• 제목/요약/키워드: Main span

검색결과 511건 처리시간 0.022초

노면조도와 단차를 고려한 2경간연속 판형교의 충격계수에 관한 실험 및 해석적 연구 (An Experimental and Analytical Study on the Impact Factors of Two-Span Continuous Plate Girder Bridge Due to Road Surface Roughness and Bump)

  • 박영석;정태주
    • 한국강구조학회 논문집
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    • 제9권3호통권32호
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    • pp.309-321
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    • 1997
  • 차량이 교량을 통과할 때 교량에 발생하는 충격계수는 교량의 설계시 매우 중요한 인자이다. 본 연구에서는 2연속 강판형교의 지간 중앙점에 발생하는 충격계수에 관한 실험 및 해석적 연구를 수행하였다. 교량의 수치해석시 교량과 차량은 3차원으로 모델링하였으며. 교량의 노면조도는 Intelligent Total Station으로 직접 측정하여 사용하였다. 이때 교량의 주형은 보요소, 콘크리트 바닥판은 쉘요소를 사용하고 주형과 콘크리트 바닥판 사이는 Rigid Link를 사용하여 연결시켰다. 교량과 차량 사이의 상호작용을 고려하여 차량의 운동방정식을 유도하였으며, 차량의 여러 가지 주행속도에 따른 교량의 지간 중앙점에서의 충격계수를 구하여 우리나라 및 외국의 시방서 규정과 비교 검토하였다.

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전단경간비에 따른 합성지하벽의 거동과 접촉면의 조건을 고려한 유한요소 해석 (Structural Behavior of Composite Basement Wall According to Shear Span-to-Depth Ratio and FE Analysis Considering the Condition of Contact Surface)

  • 서수연
    • 한국구조물진단유지관리공학회 논문집
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    • 제15권6호
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    • pp.118-126
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    • 2011
  • 본 연구의 목적은 전단경간비에 따른 합성지하벽의 거동을 실험적으로 연구하고 유한요소해석 프로그램인 ADINA를 활용하여 합성지하벽 (Composite Basement Wall, CBW)의 비선형 거동의 예측이다. 특히 각 층 바닥 부근과 같이 콘크리트가 압축응력상태일 때의 합성벽의 거동을 연구하였다. 특히 강재와 콘크리트가 접촉되는 부분의 모델링 방법에 따른 해석방법의 적합성을 검토하고자 하였다. 콘크리트 벽체부분이 압축응력상태에 있는 합성지하벽의 거동을 이해하기 위하여 합성지하벽에 대한 실험을 실시하고 ADINA 프로그램을 이용하여 유한요소해석을 실시하였다. 해석의 편의를 위하여, 철근은 별도의 독립 요소로 모델링하지 않고, 콘크리트에 등분포되어 콘크리트와 함께 거동하는 것으로 하고 모든 요소는 소성거동을 표현하기 위하여 이선형 모델로 하였다. 강재와 콘크리트의 접촉면과 관련해서는 접촉면의 연결조건에 따라, AGO, SEGO-T 그리고 SEGO-NT로 모델링하여 해석을 실시한 뒤 각 조건에 따른 응력흐름과 집중정도를 관찰하고 그 결과를 실험결과와 비교하였다. 연구결과, 합성지하벽은 전단경간비가 비록 1에 가깝더라도, 강재의 소성변형에 의해 충분히 연성적인 거동을 보이는 것으로 나타났으며, 이와 같은 거동을 묘사하기 위하여 ADINA 프로그램을 이용하여 콘크리트와 강재 및 스터드볼트의 비선형특성을 고려하고 접촉면 요소로서 강재와 콘크리트의 접합면을 모델링하여 해석한 결과 접촉면연결과 모든 절점공유 옵션을 사용한 모델을 적용할 경우, 실험결과와 근사한 예측이 가능한 것으로 나타났다.

