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瑞利波探测技术用于矿井地质超前探测 总被引：3，自引：1，他引：2
鹤岗矿区煤系曾遭受多次构造运动的改造,地质情况复杂。为满足采区和生产布置的需要,采用瑞利波探测技术对地质情况进行精细探查和预报。在井下用瑞利波方法探测下部煤层、超前探测煤巷、岩巷前方的构造,取得了满意的效果。该技术方法提高了地质预报的准确性,在煤矿有良好的应用前景。 相似文献
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Natural Hazards - Because a change in the frequency (number/year) of hurricanes could be a result of climate change, we analyzed the historical record of Atlantic basin and US landfalling... 相似文献
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Summary A surface instability detection apparatus for investigating axial splitting and spalling phenomena in rocks and rock-like materials is described. The apparatus simulates the conditions under which these phenomena occur and allows one to accurately measure them. Experimental results from tests on Berea sandstone are presented where the successive formation of spalling fractures was monitored with an acoustic emission system and the location of the seismic events was mapped. The test results show the potential for benchmark tests in determining the spalling tendency and characteristics of different rocks. 相似文献
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钢管混凝土超声波检测 总被引：4，自引：0，他引：4
阎鸣 《水文地质工程地质》2001,28(3):23-27
钢管混凝土超声波检测是检测钢管内混凝土灌注的质量。某高速公路K20＋544．7－K20＋698．3钢管混凝土拱桥的钢管混凝土拱经超声波检测，判定钢管混凝土有严重缺陷，钢管内混凝土灌注质量是不合格，经开孔取心、挤压试验等方法的验证，不仅证明了检测结论正确，而且证明了超声波是检测钢管混凝土质量的最佳手段。本文就检测实践和检测研究的体会论述了在钢管混凝土拱中可能出现的缺陷类型及其常见部位和混凝土超声波检测的基本原理、检测技术方法及检测信号的分类与分析。 相似文献
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煤层中含有各类轻烃,当煤层燃烧后,上覆地层完整性被破坏,给煤层内的烃类散逸提供了良好的通道,这一过程符合轻烃微渗漏原理。因此,引入轻烃微渗漏的微生物烃检测技术对煤层火烧区及其范围进行识别。在陕北侏罗纪煤田郝家梁煤矿进行了2条测线的试验,选择丁烷氧化菌作为检测指标,通过土壤样品采集、微生物培养、菌落计数等微生物检测工作后,结合地质钻孔对微生物值进行标定和异常值分组,并对煤层火烧区轻烃微渗漏的微生物响应特征进行研究。结果表明,在完全火烧区微生物以背景值分布为主,在火烧过渡区微生物以连续高值异常为主,在正常煤层区微生物以中低值为主,从而建立了研究区煤层火烧区微生物响应模型。微生物烃检测技术所解释的煤层火烧区地质成果与磁法解释的火烧边界吻合,且有钻孔验证。微生物烃检测技术的野外实施简单环保,大部分工作在室内完成,更适用于类似陕北生态脆弱区的煤层火烧区探测,有显著的实际意义和经济价值。 相似文献
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Identification of lineaments has important ramifications in geology because lineaments can signify zones of both hazardous
potential and economically valuable environments The synoptic view of local and regional lineament patterns by Landsat is
a useful mapping technique in areas considered to be well mapped as well as in poorly mapped areas Image enhancement of digitally
constructed Landsat images increases contrast and sharpness between geologic features and improves the recognition of subtle
differences
Five enhancement techniques are applied to Landsat digital data for lineament detection (1) mean value of all four bands,
(2) principal components, (3) band ratio, (4) histogram equalization, and (5) high-pass digital filtering Of the five enhancement
techniques evaluated, the principal components analysis identified the greatest number of lineaments and the greatest total
length of the lineaments. All five techniques identified a significant amount of unique lineaments, which were not found by
any other technique. Unique lineaments identified by each technique are combined through a composite process yielding a lineament
interpretation which exceeds the detection capability of the principal components interpretation 相似文献
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Identification of seismic events from continuously recorded seismic data in real-time through a Digital Seismic Data Recording
system is a difficult task. Despite the vast amount of research in this field, the signal processing and event parameters
discrimination algorithms have not yet fully come of age. Presently, we have a wide spectrum of trigger algorithms, ranging
from a very simple amplitude threshold type to the sophisticated ones based on pattern recognition approaches. Some of the
other approaches use adaptive technique and neural network methods. Researchers are continuously making efforts for the development
of algorithms using various techniques, which produce minimum false trigger. Some approaches have been reported which are
accurate for detecting first phase of events and take minimum possible computational time. In this paper several approaches
for detecting event signals in background noise are presented and their precision evaluation is discussed. 相似文献
