• 지질공학
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• 제19권4호
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• pp.493-499
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• 2009

우리나라는 암석자원이 풍부하기 때문에 콘크리트표면 차수벽형 석괴댐(CFRD)의 시공이 증가하고 있는 실정이다. 콘크리트표면 차수벽형 석괴댐에서의 표층부 기초지반인 Bedding Zone 구간은 콘크리트 차수벽을 균등하게 지지할 수 있는 지지력과 콘크리트 차수벽의 누수시 세립토의 유실을 억제할 수 있는 차수성을 유지하여야 한다. 따라서 Bedding Zone 구간의 차수성 확보 여부가 댐의 안정성을 좌우하는 주요 요인이 될 수 있다. 본 연구에서는 기존의 시방서에 제시된 Zone-1 구간의 설계입도분포를 만족하는 시험재료를 선정한 후, 차수성을 평가하기 위하여 실내시험을 실시하였다. 시험 분석 결과 투수계수, 건조단위중량 및 흙의 입도분포에 따른 차수효과의 상관관계를 제시하였다. 특히, 투수계수와 건조단위중량의 상관관계, No. 4체 중량통과백분율과 투수계수 관계가 제시되었고, 또한 시간경과에 따른 투수계수의 변화도 제시되었다.

• 한국지반신소재학회논문집
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• 제6권2호
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• pp.9-15
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• 2007

콘크리트 표면 차수벽형 석괴댐(CRFD)에서의 표층부기초지반은 콘크리트 차수벽을 균등하게 지지할 수 있는 지지력과 사면안정을 위한 소요강도를 확보하여야 하며, 콘크리트 차수벽의 누수시 세립토의 유실을 억제할 수 있는 차수성을 유지하여야 한다. 본 연구에서는 사면부 표층기초지반에 대하여 시험시공을 실시하여 다짐회수에 대한 제체의 변위량과 현장다짐밀도의 변화, 살수량에 따른 함수비 변화 등을 측정하여 효율적인 다짐관리기준을 마련하고자 하였다. 일련의 현장다짐시험결과 CFRD에서의 표층부기초지반은 층별 포설두께 및 다짐회수에 따라 영향 받고 있음을 확인할 수 있었다.

• 한국지반공학회지:지반
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• 제12권1호
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• pp.47-62
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• 1996

The bedding zone which influence directly to the safety of dam is supporting the face slab under hydraulic load in concrete faced rockfill dam. In case that leakage is developed due to various ruptured joint or cracks of face slab and etc., the bedding zone should limit the leakage by low permeability and keep the internal stability. In this study for the proper coefficient of permeability various properties, such as gradation, dry density, performance of embankment work and etc. were analysed. The results from the large scale test of permeability and density are summerized as follows : 1. Coefficient of permeability is decreased clearly by increase of dry density. 2. The particles smaller than the No.4 strive( p,) greatly influences the permeability under dry density of 2.24t 1 m3. 3. In case of C.40 and p,40%, even if dry density decreased to 2.0t/m3, the permeability coefficient is assumed to u x1-scm/s and internal stability is abtained. 4. Generally in dam construction since dry density and uniformity coefficient of bedding zone were higher than 2.2t/m3 and 50 respectively p, of 30~40% is assumed to be suitable and permeability coefficient of below 1$\times$10-3cm l s is expectable.

• 한국해양학회지
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• 제20권2호
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• pp.40-48
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• 1985

강원도 정선군 회동리 일대와 행매동일대에 분포하는 조선누층군의 회동리 석 회암층(사일무리아기)에 대한 고퇴적환경의 규명을 목적으로 암상과 퇴적구조에 대 한 연구가 시행되었다. 연구 결과 회동리층은 불용성 잔류물의 함량이 많고 (평균17 %), 화석의 산출이 빈약한 mudstone facies와 wackestone facies로 구성되며 crypt-algalaminates, bird's eye structures, evaporite pseudomorphs, bioturbated mottle structures, detrital quartz pockets, 및 cross bedding등의 특징적인 퇴적구 조가 나타나고 있음이 밝혀졌다. 회동리층의 이러한 퇴적구조들의 층서적 분포양상 과 암상적 특성을 종합하여 볼 때, 본 역의 회동리석회암층은 주로 고염분의 상조 대(supratidal zone)와 조간대(intertidal zone)에서 퇴적된 것으로 사료된다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1998년도 사면안정 학술발표회 논문집
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• pp.99-110
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• 1998

