• 제목/요약/키워드: curved concrete

검색결과 121건 처리시간 0.026초

UHPC 비정형 패널 제작 시 수화열에 의한 PCM 거푸집의 형상오차 분석 (Evaluation of Shape Deviation in Phase Change Material Molds Subjected to Hydration Heat During Ultra-High Performance Concrete Free-form Panel Fabrication)

  • 김홍연;차재혁;윤종영;김성진;이동훈
    • 한국건축시공학회지
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    • 제23권3호
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    • pp.251-260
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    • 2023
  • 비정형 건축물은 외부면이 다양한 곡선이기 때문에 비정형 거푸집은 맞춤제작되어 사용된다. 비정형 거푸집 제작에 있어 재활용이 가능한 Phase Change Material(PCM)과 곡률구현에 용이한 Ultra-High Performance Concrete(UHPC)가 사용된다. 그러나 PCM은 약 58~64℃가 융점이며, UHPC의 수화열로 PCM 거푸집이 손상될 수 있어 실험을 통해 형상을 확인한다. 실험은 제작한 PCM 거푸집에 Silicone sheet 3mm를 설치한 (A)와 설치하지 않은 (B) 거푸집에 UHPC를 타설한다. 실험결과 (A) 3.793mm, (B) 5.72mm가 측정되었으며, (B) 거푸집이 수화열에 취약한 것으로 분석되었다. 이러한 연구는 초고강도 비정형 패널 및 PCM 거푸집 제작 관련 기초자료로 활용될 것으로 기대된다.

축소 철근콘크리트 벽체의 내력과 균열진전에 대한 개구부모서리 균열제어 띠의 영향 (Effect of Crack Control Strips at Opening Corners on the Strength and Crack Propagation of Downsized Reinforced Concrete Walls)

  • 왕혜린;양근혁
    • 한국구조물진단유지관리공학회 논문집
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    • 제26권4호
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    • pp.40-47
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    • 2022
  • 이 연구의 목적은 철근콘크리트 벽체의 내력, 변형 및 균열진전에 대한 개구부 모서리의 사인장 균열 제어를 위한 다양한 보강방법들이 효율성을 평가하는 것이다. 개구부 모서리의 사인장 균열제어 보강방법으로서 이 연구에서 제안한 균열제어 띠, 기존의 경사보강근 배근방법, 그리고 응력분산곡면판을 선택하였다. 균열제어 띠에서는 균열치유 기능성이 부여된 것도 함께 고려하였다. 개구부 주위의 체적변화 및 균열 폭 진전을 평가하기 위하여 개구부 모서리에서 사인장 균열 유도를 위한 축소 벽체 실험을 수행하였다. 실험결과 균열제어 띠는 경사보강근 및 응력분산곡면판에 비해 개구부 주위의 체적변화 감소 및 개구부 모서리 균열 폭 제어에 효율적이었다. 균열 치유 기능이 포함된 균열제어 띠는 사전 실험에서 발생한 균열들을 치유하면서 축소 벽체의 내력 향상 및 균열 폭 감소에 가장 좋은 성능을 보였다.

淸州 및 報恩地方의 頭首工洪水災害에 關한 調査硏究(II) -災害原因 및 對策方案을 中心으로- (A Study on the Damages of Head Works by the Storm Flood in the Area of Cheong Ju and Boeun -Emphasis onFactors Influenced on the Disasters and their Countermeasures-)