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We consider the detection of cosmic strings using observations of the anisotropy of the Cosmic Microwave Background. Several methods for detecting cosmic strings are analyzed, using a threshold filter and expansion in orthogonal Haar functions. Computer simulation provides estimates of the noise present in experiments aimed at detection of cosmic strings. Attempts to detect cosmic strings were carried out using the full-sky ILC map obtained as a result of the WMAP space mission. A list of cosmic string candidates has been compiled using the Haar function method. 相似文献
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Coastline change detection using remote sensing 总被引：3，自引：3，他引：3
A. A. Alesheikh Assistant professor A. Ghorbanali N. Nouri 《International Journal of Environmental Science and Technology》2007,4(1):61-66
Coast is a unique environment in which atmosphere, hydrosphere and lithosphere contact each other. Coastline is one of the most important linear features on the earth’s surface, which display a dynamic nature. Coastal zone, and its environmental management requires the information about coastlines and their changes. This paper examines the current methods of coastline change detection using satellite images. Based on the advantages and drawbacks of the methods, a new procedure has been developed. The proposed procedure is based on a combination of histogram thresholding and band ratio techniques. The study area of the project is Urmia Lake; the 20th. largest, and the second hyper saline lake in the world. In order to assess the accuracy of the results, they have been compared with ground truth observations. The accuracy of the extracted coastline has been estimated as 1.3 pixels (pixel size=30 m). Based on this investigation, the area of the lake has been decreased approximately 1040 square kilometers from August 1998 to August 2001. This result has been verified through TOPEX/Posidon satellite information that indicates a height variation of three meters. 相似文献
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为了对煤矿巷道掘进前方上覆地层的地质异常进行实时超前探测,提出了利用采掘机械为震源、在震源附近布设参考道、在地面接收其透射地震波的井-地联合随采地震方法。在某矿利用采煤机做震源进行了试验,并将试验结果与同一矿井相邻工作面某掘进巷道井下放炮、地面接收的数据做了对比。结果表明:采煤机震源的数据与炸药震源的数据,纵波初至均清晰可辨,能量都较强,横波能量团的可辨识度比较接近。这说明在采掘机械附近布设检波器采集源场信号,在地表布设测线接收透射地震波,能获得与放炮震源相似的地震记录。该技术可用来监视上覆地层在采动过程中的变化,且有潜力实现监控级地震超前勘探。 相似文献
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针对含水采空区全空间瞬变电磁响应信号识别问题,采用有限元数值模拟及现场实测方法,基于电动势—视电阻率及对应时深转换关系,获取了全扇面视电阻率随深度变化的空间分布规律,提取了低阻异常区测点感应电动势衰减曲线,得出了测点随探测角度变化的电动势量化变化规律。基于上述研究,开展了井下钻探验证及钻孔窥视,并对现场钻孔出水水样进行了水质分析。结果表明:含水采空区的瞬变电磁响应横向角度对应一致性高于纵向深度;其感应电动势升幅与感应电动势差值变化趋势相反,呈现出在二次场观测初期急剧增大而后趋缓的特征,最大升幅可达10倍以上。钻探工程及化探分析进一步验证了物探成果。 相似文献
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R. B. Arango I. Díaz A. Campos E. R. Canas E. F. Combarro 《Earth Science Informatics》2016,9(4):535-545
In Precision Agriculture one of the basic tasks is the classification of land zones in either arable or non-arable land. Several studies have been conducted using data obtained from soil analysis or local exploration of the parcels. However, sometimes only data from satellite images are available and then the problem not only becomes more challenging but also more interesting to solve because it is much more cost-effective. In this paper, we consider different spectral and thermal bands from the Landsat 8 satellite images corresponding to a vineyard located in Galicia, a region in Northeastern Spain, and apply a range of supervised Machine Learning methods to classify the different land zones. We conclude that an adequate choice of the algorithm parameters together with feature selection techniques can yield a classification that is both highly effective and efficient. 相似文献
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海堤附近新建闸站常需要采用桩基进行软土地基处理,施工区域若存在隐伏块石层将影响桩基施工进度,增加施工成本,块石的空间分布特征亦对桩基施工工艺的选择起决定性作用。针对钻探法调查地下不规则分布块石盲目性大的问题,采用地质雷达与高密度电法为先导,并在物探异常区域辅以钻探验证的综合勘察技术对某闸站工程桩基施工区域地下块石进行了详查。依据勘察成果选用以旋挖钻为主的桩基施工方案,埋深小于6 m的成片块石区域采用井点降水与土方开挖回填相结合的施工工艺,局部埋深大于8 m的块石采用螺旋钻头或岩心钻头挖除,显著提升了桩基施工效率。结果表明:地质雷达与高密度电法用于探测地下浅部块石可优势互补,前者分辨率高,能体现部分零星块石堆的电磁异常,但块石与土层分界面难以判别,其异常特征表现为强振幅、波形杂乱,在纵向上伴随一定程度的多次反射;后者更适用于成片块石层的探测,较大粒径块石电阻率大于100 Ω·m,地下水位线附近的碎石电阻率小于30 Ω·m。研究成果可为软土施工区域地下深度6 m范围内块石的高精度探测以及对应桩基工程施工钻头的选择提供参考。 相似文献
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现有液化识别方法对比分析 总被引：1，自引：0，他引：1
场地液化实时监测和报警是减轻液化灾害的新途径,其核心技术是建立依据强震记录对液化场地进行反演识别的方法。采用统一样本,其中尽可能多地包含软土场地地震动记录,按场地类别对目前国内外现有的Suzuki法、Miyajima法、KY法和SY法等4种主要液化识别方法的可靠性进行了对比分析,提出评价结果及改进建议。分析表明：对全部样本,SY法、Suzuki法、KY法和Miyajima法识别成功率依次为98%、85%、77%和52%;Suzuki法、KY法和Miyajima法的成功率受场地类别影响显著,随场地变软而明显降低,对D类场地识别成功率均在55%以下;Suzuki法、Miyajima法和KY法均采用与绝对周期相关的参数作为判别指标,而软土与液化场地上存在明显交叉,极易导致误判;SY法选取地震动参数的相对变化作为识别指标,即使对D类场地成功率也达到92%,但其方法中仍有若干细节需要进一步探讨和改进 相似文献