• Title/Summary/Keyword: allowable load

검색결과 507건 처리시간 0.025초

저온해역에서의 해양구조물에 대한 구조신뢰성 해석 (Structural reliability analysis of offshore structure at cold region)

  • 이주성
    • 한국해양공학회지
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    • 제11권3호
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    • pp.8-19
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    • 1997
  • In this study an adequate type of offshore structure at the Sakhalin region as cold region is proposed and its structural design results are presented based on the reliability analysis. Structural safety assessment has been carried out for the proposed offshore structure at the Sakhalin area as designed by the reliability method. And a rational design procedure is presented based on the reliability analysis. Followings are drawn through the present study : - Four colum TLP structure is proposed as an adequate offshore structure type at the cold region like the Sakhalin region and the reliability-based structural design results are presented. It is seen that the proposed type is a more adequate and economic than the fixed type. - Safety assessment of the proposed structure applying the extended incremental load method is performed. - Referring the allowable safety level for offshore structures it has been found present TLP structure has sufficient structural safety at the system level as well as at the component level.

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한옥의 내진설계를 위한 비틀림비정형 평가 방안 (An Evaluation Scheme of Torsional Irregularity for Seismic Design of Hanok)

  • 김영민
    • 대한건축학회논문집:구조계
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    • 제35권10호
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    • pp.191-198
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    • 2019
  • In this paper the evaluation scheme for determining torsional irregularity of Hanok has been proposed. The proposed method can evaluate torsional irregularity of Hanok easily only with characteristics of Hanok shapes, arrangement of lateral load resisting frames and their lateral stiffness without time consuming and complicate 3-dimensional structural analysis. The proposed formula is expressed as allowable maximum eccentricity, and torsional irregularity is evaluated by comparing this value with actual eccentricity. The applicability of the proposed scheme was evaluated by applying it to the line shape plan Hanok with two symmetrically arranged walls and the result was expressed by formula and graph. The results showed that the allowable maximum eccentricity is 10% of plan dimension perpendicular to the seismic load when the walls are placed at the extreme end. The proposed formula was expressed as a generalized formula so it can be applied generally to the various plan shape and wall arrangement of Hanok.

Load-Carrying Capacity Assessment of Deteriorated Rural Bridge

  • Kim, Han-Joong;Kim, Jong-Ok;Yang, Seung-Ie
    • 한국농공학회지
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    • 제44권7호
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    • pp.36-45
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    • 2002
  • Most of rural bridges have passed 30 years of age since they were built, which have to support unexpected overload caused by changed design load and excessive amount of transportation. For these rural bridges, repairs and replacements are needed. Even though there have been attempt to estimate the safety of existing bridges deteriorated with major defects, those approaches must rely on the observable damage and subsequent decisions are made subjectively. To avoid the high cost of rehabilitation, the bridge rating must correctly represent the present load-carrying capacity. Rating engineers use a methods such as Allowable Stress Design (ASD), Load Factor Design (LFD), and Load Resistance Factor Design (LRFD) to evaluate the bridge load carrying capacity. In this paper, the load rating methods are introduced, and it is illustrated how to use the load test data from literature survey. Load test is conducted to the bridge that was built 30 years ago in rural area. From load test results, new maintenance method is suggested instead of the bridge replacement.

고강력 PET Interlace Yarn 밀도변화가 Pack Style Shock Energy Absorber의 물성에 미치는 영향 (Effect of Density Variation of High Tenacity PET Interlace Yarn on the Physical Properties of Pack Style Shock Energy Absorber)

  • 조진원;권상준;최종덕;김상태;지병철;양성백;염정현
    • 한국염색가공학회지
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    • 제27권2호
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    • pp.132-141
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    • 2015
  • Fall-arrest systems(maximum arrest force and allowable free-fall) have been widely applied to provide a safe stop during fall incidents for various industrial activities. Fabric structure affects on the mechanical properties of shock energy absorber. The object of this study is to perform the basic research for the evaluation of the capacity of fall arrest energy absorber in relation to the different interlace yarn density. In this work, pack style energy absorber was prepared by weaving 10 types(Interlace yarn density used high tenacity PET 1000D : 60, 59, 58, 57, 56, 55, 54, 53, 52, 51). The paper presents the results of theoretical investigations of the performance of adjustable absorber during fall arrest. Dynamic load tests based on the EU fall protection equipment standard(CE : EN355:2002) were conducted. Results showed that the maximum arrest force by dynamic load test of energy absorber was satisfied with global standard(below 6,000N). Also, Maximum allowable free-fall of energy absorber showed below 1.75m.

