共查询到18条相似文献，搜索用时 122 毫秒
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煤矿井下地球物理水害超前探测要求探测点20 m范围内不得有积水和金属物体,传统电磁法超前探测技术已不能满足要求,钻孔瞬变电磁法通过将收发装置送入掘进工作面前方的钻孔中进行探测,既远离了巷道中的各种干扰,又提高了隐蔽致灾水体的探测精度。为解决该方法对钻孔径向异常体的准确定位解释难题,通过三维正演总结了其水平分量异常响应特征,提出了异常体象限确定准则,研究了根据水平分量幅值和异常象限综合求取异常体工具面角的计算方法。将由垂直分量计算得到的每一个视电阻率视为独立异常体,基于K-means聚类算法对相应的水平分量异常曲线特征值进行二分类,实现了全数据集的视电阻率象限自动划分,结合异常工具面角算法研究得出钻孔瞬变电磁视电阻率立体成像方法。最后计算了三维数值模型的立体成像结果,对钻孔径向的小规模低阻异常体取得了良好效果。结果表明:基于K-means聚类算法的钻孔瞬变电磁视电阻率立体成像方法是地球物理与机器学习的有机结合,该方法能够为井下掘进工作面隐伏水害超前探测精细解释提供技术支撑。 相似文献
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西华县五二农场的电法勘探成果证明,在以砂、粘土互层为特点的中深层咸水区,五极纵轴视电阻率测深法分层明显,划分咸淡水分界线及确定深部淡水层效果较好。在解释过程中,用视电阻率曲线的二分之一异常幅值点确定含水层位置较为合适。 相似文献
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视电阻率定义在电法勘探中得到广泛的应用。目前在频率域电磁法中常常采用远区视电阻率定义。由于在频率域中收发距并非足够大,以致在低频段远区定义视电阻率往往不能反映地下电阻率值。我们定义全区电阻率及引入校正系数K,经二层三层模型及野外实测资料的计算,证明了方法的有效性。 相似文献
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相位激电法在沱沱河地区的应用中,圈定了29处激电异常,综合测区的岩石标本的电物性特征对异常进行了推断和解释.从所测量的视相位和视电阻率结果分析,相位激电法完全能适应沱沱河地区这种气候寒冷、海拔高、地形起伏大的的地区,并能取得良好的找矿效果. 相似文献
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三十多年来，传统的找水方法，多数使用DDC-2系列仪，都是测电位，读电流，计算电阻率，观测主参数是视电阻率，利用观测到的电阻率联剖“正交点”处的异常特征来分析，推断涌水量的大小。若没有发现电阻率“正交点”，则认为没有发现含水构造带，找水参数单一。上述方法在电阻率异常反应明显的地区，找水效果比较好。而在电阻率异常差很小的地区，很难发现电阻率“正交点”的地方，利用电阻法进行找水，给推断解释带来了困难。 相似文献
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三维电阻率概率成像法研究 总被引：1，自引：0，他引：1
电阻率概率成像法是利用地表电场的测量值与电场扫描函数进行归一化的相似程度作为概率的成像方法。根据概率论的基本理论,引入幂函数并推导了电阻率异常发生概率函数。通过数值模型实验对此方法进行了验证,对多个孤立异常体和凹陷模型进行了概率成像。通过对浙江某地实测资料概率成像结果与常规最小二乘法反演结果进行比较表明,三维电阻率概率成像法能较好地分辨地下地电结构。 相似文献
8.