  • 남성우;김철기
    • 한국농공학회지
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    • 제24권2호
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    • pp.49-55
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    • 1982
  • The purpose of this study is to classify the factors influenced on the damages of head works suffered from the storm flood occurred on July 22 1980 in both Musim and Bochong rivers and to find out an integral counter measures against the causes influenced on the disaster of head works in the engineering aspect of planning, design, construction and maintenance. In this survey, number of samples was taken 25 head Works, and the counter measures against the causes of their disasters summarized was as follows, 1. In the aspect of planning a. As the flood water level after the establishment of head works is more increased than the level before setting of head works owing to having more gentle slope of river bed between the head works than nature slope of river bed. Number of head works should be reduced for the appropriate annexation of them b. In the place where head works is established on the curved point of levee, the destruction of levee becomes severe by the strong deflective current. Therefore the setting of head works on the curved point should be kept off as long as possible and in case of unavoidable circumstances the construction method such as reinforced concrete wall or stone wall filed with concrete and anchored bank revetments should be considered. 2. In the aspect of design a. As scoring phenomena at up stream is serious around the weir Where the concentration of strong current is present in such a place, up stream apron having impermeability should be designed to resist and prevent scoring. b. As the length of apron and protected bed is too short to prevent scoring as down stream bed, the design length should be taken somewhat more than the calculated value, but in the case the calculated length becomes too long to be profitable, a device of water cushion should be considered. c. The structure of protected river bed should be improved to make stone mesh bags fixed to apron and to have vinyl mattress laid on river bed together with the improvement for increasing the stability of stone mesh bags and preventing the sucked sand from the river bed. d. As the shortage of cut-off length, especialy in case of the cutoffs conneting both shore sides of river makes the cause of destruction of embankment and weir body, the culculation of cut-off length should be taken enough length based on seepage length. 3. In the aspect of design and constructions a. The overturing destruction of weir by piping action was based on the jet water through cracks at the construction and expansion joints. therefore the expansion joint should be designed and constructed with the insertion of water proof plate and asphalt filling, and the construction joint, with concaved shape structure and steel reinforcement. b. As the wrong design and construction of the weep holes on apron will cause water piping and weir destruction, the design and construction of filter based on the rule of filter should be kept for weep holes. c. The wrong design and construction of bank revetment caused the severe destruction of levee and weir body resulting from scoring and impulse by strong current and formation of water route behind the revetment. Therefore bank revetment should be designod and constructed with stone wall filled with concrete and anchored, or reinforced concrete wall to prevent the formation of water flow route behind the wall and to resist against the scoring and impulse of strong stream. 4. In the aspect of maintenance When the damaged parts occurred at head works the authorities and farmers concerned should find and mend them as soon as possible with mutual cooperation, and on the other hand public citizen should be guided for good use of public property.

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복합트러스교의 격점구조별 비틀림 거동 (Torsional Behavior of Hybrid Truss Bridge according to Connection Systems)

  • 정광회;이상휴;이종원;최지훈;김장호
    • 콘크리트학회논문집
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    • 제25권1호
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    • pp.63-72
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    • 2013
  • 복합트러스교는 프리스트레스 박스거더교의 복부를 강재 트러스로 대체한 교량으로 자중이 경감되는 구조적 장점과 복부 개방구조로 인한 경관성이 매우 우수하여 최근 들어 많이 사용되고 있다. 이러한 복합트러스교의 핵심기술은 강재 트러스와 콘크리트 슬래브를 연결하는 격점구조이며 지금까지 여러가지 격점구조들이 개발되어 실험적 검증을 통해서 실교량에 적용해 오고 있다. 이러한 격점구조는 격점부 국부적인 거동뿐만 아니라 복합트러스 거더의 휨 및 피로 등 전체적인 거동을 좌우하기 때문에 이에 대한 연구가 계속 진행되고 있다. 한편, 복합트러스 교량의 복부 개방구조는 프리스트레스 박스교량에 비해 비틀림 성능을 저하시키는 단점을 가지고 있어 편심하중을 받는 교량이나 곡선교 등에는 아직까지 적용된 사례가 없다. 따라서 복합트러스교가 보다 널리 사용되기 위해서는 비틀림 거동에 대한 정확한 분석이 필요한 상황이다. 이 연구에서는 복합트러스교의 격점구조 형식에 따른 비틀림 거동 특성을 알아보기 위해서 3가지 형태의 박스형 복합트러스 실험체를 제작하여 비틀림 실험을 수행하고 분석해 보았다.

