共查询到19条相似文献,搜索用时 343 毫秒
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电位噪声是影响高密度数据采集质量进而影响反演成像解释可靠性的重要因素。通过模拟四种不同水平电位噪声并获得噪声数据,对比分析四种装置(温纳装置、三极装置、偶极装置、温纳-施伦贝谢装置),在噪声条件下的反演模型电阻率差异,并评估各装置对噪声响应的灵敏程度以及不同噪声水平对反演模型分辨率和各装置的勘探深度的影响。将反演模型分辨率和各装置勘探深度进行了量化,定量分析模型分辨率和不同装置勘探深度在各噪声水平下的变化规律,综合评估噪声对四种装置反演模型分辨率和勘探深度的影响得出:①偶极和三极装置对噪声灵敏程度较高,而温纳和温施装置对噪声灵敏程度相对较低;②噪声对深层地电模型分辨率影响较大,在有效分辨地电模型的深度范围内,温纳和温施装置的模型分辨率降低2/5,三极装置降低一半,偶极装置降低3/5左右;③勘探深度在噪声影响下均有所减小,温纳和温施装置减小约1/4,偶极和三极装置减小约1/3。 相似文献
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海域环境对高密度电阻率法在仪器设备、测量技术和反演解译等方面提出了更高要求,开展海上高密度电法的数值模拟和实测研究将进一步丰富近岸海域地质、资源和环境等问题的勘查手段.基于数值模拟和野外实测,深入研究了偶极-偶极、温纳、斯贝等不同装置对近岸海域典型地电模型的分辨能力和空间定位效果,并详细分析了海水导电性的影响,最后在珠江口伶仃洋海域开展了国内首次2条长剖面的实际测量.结果表明海水电导率对不同测量装置在探测深度和精度方面存在差异化影响,井中电缆利用浮力材料固定后,进行水面拖缆式偶极-偶极测量能大幅降低海底沉缆式测量的施工风险,实现复杂海域环境下高密度电法探测效果、深度与效率的优化折中. 相似文献
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为了提高电阻率法对地下介质污染问题的探测能力,分析了含油污水污染地下介质后引起的导电性变化,建立了适用于该问题分析的地电模型。利用2.5维有限元的方法正演模拟了采用温纳、施龙贝格、偶极和二极装置监测时所得的典型电异常剖面。正演模拟结果显示不同装置对污染区的反映能力不同,相对而言施龙贝格和温纳装置对污染区分布的反映较为直观。饱和粘土的含油污染区用温纳装置测量,剖面上表现为相对高阻异常特征,异常区域分布和污染通道相吻合。应用实例也证实了这一分析。 相似文献
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《物探化探计算技术》2021,(1)
为分析二极和偶极装置的分辨率,首先建立数值模型,并定义了均匀度、数据密度、层间分辨率、盲区的计算方式,从数据结构的角度定量讨论三维高密度电阻率法中偶极、二极装置的分辨能力。通过不同埋深、不同规模的高、低阻异常体的正演计算,对获取的数据反演后分析结果与初始模型的契合程度,定量分析两种装置对异常体的分辨能力,结果显示,在浅部异常勘探中偶极装置比二极装置整体分辨率高、细节信息丰富,尤其是异常体为低阻特征时更为明显。为了验证偶极法的有效性,选取吉林大学朝阳校区内某处地下管道为探测场地,利用E60DN高密度电法工作站进行三维高密度电法数据采集,经反演计算,精细的探测出地下管道的空间展布规律,效果较好。 相似文献
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基于不同装置的二维高密度电法勘探效果比较与分析 总被引:1,自引:0,他引:1
为比较分析高密度电法不同装置对探测异常地质体的效果,通过建立高阻异常体和隐伏直立低阻体地电模型,正演计算了不同装置类型下的视电阻率,并加噪进行二维电阻率反演。各种装置的反演结果表明:在探测地下高阻异常体时,温纳α、β、γ装置优于其他装置,揭示异常位置与形态相对较好;对于隐伏直立低阻体而言,温纳p装置和三极装置探测效果好,其中温纳β为最理想装置,实例验证表明,温纳α、β、γ装置在探测地下防空洞时体现了其装置的优越性,验证了理论模拟结论的正确性。 相似文献
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利用高密度电法温纳装置,结合第四系电阻率分布特征,并在有效探测深度范围内,研究高密度电法测量温纳装置对工作区内基岩面起伏情况及完整性的判别效果;最终通过数据处理,反演解译,结合已有的水文、地质等其他方面的资料和附近现有水井的相关情况,圈定工作区内第四系地下水储存的有利位置。根据异常对比解译、确定目标体范围、经过钻孔验证:高密度电法温纳装置对基岩面的区分反应明显,对较浅层地下水储存位置的确定较为准确,为以后需找类似地层地下水起到了一定参考依据。 相似文献
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The effectiveness of inversion apparent resistivity data to determine accurately the true resistivity distribution over 2D structures has been investigated using a common inversion scheme based on smoothness-constrained nonlinear least-squares optimization with enhancing horizontal resolution (EHR) technique by numerical simulation. The theoretical model generates in RES2DMOD software at specific distance and depth using Wenner, Wenner–Schlumberger, and pole–dipole arrays were inverted. The inversion model was compared with the original 2D model in RES2DINV software. The study model includes horizontal layering, vertical resolution, and horizontal two layers with different resistivity. Also, the response to variations in data density of these arrays was investigated. The study shows the best array suitable to be used in the survey was chosen for real data acquisition at the actual site. Subsequently, the results from borehole were used to verify the results of 2D resistivity imaging method with and without EHR technique. Saturated zone (0–40 Ω-m) was found scattered at the depth of 10–20 m. The borehole is located at 63 m at 2D resistivity imaging survey which shows at depth 10–20 m is sandy silt. Highly weathered sandstone was found at 6 m depth with resistivity value of 800 Ω-m and SPT N value of 20. The bedrock was found at 27 m depth with resistivity value of 3,000 Ω-m and SPT N value of 50. The application of 2D resistivity imaging with EHR technique indicate the ability of the proposed approach in terms of density, depth, and resistivity value of anomalous and layer in a computationally and numerically efficient manner and to exhibit good performance in the data inversion. 相似文献
