguashan Copper Mine has installed an ISSI seismic monitoring system, which can make a real-time monitoring of rock mass respond to mining. This paper briefly described the layout of the monitoring system in Dongguashan Copper Mine,then analyzed how to process various kinds of event waveforms. By contrasting the different locations resulting from the automatic processing and the artificial processing, it is confirmed that the accuracy of an event location has been improved greatly by the artificial processing, which will make the calculation of seismic source parameters even more accurate. Based on the corresponding relations between waveforms recorded and mining practice, the event waveforms are assorted, which can identify events quickly. According to the analysis results of a detecting blast and an identified seismic event,the waveform analysis method put forward in this paper is validated. It will establish a sound basis for subsequent analysis of the stress or strain status,delineation of hazardous areas of rock mass and adoption of reasonable measures.
Keywords: deep mining rockburst seismic monitoring waveform analysis
Ruochen Jiang, Feng Dai, Yi Liu, Ang Li
Engineering 2021, Volume 7, Issue 7, Pages 1023-1034 doi: 10.1016/j.eng.2020.10.019
Microseismic (MS) event locations are vital aspect of MS monitoring technology used to delineate the damage zone inside the surrounding rock mass. However, complex geological conditions can impose significantly adverse effects on the final location results. To achieve a high-accuracy location in a complex cavern-containing structure, this study develops an MS location method using the fast marching method (FMM) with a second-order difference approach (FMM2). Based on the established velocity model with three-dimensional (3D) discrete grids, the realization of the MS location can be achieved by searching the minimum residual between the theoretical and actual first arrival times. Moreover, based on the calculation results of FMM2, the propagation paths from the MS sources to MS sensors can be obtained using the linear interpolation approach and the Runge–Kutta method. These methods were validated through a series of numerical experiments. In addition, our proposed method was applied to locate the recorded blasting and MS events that occurred during the excavation period of the underground caverns at the Houziyan hydropower station. The location results of the blasting activities show that our method can effectively reduce the location error compared with the results based on the uniform velocity model. Furthermore, the obtained MS location was verified through the occurrence of shotcrete fractures and spalling, and the monitoring results of the in-situ multipoint extensometer. Our proposed method can offer a more accurate rock fracture location and facilitate the delineation of damage zones inside the surrounding rock mass.
Keywords: Fast marching method Microseismic event location Cavern-containing complex rock mass Runge–Kutta method
Velocity-Free MS/AE Source Location Method for Three-Dimensional Hole-Containing Structures Article
Longjun Dong, Qingchun Hu, Xiaojie Tong, Youfang Liu
Engineering 2020, Volume 6, Issue 7, Pages 827-834 doi: 10.1016/j.eng.2019.12.016
Microseismic source/acoustic emission (MS/AE) localization method is crucial for predicting and controlling of potentially dangerous sources of complex structures. However, the locating errors induced by both the irregular structure and pre-measured velocity are poorly understood in existing methods. To meet the high-accuracy locating requirements in complex three-dimensional hole-containing structures, a velocity-free MS/AE source location method is developed in this paper. It avoids manual repetitive training by using equidistant grid points to search the path, which introduces A* search algorithm and uses grid points to accommodate complex structures with irregular holes. It also takes advantage of the velocity-free source location method. To verify the validity of the proposed method, lead-breaking tests were performed on a cubic concrete test specimen with a size of 10 cm × 10 cm × 10 cm. It was cut out into a cylindrical empty space with a size of ϕ6cm × 10 cm. Based on the arrivals, the classical Geiger method and the proposed method are used to locate lead-breaking sources. Results show that the locating error of the proposed method is 1.20 cm, which is less than 2.02 cm of the Geiger method. Hence, the proposed method can effectively locate sources in the complex three-dimensional structure with holes and achieve higher precision requirements.