• 자원환경지질
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• 제31권6호
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• pp.519-526
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• 1998

A high-resolution seismic survey was conducted at the northeastern boundary of Pungam basin, one of the Cretaceous sedimentary basins in Korea. A 100 kg weight was used as an energy source and was found to be better than a sledge hammer in mapping deeper geologic structures. Several processing techniques such as f-k filtering, predictive deconvolution, and time-variant filtering are useful to enhance the signal-to-noise ratio by suppressing unwanted seismic energy. Four seismic units are recognized where many vertical faults are developed. The boundary fault between sedimentary rocks and Precambrian gneiss is identified along with a fracture zone of approximately 30 m wide. Bedding planes of the sedimentary rocks dipping westward are interpreted to be limbs of a syncline or volcanic flow. There faults and tilted bedding planes indicate that the basin had undergone significant tectonic deformation.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 춘계학술대회
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• pp.507-510
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• 2007

Piston cores retrieved from the western Ulleung Basin, East Sea were analyzed to examine the potential for hydrocarbon generation and to determine the hydrocarbon indicators. 2D multi-channel reflection seismic and Chirp data were also investigated for mapping and characterizing the geophysical hydrocarbon indicators such as BSR (bottom simulating reflector), blank zone, pock-mark etc. High organic carbon contents and sedimentation rates that suggest good condition for hydrocarbon generation. High pressure and low temperature condition, and high residual hydrocarbon concentrations are favor the formation of natural gas hydrate. In the piston cores, cracks generally oriented to bedding may indicate the gas expansion. The seismic data show several BSRs that are associated with natural gas hydrates and underlying free gas. A number of vertical to sub-vertical blank zones were well identified in the seismic sections. They often show the seismic pull-up structures, probably indicating the presence of high velocity hydrates. Numerous pockmarks were also observed in the Chirp profiles. They may indicate the presence of free gas below the hydrate stability zone as well.

• 자원환경지질
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• 제56권6호
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• pp.629-646
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• 2023

천전리 각석의 모암은 백악기 경상누층군의 대구층에 속하는 셰일이다. 이 암석은 열변질을 받아 혼펠스화 되어 경도가 높고 치밀한 조직을 갖는다. 각석의 표면은 일정한 깊이의 풍화대를 형성하고 있으며 비풍화대와는 광물 및 화학조성에 차이가 있다. 각석의 물리적 손상도 평가 결과, 균열은 대부분 층리와 평행하게 나타나며 상대적으로 조직의 치밀도가 낮은 상부에 집중된다. 탈락은 각석의 상부와 하부에서 전체 면적의 6.0%를 차지하며, 균열이 교차하는 쐐기작용에 따라 생성된 것으로 보이다. 표면을 점유하는 1차 박락은 전체면적의 23.8%이며, 2차 박락은 9.3%, 3차례 이상 발생한 박락은 3.4%로 산출되었다. 이는 자연적 풍화와 과거 이곳에서 화장하던 풍습으로 인한 열충격이 영향을 주었을 것으로 판단된다. 초음파 물성으로 보아 각석은 층리와 평행한 수평방향으로 높은 강도를 지시하며, 물리적 손상이 적은 영역은 평균 4,684m/s를 기록하였으나 균열대 및 박리박락이 심한 곳은 평균 2,597에서 3,382m/s로 차이를 보였다. 천전리 각석의 물리적 손상은 풍화작용이 반복되면서 암석 표면이 내부보다 정도가 심화되고 광물의 결합력이 약해져 나타난 것으로 보인다. 따라서 비풍화대보다 풍화대에서 응력이 크게 발생할 때 상대적으로 풍화된 표면이 지지력을 잃고 박락이 발생한 것으로 이해할 수 있다.

• 자원환경지질
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• 제2권3호
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• pp.58-67
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• 1969

