• Title/Summary/Keyword: earth system

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Interpretation of Paleostress using Geological Structures observed in the Eastern Part of the Ilgwang Fault (일광단층 동편에서 관찰되는 지질구조를 이용한 고응력사 해석)

  • Kim, Taehyung;Jeong, Su-Ho;Lee, Jinhyun;Naik, Sambit Prasanajit;Yang, Wondong;Ji, Do Hyung;Kim, Young-Seog
    • The Journal of Engineering Geology
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    • v.28 no.4
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    • pp.645-660
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    • 2018
  • In the southeastern part of the Korean Peninsula, huge fault valleys, including the Yangsan and Ulsan faults, are recognized. These NNE-SSW trending lineaments are called as a whole Yangsan Fault System. However, this fault system is relatively poorly studied except the Yangsan and Ulsan faults. This study deduced the paleostress history based on the mutual cross-cutting relationships between geologic structures developed in the granite body near the Ilgwang fault, which is compared with previous studies. In the study area, four lineaments parallel to the Ilgwang fault are recognized, and three of them show evidences of faulting. In each lineament, both slip-senses of left-lateral and right-lateral are recognized. It indicates that these faults consistently underwent multiple deformations of inversion along the faults. The inferred paleostress directions based on the mutual cross-cutting relationships of the geological structures are as follows: 1) Tensile fractures developed in the late Cretaceous under the ENE-WSW direction of compressive stress, 2) NW-SE trending maximum horizontal principal stress generated conjugate strike-slip faults, and 3) selective reactivations of some structures were derived under the compression by the NE-SW trending principal stress.

Instrumented Field Performance of an Isolated-Reinforced Earth Wall (분리형 보강토옹벽의 현장계측 및 분석)

  • 김영윤;한경제;김경모
    • Proceedings of the Korean Geotechical Society Conference
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    • 2000.11a
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    • pp.117-124
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    • 2000
  • As the reinforced earth wall is constructed with step by step backfill compaction method, the accumulative horizontal deformation is inevitable. It has been reported that about 80% of horizontal deformation is occurred during the construction stage of reinforced earth retaining wall. To reduce the horizontal deformation, an isolated-reinforced earth wall method(KOESWall system) was newly developed. In this system, the reinforced earth is constructed first with reinforcements and backfills only, and then facing blocks are installed after the horizontal displacement of reinforced earth is fully occurred. To evaluate the effect of a construction method and the performance of KOESWall system, two cases of full scale field performance was monitored during and after the construction stages.

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Development of the K-12 Science Literacy Education Program focused on the Earth System and Environment

  • Lee, Eun-Ah;Fortner, Rosanne W.
    • Journal of the Korean earth science society
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    • v.27 no.7
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    • pp.723-729
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    • 2006
  • The purpose of this study was to develop a program based on the Earth system based program to help students achieve science literacy. This program was designed to be connected across grade levels, and contents of the program were constructed to have meaningful interdisciplinary context. All the activities in the program were inquiry-based, and understanding of the nature of science was considered essential throughout the program. In addition, appreciation and stewardship for the Earth system were systematically emphasized on any grade level. Design of the program applied U.S. National Science Education Standards for the quality of and conditions for school science programs.

Evaluation on the Performance of Design Parameters in Earth Tube System (지중튜브시스템 주요 설계 변수의 성능 평가)

  • Hwang, Yong-Ho;Hwang, Seok-Ho;Choi, Jeong-Min
    • Journal of the Korean Solar Energy Society
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    • v.36 no.3
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    • pp.87-94
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    • 2016
  • Earth tube system can be installed in many ways. However, performance data on earth tube system is still insufficient. Therefore, in this study seven design parameters of earth tube systems were chosen such as underground earth tube length, depth, tube thermal conductivity, thickness, radius, soil conditions, and fan type. And the change effects in the values of the seven parameters on earth tube exit temperatures and heat transfer rate were examined through Energyplus simulations.

Behavior of Reinforced Earth Retaining Wall for Connector System Driving the Settlement of Reinforcement (보강재 침하를 허용하는 연결시스템을 적용한 보강토옹벽의 거동)

  • Jong-Keun Oh;Jeong, Jong-Gi;Lee, Song
    • 기술발표회
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    • s.2006
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    • pp.156-161
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    • 2006
  • Recently, construction of soil-reinforced segmental retaining walls which used geosynthetics are being increased day by day due to its construction efficiency, economic efficiency, and its aesthetic view. The conventional reinforced earth retaining wall has the connector system to fix the reinforcement and block However, this system may cause the crack of block and the rupture of reinforcement due to the stress concentration near the face of reinforced earth retaining wall In this study, the new connector system, which is able to allow the settlement of reinforcement, was applied to analyze the effect of connector system of reinforced earth retaining wall The connection strength tests and centrifugal tests for both the conventional reinforced earth retaining wall and the settlement reinforced earth retaining wall were performed to compare the results

