• Title/Summary/Keyword: Construction level

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Centrifuge Model Tests on the Pullout Capacity of Embedded Suction Anchor without Flanges in Sand layer (모래지반에 매입된 날개없는 석션앵커의 인발력에 대한 원심모형실험)

  • Kim, Kyoung-O;Kim, You-Seok;Ko, Boo-Hyun
    • Proceedings of the Korean Geotechical Society Conference
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    • 2005.10a
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    • pp.517-520
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    • 2005
  • The embedded suction anchor(ESA) is and anchor that is driven by a suction pile. The cross-sectional shape of the ESA anchor is circle. Its diameter is the same as that of the suction pile that is used to drive it into the seafloor. For the installation, the anchor is attached to the tip of the suction pile and then driven as a unit with the pile by and applied suction pressure. Once the ESA anchor reaches the desired depth, the pile is retrieved by applying a positive pressure. Finally, only the ESA anchor remains in the soil layer. This paper presents the results of centrifuge model tests to investigate ESA pullout capacity. The main parameters that have effects on the pullout capacity of ESA may include g-level, embedded depth, direction of loading, and loading point. The results of tests show that the pullout loading capacities increase as the loading point shift toward the tip of the anchors for a given loading direction. They also indicate that the loading point associated with the maximum pullout loading capacity is located at approximately 67 percent of the anchor length from the top for the horizontal load.

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Assessing Nonpoint Sources Pollution Affected by Regulating Gate and Liquid Manure Application in Small Agricultural Watershed (제수문 영향 및 액비시용 증가에 따른 농업소유역에서의 비점오염원 특성 평가)

  • Song, Jae-Do;Jang, Taeil;Son, Jae-Kwon
    • Journal of The Korean Society of Agricultural Engineers
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    • v.58 no.6
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    • pp.31-38
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    • 2016
  • The purpose of this study was to assess nonpoint sources (NPS) pollution affected by liquid manure and regulating gate in a small agricultural watershed. The study area, which is a wide plain farmland, was operating by the Buyong regulating gate in order to maintain irrigation water level during irrigation period. Consequentially, runoff only occurs through the gate at each event in rainy season for avoiding farmland inundation. In addition, the usage ratio of liquid manure in the study area has been increased greatly since 2014. Discharge loads at the Hwaingsan bridge subwatershed were 1.2 times for T-N, 4-10 times for T-P, and 3-8 times for TOC compared with the Soyang watershed (control) during study period. The reason was that NPS pollutants from upper Gpeun and Sangri bridge subwatersheds, which are widely spraying with livestock liquid manure, were stack at this subwaterehd because of regulating gate in non-rainy seasons. A number of agricultural watersheds in Saemangeum watershed are affected by regulating gate and vigorous livestock activities so that substantial management schemes under controling regulating gate are needed for minimizing livestock related NPS.

Analysis of River Channel Morphology and Riparian Land Use Changes Using Aerial Photographs and GIS (항공사진과 GIS를 이용한 하천형태 및 하천부지 변화추세 분석)

  • Park, Geun-Ae;Lee, Mi-Seon;Kim, Hyeon-Jun;Kim, Seong-Joon
    • Journal of The Korean Society of Agricultural Engineers
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    • v.47 no.2
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    • pp.15-21
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    • 2005
  • This study is to trace the change of stream shape using the past series of aerial photographs, and to compare the land use changes of riparian area along the stream. For the Gyeongan national stream, aerial photographs of 1966, 1981 and 2000 were selected and ortho-photographs were made with interior orientation and exterior orientation, respectively. Apparent changes of the stream were found that the consolidated reaches of stream by levee construction became straight together with widening of their stream widths. Especially the stream width of inlet part of Paldang lake widened almost twice because of the rise of water level by dam construction in 1974. The land use of riparian areas of three selected years were classified into six categories (water, forest, agricultural land, urban area, road, sandbar) by digitizing method. The forest and agricultural lands decreased and urban area increased as the stream maintenance had been performed.