Large-scale pilot test study on bearing capacity of sea-crossing bridge main pier pile foundations

  • Zhang, Xuefeng;Li, Qingning;Ma, Ye;Zhang, Xiaojiang;Yang, Shizhao
    • Geomechanics and Engineering
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    • 제7권2호
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    • pp.201-212
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    • 2014
  • Due to the sea-crossing bridge span is generally large and main pier pile foundations are located in deep water and carry large vertical load, sea-crossing bridge main pier pile foundations bearing mechanism and load deformation characteristics are still vague. Authors studied the vertical bearing properties of sea-crossing bridge main pier pile foundations through pilot load tests. Large tonnage load test of Qingdao Bay Bridge main pier pile program is designed by using per-stressed technique to optimize the design of anchor pile reaction beam system. Test results show that the design is feasible and effective. This method can directly test bearing capacity of main pier pile foundations, and analysis bearing behaviors from test results of sensors which embedded in the pile. Through test study the vertical bearing properties of main pier pile foundation and compared with the generally short pile, author summarized the main pier pile foundations vertical bearing capacity and the main problem of design and construction which need to pay attention, and provide a reliable basis and experience for sea-crossing bridge main pier pile foundations design and construction.

Shear strength of reinforced concrete dapped-end beams

  • Lin, Ing-Jaung;Hwang, Shyh-Jiann;Lu, Wen-Yao;Tsai, Jiunn-Tyng
    • Structural Engineering and Mechanics
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    • 제16권3호
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    • pp.275-294
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    • 2003
  • In this study, 24 high-strength concrete dapped-end beams were tested to study the effects of the amount of main dapped-end reinforcement, the nominal shear span-to-depth ratio, and the concrete strength on the shear strength of dapped-end beams. Test results indicate that the shear strength of dapped ends increases with the increase in the amount of main dapped-end reinforcement and the concrete strength. The shear strength of dapped-end beam increases with the decrease of nominal shear span-to-depth ratio. A simplified method for determining the shear strength of reinforced concrete dapped ends is also proposed in this paper. The shear strengths predicted by the proposed method and the approach of PCI Design Handbook are compared with test results. The comparison shows that the proposed method can more accurately predict the shear strength of reinforced concrete dapped-end beams than the approach of PCI Design Handbook.

Shear Crack Control for High Strength Reinforced Concrete Beams Considering the Effect of Shear-Span to Depth Ratio of Member

  • Chiu, Chien-Kuo;Ueda, Takao;Chi, Kai-Ning;Chen, Shao-Qian
    • International Journal of Concrete Structures and Materials
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    • 제10권4호
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    • pp.407-424
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    • 2016
  • This study tests ten full-size simple-supported beam specimens with the high-strength reinforcing steel bars (SD685 and SD785) using the four-point loading. The measured compressive strength of the concrete is in the range of 70-100 MPa. The main variable considered in the study is the shear-span to depth ratio. Based on the experimental data that include maximum shear crack width, residual shear crack width, angle of the main crack and shear drift ratio, a simplified equation are proposed to predict the shear deformation of the high-strength reinforced concrete (HSRC) beam member. Besides the post-earthquake damage assessment, these results can also be used to build the performance-based design for HSRC structures. And using the allowable shear stress at the peak maximum shear crack width of 0.4 and 1.0 mm to suggest the design formulas that can ensure service-ability (long-term loading) and reparability (short-term loading) for shear-critical HSRC beam members.

신개념 FRP-콘크리트 합성 바닥판의 거동 특성 고찰 (A Study on the Behavior Characteristics of a New-Type FRP-Concrete Composite Deck)

  • 조근희;진원종;김성태;조정래;김병석
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
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    • pp.746-749
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    • 2004
  • A new-type of FRP-concrete composite bridge deck system is proposed and its behaviors are experimentally studied. The new-typedeck consists of FRP as a permanent form and main tension resisting member and concrete as a compression resisting member. A suitable bonding method such as silica coating is applied to the interface between FRP and concrete to ensure composite behavior. The proposed deck system uses the box-shape FRP member, while a typical FRP-concrete composite deck uses the I-shape FRP member. Theproposed deck system has inherent advantages of a FRP-concrete composite deck like corrosion free and easy construction. The new-type deck shows the equal performances compared to a previous one, and has the advantage of reducing self-weight. In this study, the static tests on 3-span FRP-concrete decks in full scale are carried out, so that load-displacement relation, stress distribution, failure mode and design criteria are analyzed. The test results show that the deflection design criterion (L/800, L: span length) is satisfied at the service load state. No concrete tensile crack occurs in the negative moment region above the main girder, regardless of no tensile reinforcement at upper concrete portion.

