• Title/Summary/Keyword: 연결부

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An experimental study for water tightness of segment under high water pressure (고수압 조건에서의 세그먼트 방수성능평가에 대한 실험적 연구)

  • Choo, Seok-Yean;Park, Young-Jin;Kim, Dong-Hyun;Kim, Yong-Il;Lee, Du-Wha;Cho, Sang-Kook
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.5 no.4
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    • pp.361-370
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    • 2003
  • In this study, the performance of water tightness of water expansional sealing material and gasket was evaluated. The water tightness test was performed varying the type of inner pressure condition, for which the water expansional sealing material was inundated for 5 days to evaluate the ability of water tightness. In order to carry out this test, we made use of two types of water expansional sealing material; general type and combined type with non-expansional rubber. In the case of gasket, EPDM gasket and complex gasket sticked to the water expansional sealing material were applied. The performance of water tightness depended on the construction defect and the deformation of segment. The construction defect and segment deformation were generally expressed by gap and offset of the construction joint. The results, of tests showed that the performance of water tightness was largely influenced by the gap between segments. Management criteria of gap and offset were proposed.

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Reversed Cyclic Loading Tests on Precast Beam-Column Joints with Headed Reinforcement (프리캐스트 보-기둥 헤드철근 연결부 반복하중 실험)

  • Kim, In-Gyu;Yu, Sung-Yong
    • Journal of the Korea Concrete Institute
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    • v.15 no.3
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    • pp.369-376
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    • 2003
  • One of the most complex reinforcement location in the precast building frame is the beam-column joint in a prefabricated construction. It is generally resulted from the vortical bars of column, anchorage bars of beam, and bars of hoop. Particularly the hooked anchorage bars of beam are confronted with hoop and main column bars. The headed reinforcement is considered to place them easily and to reduce the anchorage length in a precast construction. Reversed cyclic loading tests are performed on four beam-column specimens to evaluate the strength and behavior of beam to column and column to column connections. The result of test shows that the headed reinforcement has a similar performance than that of hooked reinforcement in a precast specimen with strong column and weak beam joints. The splice column joints which are used frequently in the domestic fields also show reliable behaviors in those tests with strong column and weak beam joints.

Fatigue Tests on Transverse Joints of Precast Prestressed Concrete Bridge Deck (프리스트레스를 도입한 프리캐스트 콘크리트 교량 바닥판의 연결부에 관한 피로실험)

  • 정철헌;김영진;장성욱;김철영;심창수
    • Magazine of the Korea Concrete Institute
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    • v.10 no.5
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    • pp.159-165
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    • 1998
  • 중트럭 통행으로 인한 철근콘크리트 교량바닥판의 열화는 교량구조물을 유지보수하는데 있어 심각한 문제 중 하나이며, 프리캐스트 바닥판을 이용한 교량바닥판의 시공 및 교체 방법이 실용적이며 효과적인 방법으로 인식되고 있다. 본 연구에서는 횡방향 ddusruf부에 종방향 프리스트레싱을 도입한 프리캐스트 바닥판의 모델을 제작하여 바닥판간 횡방향 연결부의 강성 평가 및 연결부의 피로 거동을 파악하기 위해서 피로실험을 수행하여 피로하중하에서의 휨강성의 변화, 균열발생 및 파괴하중 등을 측정하였다. 실험결과를 통해서 피로하중하에서 프리스트레스 프리캐스트 부재의 프리스트레스 효과를 평가하였으며, 현장타설에 의해서 시공되는 일반 RC 부재에 비해서 우수한 구조적 거동을 보여주는 적정량의 종방향 프리스트레스 크기를 결정하였다.

Techniques for Revetment Design around River-Crossing Structures (하천횡단구조물 연결호안 설계 기법 검토)