실대형 반복재하시험을 통한 매립형궤도 소성누적침하 평가 (Evaluation of Plastic Accumulative Settlement of Embedded Rail Track by Real-scale Repetitive Load Tests)

  • 이수형;강윤석;오상호;박정근
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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    • pp.406-411
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    • 2011
  • An active application of tram is being expected in Korea in the near future. For the tram operation in urban area, the embedded rail tracks where rails are completely embedded with pavements is required. When the embedded rail track is constructed on fine-grained subgrade soil, excessive cumulative plastic settlements due to repetitive tram road may occur. In this study, repetitive load tests were carried out to evaluate the accumulative plastic settlements of subgrade soils underneath embedded rail tracks. Two real-scale track specimens of 5 m lengths were constructed considering the maximum cant of a curved line. Repetitive tram loads of three million times were applied to the tracks in 5 Hz frequency. The accumulating patterns of plastic settlements were analyzed. Tram load distributing effects of the concrete slabs were also evaluated using the measured data of earth pressures cells that were installed underneath track. Also the measured settlements were compared with the estimated settlements calculated from an existing experimental equations, and its validity is discussed.

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18세기 '중국풍 정원(Anglo-Chinese garden)'의 문화전이에 관하여 (A Transcultural Reflection on Anglo-Chinese Gardens in the 18th Century)

  • 김대신
    • 미술이론과 현장
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    • 제16호
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    • pp.201-224
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    • 2013
  • The tradition of the representative art style in the Sinosphere, Shanshui hua, expresses the traditional representation of the harmony and principle of the universe. This tradition is reflected in the Chinese garden. These Chinese gardens were precisely the three-dimension representations of Shanshui hua, a visual form of abstract expression of the oriental philosophical thinking. This research determines and draws attention to the vestiges of the reflection of Shanshui hua in the European gardens through visual art and culture. It will also approach the two subjects, Shanshui hua and garden, from a transcultural view to integrally analyze visual art. The appearance of Anglo-Chinese gardens, reflecting Shanshui hua, foreshowed a big change in traditional European gardens. This is a concrete example of the transcultural phenomenon. This has formed the typical naturally curved English gardens in the gardening history. This also divided these English gardens completely from the symmetrical, geometrical French gardens. This study considers the influence and the reverberation of Shanshui hua reflected on European gardens in the European culture. The cultural exchange of European and Chinese styles in the 18th century left an impact on the European gardening style history. Finally, this study analyzes the origin of these Anglo-Chinese gardens and its content to approach it with a transcultural view as a research methodology.

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Nonlinear dynamic analysis of RC frames using cyclic moment-curvature relation

  • Kwak, Hyo-Gyoung;Kim, Sun-Pil;Kim, Ji-Eun
    • Structural Engineering and Mechanics
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    • 제17권3_4호
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    • pp.357-378
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    • 2004
  • Nonlinear dynamic analysis of a reinforced concrete (RC) frame under earthquake loading is performed in this paper on the basis of a hysteretic moment-curvature relation. Unlike previous analytical moment-curvature relations which take into account the flexural deformation only with the perfect-bond assumption, by introducing an equivalent flexural stiffness, the proposed relation considers the rigid-body-motion due to anchorage slip at the fixed end, which accounts for more than 50% of the total deformation. The advantage of the proposed relation, compared with both the layered section approach and the multi-component model, may be the ease of its application to a complex structure composed of many elements and on the reduction in calculation time and memory space. Describing the structural response more exactly becomes possible through the use of curved unloading and reloading branches inferred from the stress-strain relation of steel and consideration of the pinching effect caused by axial force. Finally, the applicability of the proposed model to the nonlinear dynamic analysis of RC structures is established through correlation studies between analytical and experimental results.

