• 지구물리와물리탐사
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• 제27권1호
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• pp.69-83
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• 2024

사용후핵연료 심층처분 부지조사는 그 중요성과 특수성을 고려할 때, 터널, 교량 등과 같은 일반적인 지반조사와는 달리 높은 수준의 품질관리가 요구된다. 본 논문에서는 단계별 부지조사에 적용할 물리탐사 기법을 선정하고, 탐사방법별 물리탐사 수행지침서를 작성한 사례를 소개하고자 한다. 물리탐사 수행지침서는 탐사계획, 자료획득, 자료처리 및 해석의 수행 절차와 고려사항 및 품질관리에 대한 내용이 포함되어 있으며, 이 중 항공전자탐사와 탄성파 반사법탐사 내용을 간략히 정리하였다.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2008년도 공동학술대회
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• pp.113-118
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• 2008

Among the geophysical methods, Ground Penetrating Radar (GPR) and Electrical Resistivity Tomography (ERT) comprise the most promising techniques in resolving buried archaeological structures in urban territories. In this work, two case studies which involve an integrated geophysical survey employing the surface three dimensional (3D) ERT and GPR techniques, in order to archaeologically characterize the investigated areas, are presented. Totally more than 4000 square meters were investigated from the test field sites, which are located at the centre of two of the most populated cities of the island of Crete, in Greece. The ERT and the GPR data were collected along dense and parallel profiles. The subsurface resistivity structure was reconstructed by processing the apparent resistivity data with a 3D inversion algorithm. The GPR sections were processed with a systematic way applying specific filters to the data in order to enhance their information context. Finally, horizontal depth slices representing the 3D variation of the physical properties were created and the geophysical anomalies were interpreted in terms of possible archaeological structures. The subsequent excavations in one of the sites verified the geophysical results, enhancing the applicability of ERT and GPR techniques in the archaeological exploration of urban territories.

• 산업기술연구
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• 제27권B호
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• pp.115-119
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• 2007

Currently, geophysical method is applied for understanding the subsurface geologic structure economically and systematically, but there exists some limitations on recognizing complex subsurface structures precisely by a single geophysical method. In order to understand the complex subsurface structures, we applied various geophysical methods including seismic refraction survey, two-dimensional resistivity survey, seismic tomography survey, suspension-ps log, and understood distribution of low velocity, low resistivity range of resistivity survey and correlation of an intersecting point, velocity distribution of seismic tomography survey.

• 한국지구과학회지
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• 제26권5호
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• pp.429-435
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• 2005

물리탐사와 시추자료에 대해 지구통계학적 복합해석 기술을 적용하여 3차원의 암반등급 해석을 수행하였다. 자료 복합 해석을 위한 다양한 지구통계학적 기술 중에서, 본 연구에서는 물리탐사 자료의 값을 추정하고자 하는 지점의 암반등급의 평균치로 치환하는 국소 변이 평균에 의한 단순 크리깅 기술(Simple Kriging with local varying means)을 사용하였다. 암석의 전기비저항 값은 RMR(Rock Mass Rating)값과 양의 상관관계를 갖는 것으로 알려져 있으나 상관 관계 만에 의한 대응방식은 그 양상이 매우 복잡하고 공간적으로 연관되어 있는 경우가 많아 단순히 적용하기 어려운 경우가 많다. 본 연구에서는 전기비저항과 RMR의 일반적 선형 상관관계 외에 지시자 변환(indicator transform)에 의한 비선형 상관관계를 유도하는 방식을 제안하였다. 또한 본 연구에서는 선형 및 비선형 상관관계에 의해 대응된 비저항 값이 실제 RMR과 비교할 때 나타나는 잔차(residual)에 대해 3차원 지구통계학적 분석을 적용하여 이 결과를 상관관계 결과에 추가함으로써 공간적 특성을 반영하는 RMR 평가를 수행할 수 있었다. 사용된 물리탐사 자료는 전기비저항 및 MT(Magnetotelluric) 탐사 자료이며, 총 10공의 시추자료를 통해 획득한 암반등급 값을 이용하였다. 이와 같은 해석은 조사 대상에 대한 광역적 지질조건을 보다 현실적으로 반영하는 암반등급 분포를 만들어내는 것으로 보인다.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 1999년도 제2회 학술발표회
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• pp.156-175
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• 1999

