• Title/Summary/Keyword: excavations

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A Study for Safety Management on the Basis of Lateral Displacement Rates of Anchored In-situ Walls by Collapse Case Histories (붕괴 사례를 통한 앵커지지 가설흙막이벽체의 수평변위속도에 의한 안전관리 연구)

  • Chung, Dae-Seouk;Lee, Yong-Beom
    • Journal of the Society of Disaster Information
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    • v.14 no.3
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    • pp.367-378
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    • 2018
  • Purpose: The objective of this study is to present a reasonable safety management of the anchored in-situ wall systems constructed in the ground conditions consisting of multi-layered soils underlain by bedrocks in the urban area of Korea. Method: Field measurements collected from collapse case histories with deep excavations were analyzed for the safety management of the wall systems supported by the earth anchors in terms of lateral displacement rates. Results: The average maximum lateral displacement rate in a collapsed zone of the in-situ wall significantly increased upon the completion of the excavation. Particularly, the collapse of the in-situ wall system due to the sliding occurring along the discontinuities of the rock produced a considerably large lateral displacement rate over a relatively short period. Conclusion: For predicting and preventing the collapse of the wall system during or after the excavation work, the utilization of the safety management criteria of the in-situ wall system by the lateral displacement rate was found to be much more reasonable in judging the safety of earthworks than the application of the quantitative management criteria which have been commonly used in the excavation sites.

SOC Project Plans and Cultural Resource Management in the North Korean Region : Suggestions for Systematic Investigation and Management of North Korean Cultural Heritage (북한지역 SOC사업 구상과 문화유산 - 북한 문화유산의 효율적인 조사·관리를 위한 제언 -)

  • Kim, Beom-Cheol
    • Korean Journal of Heritage: History & Science
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    • v.52 no.2
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    • pp.4-19
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    • 2019
  • Despite continuous volatility in ideological leanings, South Korean governments, conservative or progressive, have published a series of plans for aiding the economic development of North Korea. The Moon administration's plan is the paragon of such efforts. In addition, recent detente between the North Korean regime and the US government evokes much hope in its success. There is, hidden behind the veil of hope, apprehension about the crisis of management of cultural heritage in the North Korean region. It is believed that development policies may overwhelm efforts at conservation of cultural heritage, in particular that the hurrying of development projects would provoke insufficient and inappropriate investigation of archaeological sites., If these problems arise, responsibility for their resolution would be carried by South Korean archaeologists and governmental institutes. This paper reviews what the South Korean government has suggested for North Korea's economic recovery and examines what capability the South Korean archaeology sector has for investigating North Korean cultural heritage. It then discusses the scale of investigation needed, and what should beused as precedent in planning substantial excavations when development projects are performed in the North Korean region. Constructing a digital map system for cultural heritage of North Korea is suggested as one of the most urgent tasks precedent to substantial excavations. It is of great importance because we do not currently have any substantial information about the locations and current condition of cultural heritage sites and artifacts in the North Korean region. The mapping of Bronze Age sites in North Korea, conducted as a sort of pilot test, revealed that archaeological sites are densely distributed in several regions, especially Hwanghae-do and Pyoyang Directly-Administrated City, and that there is high potential of discovering new sites.

Ground Anchor Testing on Temporary Excavations (일반 가설앵커의 문제점과 개선방향)

  • 김성규;김낙경;김정렬
    • Proceedings of the Korean Geotechical Society Conference
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    • 2003.03a
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    • pp.545-552
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    • 2003
  • For temporary excavation support in a congested urban area, the strand of ground anchor should be removed to get permission of the private land to install anchors. But the strand doesn't need to be removed in the outside city area after use. So the anchor body, tension anchor, is fabricated in-situ. The unbonded length of This anchor has several strands, which wrap only one sheath. When the anchor body is carried into job-site or installed in the bore hole, the sheath is torn easily because it is a very week material. So the grout permeate into the torn sheath. Because of that, the load doesn't transfer to the bond length of ground anchors. It may indicate that load is being transferred along the unbonded length and thus within the potential slip surface assumed for overall stability of the anchored system. The load tests were performed on seven low-pressure grouted anchors installed in weathered soil to verify its problems. Four anchors(Type A) have the unbonded length, which consist of five strands and a week sheath and three anchors(Type B) have strands, which is covered by plastic sheath filled with grease, in the unbonded length. Both anchors are compared with load tests results.

