• Title/Summary/Keyword: wall facing

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The Stones of Seokguram Speak: Floor Plan and Wall Design of Seokbulsa Grotto (석굴암의 돌은 말한다: 석불사 석굴의 건축 평면과 벽면 설계)

  • Yoon, Chae-Shin
    • Journal of architectural history
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    • v.29 no.1
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    • pp.21-37
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    • 2020
  • The purpose of this paper is to reconstruct the original floor plan and wall design of Seokbulsa Grotto in Kyungju; commonly known as 'Seokguram'. The paper presents an array of dimensional studies of the existing Seokguram to examine its architectural form, and infers the original floor plan and wall design of Seokbulsa Grotto. Seokbulsa Grotto is designed as a system of 'coherent modules' and was constructed using the dry stone method, which interlocks large stone modules into a whole that becomes the load-bearing structure itself. The design principles governing Seokbulsa Grotto are the spatial axis of symmetry, modular coordination, and the layout grid of a quarter Tang-Ruler(TR: 唐尺). Dimensional studies were conducted with these governing principles in mind and concludes the following about the original floor plan design. In the main chamber, Ansang-stone's radius is 12 TR, and Flagstone's radius is 12¼ TR. In the front chamber, the width between the two Ansang-stones facing each other is 22 TR and the longitudinal space depth is 12 TR, while the width between the two Flagstones facing each other is 22½ TR and Flagstone's depth is 12 TR. In the passageway, the width between the two Ansang-stones facing each other is 11½ TR and longitudinal space depth is 9 TR, while the width between the two Flagstones facing each other is 12 TR and Flagstone's depth is 7¾ TR. The distance from the center to the entrance line of the main chamber is 10½ TR. Therefore, the total longitudinal length of the Grotto is 43½ TR at the level of the Ansang-stones, and 44 TR at the level of the Flagstones.

A Case Study on the Reinforcement of Existing Damaged Geogrid Reinforced Soil Wall Using Numerical Analyses (수치해석을 이용한 기존 피해 보강토 옹벽의 보강에 관한 사례 연구)

  • Won, Myoung-Soo;Langcuyan, Christine P.;Choi, Jeong-Ho;Ha, Yang-Seong
    • Journal of the Korean Geosynthetics Society
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    • v.19 no.1
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    • pp.75-82
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    • 2020
  • There have been often cases of collapse for geogrid reinforced soil (GRS) retaining wall. Hence, social interest in the reinforcement and restoration of the collapsed GRS wall is increasing day by day. However, there are only few researches. For this reason, a series of numerical analyses using the Plaxis 2D program was conducted in this study to analyze the suitable reinforcement methods that can be applied on the existing damaged GRS wall caused by overturning of the modular blocks facing and the surface settlement at the backfill as the results from the design failure. The restoration plan used in this study is composed of two cases: (Case 1) soil nailing reinforcement and reinforced concrete (RC) wall facing construction on the existing damaged GRS wall; and (Case 2) removal of the entire damaged GRS wall and then reconstruction. The results on the internal stability of the GRS wall show that Case 1 obtained a greater safety factor than Case 2 for tensile force while Case 2 had a greater safety factor than Case 1 for pullout failures. Case 1 was found to be more stable than Case 2 in terms of the global slope safety by shear strength reduction method and the external deformation behavior by numerical analysis. In this study, the existing damaged GRS wall which was reinforced using Case 1 method shows more stable external behavior.