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岩溶是某垃圾焚烧环保发电站场场址勘察的主要不良地质作用,为了查明岩溶和破碎带的分布情况,本文利用高密度电阻率法来探测能引起低阻异常的岩溶等地质体。在调查该区地层和溶洞的类型、分布及电性特征的基础上,利用RES2Dmod建立包含不同规模和埋深的低阻溶洞或破碎带模型,通过对比模型的温纳、偶极和微分三种装置类型的正反演结果,在本地区选用分辨率和稳定性高的温纳装置进行高密度勘测。利用高密度电阻率法查明了两个落水洞的埋深和分布情况,推测了4个疑似溶洞和破碎带,部分与后期验证钻孔吻合。利用合适的装置类型进行高密度探测可以查明充水充泥低阻溶洞的规模及分布,是一种经济有效的场址勘察方法。 相似文献
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Hamdan Hamdan Nikos Andronikidis George Kritikakis Nikos Economou Zacharias Agioutantis Paul Schilizzi Chrysanthos Steiakakis Christodoulos Papageorgiou Panagiotis Tsourlos George Vargemezis Antonis Vafidis 《Environmental Earth Sciences》2014,72(5):1589-1598
In this paper, the application of 2D and 3D electrical resistivity methods in geotechnical investigations is explored through a case study in Northern Greece. These two methods were employed at a lignite surface mining operation where fracture zones and discontinuities have been recently observed close to the pit boundaries. The main aim of the geophysical survey was to estimate the inclination of the contact between the Neogene and Schist/Carbonate formations near the southern limits of the pit, as well as to estimate the thickness of the carbonate rocks on top of the Schist formations to evaluate the stability of the southern slopes. Synthetic data were initially generated to help plan an efficient electrical tomography survey, in a region with complex geology and irregular terrain. Three configurations (Wenner–Schlumberger and dipole–dipole or pole–dipole) proved essential in such conditions and helped improving the resolution of the resistivity section. The sections were then calibrated by boreholes. Finally, the geophysical survey provided invaluable data regarding the geometry of the bedrock and possible faults, which was essential for the slope stability calculations. 相似文献
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S xxxV Suryanarayana Rao S Murali V L S Bhimasankaram 《Journal of Earth System Science》1981,90(1):75-83
A new variant of the four-electrode system is proposed for geophysical resistivity investigations, particularly for profiling over conductive bodies. Model tank resistivity profiling experiments with Wenner, Schlumberger and the proposed T-shaped four-electrode arrays were carried out over a thin conducting vein type model to evaluate the efficacy of the new array. The proposed array appears to possess a larger response, a greater depth of investigation and a higher vertical resolution in detecting conducting bodies, as compared to the two-conventional arrays. 相似文献
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高密度电阻率勘测方法分辨率研究与探讨 总被引:2,自引:0,他引:2
随着高密度电阻率法在工程中的应用日益广泛,对分辨率的影响因素分析研究也受到重视。论文以均匀半空间局部直立异常体为探测目标,建立多个基于温纳高密度电法装置的地电模型,采用有限元等方法进行正反演数值模拟分析,对高密度电阻率法探测分辨率的影响规律进行探讨。分析表明,地形起伏会引起异常体的位置与形态发生畸变和位移,分辨率降低; 电阻率差异增大,分辨率提高; 深径比增大,分辨率降低; 当异常体的水平范围一定时,探测分辨率随纵深的增大而提高。 相似文献
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