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Evaluation of Face Stability of Tunnel with Steel Pipe-Reinforced Multi-step Grouting (강관다단 그라우팅으로 보강된 터널의 막장 안정성 평가)

  • 이인모;이재성;남석우
    • Proceedings of the Korean Geotechical Society Conference
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    • 2003.03a
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    • pp.273-280
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    • 2003
  • Tunneling in difficult geological conditions is often inevitable especially in urban areas. Ground improvement and reinforcement techniques are often required to guarantee safe tunnel excavations and/or to prevent damage to adjacent structures. The steel pipe-reinforced multi-step grouting method has been recently applied to tunnel sites in Korea as an auxiliary technique. In this study, the face stability with steel pipe-reinforced multi-step grouting was evaluated by simultaneously considering two factors: one is the effective stress acting on the tunnel face calculated by limit theorem and limit equilibrium method; the other is the seepage force obtained by means of numerical analysis. The study revealed that the influence of the steel pipe-reinforced multi-step grouting on the support pressure in dry condition is not significant while there is relatively a large amount of reduction in seepage forces by adopting the technique in saturated condition. The effect of the anisotropy of permeability on the seepage force acting on the tunnel face was also estimated by conducting the coupled analysis. It was found that a higher horizontal permeability compared with the vertical one causes reduction in the seepage force acting on the tunnel face.

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Geotechnical field investigation on giresun hazelnut licenced warehause and spot exchange

  • Angin, Zekai
    • Geomechanics and Engineering
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    • v.10 no.4
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    • pp.547-563
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    • 2016
  • This paper describes a geotechnical field investigation in Giresun hazelnut licenced warehause and spot exchange during twelve months to determine the soil profile and static project applicability. It is also aimed to determine the superstructure loads and evaluate the relevance of foundation filling materials of the main, laboratory, package and admin buildings. The main building has $88.50{\times}63.20(5593.2)m^2$ site area. It has a big raft foundation. Eleven geotechnical reports were prepared between 2 December 2014 and 25 May 2015. Maximum settlements and safe bearing capacities were calculated to decide to be able to proceed to the next step. Also, the detail observations and evaluations were presented from October 2014 to December 2014. It has been seen that the foundation is designed as a single foundation one. But, in the light of observations, it has been evaluated that the foundation project for package building is not adequate, and after these excavations it must be revised as a raft foundation. The thickness of foundation and structural details should be defined/drawn after analyzing the details by using a special software. Construction joints should be designed between different buildings interfaces to avoid damages and cracks with in different settlements. The environmental drainage must be projected and applied to avoid the probable damage of surface waters on foundations.

Origin and meaning of Circular stone Pagoda in Unjusa Temple (운주사 원형석탑의 시원과 의미)

  • Kim, Ki-Yong;Cheon, Deuk-Youm
    • Journal of architectural history
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    • v.23 no.4
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    • pp.91-100
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    • 2014
  • There are lots of and kinds of stone pagoda and stone Buddhas at Unjusa Temple in Hwasun, Jeonnam, which is thus called as Cheontap(千塔) or Cheonbul.(千佛) Several archaeological excavations have been conducted in Unjusa though, the foundation purpose or background motivation is yet wrapped in mystery. Circular shape is representative pagoda of Unjusa made of round frame or spherical roof but circular stone pagoda is unusual that there is no similar example found in India or China as well as in Korea. Located in the symbolic center, Circular stone pagoda is a key to understand Unjusa. Yundeung(輪燈) is made of stone for circular stone pagoda and there are craft lamp and large lamp. The large lamp, for the palace courtyard on the occasion of Palgwanhoe,(八關會) consists of discs and light on each disc. Outdoor lamp of circular stone pagoda made of stone for permanent preservation purpose. Unjusa is a very special temple with stone-yundeung for circular stone pagoda. In this study, a circular stone pagoda that is the source of yundeung said. Unjusa circular stone pagoda next to the title of 'yundeung pagoda' and proposes to call.

