• 제목/요약/키워드: steel arch

검색결과 248건 처리시간 0.025초

지중압입체를 이용한 지하구조물 축조방법의 적용성 연구 (A Study on application of Trapezoidal Steel Box Tunnelling Method)

  • 전승배
    • 한국재난정보학회 논문집
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    • 제4권2호
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    • pp.138-154
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    • 2008
  • The conventional non-dig underground structure building method which made an appearance to reduce the social and environmental costs and maximize the efficiency of the social overhead capital facilities could not help being uneconomical because of many problems such as unnecessary excessive excavation, water leakage, obstacle interference, difficulty of curvilinear application and connection complexity between propelled and injected bodies due to indiscriminate application of small and large circular steel pipes without consideration of the site conditions. The T.S.T.M, in which a protruded square tube is applied as a propulsion and injection body in a design that considered site conditions such as ground condition, depth of soil and live load, was able to be economical as it solved the problems of water resistance, minimization of obstacle interference and curvilinearity, and we can see that it can be applied to all grounds by utilizing or complementing the target ground in terms of engineering. Also in configuring the transverse section, it is possible to not only secure excellent structural safety but also implement all of the above engineering characteristics not only in the square cross section but also in the arch cross section, so it was possible to build structures on any section or ground, and we could confirm the LCC reduction effect and the VE effect.

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CFTA거더의 선형거동 분석 및 안정성 평가 (Linear Behavior Analysis and Stability Assessment of CFTA Girder)

  • 정민철;이선애;공정식
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2009년도 정기 학술대회
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    • pp.271-274
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    • 2009
  • 강관의 내부에 콘크리트를 충전한 콘크리트 충전 강관 구조(CFT 구조, Concrete Filled Steel Tubular Structure)는 강재와 콘크리트의 단점을 상호 보완하고, 장점을 극대화 할 수 있다는 이점 때문에 최근 실제 구조물의 시공에 적용하는 사례가 증가하고 있는 추세이다. 이와 같은 CFT 거더의 장점을 살리면서 CFT 거더보다 더 뛰어난 경제적, 구조적 효율성을 얻기 위해 기존의 CFT 구조에 아치 형식과 프리스트레스를 도입한 CFTA(Concrete Filled and Tied Tubular Arch) 거더에 관한 연구가 현재 진행중이다. 본 연구에서는 CFTA 거더의 현장 실험과의 비교를 위해 ABAQUS 6.5-1을 이용하여 CFTA 거더의 유한요소 해석을 수행하였고, 이를 바탕으로 구조물의 선형거동을 분석하였다. 또한 구조물의 위험도 분석을 위해 본 구조물의 가장 약점으로 지적되고 있는 외부로 노출되어 있는 긴장재의 차량 충돌에 의한 사고를 가정하여 이를 고려한 유한 요소 해석을 수행하여 CFTA 구조물의 동적 및 정적 안전성 평가를 수행하고 그 결과를 분석하였다.

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중지압 운반 갱도내 변형계측 및 하중역산에 관한 연구 (A Study on the In-Situ Measurement of the Deformation and the Back Calculation of the Load in the Mine Roadway Over-Stressed Rocks)

  • Cho, Young-Soo;Kim, Hong-Woo;Shin, Hee-Soon;Chung, So-Keul;Lee, Hi-Keun
    • 터널과지하공간
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    • 제3권1호
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    • pp.40-49
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    • 1993
  • In this study, the indirect estimation method of the support load which is based upon the integrated measuring technique suggested by Kovari was applied to the calculation of support load in the mine roadway. Four test supports were installed in the area where they had to be replaed. Two of those were GI-130 rigid supports and the others were U-26 yieldable supports. The vibrating wire strain gages which were attached inpairs on the steel arch support were used to provide an accurate measurement. Bending moments and normal forces obtained from strain gage pairs were used to calculate the support load. This method was also verified by laboratory bending tests. The results obtained from the back-calculction method showed relatively good agreement with the measured convergence for each crossection.

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시공단계를 고려한 CFTA 거더교의 해석기법 (Analytical Technique on CFTA Girder Bridge Considering Construction Sequence)

  • 박성재;김용재;전종수;박명균;박경훈
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2009년도 춘계 학술대회 제21권1호
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    • pp.167-168
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    • 2009
  • CFT 구조는 강재내부와 심부콘크리트 사이의 상호작용에 의한 구조물의 변형성능, 강성, 내력의 증가때문에 새로 개발된 CFTA 거더에 적용되었다. CFTA 거더는 아치형상과 긴장력을 이용하여 외부하중에 의한 인장응력을 감소시키는 구조물이다. 본 논문은 CFTA 거더교의 제작중 및 공용중 안정성을 검토하기 위하여 시공절차를 제안하였으며, 이에 따른 시공단계해석을 수행하였다.

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국내최장 고속철도 정지고가(L=9.3km) 교량형식 개발 및 설계 - 35m PSM PSC Box교, 80m 3경간 Arch교, 국내최초 ED교 - (The Planning and Design of Jeong-Ji High Speed Railway Bridge)

  • 장인호;박경호;박종화;김영남;김선필
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2010년도 춘계학술대회 논문집
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    • pp.1691-1696
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    • 2010
  • Jeong-Ji overbridge is designed to be 9.3km long, the longest for a high speed railway bridge ever constructed in Korea. This bridge is constituted of three types of structure. Standard type bridge is 35m PSC Box bridge which will be constructed by Precast Span Method. To cross the Cheonan Nonsan Expressway, 80m three-span steel arch bridge is designed to avoid rail expansion joint. Finally, Extradosed bridge is planned for high speed railway bridge for the first time in Korea based on originative and advanced design techniques. It is expected that this will contribute to the development of national technology for long-span high speed railway bridges.

