• 제목/요약/키워드: limit state

검색결과 1,417건 처리시간 0.025초

초기함수비, 비표면적, 풍건 및 동결.융해작용이 흙의 액성한계에 미치는 영향 (Influence of Initial Water Content, Specific Surface, Air Drying and Freezing-thawing Action on the Liquid Limit of Soils)

  • 류능환
    • 한국농공학회지
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    • 제38권5호
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    • pp.116-124
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    • 1996
  • The purpose of The work described in this paper is to clear up the initial moisture content, specific surface, air drying and freezing-thawing process on liquid limit of clayey soils distributed widely at estuary of three main rivers in the west coast. To this end, a series of tests were conducted on clayey soils samples with natural state and treated state. From the test results, the liquid limit was decreased with decrement of initial moisture content, air drying process, and freezing-thawing cycles and increased with increment of specific surface. The specific surface which influenced on the liquid limit is over $25 m^2$m$^2$/g, and their relationships are well formulated. Air drying process is expected to improve the engineering properties of the soils such the pro-water properties were changed to anti-water proper-ties through lowering of water holding as resulted to incline from A-7-5 to A-5 on the soil classificaction plastic chart. The freezing-thawing process decreased 20% of liquid limit, especially under the first cycle of the behavious, as a result of above mentioned reasons, phase change of soil-water system brought the decrement of specific surface and affected to the liquid limit.

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Seismic vulnerability assessment criteria for RC ordinary highway bridges in Turkey

  • Avsar, O.;Yakut, A.
    • Structural Engineering and Mechanics
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    • 제43권1호
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    • pp.127-145
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    • 2012
  • One of the most important and challenging steps in seismic vulnerability and performance assessment of highway bridges is the determination of the bridge component damage parameters and their corresponding limit states. These parameters are very essential for defining bridge damage state as well as determining the performance of highway bridges under a seismic event. Therefore, realistic damage limit states are required in the development of reliable fragility curves, which are employed in the seismic risk assessment packages for mitigation purposes. In this article, qualitative damage assessment criteria for ordinary highway bridges are taken into account considering the critical bridge components in terms of proper engineering demand parameters (EDPs). Seismic damage of bridges is strongly related to the deformation of bridge components as well as member internal forces imposed due to seismic actions. A simple approach is proposed for determining the acceptance criteria and damage limit states for use in seismic performance and vulnerability assessment of ordinary highway bridges in Turkey constructed after the 1990s. Physical damage of bridge components is represented by three damage limit states: serviceability, damage control, and collapse prevention. Inelastic deformation and shear force demand of the bent components (column and cap beam), and superstructure displacement are the most common causes for the seismic damage of the highway bridges. Each damage limit state is quantified with respect to the EDPs: i.e. curvature and shear force demand of RC bent components and superstructure relative displacement.

Weavability Limit of Yarns with Thickness Variation in Shuttleless Weaving

  • Seyam, Abdelfattah M.
    • Fibers and Polymers
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    • 제4권4호
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    • pp.176-181
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    • 2003
  • Theoretical weavability limit relationships of fabrics from regular warp yarns and fancy filling yams with thickness variation in shuttleless weaving are reviewed. The relationships correlate maximum warp and filling cover factors, warp and filling yarn characteristics, the distribution of thick and thin places of filling yarn over the fabric surface, and the warp and filling weave factor. The research considers single filling feeder and multiple feeders cases. Additionally, comparisons between the weavability limit of regular yarns and fancy yams in shuttle and shuttleless weaving are given.