A Study on the Periodization in the History of Korean dwellings during the age of prehistory and the ancient Kingdomes (한국(韓國) 선사시대(先史時代) 및 삼국시대(三國時代) 주거사(住居史)의 시대구분(時代區分)에 관한 재고(再考))

  • Kang, Young-Hwan
    • Journal of architectural history
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    • v.5 no.2 s.10
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    • pp.9-24
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    • 1996
  • Owing to the energitic studies of the leading shcolars, some paradigmatic theories on the history of Korean dwellings have been suggested. They constructed periodization of their own and defined characteristics of each period with very limited historical materials. However the new historical materials have been discovered in the neighboring academic fields, which require to review the existing theories. This study aims at restructuring periodization in the history of Korean dwellings during the age of The prehistory and The ancient Kingdomes. Through the study, the existing theories on the same period are revived and evaluated based on the new materials. I suggest a new theory on the periodization and the characteristics of each period: a. the paleolithic period(6,000,000 B.P.-10,000 B.P.) : natural shelter, the emergence of man-made dwellings b. the neolithic period(10,000 B.P.-1,000 B.C.) : construction of pit house c. the bronze period(1,000 B.C.- 300 B.C.) : construction of semi-pit house d. the early metalic period(300 B.C. - 300 AD.) : construction of house on the ground level development of the Ondol system e. the ancient kingdomes period(300 AD - 700 AD): classification of housing type

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The Study of Load Test Method for In-Site Casting Pile In High Rise Building. (초고층에서의 현장타설말뚝 재하시험방법 고찰)

  • Kim, Dae-Hak;Hong, Young-Kil;Han, Sung-Moo;Gu, Ung-Hwoe;Park, Chan-Duck
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.03a
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    • pp.385-392
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    • 2008
  • Modern city have had a lot of high-rise building in high standards and multi-level performance. Using of city space reach better stages by using integration. These skyscraper have increased working load on ground. that building is efficiently designed for that soil capacity is well applied. With material side, big size pile, high strength concrete and high strength steel is used for that getting enough lobby space and resisting load increased of high-rise building. limit load test and load transmitted test can make soil capacity optimized. By the way, method of measuring pile capacity is more advanced and bigger. pile type applied by high rise building have underground excavation space, also reflect regional soil property and have some fact reviewed. A lot of high rise building recently is built as land mark in Seoul, Busan and Incheon. about method of measuring capacity of foundation pile, example of construction field is compared and reviewed.

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Failure Mechanism of NATM tunneling using Computational Methods and Geology Investigation (수치해석수법과 지질공학적 분석을 통한 NATM터널의 붕괴메커니즘에 관한 연구)

  • Lee, Jae-Ho;Kim, Young-Su;Choi, Hea-Jun;Jeong, Yun-Young;Jin, Guang-Ri;Rim, Hong-Rae
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.03a
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    • pp.742-753
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    • 2008
  • Currently an increasing number of urban tunnels with small overburden are excavated according to the principle of the New Austrian Tunneling Method (NATM). Therefore, a possibility of a tunnel collapse during excavation is getting higher in a proportionate manner. This paper will analyze causes the failure mechanism of a shallow NATM tunnel for different geological conditions, ground-water and invert solutions by investigation typical collapse site during tunnel construction. In this paper, this analysis performed two phase, firstly, the field investigation considering displacement measurement, ground-water level, geological characteristic, secondly, the numerical simulation considering the exist of invert construction and the effect of ground-water. It has been found that environmental factors such as state of underground water or construction sequences could influence failure mechanism of a shallow tunnel.

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Numerical Study for Tunnel Shotcrete Lining Operated Stress Measurement Techique Development During a Construction (시공중 터널 숏크리트 라이닝 작용응력 측정기법 개발을 위한 수치해석적 연구)

  • Shin, Hyu-Seong;Kim, Dong-Gyou;Jung, Yong-Su;Hwang, Jae-Hong;Bae, Gyu-Jin
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.03a
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    • pp.754-761
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    • 2008
  • In general, stress measurement of existent shotcrete lining be used by pressure cells. but, measuring instrument is lost by high pressure at shotcrete lining construction and pressure cell's measurement value have to low believability by natural conditions like curing temperature. In this study, proposed techniques to measure without utilizing sensitive stress sensor in natural condition at point that want stress of shotcrete lining after shotcrete lining construction. Executed numerical analysis to forecast stress level that interact in tunnel shotcrete lining, measured strain of hole by load action through hole in shotcrete lining. 3D FEM(finite element method) is enforced through various parameters curing time of shotcrete lining, thickness, load condition. Different model cases applied by parametic study. As analysis result, it could grasp development possibility of method that propose this time because it could examine corelation with strain by near hole of shotcrete lining and stress about load condition.