A Study on humanistic Imagination of Games using Oral Literature (구비문학을 활용한 게임의 인문학적 상상력에 관한 고찰)

  • Lee, Jae-Hong
    • Journal of Digital Convergence
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    • v.10 no.2
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    • pp.279-286
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    • 2012
  • Game contents are the driving force of the digital media era. As the gaming industry grows bigger, contents technologies are also rapidly developing in both their quality and quantity, while the story sources of the contents are depleting. Accordingly, digging out new stories that can support development of the cultural contents industry is emerging as an urgent issue. Since games took roots as a form of contents in our society, negative images have outweighed positive aspects. This study aims at finding cures for the side effects from storytelling. Important factors here are how to converge the technical nature of engineering imagination and the epic nature of humanities imagination. Recently, The excavations of the story is very important. This article demonstrates cases where the oral literature, an archetypical cultural genre, provides the sources of game storytelling.

A numerical study on the seepage failure by heave in sheeted excavation pits

  • Koltuk, Serdar;Fernandez-Steeger, Tomas M.;Azzam, Rafig
    • Geomechanics and Engineering
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    • v.9 no.4
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    • pp.513-530
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    • 2015
  • Commonly, the base stability of sheeted excavation pits against seepage failure by heave is evaluated by using two-dimensional groundwater flow models and Terzaghi's failure criterion. The objective of the present study is to investigate the effect of three-dimensional groundwater flow on the heave for sheeted excavation pits with various dimensions. For this purpose, the steady-state groundwater flow analyses are performed by using the finite element program ABAQUS 6.12. It has been shown that, in homogeneous soils depending on the ratio of half of excavation width to embedment depth b/D, the ratio of safety factor obtained from 3D analyses to that obtained from 2D analyses $FS_{(3D)}/FS_{(2D)}$ can reach up to 1.56 and 1.34 for square and circular shaped excavations, respectively. As failure body, both an infinitesimal soil column adjacent to the wall (Baumgart & Davidenkoff's criterion) and a three-dimensional failure body with the width suggested by Terzaghi for two-dimensional cases are used. It has been shown that the ratio of $FS_{(Terzaghi)}/FS_{(Davidenkoff)}$ varies between 0.75 and 0.94 depending on the ratio of b/D. Additionally, the effects of model size, the shape of excavation pit and anisotropic permeability on the heave are studied. Finally, the problem is investigated for excavation pits in stratified soils, and important points are emphasized.

A study on the Scythian Bracelets

  • Kim, Moon-Ja
    • Journal of Fashion Business
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    • v.8 no.3
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    • pp.1-9
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    • 2004
  • Scythians kept herds of horses, cattle, and sheep, lived in tent-covered wagons, and fought with bows and arrows on horseback. They developed a rich culture characterized by opulent tombs, fine metalwork, and a brilliant art style. The excavations of royal burials have provided the most complete record of the jewelry of the Scythians. Typical art objects were in the form of stags or other animals, hammered or stamped out of gold and often inlaid with colored stones or glass. The Bracelet consisted of two of distinct technique : One made from heavy forged gold bars, terminated with more delicate spiraled finals. Another technique used beaten gold foil, perhaps as thick as a piece of paper with fabulous designs repousse and chased (impressed in relief into the gold with small hammers and chisels) into the metal. They also used stones and clay dies to form gold foil into people repeated also motifs for use in torques and belts. The Scythian Bracelet were divided into 4 styles according to the shape, Bracelets with ends shaped like beasts style, Spiral style, Layers style, Crown with openwork style. Scythian Bracelet in the Black Sea region had completely degenerated, stifled by motifs and shapes of Greek origin, retaining its representational realism and its full emotional vitality.

Effects of Strut Preloading on the Restraining of Adjacent Ground Displacement at Braced Excavations (버팀 굴착시 버팀대 선행하중의 인접지반 변위 억제 효과)

  • 백규호;조현태
    • Journal of the Korean Geotechnical Society
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    • v.15 no.1
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    • pp.31-40
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    • 1999
  • The bracing system using screw jack is not effective for the restraining of adjacent ground displacement. since the screw jack dose not induce sufficient preloading on struts. In order to protect excessive displacement of adjacent ground at braced excavation, new preloading jack was developed in the country. In this paper, the new preloading jack and the measurement results of the lateral displacement of braced wall at three deep excavation sites in Seoul city are introduced. The measurement results showed that the maximum displacements of braced wall are smaller than 0.15% of excavation depth, therefore the wall displacements can be minimized by preloading which is acted on bracing. If the bracing system with new preloading jack is used in braced excavation, it is effective for reducing the cost and period of construction.

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