卿志 《国土资源导刊(湖南)》2014,(5):59-61
近年来,＂人造天坑＂吞噬房屋、阻断道路的新闻时常见诸报端。这些＂天坑＂主要是人类对地下资源无节制的开采,留下的大面积采空区塌陷后所形成的,给人们的生产生活带来了极大的灾难。本文叙述了采用瞬变电磁法对某地石膏矿采空区范围圈定的一次应用实例,通过分析多测道剖面图和视电阻率断面图,准确探测出地下采空区位置,结果表明该方法行之有效。 相似文献
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本文给出球体上单极梯度测深装置的ρ_s表达式及理论曲线,讨论了视电阻率异常特征及与各参数之间的关系。通过两个实例,探讨了该方法的应用效果和特点。单极梯度视电阻率测深在等轴状地质体上具有简单的高阻或低阻异常,异常大小和地质体的参数密切相关;在地面障碍物多的地区开展工作,相对对称四极电测深、五极纵轴测深有明显优势;在均匀介质中存在独立等轴状地质体时,单极梯度测深曲线出现单峰值异常;相对于四极测深其勘探深度较小受地表起伏及表层不均匀干扰大。 相似文献
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张秀霞 《大地测量与地球动力学》2016,36(11):977-980
从观测值奇异值、观测值分布及反演模型的先验信息3个方面入手,研究观测值对反演结果的影响。以观测点到微分断层的距离倒数为权,构建顾及观测值权值影响的反演模型。以位错理论为基础,结合遗传算法,对龙门山断裂带进行三维滑动速率反演研究。结果表明,经过奇异值剔除的数据应用于顾及观测值权值的反演模型,给定合理的“先验信息”,其结果比已知观测值直接参与反演模型更稳定、可靠。 相似文献
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As an important geophysical tool,high density electrical technique infers the underground geological structures by processing and inverting the apparent resistivity data.Currently,the false anomalies have been frequently occurred in the graph of apparent resistivity pseudo-section or inverted geoelectrical section obtained from high-density electrical technique,and are difficult to remove.In this study,the authors explain the mechanism of the false anomalies and put forward the horizontal differential field method to identify the false anomalies.Based on the analysis of modeling results,this method is applied in the surveying data in Xinlei Quarry of Jiuquan,and the results confirm the effectiveness of the horizontal differential field method. 相似文献
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Investigation of fractured rock aquifer in South China using electrical resistivity tomography and self-potential methods 总被引：1，自引：0，他引：1
Assessment of fractured rock aquifers in many parts of the world is complicated given their strong heterogeneity. Delineation of the subsurface geological formation in the weathered terrain is essential for groundwater exploration. To achieve this goal, 2D electrical resistivity tomography(ERT) and self-potential(SP) in combination with joint profile method(JPM) and boreholes have been carried out to delineate the subsurface geological units, detect the fracture/fault zones in hard rock, monitor the groundwater flow, and estimate the groundwater reserves contained within the weathered terrain at a complex heterogeneous site of Huangbu, South Guangdong of China. The integration of resistivity images with the borehole lithology along three profiles delineates three subsurface distinct layers namely topsoil cover, weathered and unweathered layers. The incorporation of ERT and SP with JPM reveal five fractures/faults, i.e., F_1, F_2, F_3, F_4 and F_5. 2D ERT models interpret the less resistive anomalies as the fractures/faults zones, and high resistive anomalies as the fresh bedrock. The inversion program based on the smoothness-constraint is used on the resistivity field data to get more realistic three layered model. SP measurements are obtained along the same electrical profiles which provide the negative anomalies clearly indicating the groundwater preferential flow pathways along the fracture/fault zones. Hydraulic parameters namely hydraulic conductivity and transmissivity were determined to estimate the groundwater resources contained within the fractures/faults. The integrated results suggest that the fractures/faults zones are most appropriate places of drilling for groundwater exploration in the investigated area. Geophysical methods coupled with the upfront borehole data provides better understanding about the conceptual model of the subsurface geological formations. The current investigation demonstrates the importance of the integrated geophysical methods as a complementary approach for groundwater assessment in the hard rock weathered areas. 相似文献