Sun Wei
Strategic Study of CAE 2007, Volume 9, Issue 7, Pages 7-17
What is discussed here is that the earthquake precursor have their own physical model, which is divided into the load stage, the stage of stalemate, the unload stage, the short stage before occurrence and the quake stage. Up till now, numerous earthquakes that occurred worldwide have proved that the quake-breeding physical model of destructive earthquakes may repeat and reappear. An analytic method is brought forward for tracing the information on the warning signs of an earthquake and predicting earthquakes step by step. Also, earthquake prediction is preactically divided into stages, making it possible to realize the predicting of destructive earthquakes.
Keywords: destructive earthquake quake-breeding physical model signals before an earthquake earthquake precursor
Review on the prediction before the Wenchuan Earthquake
Guo Zengjian,Guo Anning
Strategic Study of CAE 2009, Volume 11, Issue 6, Pages 166-168
According to the index of solar activity we predicted in 2006 that during 2007 ~2008 an earthquake M >7 will possibly occur in segment between Tianshui and Kangding.Based on the flood-earthquake chain along the latitude circle of 30°,we predicted in the end of 2007 that an earthquake M6 ~7 will possibly occur in Kangding region in 2008.
Keywords: earthquake prediction valley of solar activity flood-earthquake chain
Prospects of Microsystems Research and Development
Zhong Xianxin
Strategic Study of CAE 2000, Volume 2, Issue 1, Pages 81-84
The microsystems research and development extends into various fields including the micro electronic, micro machine, micro-optics, chemistry, biotechnology and materials, making it a multidisciplinary technology integrating various technologies and knowledges. When considering potential uses in future, microsystems technologies are still at the elementary stage. Research today is mainly centered on fundamental technologies common to various microsystems.
May be the focus of the microsystems research and development as followings: science and technology at the microdomain, new signal sensing, transmission and processing technique, nanometer measurement and operation ,new microsystem materials, microfabrication technique.
Keywords: microsystems microdomain sensing and processing nanometer measurement new materi-als microfabrication
Seismic input of NPP & topic of seismic-isolated research for AP1000 nuclear island
Xia Zufeng
Strategic Study of CAE 2013, Volume 15, Issue 4, Pages 52-56
The article introduces seismic input of nuclear power plant in the world briefly, and mentions some exploratory work for seismic-isolated foundation of nuclear island in France, Japan and China. The article mainly focuses on a general concept design of nuclear island seismic-isolated foundation for AP1000 units by our institute. There are more useful information for seismic input of nuclear power plant & seismic-isolated foundation of nuclear island as a reference.
Keywords: nuclear power plant seismic design AP1000 seismic-isolated foundation
Dynamical Experiment Research on New Seismic Isolation Bearings with SMA Wires
Deng Zongcai,Sun Hongjun,Liu Chunguo,Niu Kun,Deng Hongliang
Strategic Study of CAE 2005, Volume 7, Issue 12, Pages 61-68
As the aim of improving the utilization ratio of SMAs in SMA-rubber seismic isolation bearings, several different SMA-rubber seismic isolation bearings were designed, and energy dissipation experiments were done. The factors which affect the level stiffness, energy dissipation and equivalent damping ratio of SMA-rubber seismic isolation bearings including level displacement amplitude, level loading frequency and vertical load were studied. Result showed that the new SMA-rubber seismic isolation bearings have better hysteresis and energy dissipation capabilities. It provided the base to optimize the SMA-rubber seismic isolation bearings.
Keywords: shape memory alloy seismic isolation bearings initial stiffness hysteresis energy dissipation equivalent damping ratio
Micro-seismic signal propagation of low attenuation
Xiao Jian,Sun Shuting,Liu Jianzhong
Strategic Study of CAE 2014, Volume 16, Issue 8, Pages 83-87
This article explored the possibility of spread of weak seismic signals and low attenuation. The results showed that both underground seismic signal propagation medium showed a degree of elasticity,the vibration signal amplitude,just below the elastic limit attenuation is very small,showing low attenuation characteristics. This feature ensures that on the ground,and even the loess coverage area of micro seismic signal detected.
