• Title/Summary/Keyword: 변형시기

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On the penecontemporaneous deformation structures of the Sinri area at the mid western boundary of the Jinan Basin (진안분지 서변 중앙부 신리지역의 준퇴적동시성 변형구조)

  • Lee Young-Up
    • The Korean Journal of Petroleum Geology
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    • v.6 no.1_2 s.7
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    • pp.8-19
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    • 1998
  • In the Sinri area located at the mid western boundary of the Jinan basin, the Manduksan Formation which mainly consists of coarse sandstone narrowly intercalated with shale and the alternation of sand and shale and the Dalgil Formation mainly of shale are distributed. It consists of four lithofacies, such as coarse sandstone, interbedded sandstone/shale, shale and volcanic rock lithofacies. All sediments are interpreted to be deposited by turbidity currents and free fallouts in a lacustrine basin. In these rocks many penecontemporaneous defomation structures are observed such as fold and thrust fault at large scale, and swelling, boudin structure, flame structure, load structure, ptygmatic fold and convolute bedding at small scale. All these structures are developed between upper and lower undisturbed sedimentary strata. Two large folds are similar folds, but lower one gradually developed into concentric shape. The swelling structures by convergence of the sediments are observed in the hinge area and the boudin structures are developed in the limb. The thrust faults including minor folds and sandstone lobes show duplex structure with asymmetric and kink fold on and below in front of the detached sandstone layer. Development of the swellings, boudins and lobes indicates the flexbility of the sediments during deformational episodes. The folds and thrust faults rarely contain fractures relative their scales and lithologies. This feature also indicates the retrievability of sediments during deformation. At the flanks of the thrust faults the normal faults are formed contemporaneously. The deformation structures at small scale such as flame structures, load structures, ptygmatic folds and convolute beddings are syndepositional and penecontemporaneous, which show the effects of tectonic movements. All these deformed sedimentary structures of the Sinri area suggest the continuing tectonic movements during and/or after deposition.

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New Methods for Assessing Liquefaction Potential Based on the Characteristics of Material (재료의 역학적 거동특성에 기초한 액상화 평가방법)

  • Kim, Gyeong-Hwan;Park, In-Jun;Kim, Su-Il
    • Geotechnical Engineering
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    • v.14 no.5
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    • pp.205-218
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    • 1998
  • The purpose of this study is to develop and utilize new assessment of liquefaction potential based on DSC(disturbed state concept) and dissipated energy concept. The term liquefaction has suddenly loses its shear strength and behaves like a fluid. Liquefaction has been a source of a major damage during severe earthquake. In this study, the cyclic undrained behavior of Joomoonjin strand is investigated by using an automates triaxial testing device(C. K. Chan type). In order to assess liquefaction potential of saturated strand, DSC method and energy method are applied for the experimental data. The use of DSC method and energy method to define the liquefaction potential is verified through laboratory testis of cyclic triaxial test on saturated sand specimens. Based on the analytical results of DSC method, the relationship between the factor affecting liquefaction characteristics(Dr) and physical properties of the saturated santa(fs and D.) is found. Based on the analytical results of energy method, it is found that the initial liquefaction of rand is related to the significant change in the dissipated energy. Finally, it is shown that the DSC method and energy method can capture the liquefaction mechanism.

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Formation Processes of Fault Gouges and their K-Ar Ages along the Dongnae Fault (동래단층 지역 단층비지의 생성과정과 K-Ar 연령)

  • 장태우;추창오
    • The Journal of Engineering Geology
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    • v.8 no.2
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    • pp.175-188
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    • 1998
  • This paper describes the internal structures and K-Ar ages of fault gouges collected from the Dongnae fault zone. This fault zone is internally zoned and occurs in the multiple fault cores. A fault core consists of thin gouge and narrow cataclastic zones that are bounded by a much thicker damage zone. Intensity of deformation and alteration increases from damage zone through cataclastic zone to gouge zone. It is thought that cataclasis of brittle deformation was the dominant strain-accomodation mechanism in the early stage of deformation to form the gouge zone and that crushed materials in the regions of maximum localization of fault slip subsequently moved by cataclastic flow. Deformation mechanism drastically changed from brittle processes to fluid-assisted flow along the gouge zone as the high porosity and permeability of pulverzied materials during faulting facilitated the influx of the hydrothermal fluids. Subsequently, the fluids reacted with gouge materials to form clay minerals. Fracturing and alteration could have repeatedly taken place in the gouge zone by elevated fluid pressures generated from the reduction of pore volume due to the formation of clay minerals and precipitation of other materials. XRD analysis revealed that the most common clay minerals of the gouge zones are illite and smectite with minor zeolite and kaolinite. Most of illites are composed of 1Md polytype, indicating the products of hydrothermal alteration. The major activities of the Dongnae fault can be divided into two periods based upon K-Ar age data of the fault gouges : 51.4∼57.5Ma and 40.3∼43.6Ma. Judging from the enviromental condition of clay mineral formation, it is inferred that the hydrothermal alteration of older period occured at higher temperature than that of younger period.