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涉密矢量数字地图中敏感要素几何信息的定量测度,是实现定量化密级评定的基础和前提。如何进行敏感要素几何信息量的计算,目前尚缺乏相关研究。在现有地图信息论研究成果的基础上,论文主要开展了3方面的研究工作：首先,从地理对象的敏感性入手,探讨了地图要素敏感性的定义与要素集合的敏感性表征指标;然后,基于任意发生元的Voronoi构建方法,实现了对点要素集、线要素集、部分覆盖面要素集及综合要素集的信息单元自动化剖分;最后,基于长度系数、面积系数和角度系数,提出了线、面要素图形复杂度的计算方法,并在此基础上形成了涉密矢量数字地图中敏感几何信息量的测度方法。实验表明,该方法的计算结果遵循了信息量的非负性、连续性、可加性等特点,较为合理地反映了相关因素（地图比例尺、要素空间分布、要素图形复杂度、要素敏感系数等）对计算结果的影响。相关成果将支持矢量数字地图的定量化密级评定,并有助于完善地理信息安全监管的理论和方法体系。 相似文献
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分析安徽省观测台网12套TJ-Ⅱ型体应变资料发现，其数据形态存在3类典型特征：一是数据连续漂移上升的年变化形态，日变化能记录到明显的固体潮汐；二是数据年变化形态同步于同井水位变化，体应变和水位的相关系数约为0.85；三是数据没有明显的年变化，数据形态多变。结合数据资料的内精度、钻孔环境、安装情况、干扰因素及产出资料显示的图像特征发现，3类典型特征主要和仪器、钻孔环境、安装质量关系密切。 相似文献
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本文介绍了可控源音频大地电磁法和高密度电法在山东省济南市章丘区某建设场地注浆充填效果检测中的应用情况。通过对建设场地内可控源音频大地电磁法和高密度电法在注浆前后电阻率的变化分析,发现注浆前采空区及其影响区域在等值线上呈现出明显的闭合或半闭合状低阻反映,注浆充填后采空区及其影响区域在注浆后视电阻率明显升高,视电阻率闭合、半闭合异常消失,整体表现为平滑、连续。两种方法获取的电阻率等值线图在注浆前后存在明显差异,并且对物探检测推断成果进行了钻探验证,钻探揭露情况与物探推断成果基本吻合。 相似文献
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The Duobaoshan mine area in Heilongjiang is located in the northeast section of Xingmeng orogenic belt and is in the west side of Hegang Mountain-Heihe fault zone .There exist many deposits in this area , and its metallogenic conditions are superior , which has been one of the hotspots in geological prospecting and metal -logenic research in Northeast China .On the basis of previous studies , the authors used the EH-4 electromagnet-ic imaging system to carry out the data acquisition of three survey lines in Woduhe Village , Duobaoshan Town , Nenjiang County .Through the analysis of apparent resistivity section under TE and TM polarization modes , in-tegrating regional geological data , it is concluded that:①the electrical characteristics of the metal ore in this area show a relatively low resistance , and according to its resistivity difference with surrounding rocks , the geo-metrical structures and apparent resistivity parameters of the low resistivity bodies in the lower section of the sur -vey line are defined , and the electrical anomalies can be identified;②faults F1 and F2 may have a good metal-logenic environment , so they are recommended for further exploration;③low resistance metal ore bodies have good correlation with local small structures or faults , which may play an iconic role for the delineation of key target areas;④in the process of using apparent resistivity to define the geometric structures of ore bodies un -derground , comprehensive analysis integrating the advantages of TE and TM models should be carry out to achieve more reliable inversion results . 相似文献
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首先,应用 Venedikow 调和分析方法计算体应变仪观测记录的M2波视潮汐因子;然后,对体应变仪井下传感器观测层岩芯进行单轴压缩试验,根据应力-应变曲线求取岩芯试样的力学参数。对比研究试样的单轴抗压强度和弹性模量与M2波视潮汐因子的关系,结果表明,弹性模量E对M2波视潮汐因子有明显的影响,随着M2波视潮汐因子的增大,岩石弹性模量呈线性函数降低,二者具有很好的相关性。钻孔岩芯力学性质的差异性是造成体应变仪之间M2波视潮汐因子差异较大的主要因素。 相似文献
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References： 《东北亚地学研究》2008,11(1):52-58
In order to investigate the influences of caliper, formation thickness and invaded zone on the form of dual laterologs, forward modeling technique were applied to calculate the dual laterologs for different cases. The result shows that the resistivity logs become smoother and lower as the borehole diameter increases, the increase of the contrast between mud resistivity and formation resistivity induce the logs to be more pointed. When the formation thickness is less than lm, the two-peak on the logs for resistive invasion vanished, and for thickness between 1 m and 4 m, the form of logs does not vary significantly. If the formation thickness is greater than 4 m, a platform appears on the logs at the middle of the formation. The thinner the invaded zone is, the more obvious the invasion feature on the laterologs is. For thick invaded zone the form of logs tend to be that of an uninvaded resistive formation. The form and amplitude of logs depend on the resistivity contrast between invaded zone, uninvaded formation and adjacentlayers. 相似文献