Keywords: micro-seismic low attenuation inelastic attenuation
The earthquake threat and countermeasures to the safety of nuclear power plants
Zhou Fulin,Tan Ping,Liu Dewen
Strategic Study of CAE 2013, Volume 15, Issue 4, Pages 36-40
Nuclear energy is a carbon-free, clean and efficient energy. It is very important in the progress of human civilization and modern development of the world. However, there are still some problems such as nuclear leak and nuclear waste. In this paper, the world's nuclear energy utilization and nuclear power plant constructions are reviewed and plans are forecasted. The basic reason of previous nuclear power plant accidents in history is summarized. Taking 2011 Tohuku earthquake -fukushima nuclear power station accident as an example, threats to the nuclear power plant by earthquake are investigated and impacts on social, economic and ecological environment caused by nuclear power station accident are analyzed. This paper drew lessons from previous accidents and put forward a variety of countermeasures which are from both the technical and management aspects. This paper also put forward some suggestions. Security measures of the existing nuclear power plants should be assessed carefully. The long-term construction plan of the nuclear power plant should be improved. In addition, emergency management mechanism of the nuclear power plant can be enhanced in the future. The earthquake monitoring and earthquake early-warning system is critical and promoted to be established widely. The nuclear probability safety analysis (PSA) could be investigated in depth. The security education of the public should be continuously popularized and disaster drills be carried out regularly. International cooperation and communication are also advocated to be strengthened. All these measures can be significant in human process to explore nuclear energy correctly. We also appeal people all over the world to respect the nature, enjoy the nature, and to create and enjoy the new civilization of human beings.
Keywords: nuclear power plant seismic hazard tsunami location safety base isolation energy dissipation three-dimensional base isolation
Microseismic monitoring technology
Tang Chunhua,Gu Guangqing
Strategic Study of CAE 2012, Volume 14, Issue 4, Pages 95-99
Microseismic (MS) monitoring is a hot topic in the applied geophysics recently. The MS mechanism and histories are introduced firstly in this article, and then the instruction of the MS equipment such as acquisition strategies, optimal sensors, array design, digital-signal processing, event location, velocity calibration, and monitoring deployment, is discussed. MS is a great technology with a long future, and we need to foster the understanding and acceptance of this technology.
Keywords: microseismic monitoring hydraulic fracturing oil and natural gas SNR (signal to noise ratio) event location
Micro-Intervention Rural Planning Based on Cultural Heritance
Guo Haian
Strategic Study of CAE 2019, Volume 21, Issue 2, Pages 27-33 doi: 10.15302/J-SSCAE-2019.02.019
For a long time, rural planning has been following the system of urban planning and design, and the results of rural planning are expressed in general maps or aerial views. Many local governments have made rounds of planning, but only little improvement has been made on rural landscape. This results from the neglect of the inherent cultural heritance of villages and the inherent role of cultural values. Urban planning and design methods cannot be used directly to demarcate rural areas. Therefore, we need to form a new planning and design theory which considers rural culture heritance. The micro-intervention planning theory is a cultural-guided planning strategy for rural revival, where the rural areas are transformed and revived using a progressive approach. This strategy is more suitable for rural planning than the big-scale demolition and reforms being conducted in the new round of rural planning process in China.
Keywords: rural planning micro-intervention planning consequential fault-tolerant rural culture rural revival
Application of microseismic monitoring technology in Daqing Oilfield A block well net design
Ma Jisheng
Strategic Study of CAE 2012, Volume 14, Issue 4, Pages 74-76
The artificial fracture position and the well row direction influence the exploitation effect of low permeability reservoir. In the process of creating artificial fractures, we apply microseismic to monitor their direction, location, orientation, length and height, and determine the well alignment direction combined with the stress orientation, all of which establish well foundation for improving the development effect of A block.