물리검층은 최근에 토목지반조사분야에 대한 활용성이 증가하고 있다. 이것은 물리 검층이 시추공 내에서 분해능 높은 다양한 원위치 물성정보를 제공할 수 있는 장점이 있기 때문이다. 현재 토목지반조사분야에서 적용되고 있는 것은 주로 암상구분, 파쇄대 인식과 동탄성계수의 산출, 지하수흐름검층 등이다. 이와 관련하여 최근에 활용성이 증가하는 물리검층법에 대한 소개와 지반조사와 관련한 물리검층 사례, 그리고 완전파형음파검층에 의한 탄성파 속도와 암반분류와 관계에 대한 사례를 소개한다.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2003년도 Proceedings of the international symposium on the fusion technology
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• pp.340-343
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• 2003

This study presents a practical procedure for the Bayesian inversion of geophysical data by Markov chain Monte Carlo (MCMC) sampling and geostatistics. We have applied geostatistical techniques for the acquisition of prior model information, and then the MCMC method was adopted to infer the characteristics of the marginal distributions of model parameters. For the Bayesian inversion of dipole-dipole array resistivity data, we have used the indicator kriging and simulation techniques to generate cumulative density functions from Schlumberger array resistivity data and well logging data, and obtained prior information by cokriging and simulations from covariogram models. The indicator approach makes it possible to incorporate non-parametric information into the probabilistic density function. We have also adopted the MCMC approach, based on Gibbs sampling, to examine the characteristics of a posteriori probability density function and the marginal distribution of each parameter. This approach provides an effective way to treat Bayesian inversion of geophysical data and reduce the non-uniqueness by incorporating various prior information.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2000년도 추계학술대회
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• pp.103-106
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• 2000

Geophysical data sets from the Chojeong area in the Chungbuk-Do are compositely studied in terms of multi-attribute interpretation for the subsurface mapping of shallow fracture zones, associated with groundwater reservoir. Utilizing a GIS software, the attribute data are implemented to a database; a lineament from the satellite image, electrical resistivities and its standard deviation, radioactivity, seismic velocity, bedrock depth from exploration data. In an attempt to interpret 1-D electrical sounding data in 2-D and 3-D views, 2-D resistivities structures are firstly made by interpolating 1-D plots. Reconstruction of a resistivity volume is found to be an effective scheme for subsurface mapping of shallow fracture zones. Shallow fracture zones in the southeastern part of the study area are commonly correlated in the various exploration data.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2007년도 공동학술대회 논문집
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• pp.48-53
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• 2007

A new way to integrate various geophysical information for evaluation of RQD was developed. In this study, we did not directly define the RQD value where borehole data are not sampled. Instead, we infer the probability of RQD values with prior probability from borehole direct data, and secondary supporting probability from resistivity and seismic tomography data. For the integration, we applied the geostatstical indicator kriging to get prior probability of RQD value, and indicator kriging with soft data to get the supporting probability from resistivity and seismic data. And we finally use the permanence ratio rule to integrate these information. The finally obtained result was also analyzed to fully utilize the probabilistic features. We show the probability of wrongly classifying the RQD evaluation and vice versa. This result may be used for decision making process based on the geophysical exploration.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 임시총회 및 추계학술발표회
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• pp.373-376
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• 2004

To investigate the vertical petrological and hydrological characteristics of fractured rock, geophysical and chemical logging were executed at 5 boreholes installed in the study area. The geophysical and hydrochemical logging data were analysed by using principal components analysis (PCA). Three main variables from PCA explained 86.4% of total variance of geophysical log data. The PCA results showed that PCl is closely related to groundwater properties and PC2 and PC3 are influenced by rock and fracture properties. Hydrochemical analysis indicated the presence of highly fractrued zone at the depth of 60m.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2003년도 Proceedings of the international symposium on the fusion technology
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• pp.455-458
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• 2003

A combination of drilling, hydrogeochemical survey, geophysical survey and the numerical modelling for the flow and transport of groundwater was performed to evaluate the seawater intrusion in Baeksu-eup, Yeonggwang-gun, Korea. The survey area extends to over 24 $km^2$. Twelve wells were also drilled for the collection of geologic, geochemical, hydrologic, and geophysical logging data to delineate the degree and vertical extent of seawater intrusion. To evaluate and map the salinity in a coastal aquifer, geophysical data and hydrogeochemical results were used. Layer parameters derived from VES data, various in situ physical properties from geophysical well loggings, and the estimated equivalent NaCl concentration were used as the useful input parameters for the numerical simulation with density-dependent flow. Our multidisciplinary approach for evaluating the seawater intrusion can be considered as a valuable attempt to enhancing the utilization of various data and the reliability of numerical ground modelling.