  • Yoon, Kwang-Seok;Bae, Deok-Won;Kim, Hyeong-Jun;Ryu, Yong-Uk
    • Proceedings of the Korea Water Resources Association Conference
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    • pp.1931-1935
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    • 2010
  • 최근 기후변화에 의한 강우량 및 집중호우의 증가로 인하여 설계규모를 초과하는 홍수발생 가능성이 커지고, 이에 따라 제방월류 위험성이 증대되고 있다. 특히, 하천을 횡단하는 보 또는 낙차공이 있는 경우, 구조물 영향에 의해 국부적으로 유속이 증가하여 연결호안을 유실시킴으로서 제방붕괴에 의해 홍수피해가 가중될 수 있다. 과거 피해사례를 보면 횡단구조물과 제방과의 연결부가 세굴되어 파괴되는 사례가 많이 발생하고 있으며, 이는 하천횡단구조물 주위에 설치되는 연결호안에 대한 정량적인 설계기법이 정립되어야 할 필요성을 보여 준다. 경험적인 요소만으로 연결호안의 안정성을 판단함으로써, 과소설계에 의한 홍수피해가 발생하거나, 과대설계에 의한 비용손실을 초래하게 된다. 본 연구에서는 기존에 제시되어 있는 호안설계식을 연결부에서의 국부유속증가특성을 고려하여 적용한 결과를 비교하였다. 비교 결과, 연결부에서의 호안 크기가 증가될 필요가 있으며, 이에 대한 실험 실증적 연구가 필요한 것으로 분석되었다.

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Analysis of Seismic Performance of Modular Containment Structure for Small Modular Reactor (소형 원자로용 모듈화 격납구조의 내진성능 분석)

  • Park, Woo-Ryong;Yhim, Sung-Soon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.1
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    • pp.409-416
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    • 2020
  • The seismic performance of a containment structure should be secured to maintain the structural soundness of a containment structure under various earthquakes that occur globally. Therefore, an analysis of the seismic performance of a modular containment structure for a small modular reactor is also required. To analyze the seismic performance of modular containment, FEM models with contact surfaces between the modules and tendon were prepared and the modal and seismic analyses were performed. The displacement, stress, and gap size of modular containment under earthquake wave were analyzed. The effects of the tendon force, friction coefficient, and earthquake wave on the seismic performance were analyzed. The seismic performance of monolithic containment was also analyzed for comparison. In the 1st and 2nd natural modes, which most likely affect, the modular containment showed horizontal dynamic behavior, which is similar to monolithic containment, because of the combined effects of the tendon force and friction force between modules. When the combined effect is sufficient, the seismic performance of the modular containment is secured over a certain level. An additional increase in seismic performance is expected when some material with a larger friction coefficient is adopted on the contact surface.

Numerical study on tunnel design for securing stability at connection between submerged floating tunnel and bored tunnel (수중터널 지반 접속부 안정성 확보를 위한 터널 설계에 대한 수치해석적 연구)

  • Kang, Seok-Jun;Cho, Gye-Chun
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.22 no.1
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    • pp.77-89
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    • 2020
  • Submerged floating tunnel (SFT) is a type of tunnel that allows tunnel segments to float underwater by buoyancy, and is being actively studied in recent years. When the submerged floating tunnel is connected to the ground, the tunnel and the bored tunnel inside the ground must be connected. There is risk that the stress will be concentrated at the connection between the two tunnels due to the different constraints and behavior of the two tunnels. Therefore, special design and construction methods should be applied to ensure the stability around the connection. However, previous studies on the stability at the connection site have not been sufficiently carried out, so study on the basic stage of the stability at connection site are necessary. In this study, numerical analysis simulating the connection between submerged floating tunnel and the bored tunnel confirmed that the shear strain concentration occurred in the ground around the connection, and it was analyzed that the structural factors can be handled during construction to have effects on the stability of the ground around the connection. Numerical results show that the risks from disproportionate displacements in the two tunnels can be mitigated through the construction of grouting material and joint design. Although the results from this study are qualitative results, it is expected that it will contribute to the determination of structural factors and risk areas that should be considered in the design of connections between the submerged floating tunnel and bored tunnel in the future studies.