Lipid and Lipase Distribution on Endosperm Cell of Panax ginseng Seed for the Electron Microscope (전자현미경을 이용한 인삼종자 배유세포내의 지질 및 지질가수분해 효소의 분포)

  • 유성철;노미전
    • Journal of Ginseng Research
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    • v.16 no.2
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    • pp.129-137
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    • 1992
  • This study was carried out to investigate the localization of lipids and lipase activity with lipid staining and cytochemical technique in endosperm cells of Panax ginseng C.A. Meyer seed. In endosperm cells of indehiscent seed, protein bodies facing the umbiliform layer are different in electron density during the various degraded processes. Gradually, protein matrix near the cell wall was lysed and electron lucent inclusions appeared on umbiliform layer. The protein body with high electron density and the spherosome with low electron density were observed in endosperm cells. As a result of lipid staining, electron density of spherosome is more intense than those of the protein matrix within the protein body in endosperm cells of indehiscent seed. Free spherical spherosomes within the umbiliform layer have a high electron density. The spherical spherosomes were more electron densed and were uniform in comparison with the cytoplasmic proteinaceous granules in endosperm cells of seed with red seed coat. The major component of spherosome was determined to be lipid. Lipase activity occurs in the spherosome and near the endosperm cell wall facing the umbiliform layer. Cytochemical reaction products of lipase were observed in the spherosome membrane and in the inner regions of spherosome. After protein bodies were digested, lipase activities were observed in free spherosomes and near the cell wall of endosperm cells. Umbiliform layer composing of fibrillized wall and digested materials of the endosperm cell showed a little lipase reaction products.

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A Study on Practices and Troubles of Reinforced Soil Wall (국내 보강토 옹벽 적용 현황 및 문제점 조사 연구)

  • Park, Jong-Kwon;Lee, Kwang-Wu
    • Journal of the Korean Geosynthetics Society
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    • v.11 no.1
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    • pp.65-75
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    • 2012
  • Since the modem reinforced soil wall technology was introduced in domestic civil engineering society in the year 1980, the reinforced soil walls have been extensively used because these technologies have advantages such as economical efficiency, graceful appearance, and easy construction. This paper describes the application of reinforced soil wall, design criteria, and construction problems. Many cases of troubles, which include a severe deformation of facing, cracks of facing block, overall sliding failure and so on, have been reported. Inappropriate design and construction management mainly induce these problems. The technological level of design and quantity control for reinforced soil wall is not sufficiently supported to cope with the growth quantity of reinforced soil wall construction market and the increasing number of construction companies. The unified standard design and construction criteria of reinforced soil wall should be established with the detail consideration of overall performance and stability. The quality control of design and construction, and cost of construction must be seriously executed to construct a high quality of reinforced soil wall.

Numerical Analysis for Optimum Reinforcement Length Ratio of Reinforced Earth Retaining Wall (보강토옹벽의 최적 보강길이비 산정을 위한 수치해석적 연구)

  • Park, Choonsik;Ahn, Woojong
    • Journal of the Korean GEO-environmental Society
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    • v.19 no.12
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    • pp.5-14
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    • 2018
  • Recently, method of reinforced earth retaining wall have been proposed according to the material of facing, geosynthetic, construction method, and facing slope. However, the regulations such as the design method and detailed review items according to each construction method are not clear, and collapse due to heavy rainfall frequently occurs. In this study, to obtain a more stable technical approach in the design of reinforced earth retaining wall, the combination of the pullout failure of reinforced earth retaining wall and the optimal reinforcement ratio of height using reinforced earth retaining wall using a single strength reinforcement is assumed, optimum design of stiffener, optimal design of superimposed wall and optimum length ratio of reinforcement material of geosynthetics are proposed through safety factor according to reinforcement length ratio (L/H).

A study of backward-facing step flow in a rectangular duct (후향계단이 있는 사각덕트 내부의 유동특성 연구)

  • Kim, Sung-Joon;Choi, Byung-Dae
    • Journal of Industrial Technology
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    • v.19
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    • pp.59-65
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    • 1999
  • This study is to analyze turbulent flow over a backward-facing step in a rectangular duct. The side wall effects on the internal flow were determined by varying the aspect ratio(defined as the step span-to-height ratio) from 1 to 20. In the flow behind a backward-facing step, separation, recirculation and redeveloping is occurred frequently. These phenomena appear in a particular variation by varying the aspect ratio. The results show that the aspect ratio has an influence on the velocity and reattachment length. When the AR is increased, the reattachment length is increased. For 6 over aspect ration, the rate of increase is decreased. The length of recirculation in the upper corner is increased, as the increase of aspect ration. It's width is not changed in the variation of aspect ration. The transverse, streamwise and spanwise velocities were decreased along the flow down stream of the step.

