• Title, Summary, Keyword: 슬래브 조인트

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Static and Dynamic Behavior at Low-Frequency Range of Floating Slab Track Discretely Supported by Rubber Mounts in Real-Scale Laboratory Test (고무 마운트로 이산 지지되는 플로팅 슬래브 궤도의 실모형 실내 실험에서의 정적 및 저주파 대역 동적 거동)

  • Hwang, Sung Ho;Jang, Seung Yup;Kim, Eun;Park, Jin Chul
    • Journal of the Korean Society for Railway
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    • v.15 no.5
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    • pp.485-497
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    • 2012
  • Recently, with increasing social interests on noise and vibration induced by railway traffic, the application of floating slab track that can efficiently reduce the railway vibration is increasing. In this study, to more accurately understand the dynamic behavior of the floating slab track, a laboratory mock-up test has been performed, and the static and dynamic behaviors at frequency range near the system resonance frequency were explored. Based on the test results, the design of the floating slab track and the structural analysis model used in the design have been verified. The analytic and test results demonstrate that the dominant frequency of the floating slab track occurs at the frequencies between vertical rigid body mode natural frequency and bending mode natural frequency, and the dominant deformation mode is close to the bending mode. This suggests that in the design of the floating slab track, the bending rigidity of the slab and the boundary conditions at slab joints and slab ends should be taken into consideration. Also, the analytic results by the two-dimensional finite element analysis model using Kelvin-Voigt model, such as static and dynamic deflections and force transmissibility, are found in good agreement with the test results, and thus the model used in this study has shown the reliability suitable to be utilized in the design of the floating slab track.

Curling Behavior of Long-Span Concrete Pavement Slab under Environmental Loads (환경하중에 의한 장스팬 콘크리트 포장 슬래브의 컬링 거동 특성 분석)

  • Kim, Seong-Min;Shim, Jae-Soo;Park, Hee-Beom;Yun, Dong-Ju
    • International Journal of Highway Engineering
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    • v.11 no.3
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    • pp.151-161
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    • 2009
  • This study was conducted to investigate the characteristics of the curling behavior of long-span pavement slabs under environmental loads. By developing and using finite element models of the long-span pavement slabs, the stress distribution and the effects of slab length, slab thickness, stiffness of underlying layers, and the restraints of the slab ends on the curling behavior were analyzed. In addition, the field experiments were performed with the actual long-span pavement slab to obtain the curling behavior of the real structure under environmental loads. As a result of this study, it was found that the vertical displacements of the long-span pavement slab along the centerline due to the curling behavior were zero except for the areas near the slab ends, and the curling stresses were maximum and constant where the displacements were zero. The slab length and the stiffness of underlying layers did not affect the maximum curling stresses. The restraints at the slab ends made the curling stresses occur near the slab ends, but did not much affect the maximum curling stresses.

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Continuity for Double Tee Slabs (더블티 슬래브의 연속화)

  • 유승룡
    • Journal of the Korea Concrete Institute
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    • v.13 no.2
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    • pp.99-106
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    • 2001
  • The main objective of this study is to develop a continuity of double tee slab with two modified dap-ends to solve the problems of excessive moment, slab depth, deflection, and joint cracking in the original simply supported double tee slab systems. The modified joint is produced in a combination with two slabs with modified dap and one rectangular beam. The modified joint can be justified as following different merits. The span capacity for a design load is increased, while the deflection of the slab is decreased due to the decrease of positive moment at the center span of the slab. The joint cracking between slab and beam, which occur frequently in the original slab systems of double tee will be reduced. No more additional form work is needed to cast topping concrete for continuity. Three point loading tests are performed on the specimens with a variable of an amount of main longitudinal reinforcement to evaluate flexural and shear behavior. Following conclusions are obtained from the experimental investigation. The continuity of double tee slab effectively is provided by placing longitudinal steel reinforcement in the topping concrete over the connection, and generally leads to an increase in span capacity of double tee slabs with reduced deflection. It is more effective to control the initial cracking at the connection than that of some simply supported double tee slab systems.

Fracture Behavior of Dowel Joint of Concrete Slab Track (콘크리트궤도 슬래브의 다웰 연결부 파괴 거동)

  • Kwon, Kusung;Jang, Seung Yup;Chung, Wonseok
    • Journal of The Korean Society of Civil Engineers
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    • v.33 no.5
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    • pp.2125-2133
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    • 2013
  • Recently, an interest on joint behavior between adjacent concrete slab tracks has increasing due to large application of such track system. Dowel bars are widely used to improve load transfer capacity across the joints. Dowel bars reduce the deflections and stresses by transferring the load between the slabs. This study proposes the lumped shear spring model to efficiently model dowel joints of adjacent slabs. This model includes bearing stiffness between dowel bar and concrete as well as dowel gap. Strength of the proposed spring model is evaluated based on Concrete Capacity Design method under the assumption of shear failure mode in the joints. Experiments are also performed up to failure to evaluate the accuracy of the proposed model. It has been observed that the proposed model is able to predict initial nonlinearity due to dowel gap, and capture material nonlinearity of the test slabs. Thus, it is recommended that the proposed model can be effectively applied to the dowel joints of concrete slab track.