차량 하중 방향 변경에 의한 기존교량의 피로안정성 연구 (A Fatigue Stability Study of an Existing Bridge Due to Vehicle Load Direction Change)

  • 이규세;이승열
    • 한국산학기술학회논문지
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    • 제10권8호
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    • pp.2062-2067
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    • 2009
  • 도로 건설 중 기존 교량에 가교를 접속하여 사용하는 경우가 종종 발생한다. 이 경우 차량 하중 방향의 변경으로 인하여 기존 교량의 주형의 설계 시 고려하지 못한 피로 안정성 문제가 발생할 수 있다. 따라서 본 연구에서는 기존 교량의 내민 슬라브와 주형의 안정성을 도로교 설계기준의 허용 피로 응력을 이용하여 검토하였다. 응력변동이 가장 큰 지점은 가교 접속 구간의 교량 시점에서 55m 떨어진 지점부, 그리고 교량 시점과 지점부 사이의 중앙점(교량 시점에서 32.5m 떨어진 지점)의 응력 변동이 크다는 것을 알 수 있었다. 이에 대한 기존 교량의 내민 슬라브와 주형에 보강이 필요함을 확인하여 보강대책을 수립하였고 보강 후 가교와 기존 교량의 피로 안정성 검토를 다시 수행하여, 도로교 설계 기준의 허용 피로 응력에 만족함을 확인하였다.

중공 슬래브의 국부지압강도에 대한 시공안전성 평가 (Construction Safety Evaluation of Local Bearing Strength of Hollow Core Slab)

  • 허무원;윤정환;황규석;윤성호;박태원
    • 한국구조물진단유지관리공학회 논문집
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    • 제22권2호
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    • pp.8-15
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    • 2018
  • 중공슬래브는 휨 성능에 영향을 미치지 않는 부분의 콘크리트 단면을 삭제하고 중공재로 치환함으로써 중공재 부피만큼 콘크리트가 줄어들어 자중 감소효과를 가져오는 장점이 있다. 또한, 콘크리트의 물량절감뿐 아니라 친환경적 측면에서 이산화탄소의 배출도 저감할 수 있어 효과적이다. 하지만, 중공재로 치환한 부분의 지압강도가 명확하지 현장 적용 시에 여러 가지 문제점이 발생한다. 이에 본 연구에서는 중공재가 포함된 중공슬래브를 제작하여 각 타입별(트럭 하중 적용 시, 동바리 하중 적용 시 및 잭 서포트 하중 적용 시)로 국부지압강도 실험을 수행하여 중공슬래브 국부 지압강도의 안전성을 평가하고자 한다. 트럭하중 적용 시, 동바리 하중 적용 시 및 잭 서포트 하중 적용 시의 실험결과 중공재 연결부위 및 중공재 상부의 지압강도는 모든 실험체에서 허용 하중 이상을 보유한 것으로 나타났다. 또한 데크 적용 유무에 따른 실험결과도 모두 허용 하중을 초과하여 안정성을 확보하는 것으로 나타났다.

대구경 해상 강관말뚝의 설계지지력 확인을 위한 여러 가지 재하시험의 적용 (Case Studies of Several Load Tests for Large Diameter Battered Steel Pipe Piles Constructed on the Offshore Area.)

  • 이정학;서덕동;정헌주
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2001년도 봄 학술발표회 논문집
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    • pp.291-298
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    • 2001
  • It is very difficult to accomplish load tests of piles with large diameter constructed on the offshore area, because of requirement for large scaled loading equipment and bad testing conditions. Therefore, so far in many cases pile driving dynamic formulas have applied to quality control, and recently dynamic load test method is widely used for confirming bearing capacities of such piles. However, in cases of piles with very large diameter about 2,500mm, it is nearly impossible for regular type load test methods of piles such as static and dynamic to apply owing to very large design load. This is case studies of load tests such as modified static and dynamic load tests of piles and point load tests of rock samples for estimating rational allowable bearing capacity of very large diameter piles constructed on the marine area.

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감육배관의 굽힘하중에 의한 손상모드와 파괴거동 평가 (Failure Mode and Fracture Behavior Evaluation of Pipes with Local Wall Thinning Subjected to Bending Load)

  • 안석환;남기우;김선진;김진환;김현수;도재윤
    • 대한기계학회논문집A
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    • 제27권1호
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    • pp.8-17
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    • 2003
  • Fracture behaviors of pipes with local wall thinning are very important for the integrity of nuclear Power Plant. In Pipes of energy Plants, sometimes, the local wall thinning may result from severe erosion-corrosion (E/C) damage. However, the effects of local wall thinning on strength and fracture behaviors of piping system were not well studied. In this paper, the monotonic bending tests were performed of full-scale carbon steel pipes with local wall thinning. A monotonic bending load was applied to straight pipe specimens by four-point loading at ambient temperature without internal pressure. From the tests, fracture behaviors and fracture strength of locally thinned pipe were manifested systematically. The observed failure modes were divided into four types; ovalization. crack initiation/growth after ovalization, local buckling and crack initiation/growth after local buckling. Also, the strength and the allowable limit of piping system with local wall thinning were evaluated.