共查询到19条相似文献，搜索用时 203 毫秒
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探地雷达作为一种高精度无损探测新技术，已广泛应用于工程勘察各领域，具有探测速度快、定位准确、轻便灵活、可实现连续透视扫描以及二维彩色图像实时显示等优点。不同的地质条件，探地雷达将表现为不同的波谱特征。文章在分析了探地雷达的分辨率与地层介质、探测深度、天线频率的基础上，例举了其在第四系地质、活动断裂、滑坡、土体性质等不同地质条件下的探测效果。 相似文献
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地质雷达在隧道检测中的应用 总被引：3，自引：0，他引：3
隧道施工完成后用常规方法很难对衬砌质量做出系统评价，地质雷达利用超高频脉冲电磁波探测目标介质的介电常数，很容易掌握砼衬砌结构的厚度、衬砌周围回填及空隙情况，围岩断层裂隙构造情况等，为工程技术评价提供依据。文章以实例，介绍了利用地质雷达对隧道进行检测所使用的仪器、工作参数及地质雷达资料处理解释步骤，并通过对几幅典型雷达图像进行分析介绍了不同异常结构在雷达剖面上的反映。 相似文献
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地质雷达探测以其分辨率高、定位准确、快速经济、灵活方便、剖面直观、实时图像显示等优点,成为地质调查中广泛使用的一种探测方法。本次宁夏青铜峡地区1∶5万新构造与活动构造区填图中运用地质雷达探测技术对第四系和隐伏断层进行了探测。结果表明,40 MHz地质雷达可以有效地探测地表以下30 m内的第四系结构,可清晰地识别出3套第四纪地层。这一地层结构划分被第四系浅钻证实,其为第四系全新统灵武组,自下而上由泥岩、砂砾石层和含砾的砂或泥等3套地层组成。对测区主干断裂——柳木高断裂南段的地质雷达探测表明,断裂带表现为近地表发散向下汇聚的正花状结构,这与探槽揭露的特征一致,表明地质雷达探测可以准确标定隐伏断层平面位置与垂向精细结构。本次宁夏地质填图证实,地质雷达技术是浅覆盖活动构造区进行隐伏断裂调查和第四纪地层层序划分的可行、高效、便捷的技术方法之一。 相似文献
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煤层电性参数的测试和研究 总被引：5，自引：0，他引：5
无线电波透视和地质雷达等探测成果的好坏在很大程度上取决于对煤层电性参数事先了解的程度,而影响电性参数的因素很多,测试手段又无统一方法可循。本文从实验室测试、现场实测和电测井资料的收集分析等方面,对分布于全国80个矿井,100多个煤层的325个煤样的电性参数进行了统计,并研究了煤质、湿度、温度、测试频率对电性参数的影响及各向异性问题。指出与电磁法勘探最密切的电性参数是煤层电阻率和相对介电常数。 相似文献
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复杂山区近地表调查技术是制约地震资料品质的主要因素。这里利用地质雷达和高密度电法相配合,在四川南江山区进行了近地表结构综合调查。地质雷达探测精度高,高密度电法探测深度大且能有效补充介质电性信息。通过微测井数据进行标定,建立了近地表结构的深度和速度模型,为地震静校正提供了依据。经研究结果表明,采用近地表调查数据进行静校正的地震品质得到了提高。 相似文献
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结合上林湖区域水体电性参数测量结果,开展了探地雷达水下考古试验探索。在上林湖指定水域用机动木船承载雷达仪器和工作人员进行了水下情况调查,通过对比试验,分析了频率为100 MHz、200 MHz、400 MHz的雷达天线对不同深度水域及水底地层的反射特征,在此基础上,对探地雷达数据进行处理及解释。探地雷达探测结果清楚地显示了古水坝、窑炉遗址、陶瓷废墟、古河道和码头堤岸等多种不同的水下考古目标,并可对湖底地层中的局部隐伏异常实现高精度成像。经过潜水探摸,进一步核实了本次探地雷达的调查结果。 相似文献
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《物探化探计算技术》2016,(1)
探地雷达勘探是一种分辨率比较高的工程地球物理方法,对道路路基中存在的局部脱空、不密实和含水丰富等病害有明显的异常反应。这里介绍了地质雷达在路基中的探测原理,在分析不良地质现象与围岩之间的结构和介电性差异特征的基础上,设计了较为合理的正演模型,通过GPRMax2D软件进行正演模拟,分析正演模拟图像的波形、频率、振幅、相位等特征,总结了路基病害在雷达图像上的信号特征,并通过对实测雷达图像的解译,对道路病害的雷达反射波的频谱特征做了进一步研究,可为道路路基病害探测的地质雷达数据解译提供参考。 相似文献
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采用探地雷达进行岩溶隧道超前地质预报时,受现场探测环境、岩溶地质的复杂性以及解译技术制约,多解性问题一直未能得到很好解决。从依托工程中选取代表性的案例,分析总结隧道建设中常见的几种典型岩溶不良地质的属性特征,结果表明岩溶不良地质类型与探地雷达属性参数有很好相关性,其中:空腔型溶洞、干燥松散黏土夹碎石充填型溶洞和无水破碎带雷达反射波中心频率随时间衰减较慢,分布范围分别为90~105、85~100、70~110MHz;软塑状黏土充填型溶洞和富水破碎带雷达反射波中心频率随时间衰减较快,分布范围分别为60~80MHz和40~70MHz。研究属性特征定量表示方法,提出基于广义S变换及子波谱模拟的雷达波吸收衰减参数计算方法。实际数据分析结果表明:每种属性都能从某些角度反映岩溶不良地质体雷达反射波的特征,在综合多个特征参数后,可以较好地区分不同的岩溶不良地质类型,从而提高探地雷达目标识别精度。 相似文献
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应用RAMAC系列探地雷达进行了地下管线探测的研究。基于对城市地下管线周围介质环境的分析，设计了不同的探地雷达的工作参数，对不同类型的地下管线进行了探测，并就典型的管线异常特征进行了分析。 相似文献
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Sattam Almadani Elkhedr Ibrahim Mahfooz Hafez Hussain Alfaifi Talal Alharbi Kamal Abdelrahman Essam Abdel-Motaal 《Arabian Journal of Geosciences》2018,11(2):33
In the present study, the existence of cavities, voids, and fractures was verified at the site of the El-Elb Dam, which is located to the northwest of Riyadh City across Wadi Hanifa, using 2D electrical resistivity tomography (ERT) and ground-penetrating radar (GPR) techniques. For this purpose, four ERT profiles were measured on the downstream side of the El-Elb Dam using the Syscal Pro Switch-72 resistivity meter. In addition, a GPR survey using a 400-MHz antenna and a SIR-3000 instrument was conducted along