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A Preliminary Study on the Exhumation Mechanism of the Paleozoic Gwangcheon Gneiss in the Southwestern Margin of the Gyeonggi Massif (경기육괴 남서 연변부에 발달하는 고생대 광천편마암의 노출기작에 대한 예비 연구)

  • Park, Seung-Ik
    • Economic and Environmental Geology
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    • v.50 no.6
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    • pp.525-535
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    • 2017
  • Exhumation mechanism of migmatite in orogenic belts provides insights into thermo-mechanical evolution of lithosphere in association with orogeny. This study deals with kinematics of structures in and around the Gwangcheon Gneiss, as a preliminary study on exhumation mechanism, which is a main constituent of a domal structure (viz., Oseosan Dome) in the Hongseong area, southwestern margin of the Gyeonggi massif. Geological structures in the Gwangcheon Gneiss, which mainly comprises southern and northwestern part of the Oseosan Dome, generally have kinematic component of top-outward shear. This feature is likely to represent diapiric dome-up movement. In addition, a high strain zone, by which the tectonic domain involving the Gwangcheon Gneiss is bounded on the west, show structural features with normal sense of shear component. Taking available (thermo)chronological data into account, it is interpreted that activation of the high strain zone and exhumation of the Gwangcheon Gneiss occurred during Late Triassic, when the Gyeonggi massif was widely affected by post-collisional processes. It means that the Gwangcheon Gneiss was diapirically moved up and exhumed in the footwall of extensional high strain zone in association with Triassic post-collisional processes.

Microscopic Study of the Pig Peri-implantation Embryos (전자현미경에 의한 착상 전후 돼지수정란의 형태학적 변화에 관한 연구)

  • 김진회;백청순;이훈택;정길생
    • Korean Journal of Animal Reproduction
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    • v.18 no.2
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    • pp.141-150
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    • 1994
  • Morphological features of the interaction between the hatching blastocyst and implantation in pig were studied by electron microscopy. The observations extended from late blastocyst stage to the completion of trophoblastic erosion of the epithelium and early decidual transformation of the epithelium and early decidual transformation of the stromal cells. Between day 7 and 17 of pregnancy, blastocysts from 0.3 to 12 mm in diameter were flushed from the uterine horns of Dutch Landrace pigs. On the 7th of development in the pig blastocyst, the blastocyst shedded of the zona pellucida established the tips of microvilli and with bleb-like cytoplasmic protrusions of the epithelial cells. From day 11 on in pig embryo, the bilayered trophoblast undergoes a dramatic phase of elongation so that the initially spherical expanded blastocyst becomes tubular. In pig, close apposition to the uterine wall beg-ins at about 12 $^1$/$_2$ days and then attachment occurred during the afternoon of the 16th or 18th day post coitum. At this stage, embryonic loss compared with corpus luteum number is up to 40% of ovulated oocytes. Therefore, the implantation failture of these embryos may be mainly caused by morphological abnormality and failture of zona shedding.

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A Study on the Aspect of Space Change to Seokpajeong garden(石坡亭) in the Late Joseon Dynasty (조선후기 원림 석파정(石坡亭)의 공간변화양상에 관한 고찰)

  • Lee, Won-Ho;Kim, Dong-Hyun;Kim, Jae-Ung;Choi, Jong-Hee
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.33 no.1
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    • pp.31-40
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    • 2015
  • This study aims to comprehend that Seokpajeong garden for aspect of space change. Spatial characteristics according to the transfer of ownership are classified as period. And investigate the aspect of space change in Seokpajeong garden based on literature and painting, newspaper, photo. The results were as follows. First, Investigate the construction and change of Seokpajeong garden. Accordingly, spatial characteristics of Seokpajeong garden are classified into three period. 1st period is Kim-Heung Keun owned Samgyedong-jungsa garden. 2nd period is Daewongun hold Seokpajeong garden. 3rd period is damaged original form of Seokpajeong garden from Korean War to current time inclusive. Secondly, Kim-Heung Keun owned Samgyedong-jungsa garden has characteristics of water system centric space and many buildings. In addition accept foreign culture like chinese pavilion and Byeoldang Villa. and plant unique flower and leaf in garden. Thirdly, According to Seokpajeong garden folding screen, Daewongun owned Seokpajeong garden accept organization of space in Samgyedong garden. But different locations of Sarangchae in folding screen means possibility of move building to current position. So, additional historical research is required with representation of chinese pavilion location. Fourthly, Seokpajeong garden was damaged from original form to frequent changes of ownership. Transform of geographical features and water system as well as Anchae and Sarangchae, back side of a outbuilding are only the remained among many buildings. Also, Seokpajeong garden is more fell to the subsidiary facility of Seoul Museum than Wonrim. Therefore restoration and recovery of original form are urgent.