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선박의 교량 통항 만전성에 관한 연구 (A Study on Traffic Safety of Ship under Bridge)

  • 윤명오;김현종;금종수;성유창
    • 해양환경안전학회:학술대회논문집
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    • 해양환경안전학회 2003년도 추계학술발표회
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    • pp.67-73
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    • 2003
  • 최근 우리나라는 육지와 도서 및 도서간을 연결하는 해상교량을 건설하는 공사가 활발히 이뤄지고 있다. 이러한 교량은 보통 그 하부를 통해 선박이 통항하기 때문에 건설에 앞서 통항교통의 안전성에 관한 충분한 검토가 필요하다. 따라서, 본 연구는 건설예정에 있는 목포대교를 사례로 하여 교량통항의 안전성을 검증한 것으로 이를 위해 인접 수로의 특성을 분석하고 문헌적 검토를 거쳐 선박운항 시뮬레이터를 이용, 그 타당성과 안전성을 평가한 것이다.

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휨 구조시스템의 구조디자인적 구성요소와 디자인 조합 수법 분석 (A Study on Design Methods and the Composition Elements in Flexure Structure Systems)

  • 이주나
    • 한국공간구조학회논문집
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    • 제16권1호
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    • pp.73-84
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    • 2016
  • This study analyzes the four composition elements : profile, anchorage and connection, material and member rigidity, stability, as the main composition design elements of flexure structure systems, in order to explore possibilities for more various structure designs in architectures with flexure structure system. It also examines typical design methods that use the mentioned four composition elements. At the results, this research presents an understanding of the differences between funicular shape and non-funicular shape and mechanical features of the shapes in the profile element, regarding to the ratio of rise height to span length(f/l). Also, the typical design methods are presented for the designable usages of the hinge joints and the fix joints, and for the applications of member rigidity expressed by the index of the ratio of member depth to span length(d/l). And it was presented that connection styles, addition of brace members, placement of shear walls are the main design methods in the stability element. This data would be useful to architectural designs concerning integrated design with structures.

Linear regression analysis of buffeting response under skew wind

  • Guo, Zengwei;Ge, Yaojun;Zhao, Lin;Shao, Yahui
    • Wind and Structures
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    • 제16권3호
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    • pp.279-300
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    • 2013
  • This paper presents a new analysis framework for predicting the internal buffeting forces in bridge components under skew wind. A linear regressive model between the internal buffeting force and deformation under normal wind is derived based on mathematical statistical theory. Applying this regression model under normal wind and the time history of buffeting displacement under skew wind with different yaw angles in wind tunnel tests, internal buffeting forces in bridge components can be obtained directly, without using the complex theory of buffeting analysis under skew wind. A self-anchored suspension bridge with a main span of 260 m and a steel arch bridge with a main span of 450 m are selected as case studies to illustrate the application of this linear regressive framework. The results show that the regressive model between internal buffeting force and displacement may be of high significance and can also be applied in the skew wind case with proper regressands, and the most unfavorable internal buffeting forces often occur under yaw wind.

Exact and approximate solutions for free vibrations of continuous partial-interaction composite beams

  • Sun, Kai Q.;Zhang, Nan;Zhu, Qun X.;Liu, Xiao
    • Steel and Composite Structures
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    • 제44권4호
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    • pp.531-543
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    • 2022
  • An exact dynamic analytical method for free vibrations of continuous partial-interaction composite beams is proposed based on the Timoshenko beam theory. The main advantage of this method is that the independent shear deformations and rotary inertia of sub-beams are considered, which is more in line with the reality. Therefore, the accuracy of eigenfrequencies obtained by this method is significantly improved, especially for higher order modes, compared to the existing methods where the rotary angles of both sub-beams are assumed to be equal irrespective of the differences in the shear stiffness of each sub-beam. Furthermore, the solutions obtained by the proposed method are exact owing to no introduction of approximated displacement and force fields in the derivation. In addition, an exact analytical solution for the case of simply supported is obtained. Based on this, an approximate expression for the fundamental frequency of continuous partial-interaction composite beams is also proposed, which is useful for practical engineering applications. Finally, the practicability and effectiveness of the proposed method and the approximate expression are explored using numerical and experimental examples; The influence factors including the interfacial interaction, shear modulus ratio, span-to-depth ratio, and side-to-main span length ratio on the eigenfrequencies are presented and discussed in detail.