Development of A Component and Advanced Model for The Smart PR-CFT Connection Structure (스마트 반강접 (PR) 콘크리트 충전 강재 합성 (CFT) 접합 구조물에 대한 해석모델의 개발)

  • Seon, Woo-Hyun;Hu, Jong-Wan
    • Journal of the Korean Society for Advanced Composite Structures
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    • v.2 no.4
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    • pp.1-10
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    • 2011
  • This study investigates the performance of composite (steel-concrete) frame structures through numerical experiments on individual connections. The innovative aspects of this research are in the use of connections between steel beams and concrete-filled tube (CFT)columns that utilize a combination of low-carbon steel and shape memory alloy (SMA) components. In these new connections, the intent is to utilize the recentering provided by super-elastic shape memory alloy tension bars to reduce building damage and residual drift after a major earthquake. The low-carbon steel components provide excellent energy dissipation. The analysis and design of these structures is complicated because the connections cannot be modeled as being simply pins or full fixity ones they are partial restraint (PR). A refined finite element (FE) model with sophisticated three dimensional (3D) solid elements was developed to conduct numerical experiments on PR-CFT joints to obtain the global behavior of the connection. Based on behavioral information obtained from these FE tests, simplified connection models were formulated by using joint elements with spring components. The behavior of entire frames under cyclic loads was conducted and compared with the monotonic behavior obtained from the 3D FE simulations. Good agreement was found between the simple and sophisticated models, verifying the robustness of the approach.

Development of Connection Model based on FE Analysis to Ensure Stability of Steel Storage Racks (적재설비 안정성 확보를 위한 FE 해석 기반의 연결부 모델 개발)

  • Heo, Gwanghee;Kim, Chunggil;Yu, Darly;Jeon, Jongsu;Lee, Chinok
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.38 no.2
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    • pp.349-356
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    • 2018
  • This paper attempts to develop a connection model based on FE analysis that can be applied to the evaluation of earthquake fragility of Steel Storage Racks lacking research in Korea. In order to accomplish this goal, shaking table tests, modal tests, and various member tests (8 case, push-over test) for structural members have been conducted to understand the behavior of steel storage racks. Based on the experimental results, detailed modeling of the joints was conducted using the NX-Nastran program in order to develop a connection model for Steel storage racks to be applied to the seismic vulnerability assessment. Especially, surface to surface contact element and spring element are applied to simulate the connection between the column member and the beam member connected by the simple latch method. Spring element model developed and applied ARX (Auto Regressive eXogenous) based mathematical model. The simulation results based on the FE model showed excellent reliability with a mutual error rate of less than 8% when compared with the member test results. As a result, it was confirmed that the FE model based connection model developed in the study can be applied to the analytical model for the seismic vulnerability assessment of Steel storage racks.

콘크리트 모듈 시공이음부의 설계기법

  • Yang, In-Hwan;Ju, Geon-Hyeong;Kim, Gyeong-Cheol
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • pp.195-197
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    • 2011
  • 플로팅 건축구조용 콘크리트 부유체 구조는 현장 근처의 제작장에서 제작한 후에 제작된 부재를 현장으로 이동하여 가설장비를 이용해 각 부재를 조립해서 함체 구조를 완성하는 방법인 프리캐스트 부재 방법을 적용하는 것이 유리하다. 따라서, 연결부의 기능과 구조적 성능을 최대한으로 유지시킬 수 있는 적절한 연결기법을 적용해야 한다. 본 연구에서는 콘크리트 함체 연결부에 적용할 수 있는 연결기법을 연구하였다.

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The Study on Local Composite Behavior of Connection Member between Steel Pipe Pile and Concrete Footing (강관 말뚝 기초 두부 연결부의 합성거동에 대한 연구)

  • You, Sung-Kun;Park, Jong-Myen;Park, Dae-Yong;Kim, Young-Ho;Kang, Won-Ho
    • Journal of the Korea Concrete Institute
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    • v.15 no.2
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    • pp.288-296
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    • 2003
  • Generally, application of steel pipe pile as deep foundation member needs special requirement for the connection method between steel pipe pile and concrete footing. Even though two types of connection method are suggested in the related specification, type B-method is provident. To investigate real structural behavior of type B connection, several load tests are done with carefully designed experimental system. The purpose of this experiment is mainly focused on the understanding of actual behavior which can be predicted by design theory. At this research stage, vertical and lateral loading test are done for three types of specimen to review stress concentration, formation and behavior of imaginary RC column in the footing and effect of non-slip device installed in the steel pipe pile. The load resistance mechanism in these specific connection method is predicted based on both experimental results. The three-dimensional finite element modeling is also done for the purpose of comparison between numerical and experimental result. With all the results gained from experiment the structural behavior of imaginary RC column in the design concept is confirmed. The role of non-slip device is very important and it affects the resistance capacity with help of composite action of concrete and steel pipe pile.