Behavior and Design of Terminal Joint Width between Post-Tensioned Concrete Pavement and Jointed Concrete Pavement under Temperature Changes (온도변화에 따른 PTCP와 JCP 접속부 줄눈 폭 변화와 설계 방안)

  • Kim, Dong-Ho;Lee, Bong-Hak;Kim, Seong-Min;Park, Seong-Tae
    • International Journal of Highway Engineering
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    • v.13 no.1
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    • pp.223-228
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    • 2011
  • The initial joint width design of the terminal joint between post-tensioned concrete pavement (PTCP) and jointed concrete pavement (JCP) was studied in this research. The joint width between PTCP and JCP directly affects noise and ride quality. If the initial joint width is very large, noise increases and ride quality decreases. If the initial joint width is very small, on the other hand, under high temperatures, PTCP slabs can blow up, or failures near the joint can occur due to excessive compressive stresses. The terminal joint width behavior between PTCP and JCP near Jumunjin at Donghae expressway under temperature changes was measured in August and November 2010 and the data was analyzed. From this study, the design methodology of the optimal initial terminal joint width was proposed.

Behavior of Steel Plate Girder Using Slab Anchor (Slab Anchor를 사용한 판형교의 거동특성 연구)

  • Han, Sang-Yun;Han, Taek-Hee;Park, Nam-Hoi;Kang, Young-Jong
    • Journal of Korean Society of Hazard Mitigation
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    • v.2 no.2
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    • pp.105-113
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    • 2002
  • Steel-Concrete composite girders have been used since early in the 1920's due to their advantages, which are lower weight, increasement of stiffness, slenderness, long span. However, in designing short to continuous composite bridges, negative moment occurs in mid-support and creates problems such as cracks in the concrete slab. Therefore, partially composite bridges are considered. In this time, slab-anchor is used in these. If the stiffness of shear connectors is insufficient, slip would happen at the contact surface. Partial interaction is the case that takes account of slips. In this paper, the evaluation of initial shear stiffness of slab-anchor in composite bridges is obtained from Push-Out specimen. Also, finite element analyses which uses the initial shear stiffness of slab-anchor got the experiment are carried out on simple composite girder and continuous composite girder. Futhermore, the ratio of composite according to various shear stiffness are investigated and the classification according to the ratio of composite is proposed.

Shrinkage Stress Analysis of Concrete Slab with Shrinkage Strip in Multi-Story Building (수축대를 사용한 고층건물 콘크리트 슬래브의 건조수축응력 해석)

  • 김한수;조석희
    • Journal of the Korea Concrete Institute
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    • v.14 no.5
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    • pp.726-733
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    • 2002
  • Shrinkage strip or separation strip is a temporary joint that is left open for a certain time during construction to allow a significant part of the shrinkage to take place without inducing stress. A shrinkage stress analysis method of shrinkage strip in concrete slab of multi-story building considering the relaxation effect of creep and construction sequence is proposed. The analysis results of 10-story example building show that the effect of shrinkage strip can be analyzed easily by the proposed method. And shrinkage strip installed in a particular floor makes the stress of that floor reduced and the stress of the other floors increased a little. The rate and amount of stress reduced with closing time mainly depends on the development of shrinkage with time of concrete model used. The amount of stress reduced is determined by the amount of shrinkage strain developed before the closing of shrinkage strip.

Performance Test of Corner Rigid Joint for Modular Structure using Channel and Coupler (채널과 커플러를 사용한 모듈식 구조체 우각부 연결구조의 성능검증 실험)

  • Lee, Jun-Kyoung;Lee, Jong-Soon;Lee, Sung-Hyung;Kim, Hee-Sung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.3
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    • pp.2255-2262
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    • 2015
  • Recent study about near-surface is proposed to overcome non-economic of underground railway and to reduce people's complaints of ground elevated railway. In this report, precast modular structure system replacing temporary facilities is applied to ensure the construction ability and economic feasibility. To verify the performance of connection joint between permanent structural wall and upper slab, loading test is carried out. As a result of the test, wall replacing temporary structure to slab connection is possible to transfer bending moment. By 30% increase of bending resistant performance for connection joint using coupler, coupler connection joint is more advantageous to resist bending moment compared to channel connection.

Cyclic Loading Test for TSC Beam - PSRC Column Connections (TSC 합성보 - PSRC 합성기둥 접합부에 대한 주기하중 실험)

  • Hwang, Hyeon Jong;Eom, Tae Sung;Park, Hong Gun;Lee, Chang Nam;Kim, Hyoung Seop
    • Journal of Korean Society of Steel Construction
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    • v.25 no.6
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    • pp.601-612
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    • 2013
  • In the present study, details of the TSC beam-to-PSRC column connection for low and middle seismic zones were developed. For ease construction, the top and bottom flanges of the steel section of the TSC beam were discontinuous at the joint face on purpose, while the web passes through the joint. Thus, tensile resistance of the top and bottom flanges is not considered in the calculation of nominal strength of the connection. Cyclic loading tests on two interior connections and an exterior connection were performed to verify the seismic performance. The test parameter for two interior connections was the depth of the TSC beams: 600 and 700 mm including the slab depth. The test results showed that the nominal strength of the connections predicted by KBC 2009 correlated well with the test results. The connection specimens exhibited relatively good deformation and energy dissipation capacities, greater than the requirements for the ordinary and intermediate moment frames. Ultimately, the connection specimens were failed at the story drift ratios of 3.0 to 4.0 % due to local buckling and tensile fracture of the web of the TSC beam passing through the joint. By modifying the existing provisions of ASCE, the joint shear strength of the TSC beam-PSRC column connection was evaluated.