five profiles above the stilling basins on the downstream side of the dam and one radar profile was measured outside the stilling basins area across the course of the wadi. The resultant geophysical data were interpreted with the aid of information from a field-based structural and stratigraphic evaluation of the outcropped bedrock on the banks of the wadi course. The analysis of the inverted ERT and filtered radar sections revealed several resistivity and electromagnetic reflection anomalies that are identified laterally and vertically across the measured sections. These anomalies indicate the presence of fractures and karst features affected the limestone bedrock in the dam site. These near-surface karstified and fractured strata represent a critical hazard to the structural safety of the dam. 相似文献
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利用改进的时域有限差分算法,对不同物理和几何参数条件下各种滑坡要素组成的综合模型进行数值模拟,研究滑带厚度、滑带充填介质、滑体岩土类型、滑坡裂缝等的地质雷达探测响应效果。研究结果表明,具有各自物理和几何参数的滑坡要素与地质雷达响应特征之间存在一一对应的数学关联,通过这种关联可以从野外实测数据中有效提取和判读滑坡要素的类型及物理几何特性,为滑坡稳定性评价提供地球物理依据。为了展示该研究成果的适用性,以三峡库区将军滩滑坡的地质雷达野外实测数据为例进行解释推断,成功识别出滑坡体的滑带埋深及分布、滑体的裂缝发育程度等情况,为评价滑坡稳定性,合理优化滑坡治理方案提供了科学参考。 相似文献
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Mansour S. Alhumimidi Hussein M. Harbi Mohammed S. Alfarhan Kamal Abdelrahman Carlos L.V. Aiken 《Arabian Journal of Geosciences》2017,10(14):306
Khuff Formation is of utmost importance in Saudi Arabia for oil and gas reservoir although it is composed mainly of limestone. This reason refers to the existence of intensive fractures which play a vital role in the increase in porosity and permeability of this formation. The fracture pattern in the study area was verified through 2D and 3D ground penetrating radar (GPR)-defined and electrical resistivity tomography (ERT)-defined surveys. In this respect, ten of 2D GPR surveys were collected along an intersected grid of profiles covering the study area while ERT data were collected along three profiles of the GPR grid. The results were interpreted in light of the field-based structural and stratigraphic assessment of the outcropping rocks. The analysis of the inverted ERT and filtered GPR sections revealed the presence of fractures. Several resistivity and electromagnetic reflection anomalies were laterally and vertically identified across the measured sections clarifying fractures that extend to a depth of 24 m in the limestone. Most fractures are oriented vertical to sub-vertical dipping both east-west and north-south. 相似文献
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湘黔桂相邻区发育一套序列完整、界面清楚的武陵造山运动不整合面之上至震旦纪(820~635 Ma)时期的裂谷盆地沉积地层。通过详细的区域岩石地层划分与对比,结合年代学研究成果,显示其时空展布格局完整,充填序列连续,划分标志清楚,完全可以划分对比。在此基础上建立了其地层格架,为扬子古大陆周缘新元古代820~635 Ma时期地层划分对比研究提供了详实的资料,亦为中国前寒武系新元古代地层划分对比及国际新元古代研究提供了新的资料成果。 相似文献
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ZHAI Shen-de LI Yun-xin ZHOU Yu-jie MA Guang-qiang PENG Yan Geological Logging Company of Shengli Oilfield Company SINOPEC Dongying 《地层学杂志》2007,(Z2)
对孤北洼陷孔店组、沙四段生物、岩石、电性及地震地层等多重地层划分进行详细的研究,研究结果表明孔三段属灰紫色冲积产物,孔二段发育典型的暗色泥岩,沙四下亚段为红色砂、泥岩,沙四上亚段主要是灰色泥岩,夹有砂岩;电测结果表明:进入沙四下亚段时电阻率曲线相应抬起,沙四上亚段整体是一个低阻段,沙四段顶界划在下斜坡电阻的底部。孤北洼陷地层划分时要注重多重地层划分的方法,单一资料用于划分地层难于反映真实面貌。 相似文献
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Three-dimensional mapping of a landslide using a multi-geophysical approach: the Quesnel Forks landslide 总被引：7，自引：3，他引：4