Songgwang lead zinc mine is located in about 12km to the north-east of Jeonju City. Geology of the mine and its visinity is consisted of Jeonju series belonged to so-called Okcheon system, Seodaesan tuff formation, Silla series, and the quartz porphyry intruded into these formations. Jeonju series comprising 3 formations; that is, of Sadaeri, Sindong, and Girinbong. Jeonju series is generally distributed in southern part of the area, striking NNW, and diping NE $30^{\circ}$, or NW $30^{\circ}$. It is deformed to form synclinorium and anticlinorium plunging to the north with low angle. In the northern part of the area, Jeonju series was cut by Sinpeongri-fault of NEE direction near Sinpeongri. In the north side of the fault, it is overturned and shows NEE or NWW strikes and NW $60^{\circ}$ dips. At the west of Songgwangri, it is cut by 3 thrusts; the two are almost parallel each other, and the third oneis manifested by the fact that the lower black shale zone thrusted over the upper limestone. Songgwangri thrust, so named, is a post-mineral fault and its plane represents a premineral slip plane. Enrichment of are took place along the bedding plane or fissure parallel to it, as seen in adit No. 1 or No. 2 along the floor of the thrust, and along the sheared zone or the brecciated zone oblique to the plane near the thrust in crystalline limestone of Sindong formation as observed in the underground levels of inclined slope. Ore minerals are chiefly zincblende, galena, pyrrhotite, arsenopyrite, acompanied pyrite and chalcopyrite, and contain Au and Ag. In earlier stage of mineralization, the limestone was recrystalized, and sulphide minerals were enriched in the· permiable zone said above by pyrometasomatism, and in later stage the limestone was affected chloritization and sericitization. However hydrothermal replacement was weak, so that enrichment did not took place. It seems that minerallizing materials came up through the premineral slip plane and injected, and replaced the limestone in permiable zone said above with sulphide are minerals. Then Songgwangri thrust took place and, the lower black shale zone thrusted upon crystalline limestone.

• 자원환경지질
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• 제3권1호
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• pp.25-34
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• 1970

Very few articles are available on geologic structure and genesis of Sangdong scheelite-deposits in spite of the fact that the mine is one of the leading tungsten producer in the world. Sangdong scheelite deposits, embedded in Myobong slate of Cambrian age at the southem limb of the Hambaek syncline which strikes $N70{\sim}80^{\circ}W$ and dips $15{\sim}30^{\circ}$ northeast, comprise six parallel veins in coincide with the bedding plane of Myobong formation, namely four footwall veins, a main vein, and a hangingwall vein. Four footwall veins are discontinuous and diminish both directions in short distance and were worked at near surface in old time. Hangingwall vein is emplaced in brecciated zone in contact plane of Myobong slate and overlying Pungchon limestone bed of Cambrian age and has not been worked until recent. The main vein, presently working, continues more than 1,500 m in both strike and dip sides and has a thickness varying 3.5 to 5 m. Characteristic is the distinct zonal arrangement of the main vein along strike side which gives a clue to the genesis of the deposits. The zones symmetrically arranged in both sides from center are, in order of center to both margins, muscovite-biotite-quartz zone, biotite-hornblende-quartz zone and garnet-diopside zone. The zones grade into each other with no boundary, and minable part of the vein streches in the former two zones extending roughly 1,000 m in strike side and over 1,100 m in dip side to which mining is underway at present. The quartz in both muscovite-biotite-quartz and biotite-hornblende-quartz zones is not network type of later intrusion, but the primary constituent of the special type of rock that forms the main vein. The minable zone has been enriched several times by numerous quartz veins along post-mineral fractures in the vein which carry scheelite, molybdenite, bismuthinite, fluorite and other sulfide minerals. These quartz veins varying from few centimeter to few tens of centimeter in width are roughly parallel to the main vein although few of them are diagonal, and distributed in rich zones not beyond the vein into both walls and garnet-diopside zone. Ore grade ranges from 1.5~2.5% $WO_3$ in center zone to less than 0.5% in garnet-diopside zone at margin, biotite-hornblende-quartz zone being inbetween in garde. The grade is, in general, proportional to the content of primary quartz. Judging from regional structure in mid-central parts of South Korea, Hambaek syncline was formed by the disturbance at the end of Triassic period with which bedding thrust and accompanied feather cracks in footwall side were created in Myobong slate and brecciated zone in contact plane between Myobong slate and Pungchon limestone. These fractures acted as a pathway of hot solution from interior which was in turn differentiated in situ to form deposit of the main vein with zonal arrangement. The footwall veins were developed along feather cracks accompanied with the main thrust by intrusion of biotite-hornblende-quartz vein and the hangingwall vein in shear zone along contact plane by replacement. The main vein thus formed was enriched at later stage by hydrothermal solutions now represented by quartz veins. The main mineralization and subsequent hydrothermal enrichments had probably taken place in post-Triassic to pre-Cretaceous periods. The veins were slightly displaced by post-mineral faults which cross diagonally the vein. This hypothesis differs from those done by previous workers who postulated that the deposits were formed by pyrometasomatic to contact replacement of the intercalated thin limestone bed in Myobong slate at the end of Cretaceous period.