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Influence of Unsteady Wake on Turbulent Separated Flows over a Backward-Facing Step (후향 계단 주위 난류 박리 유동에 대한 비정상 후류의 영향)

  • Chun, Se-Jong;Sung, Hyung-Jin
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.27 no.12
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    • pp.1708-1715
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    • 2003
  • An experimental study was made of turbulent separated and reattaching flow over a backward-facing step, where unsteady wake was generated by a spoked-wheel type wake generator with cylindrical rods in front of the separated flow. The influence of unsteady wake was scrutinized in terms of the rotating speed of the wake generator (0$\leq$S $t_{H}$$\leq$0.4). A conditional averaging technique in corporation with SBF was employed to elucidate the influence of the unsteady wake on the large-scale vortical structures of the separated flow. Special attention was made during two-dimensional measurements of wall-pressure with or without unsteady wake. The wall-pressure fluctuations were used to predict dipole sound source by Curie's integral formula. It was found that the reduction of the dipole sound source was due to the reduction of turbulent kinetic energy by unsteady wake in the recirculation region.n.

A New Wall-Distance Free One-Equation Turbulence Model

  • Nakanishi Tameo
    • 한국전산유체공학회:학술대회논문집
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    • 2003.10a
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    • pp.107-109
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    • 2003
  • We propose a wall distance free one-equation turbulence model. The model is organized in an extremely simple form. Only a few model constants were introduced into the model. The model is numerically tough and easy-of-use. The model also demonstrated the ability to simulate the laminar to turbulent flow transition. The model has been applied to the channel flow, the plane jet, the backward facing step flow, the flat plate boundary layer, as well as the flow around the 2D airfoil at large angles of attack, which obtained satisfactory results.

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A Low-Reynolds-Number 4-Equation Model for Turbulent Separated and Reattaching Flows (난류박리 및 재부착 유동의 해석을 위한 저레이놀즈수 4-방정식 난류모형의 개발)

  • 이광훈;성형진
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.19 no.8
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    • pp.2039-2050
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    • 1995
  • The nonlinear low-Reynolds-number k..epsilon. model of park and Sung is extended to predict the turbulent heat transports in separated and reattaching flows. The equations of the temperature variance( $k_{\theta}$ and its dissipation rate(.epsilon.$_{\theta}$ are solved, in concert with the equations of the turbulent kinetic energy(k) and its dissiation rate(.epsilon). In the present model, the near-wall effect and the non-equilibrium effect are fully taken into consideration. The validation of the model is then applied to the turbulent flow behind a backward-facing step and the flow over a blunt body. The predicted results of the present model are compared and evaluated with the relevant experiments.

Development of Common Reinforced Concrete Block for Slope Protection (사면보호용(斜面保護用) 범용보강(凡用補强)콘크리트블록의 개발(開發))

  • Ryu, Neung-Hwan
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 2005.10a
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    • pp.404-409
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    • 2005
  • The reinforced concrete blocks for reinforced earth layer are combined with soil structures consisted of facing unit, reinforcing materials and soil. Those environmentally friendly facing units of reinforced concrete blocks are made of mine waste and tailing and that will be played a role of the effects of recycling use of wasted resources. The block are consisted of three types as curved or straight in order to control topography. The systems are also not limited to wall hight so that they are effectively used for protecting the slope of banking and cutting of earth works. The reinforced concrete blocks developed this time will be effectively applied for not only retaining wall, road, park, golf course, public office building constructions but also protecting of slope stabilization projects.

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