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IPS Earth Retention System (IPS(Innovative Prestressed Wale System) 흙막이 공법의 개발)

  • Park, Jong-Sik;Kim, Nak-Kyung;Han, Man-Yop;Kim, Jong-Woo
    • Proceedings of the Korean Geotechical Society Conference
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    • 2004.03b
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    • pp.293-300
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    • 2004
  • A new earth retention system(Innovative Prestressed Wale System) has been developed and introduced. IPR earth retention system provides an economical benefit, construction easiness, good performance and safety. IPS is a prestressed wale by using a steel wire, which provides a high stiffness to resist the earth pressure. In order to investigate the applicability and the safety of new IPS system, field tests were performed. A new IPS system applied in a trench excavation performed successfully. Basic principles and mechanism of IPS system and measure performance were presented and discussed.

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Developing a Framework of Conceptual Understandings of Earth Systems

  • Nam, Younkyeong
    • Journal of the Korean earth science society
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    • v.37 no.5
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    • pp.309-322
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    • 2016
  • This paper presents an analytical framework of Conceptual Understandings of Earth Systems (CUES) that shows a relationship between disciplinary knowledge of Earth systems and the specific thinking skills required to understand that knowledge. This framework is developed through an extensive literature review of students' and teachers' understandings of earth systems concepts and systems thinking in earth science context. This study first presents the categories of disciplinary knowledge of Earth systems, Earth System Knowledge (ESK). This study then illustrates a relationship between categories of ESK and the ontological categories (Matter, Process, Systems) that has been used to study students' conceptual understandings of Earth systems. Finally, this study presents the CUES framework to show the relationship between disciplinary knowledge and thinking skills. The implications of using this framework for curriculum development, assessment, and teacher education and ESS research are discussed.

Development of Innovative Prestressed Support Earth Retention System (IPS 흙막이 공법의 개발)

  • Kim, Nak-Kyung;Park, Jong-Sik;Han, Man-Yop;Kim, Moon-Young;Kim, Sung-Bo
    • Journal of the Korean Geotechnical Society
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    • v.20 no.2
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    • pp.107-113
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    • 2004
  • A new innovative prestressed support (IPS) earth retention system has been developed and introduced. The IPS is a wale system prestressed by steel wires. The IPS consists of wale, wires, and H-beam support. The IPS provides a high flexural stiffness to resist the bending by earth pressures. The IPS earth retention system provides a larger spacing of support, economical benefit, construction easiness, good performance, and safety control. This paper explains basic principles and mechanism of new IPS system and presents a design method of IPS earth retention system. In order to investigate applicability and safety of new IPS system, field tests were performed in a trench excavation. The new IPS system applied in a trench excavation was performed successfully. The measured performances of IPS system were presented and discussed.

A Model Test of Earth Retention System with Prestressed Wale (프리스트레스트 띠장을 적용한 흙막이 시스템의 모형 시험)

  • Park, Jong-Sik;Kim, Sung-Kyu;Joo, Yong-Sun;Jang, Ho-June;Kim, Nak-Kyung
    • Journal of the Korean Geotechnical Society
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    • v.23 no.7
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    • pp.27-36
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    • 2007
  • A model test was performed to evaluate the stability of a new earth retention system with a prestressed wale. For the model test, the dimensional analysis of a full-scaled earth retention system with prestressed wales was performed. Details of the dimensional analysis of the new earth retention system were presented in this paper. Based on the results of the dimensional analysis, the model-scaled earth retention system with a prestressed wale was simulated. The lateral earth pressures on the wall, the lateral deflection of the prestressed wale, the sectional force on members of the prestressed wale system, and the loads of struts were measured during construction simulation. The measured results were evaluated and compared with those of the design criterion. From the measurements, the behavior of this earth retention system was investigated.

Review of Remote Sensing Applicability for Monitoring Marine Microplastics (해양 미세플라스틱 모니터링을 위한 원격탐사 적용 가능성 검토)

  • Park, Suhyeon;Kim, Changmin;Jeong, Seongwoo;Jang, Seonggan;Kim, Subeen;Ha, Taejung;Han, Kyung-soo;Yang, Minjune
    • Korean Journal of Remote Sensing
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    • v.38 no.5_3
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    • pp.835-850
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    • 2022
  • Microplastics have arisen as a worldwide environmental concern, becoming ubiquitous in all marine compartments, and various researches on monitoring marine microplastics are being actively conducted worldwide. Recently, application of a remote detection technology that enables large-scale real-time observation to marine plastic monitoring has been conducted overseas. However, in South Korea, there is little information linking remote detection to marine microplastics and some field studies have demonstrated remote detection of medium- and large-sized marine plastics. This study introduces research cases with remote detection of marine plastics in South Korea and overseas, investigates potential feasibility of using the remote detection technology to marine microplastic monitoring, and suggests some future works to monitor marine microplastics with the remote detection.