Keywords: microseismic monitoring artificial fracture well pattern design
Wang Guoshun,Liu Jianzhong,Liu Linwang
Strategic Study of CAE 2012, Volume 14, Issue 4, Pages 40-44
This paper describes arrival time of microseismic signals, which were obtained from monitoring fracturing and waterfloodand were used to interpolate mechanisms of micro-earthquake and verify reliability of fracturing and waterflood monitoring. It shows that fracture orientation, waterflood front geometry, and microseismic mechanism nodal plane are consistent, and monitoring results are reliable. This study depicts a selfcheck approach to verify dependability of microseismic mapping itself, and it is an important measurement method for fracturing and waterflood projects of deep formations when no alternative verifications are viable.
Keywords: microseismic fracture waterflood performance waterflood front
Mechanically Strong Proteinaceous Fibers: Engineered Fabrication by Microfluidics Review
Jing Sun, Jingsi Chen, Kai Liu, Hongbo Zeng
Engineering 2021, Volume 7, Issue 5, Pages 615-623 doi: 10.1016/j.eng.2021.02.005
Lightweight and mechanically strong natural silk fibers have been extensively investigated over the past decades. Inspired by this research, many artificial spinning techniques (wet spinning, dry spinning, electrospinning, etc.) have been developed to fabricate robust protein fibers. As the traditional spinning methods provide poor control over the as-spun fibers, microfluidics has been integrated with these techniques to allow the fabrication of biological fibers in a well-designed manner, with simplicity and cost efficiency. The mechanical behavior of the developed fibers can be precisely modulated by controlling the type and size of microfluidic channel, flow rate, and shear force. This technique has been successfully used to manufacture a broad range of protein fibers, and can accelerate the production and application of protein fibers in various fields. This review outlines recent progress in the design and fabrication of protein-based fibers based on microfluidics. We first briefly discuss the natural spider silk-spinning process and the microfluidics spinning process. Next, the fabrication and mechanical properties of regenerated protein fibers via microfluidics are discussed, followed by a discussion of recombinant protein fibers. Other sourced protein fibers are also reviewed in detail. Finally, a brief outlook on the development of microfluidic technology for producing protein fibers is presented.
Keywords: Proteinaceous fibers Microfluidics Soft materia l Biomaterials
Title Author Date Type Operation
Research of seismic events waveform in deep copper mine
Yang Zhiguo,Yu Runcang,Guo Ran
Journal Article
Fast Marching Method for Microseismic Source Location in Cavern-Containing Rockmass: Performance Analysis and Engineering Application
Ruochen Jiang, Feng Dai, Yi Liu, Ang Li
Journal Article
Velocity-Free MS/AE Source Location Method for Three-Dimensional Hole-Containing Structures
Longjun Dong, Qingchun Hu, Xiaojie Tong, Youfang Liu
Journal Article
Destructive Earthquakes Are Predictable——The Physical Model of Earthquake Gestation and the Signal of Impending Quake
Sun Wei
Journal Article
Seismic input of NPP & topic of seismic-isolated research for AP1000 nuclear island
Xia Zufeng
Journal Article
Dynamical Experiment Research on New Seismic Isolation Bearings with SMA Wires
Deng Zongcai,Sun Hongjun,Liu Chunguo,Niu Kun,Deng Hongliang
Journal Article
Micro-seismic signal propagation of low attenuation
Xiao Jian,Sun Shuting,Liu Jianzhong
Journal Article
The earthquake threat and countermeasures to the safety of nuclear power plants
Zhou Fulin,Tan Ping,Liu Dewen
Journal Article
Application of microseismic monitoring technology in Daqing Oilfield A block well net design
Ma Jisheng
Journal Article
Analysis of using microseismic monitoring to verify fracturing and waterflood on reservoir Chang 8 of Zhengjing Oilfield
Wang Guoshun,Liu Jianzhong,Liu Linwang
Journal Article