• 자원환경지질
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• 제11권4호
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• pp.169-182
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• 1978

The Weolagsan area consists of four units; (1) Low grade meta-sediments of the upper members of Ogcheon age unknown group such as Changri (mainly black slate and phyllitic rock), Majeonri (mainly alternation of slate, limestone and chert) and Hwanggangri Formation (pebble bearing phyllitic sediments); (2) Samtaesan Formation of Chosun System of Ordovician; (3) So called meta-volcanics and (4) Weolagsan Granite and its associations which intruded above mentioned meta-sediments and meta-volcanics. This study was focused to know the Woelagsan granite and its metasomatic effects to the country rocks petrographically and petrochemically. According to the field survey, microscopic work and some chemical analysis, the granite is a "normal granite" based on the Streckeisen's classification and belongs to a mass of the Central-zone younger group in Ogcheon geosynclinal belt. The granite metasomatized the country rocks along its northern contact zone. Zone of calcareous and cherty rocks (Majeonri formation) was silicified partly and skarned locally at the contact with the granite. The chemical analysis of the zone show no difinite variations in contents of $SiO_2$ and CaO with the distance from the granite. It seems to be indicated that the silicification of this part was not so metasomatized by the granite body, but thermally affected as much as to be partially remelted in the specific parts of the formations. Meta-volcanic rock zone was slightly chloritized near contact with the granite. Limestone of Samtaesan Formation was silicified and skarned along the contact zone by the granite body. The chemical analysis of the zone show some noticiable changes in compositions of $SiO_2$ and CaO with distance from the granite boundary. It can be imagined that the silicification of this zone was metasomatically originated by Woelagsan Granite. According to chemical analysis on several trace elements, the ratio of Zn/Cr and Ni/Cr are relatively higher than that of Cu/Cr in the above mentioned silicified zones. Generally the variation of these metal elements in the zones tend to be regular with distance from the granite body.

• 한국지역지리학회지
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• 제19권4호
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• pp.737-746
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• 2013

본 연구는 광릉 숲지역 지형을 유형화하여 산지 지형변화 관리 방안을 제시하고자 하였다. 지형요소는 축척별 계층적 체계에 따라 분류하였다. 지형유형화를 위한 축척은 4가지로 등급을 결정하였다. 등급0 요소는 4가지, 등급1은 6가지, 등급2는 12가지, 등급3은 27가지로 지형요소를 분류할 수 있었다. 지도화에 제약이 따르는 곡저미지형은 상부곡, 중간곡, 인공하도곡으로 분류하였다. 지표침식에 대한 지형관리 방안으로 저목통로, 암석과 자갈을 이용한 사면이나 다리 주변의 지형관리, 풍화층보다 안정된 기반암 지역에 관리 도로 건설, 하도벽 안식각 유지와 석축 쌓기, 마지막으로 산림 간벌시 완충구역 유지 등을 제안하였다. 본 연구결과는 산간지역 지형유형별 산림 관리에 필요한 정보를 제공해 줄 수 있을 것으로 본다.

• 지질공학
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• 제19권1호
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• pp.43-50
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• 2009

터널 굴착 중 지반에 존재하는 연약대의 방향 특성에 따른 거동 및 응력 분포 특성을 3차원 수치해석을 이용하여 정량적으로 평가하였다. 수치모델에서 연약대의 방향은 RMR의 취약 불연속면에 대한 보정인자를 기준으로 설정되었으며, 위치는 각 방향 조건에 대하여 연약대가 천단부 상부 1D, 천단부, 막장 중앙부를 지나는 경우로 설정되었다. 지반정수는 현장 계측변위를 기반으로 하는 역해석을 통해 산정하였다. 최종적으로 터널 천단부에서 발생하는 변위의 크기를 기반으로 연약대 방향 및 위치 조건에 따른 영향도를 평가하여 5등급으로 분류하였다.

• 대한지하수환경학회지
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• 제4권1호
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• pp.27-40
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• 1997

화강암과 석회암으로 구성된 동해 터널굴착지 역 주변에 대한 수리지구화학적 연구를 수행한 결과, 채수한 자연수 시료는 그 화학적 특성에 따라 화강암 지역의 물(그룹 1)과 석회암 지역의 물(그룹 2)로 구분 가능하였다. 이러한 구분은 군집분석을 통하여 통계적으로 확인되며, 동일 지점에서 채수된 터널용출수는 채수시기에 따라 각각 그룹 1 및 2에 속하는 것으로 나타났다. 요인분석 결과 그룹 1은 사장석이 카올리나이트로 풍화되는 반응, 그룹 2는 방해석의 용해 반응에 의하여 각각의 화학적 특성이 결정된다. 터널용출수가 시기에 따라 상이한 특징을 보이는 이유는 두 차례의 채수시기 도중에 수행된 화강암 지역의 누수대에 대한 방수작업이 효과적으로 작용하여 지하수 유동체계를 변화시켰기 때문으로 판단된다. 한편 역학적 조사 결과 터널용출수는 다른 자연수 시료에 비하여 대수층의 조암광물과 상호 반응을 더욱 많이 거친 것으로 보인다. 질량평형에 기초한 계산을 통하여 터널용출수에 대한 두 그룹 물의 혼합율 및 물-암석반응이 정량적으로 도출되었으며 이 결과는 통계적 및 열역학적 조사 결과와 잘 일치한다.