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Development of Work Breakdown Structure for Nuclear Power Plant (원자력발전소 Work Breakdown Structure 개발)

  • Cho, Yeong-Heock;Yang, Myung-Duck
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2014.05a
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    • pp.52-53
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    • 2014
  • The Work Breakdown Structure (WBS) is a primary tool which provides a framework that defines clear scope of all deliverables throughout the project life cycle. Once the WBS is established in projects, it should allow project team members to measure and manage work performances by the WBS; further, it should provide a reference point when any work scope needs to be redefined. Based on the project information in the Progress and Performance Measurement System (PPMS) of UAE's Barakha Nuclear Power Plant (BNPP) projects, an attempt was made to develop a new WBS which provides hierarchical and systematical decomposition of the total work scope of NPP construction projects while avoiding from the preexistence concept in Korean NPP projects that the WBS is a combination of Physical Breakdown Structure (PBS) and Functional Breakdown Structure (FBS). The unique features of the new WBS are as follows: (1) defined the definition of each level of the WBS, (2) subdivided the WBS into 5 hierarchical levels, and (3) adopted globally used general coding structure. The new WBS provides a basic hierarchical structure for the project scope and can be used as a basic tool for schedule control, performance measurement, project status monitoring, and communication among project participants. In addition, by putting the Work Package (WP) under the WBS, the Earned Value Management System (EVMS) per WP can be utilized for the project.

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Characteristic Analysis of Urban Landscape Formed by Container Construction (컨테이너 건축이 만드는 도시경관 특성 분석)

  • Park, Jongil;Han, Seung-Hoon
    • KIEAE Journal
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    • v.17 no.1
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    • pp.37-42
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    • 2017
  • Purpose: Various landscapes have been created in the process of changing containers, which were a tool of trade activities, to architecture, and today, containers have formed relationships with people as complex facilities and constantly create new cultures. In this paper, considering these container constructions from the viewpoint of the landscape, consider the meaning as one of landscape factors for creating cultural landscape. Method: In this study, a methodological framework was constructed based on various statistical data and literature materials, and analyzed texts called containers from the viewpoints of physical elements and active elements and analyzed them at the level of function. Based on literature materials, specifically, this study has handled with the cultural landscape as text, the functional dimension of urban design, and the characteristics of container construction. Result: This research analyzed the physical and active characteristics of the target area by utilizing the content of the field analysis and the contents of the interview, previous research, etc., and then content was analyzed in functional dimension. Through this process, the conclusion proposed by this research is to study the construction of a container and present the direction to analyze in the functional dimension showing the landscape characteristics that it brings forward.

Experimental study on simplified steel reinforced concrete beam-column joints in construction technology

  • Teraoka, Masaru;Morita, Koji;Sasaki, Satoshi;Katsura, Daisuke
    • Steel and Composite Structures
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    • v.1 no.3
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    • pp.295-312
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    • 2001
  • The purpose of this paper is to propose a new type of steel reinforced concrete (SRC) beam-column joints and to examine the structural performance of the proposed joints, which simplify the construction procedure of steel fabrication, welding works, concrete casting and joint strengthening. In the proposed beam-column joints, the steel element of columns forms continuously built-in crossing of H-sections (${\Box}$), with adjacent flanges of column being connected by horizontal stiffeners in a joint at the level of the beam flanges. In addition, simplified lateral reinforcement (${\Box}$) is adopted in a joint to confine the longitudinal reinforcing bars in columns. Experimental and analytical studies have been carried out to estimate the structural performance of the proposed joints. Twelve cruciform specimens and seven SRC beam-column subassemblage specimens were prepared and tested. The following can be concluded from this study: (1) SRC subassemblages with the proposed beam-column joints show adequate seismic performances which are superior to the demand of the current code; (2) The yield and ultimate strength capacities of the beam-to-column connections can be estimated by analysis based on the yield line theory; (3) The skeleton curves and the ultimate shear capacities of the beam-column joint panel are predicted with a fair degree of accuracy by considering a simple stress transfer mechanism.