Analysis of Axial Restrained Behavior of Early-Age Concrete Using Sea-Sand (해사를 사용한 초기재령 콘크리트의 일축 구속 거동 해석)

  • 박상순;송하원;조호진;변근주
    • Journal of the Korea Concrete Institute
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    • v.14 no.3
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    • pp.331-340
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    • 2002
  • In this paper, finite element analysis is applied for simulation of cracks due to restraining autogenous and drying shrinkage at early-age concrete. A micro-level heat hydration model and a shrinkage prediction model along with a moisture diffusion model are adopted for the finite element analysis. Then, an axial restraint test is carried out for concrete specimens containing different amounts of chloride ions to evaluate stress development and cracking due to the restraining shrinkages at early ages. Test results show that the increase of contents of chloride ions increases restrained stress, but does not increase strength. By this increase of shrinkage strain at early-age, time to occur the crack is accelerated. Finally, stress development and cracking of concrete specimens containing different amount of chloride ions we simulated using the finite element analysis. Results of the analysis using the Proposed model are verified by comparison with test results.

Time-dependent Parametric Analyses of PSC Composite Girders for Serviceability Design (사용성 설계를 위한 PSC 합성거더교의 시간의존적 변수해석)

  • Youn, Seok-Goo;Cho, Sun-Kyu;Lee, Jong-Min
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.5A
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    • pp.823-832
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    • 2006
  • To ensure the serviceability requirements of PSC composite girder bridges, it is essential to predict the stresses and deformations of the structure under service load conditions. Stresses and deformations vary continuously with time due to the effects of creep and shrinkage of concrete and relaxation of prestressing steel. The importance of these time-dependent effects is much more pronounced in precast prestressed concrete structures built in stages than in those constructed in one operation. In this paper, time-dependent analyses for PSC composite bridges using 30m standard girders have been conducted considering with the variation of the times of introducing initial prestressing forces and casting concrete. A computer program has been developed for the time-dependent analysis of simple or continuous PSC composite girders and parametric studies are conducted. Based on the numerical results, it is investigated the long-term behaviors of PSC composite girder bridges and discussed the limitations of the current codes for the prestress loss.

Lived Experience of Difficult Times for Young Adult Street Homeless - Application of Parse's Human Becoming Research Method - (청년기에 시작된 거리노숙인의 힘겨운 시기에 대한 체험 - Parse의 인간되어감 연구방법을 적용하여 -)

  • Kim, Hyun-Kyoung;Kim, Ok-Ja
    • Korean Journal of Social Welfare
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    • v.63 no.2
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    • pp.31-56
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    • 2011
  • This study was done to identify experience of young adults street homeless aged 20-30s by knowing meaning and structure of empirical phenomena for procedure that how young adults became street homeless according to bio-psycho-social change. Five young adults street homeless were recruited who were on the air of SBS program, 'That why we want to know: young hope on the road-Young adults homeless are increased(Saturday July 26, 2008)', and from monthly magazine published by Homeless Center in Seoul. And phenomenological and heuristic Human Becoming Research Methodology of Parse was applied in this study. Although young adults street homeless made an opportunity for job, the working poor made him street homeless who suffer from social stigma and exclusion, but he struggled for self-support with social care. The quality of life for young adult street homeless depends on the social care under human rights with the bio-psycho-social aspects.

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A Review on the Stratigraphy, Depositional Age, and Composition of the Chungnam Basin Fills (충남분지 충전물의 층서, 퇴적시기, 조성에 관한 고찰)

  • Lee, Hyojong;Park, Seung-Ik;Choi, Taejin
    • Economic and Environmental Geology
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    • v.52 no.5
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    • pp.357-366
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    • 2019
  • Deposition of the Daedong Supergroup has been considered to be related with the Triassic Songrim and Jurassic Daebo orogenies. The Chungnam Basin fills is an important sedimentary succession to understand the geological evolution of the Early to Middle Mesozoic Korean Peninsula. Previous paleontological and paleomagnetic studies have suggested the Late Triassic to Early Jurassic sedimentation of the Chungnam Basin fills. However, the orogenic model of the basin development has remained controversial because recently reported zircon U-Pb isotopic ages are not harmonious with the previous studies. This paper aims to review the stratigraphy, depositional age, and composition of the Chungnam Basin fills, together with test of the basin development models.