도심형 자기부상열차 선로 종곡선 구간에서의 PSC-U 형 거더와 프리캐스트 바닥판 적용성 평가 (Applicability Evaluation of PSC-U Type Girder and Precast Deck to the Vertical Curves in Urban Maglev Train Route)

  • 진병무;김인규;김영진;이윤석;마향욱;오현철
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2008년도 춘계학술대회 논문집
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    • pp.24-30
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    • 2008
  • One of the characteristics of the Maglev Train is the prominent capability of upgoing. Maglev train with the aim of longitudinal slope 7/100 is under development by the Center for Urban Maglev Program in Korea. To realize these slope, vertical curves must be inserted before and after the slope. The inserted curve has the radius of 3,000m generally. The insertion of these vertical curve results in the additional differences between the girder upper face and the guide rail, and the alignments are controlled by cast in place concrete at present. In this study, for longitudinal curved route with longitudinal slope 6/100, the applicability of PSC-U type girder and precast deck was evaluated for the span length 25m, 30m and vertical curve radii with 3,000m and 1,500m with respect to longitudinal slope 6/100.

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여대생들의 생활한복 실용화를 위한 디자인 연구 (A Design Research for the Practical Use of College Women′s Casual Hanbok)

  • 김장향
    • 한국의상디자인학회지
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    • 제2권2호
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    • pp.55-79
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    • 2000
  • This study is the design research for the practical use of Casual Hanbok. The conclusion of basic research for Casual Hanbok design reads as follows. Today's college women are fairly positive to the practical use of Casual Hanbok. Especially, they are strongly interested in the new design and have the active intention to wear it on actually. The concrete design of every parts of Casual Hanbok which is wanted by college women is as follows. Firstly, college women like well matched two-piece dress style in colors. And they want to decide the coloration independently than to follow the traditional coloration passively. Secondly, according to the design of jacket, sometimes they like the presence of a collar, a collar strip, a gore etc. and at other times they like absence of them. Thirdly, the side line of jacket they like and the seam line of sleeve they like is smoothly curved one and the adjusting means they like is a fancy button. Fourthly, the length of jacket they like reaches to their waist and the width of an armhole they like must be convenient for moving of arm. Fifthly, one out of two college women likes mixed spinning fabrics as material for jacket, skirt, pants. In the other hand, one out of five college women likes cotton. Sixthly, the skirt style they like is A ­line one having from two to four gathers on the waist and the length of skirt they like reaches to their ankle or calf of the leg. Seventhly, the pants style they like is the western style but the hem line of pants is the korean traditional pants style.

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현대 상업공간에 표현된 디자인코디네이션 관점의 한국성 특성 분석 (Analysis of the Koreanity Expression Properties found in the Modern Commercial Spaces from a Design Coordination Viewpoint)

  • 임선희;박영순;정의철
    • 한국실내디자인학회논문집
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    • 제21권5호
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    • pp.135-144
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    • 2012
  • Since Seoul was selected as the world design capital at the end of 2007, the endeavors to modernize the Korean unique beauty is becoming more tangible. Especially, the commercial spaces to be used by the general public and tourists have the value for study in the respect that such spaces for the national iconic images and have a large and far-reaching effect to transmit the national identity. Therefore, this study analyzed the design coordination properties in the Koreanity expression found in the modern commercial spaces. the foundation for the analysis was based on Leonard Koren's work on the arrrangement rhetoric theory, 'Arranging things(2003), and the contents of Korean expression were reviewed with professional jounals. the results are as follows: First, the design coordination properties in the Koreanity expression shown in modern commercial spaces are black-white contrast, natural materials, curved shapes, brevity, and simple beauty. Especially, some elements such as wood, traditional Korean papers, stones, mid-to-low chroma natural colors, checked patterns, and crazy patterns are used with overlapping and it is viewed that it is necessay to more aggressively seek for the disappeared traditional elements in the Korean modeling properties. Second, the concrete images of Korean expressions could be summarized as four adjective image groups, Natural, Subtitle, Gentle and Magnificent.

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