콘크리트 구조물에 대한 뉴질랜드 내진설계 규준의 특성 (Characteristics of Seismic Design of Concrete Structures in New Zealand Standards(NZS))

  • 이한선
    • 한국지진공학회:학술대회논문집
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    • 한국지진공학회 2000년도 춘계 학술발표회 논문집 Proceedings of EESK Conference-Spring
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    • pp.375-382
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    • 2000
  • This paper briefly summarizes the basic concepts and main characteristics of seismic design of New Zealand Standards(NZS) with regard to reinforced concrete(RC) structures. NZS used the concept of the capacity design and the limit state design to satisfy the requirements of serviceability and safety. Plastic mechanisms and details with respect to the limit state of safety are briefly presented in this paper. The understanding of this advanced seismic design concept will enable us to implement the basic theory of capacity design and contribute to the development of Korean seismic code in new generation,

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Current practices and future directions of steel design in Japan

  • Yamaguchi, Eiki
    • Steel and Composite Structures
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    • 제5권2_3호
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    • pp.159-168
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    • 2005
  • Four design codes/regulations for steel structures in Japan are briefly reviewed. Some of them employ the limit state design concept while the others are still based on the allowable stress design concept. The process for revision is now in action. The directions in the development of structural design codes are also reported herein. It is noted that a current trend in this development is to employ the performance-based design concept that has been successfully implemented in some seismic design codes.

한계상태설계법에 의한 부분프리스트레스트 콘크리트 교량의 자동화 설계 프로그래밍 (Programming for Automatic Design of Partially Prestressed Concrete Bridge Using Limit State Design)

  • 박홍용;박인교
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1999년도 학회창립 10주년 기념 1999년도 가을 학술발표회 논문집
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    • pp.359-362
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    • 1999
  • Partially prestressed concrete members are concrete members reinforced with a combination of prestressed and non-prestressed reinforcement, and also can offer advantages of reinforced concrete. The objective of this study is to develop a design program using Visual Basic language according to the limit state design method which controls crack and check fatigue effectively for partially concrete members.

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신뢰성에 기초한 PC박스거더교의 내구성평가 모형 (A Model for Reliability-Based Durability Assessment of PC BOX Girder Bridges)

  • 조효남;이승재;이정곤
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1995년도 봄 학술발표회 논문집
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    • pp.286-291
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    • 1995
  • The deterioration of PC box girder may cause serious effect on the durability of PC structure compared to that of RC structures. In the durability assessment of PC box girder bridges, a quantitive model on crack width is considered as a measure of durability. This study suggests a durability limit state model for PC box girder bridges. This durability limit state model in formulated based on the conventional models on the cracks in concrete. And the allowable crack width is taken as an assumed value established by the design specification or provided by the maintenance authority of the structure.

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개정된 일본 내진설계기준의 한계내력계산법의 소개 (Introduction of the Capacity Design Methodology in the Building Standard Law of Japan)

  • 전대한;노필성
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2002년도 봄 학술발표회 논문집
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    • pp.861-866
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    • 2002
  • This manuscript introduces the Capacity Design Methodology in the Building Standard Law of Japan revised at 2000, June. The Building Standard Law of Japan was revised into the performance-based design format following the trend of international. The structural performance was evaluated for two limiting states; soundness limit state and safety limit state. The design seismic forces were determined on taking into consideration (a)the properties of the planned building, (b)amplification by local surfaces geology, and (c)soil-structure interaction.

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연안국의 대륙붕에서의 권리와 의무 (The right and duties of the coastal state over the continental shelf)

  • 임채현;이윤철
    • 한국마린엔지니어링학회:학술대회논문집
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    • 한국마린엔지니어링학회 2006년도 전기학술대회논문집
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    • pp.137-139
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    • 2006
  • The Continental shelf is important part of the coastal states' jurisdiction at sea, because there are many natural resources in continental shelf. This paper examines the concept and legal status of the continental shelf, the limit of the continental shelf, and expecially the rights and duties of the coastal state relating to its continental shelf.

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빔 단면형상에 대한 구조물 신뢰성 최적설계 (Reliability Based Design Optimization for Section Shape of Simple Structures)

  • 임준수;임홍재;이상범;허승진
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2002년도 춘계학술대회논문집
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    • pp.672-676
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    • 2002
  • In this paper, a reliability-based design optimization method, which enables the determination of optimum design that incorporate confidence range for structures, is studied. Response surface method and Monte Carlo simulation are utilized to determine limit state function. The proposed method is applied to the I-type steel structure for reliability based optimal design.

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