• 환경영향평가
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• 제16권2호
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• pp.143-156
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• 2007

This study has researched the management status and the pollution level of water, soil, stream sediments of 11 abandoned coal mines out of a total of 12 within Obong-Dam area except Bukyung mine, which was submerged when constructing Obong-Dam, and selected areas which are in needs to have pollution control facilities in the first place. From the results of examination on the runoff at the waste rock pile and mineheads, the runoff from Sueun mine (pH, Fe, Al), Samwon mine (pH, Al), Wangdo mine (pH, Al), Mose mine (pH, Fe, Al) and Daeryeong mine (pH) exceeded the permissible discharge standards of the water quality, but the water at merging point with Obong-Dam after joined with Doma branch satisfied both Water Quality Standards and Drinking Water Quality Standards. In regard to groundwater contamination, it is found that areas where exceeded the Drinking Water Quality Standards are Wangdo mine (pH), Jangjae mine (pH, Zn), Daeryeong mine (pH) whereas all areas satisfied Soil Contamination Warning Standards of Soil Environmental Conservation Law. When comparing a research result on underwater sediments of branches of abandoned mines to the EPA Guidelines for classification of great lakes harbor sediments, Dongguk Gaerim (Fe), Jungwon mine (Fe), Daebo mine (Mn), Samwon mine (Mn) and Daeryeong mine (Mn) showed mid-level of contamination, whereas Sueun (Fe, Mn), Daebo mine (Fe), Woosung mine (Fe, Mn), Wangdo mine (Fe, Mn), Mose mine (Fe) and Daeryeong mine (Fe) showed high-level of contamination. In addition, contamination levels of underwater sediments in Wangsan and Doma branch where abandoned mine's branches merge together, Wangsan branch showed no contamination at all whereas Doma branch shows mid-level of contamination which reflect the Doma branch is affected by waste rock pile and minehead runoff of the abandoned mines in the Doma branch area. It is concluded that Mose mine and Sueun mine required treatment of acid mine drainage. and Wangdo, Jungwon, and Samwon mines were in need of mine tailing and erosion control work. The Samwon mine additionally required a control system for closed minehead runoff. Although the Samwon mine reached a high concentration of Al, Mn $Ca^{2+}$, $SO{_4}^{2-}$ in the runoff, the levels decreased after it was combined with a tributary. It has been concluded that after further monitoring of the cause of pollution, a preventive measure system may be needed to be built.

• 한국환경복원기술학회지
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• 제9권2호
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• pp.81-89
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• 2006

The purpose of this study was to evaluate the applicability of small RC(radio controlled) helicopter and single lens reflect camera as SFAP(Small Format Aerial Photography) aquisition system to monitor the vegetation coverage of wetland. The system used to take pictures of small artificial wetland were a common optical camera(Nikon F80 with manual lens whose focal length was 28mm) attached to the bottom of a RC helicopter with a 50 cubic inch size glow engine. Three hundreds pictures were taken at the altitude of 50m above the ground, from 23rd June to 7th September 2005. Four from the images were selected and scanned to digital images whose dimension were 2048${\times}$1357 pixels. Those images were processed and rectified with GCP(Ground Control Poins) and digital map, and then classified by the supervised- classification module of image processing program PG-steamer Version 2.2. The major findings were as follows ; 1. The final images processed had very high spatial resolution so that the objects bigger than 30mm like lotus(Nelumbo nucifera), rock and deck were easily identified. 2. The dominant plants of the monitoring site were Monochoria ragianlis, Typha latifolia, Beckmannia syzigachne etc. Because those species have narrow and long leaves and form irregular biomass, the individuals were hardly identifiable, but the distribution of population were easily identifiable depending on the color difference. 3. The area covered by vegetation was rapidly increased during the first month of monitoring. At the beginning of the monitoring 23th June 2005, The rate of area covered by vegetation were only 34%, but after 27 and 60 days it increased to 74%, and the 86% respectively.