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FRP보강 그라우팅에 의한 단층대의 터널 안정성 분석 및 설계 사례 연구 (A Case Study of Analysis and Design for the Tunnel Stablization in Fault Zone by FRP Reinforced Grouting Method)

  • 박종호;최용기;박영목;권오엽;이재봉
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2001년도 봄 학술발표회 논문집
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    • pp.121-128
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    • 2001
  • This is a case study of stability analysis and reinforcement design for the tunnel where the collapse of the entrance slops occured along the fault zone developed in the bed rock. According to the site investigation, the main factor of sliding is the influence of fault gouge and heavy rainfall. Considering the in-situ condition, the versatile reinforcement methods is needed, and so the close investigation on the site area was accompanied with the stability analysis of tunnel and slops. The FRP(Fiberglass reinforced plastic) grouting method improved the defect of Steel Umbrella Arch Method, such as oxidation, low work efficiency, the material's heavy weight, is adapted as the reinforcement methods.

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Takayasu`s arteritis의 수술치험 1례 (Surgical Treatment of Takayasu`s Arteritis; Report of One Case)

  • 전희재
    • Journal of Chest Surgery
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    • 제26권6호
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    • pp.496-500
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    • 1993
  • Takaysu`s arteritis is an arteritis of unknown etiology involving larger elastic arteries. The end stage pathologic feature is vascular obstructive change and the resulting clinical manifestations are local ischemic symptoms such as syncope, visual disturbance, claudication of extremities, hypertension, and angina. Recently we have experienced one case of Takayasu`s arteritis involving aortic arch, left common carotid artery and left subclavian artery. The patient was 27 year-old female and she was admitted because of headache and neck pain. Aortogram revealed fusiform dilatation of left common carotid artery with focal narrowing on it`s distal portion. The patient underwent surgical resection and replacement of Dacron tube graft between distal and proximal left common carotid artery. 3 months after operation, she was readmitted because of shoulder pain and headache. Aortogram revealed focal narrowing of proximal left common carotid artery and total obstruction of left subclavian artery which caused subclavian steel syndrome. Aorto-left common carotid and aorto-left subclavian bypass graft replacement were done.

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Influence of Tempering Temperature and Microstructure on Wear Properties of Low Alloy PM Steel with 1-2% Ni Addition

  • Tekeli, Suleyman;Gural, Ahmet;Guru, Metin
    • 한국분말야금학회:학술대회논문집
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    • 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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    • pp.1004-1005
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    • 2006
  • The effect of tempering temperature and microstructure on dry sliding wear behavior of quenched and tempered PM with 0.3% graphite and 1-2% Ni steels was investigated. The sintered specimens were quenched from $890^{\circ}C$ and then tempered at $200^{\circ}C$ and $600^{\circ}C$ for 1 hr. Wear tests were carried out on the quenched$\neq$tempered specimens under dry sliding wear conditions using a pin-on-disk type machine at constant load and speed. The experimental results showed that the wear coefficient effectively increased with increasing tempering temperature and decreased with increasing Ni content.

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의자 다리와 스트레쳐를 중심으로 한 형상 최적화 설계 (Optimal Shape Design of Legs and Stretcher Parts of Chair)

  • 이영민;정훈
    • EDISON SW 활용 경진대회 논문집
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    • 제5회(2016년)
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    • pp.256-261
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    • 2016
  • In this paper, Shape optimal design for a chair with 4 legs and 2 stretchers consisting of stainless steel was conducted. The shape was transformed by identifying stress and deformation for the part of leg and stretcher. In addition, load condition and mesh was designed using Hypermesh. The stress analysis was carried out using CSD_Elast that is one of EDISON program. In seat test, Maximum equivalent stress was showed at the contact part between seat and legs. As a result, a leg cross-section with rectangular and arch was designed. And optimal height of stretcher was found to reduce a deformation. Also, maximum deformation was reduced by designing a stretcher with ellipse cross-section. So, Optimal chair having 4 legs with rectangular cross section and 2 stretchers with ellipse cross section was shown to satisfy the safety ratio.

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Effect of Repeated Quenching Heat Treatment on Microstructure and Dry Sliding Wear Behaviour of Low Carbon PM Steel

  • Gural, Ahmet;Tekeli, Suleyman;Ozyurek, Dursun;Guru, Metin
    • 한국분말야금학회:학술대회논문집
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    • 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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    • pp.570-571
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    • 2006
  • The mixed atomized iron powders with 0.3% graphite and 1% Ni powders were cold pressed and sintered at $1200^{\circ}C$ for 30 min under pure Ar gas atmosphere. Some of the sintered specimens were intercritically annealed at $760^{\circ}C$ and quenched in water (single quenching). The other sintered specimens were first fully austenized at $890^{\circ}C$ and water quenched. These specimens were then intercritically annealed at $760^{\circ}C$ and re-quenched in water. The experimental results showed that the wear coefficient effectively decreased in the double quenched specimen.

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