A landslide located on the Quesnel River in British Columbia, Canada is used as a case study to demonstrate the utility of a multi-geophysical approach to subsurface mapping of unstable slopes. Ground penetrating radar (GPR), direct current (DC) resistivity and seismic reflection and refraction surveys were conducted over the landslide and adjacent terrain. Geophysical data were interpreted based on stratigraphic and geomorphologic observations, including the use of digital terrain models (DTMs), and then integrated into a 3-dimensional model. GPR surveys yielded high-resolution data that were correlated with stratigraphic units to a maximum depth of 25 m. DC electrical resistivity offered limited data on specific units but was effective for resolving stratigraphic relationships between units to a maximum depth of 40 m. Seismic surveys were primarily used to obtain unit boundaries up to a depth of >80 m. Surfaces of rupture and separation were successfully identified by GPR and DC electrical resistivity techniques. 相似文献
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The Fanta Stream site is an archaeological and paleontological locality in Addis Ababa, Ethiopia. The site contains a rich assemblage of fossil mammals and Acheulean artifacts of approximately 600 ka located in a rare high‐altitude context. A ground‐penetrating radar (GPR) survey was conducted in order to provide three‐dimensional imaging of the subsurface, which the authors use to interpret the geometry and distribution of fossil‐containing stratigraphic units. Utilizing the stream's natural cut bank exposure, we calibrate GPR data to known geologic units through radar facies analysis. Shallow, high‐amplitude coherent reflection geometries are attributed to volcanic tuff deposits, as these units exhibit subparallel continuous reflections consistent with planar stratified sedimentary deposition. Deeper, discontinuous reflection packages are interpreted as conglomeritic, fossil‐containing deposits. The results of the GPR survey outline the location of the Fanta Stream's paleodepositional features as well as suggest the extent of fossiliferous stratigraphic units for use in future excavations. 相似文献
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Marcelo Accioly Teixeira de Oliveira Jorge Luis Porsani Gisele Leite de Lima Vivian Jeske-Pieruschka Hermann Behling 《Quaternary Research》2012,77(3):397-407
Paleoenvironmental interpretation of proxy data derived from peatlands is largely based upon an evolutionary model for ombrotrophic bogs, in which peat accumulates in still environments. Reports on proxies obtained from minerotrophic fens, where hydrologic inputs are variable, are less common. In this study, a highland peatland in southern Brazil is presented through ground penetrating radar (GPR) and sedimentological, palynological and geochronologic data. The radar stratigraphic interpretation suggests a relatively complex history of erosion and deposition at the site since the beginning of Marine Isotope Stage 3 (MIS 3) interstadial period. In spite of this, radar stratigraphic and palynologic interpretations converge. Electromagnetic reflections tend to group in clusters that show lateral coherence and correlate with different sediment types, while pollen grains abound and are well preserved. As a result, the study of minerotrophic fens provides a source of proxies, suggesting that ombrotrophic bogs are not the only reliable source of data in wetlands for palynological analysis. 相似文献