• 한국토양비료학회지
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• 제39권5호
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• pp.245-252
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• 2006

우리나라 토양의 분류체계를 보완하고 점토광물 조성과 분포를 파악하기 위하여 우리나라 390개 토양통 중 잔적 및 붕적토에서 유래된 26개 토양통을 대상으로 토양 층위별료 시료를 채취하여 집적층을(B층) 토양의 이화학적 특성, 토양 중 점토의 광물조성과 화학성분을 분석하였다. 잔적 및 붕적모재별로는 화강암과 화강편마암, 회장암에서 유래된 토양에서 kaolin과 quartz, 유문암, 3기층, 석영반암, 응회암에서 유래된 토양에서 quartz과 kaolin, 석회암, 혈암, 사암, 역암 등 퇴적암에서 유래된 토양에서 illite와 chlorite가 주요한 점토광물이었다. 토양통별 점토광물조성을 군집분석 (CA, cluster analysis)을 통하여 (1) illite, kaolin, vemiculite를 주광물로 하는 혼합점토광물군 (MIX), (2) kaolin을 주광물로 illite가 많은 kaolin군 (KA), (3) chlorite와 illite가 주광물인 chlorite군 (CH), (4) kaolin과 illite를 주광물로 smectite가 함유된 smectite군 (SM) 등 4개의 점토광물 조성군으로 구분하였다. 우리나라 토양의 대부분은 kaolin을 주광물로 하는 토양과 illite, kaolin, vemiculite가 함유된 토양이었으며, illite와 kaolin을 주광물로 하는 토양에서 CEC가 낮았고 vemiculite와 smectite가 함유된 점토에서 규반비가 높았다.

• 한국광물학회지
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• 제24권1호
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• pp.31-36
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• 2011

운석은 모암인 소행성(asteroid)이나 미세소행성(planetesimal)에서 충돌에 의해 분리된 후, 태양계 내의 공간을 배회하다가 지구의 중력에 이끌려 지표에 떨어진 후 수집된 돌덩이다. 따라서 생성 초기의 지구를 포함하는 태양계 내 지구형 행성의 생성 초기와 진화과정을 규명하려면 원시 태양계의 정보를 간직하고 있는 운석의 물리/화학적 분석이 반드시 필요하다. 특히 열잔류자화(thermoremanent magnetization, TRM) 대비 포화등온잔류자화(saturation isothermal remanent magnetization, SIRM)의 비율과 자화를 유도하는 자기장 강도의 상관관계를 이용하면 운석이 함유하는 자성광물을 판별할 수 있다. TRM/SIRM 비를 이용하여 2종류의 미분화운석(H5 Richardton, LL6 St. Severin)과 2종류의 화성기원 분화운석(ALH84001, DaG476)에 대해 자성광물 판별을 시도하였다. 실험 결과 H5 Richardton, LL6 St. Severin, ALH84001, DaG476의 주 자성광물이 각각 카마사이트, 테트라테나이트, 자철석, 크롬티탄함유철석임을 판별하였다.

• Geomechanics and Engineering
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• 제3권3호
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• pp.189-206
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• 2011

Amplification based on empirical relations is widely used for seismic microzonation of urban centers. Amplifications are used to represent the site effects of a particular soil column. Many empirical correlations are available to estimate the amplification of seismic waves. These correlations are based on the ratio of shear wave velocity of foundation/rock to soil velocity or 30 m equivalent shear wave velocity ($Vs^{30}$) and are developed considering deep soil data. The aim of this work is to examine the applicability of available amplification relations in the literature for shallow engineering bedrock sites by carrying out site response studies. Shear wave velocity of thirteen sites having shallow engineering bedrock have been selected for the study. In these locations, the depth of engineering bedrock (> 760 ${\pm}$ 60 m/s) is matched with the drilled bore hole. Shear wave velocity (SWV) has been measured using Multichannel Analysis of Surface Wave survey. These sites are classified according to the National Earthquake Hazards Reduction Program (NEHRP) classification system. Amplifications for an earthquake are arrived for these sites using empirical relations and measured SWV data. Site response analysis has been carried out in SHAKE using SWV and using synthetic and real earthquake data. Amplification from site response analysis and empirical relations are compared. Study shows that the amplification arrived using empirical relations does not match with the site response amplification. Site response amplification is much more than empirical values for same shear wave velocity.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2003년도 Proceedings of the international symposium on the fusion technology
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• pp.410-415
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• 2003

Ground subsidence has occurred in the downtown of Muan-eup in Korea. Integrated geophysical survey, including two-dimensional resistivity, CSMT(Controlled source magnetotelluric), magnetic, borehole logging, GPR and resistivity tomography, has been conducted to investigate the cause of subsidence and ground conditions. Since the target area is in the city downtown, there were no spaces for surface geophysical methods. To get regional geology and to facilitate the detailed geophysical interpretation in the survey area, two-dimensional resistivity, CSMT and magnetic surveys have been applied in the outer region of the downtown. From these results, we could accurately define the Gwangju fault system and estimate the geologic conditions in the downtown. For the detailed survey of the downtown area, resistivity tomography and borehole logging data have been acquired using a few tens of densely located boreholes. Among these survey results, borehole logging data provided the guide to classification of the rock type and we could define the geologic boundary of granite and limestone formations. From the resistivity tomograms of 42 sections, which are densely located enough to be interpreted in a three-dimensional manner, we could delineate the possible weak zones or cavities in the limestone formations. In particular, resistivity tomograms in the subsided area showed the real image of ground subsidence. The map of hazardous zone has been derived from the joint interpretation of these survey results and we could provide the possible reinforcement strategy in this area.