• Title/Summary/Keyword: 바닥판 상세

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Evaluation of Flexural Strength of FRP-Concrete Composite Decks According to Details of Their Connecting Parts above Girders (연결부 상세에 따른 FRP-콘크리트 합성 바닥판의 거더 위 부모멘트부 휨강도 평가)

  • Park, Sung-Yong;Cho, Keun-Hee;Kim, Sung-Tae;Cho, Jeong-Rae;Kim, Byung-Suk
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.11a
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    • pp.21-24
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    • 2008
  • Tests were performed to obtain the flexural capacity of the innovative FRP-Concrete Composite Deck (FCCD) above girders. Test parameters were details of connection parts between FCCD and girder, such as continuity of FRP module, reinforcing ratio of FRP re-bars, and existence of shear connecting plate. As a test result, we found flexural strength of FCCD in the negative zone increases when FRP module is continuous, and reinforcement is increased, and shear connecting plate exists. And the flexural strength of all specimens give enough safety compared to the value needed in Korean highway bridge design code.

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Evaluation of Static Behaviour of Orthotropic Steel Deck Considering the Loading Patterns (하중재하 패턴을 고려한 강바닥판의 정적거동 평가)

  • Kim, Seok Tae;Huh, Young
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.15 no.2
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    • pp.98-106
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    • 2011
  • The deck of steel box girder bridges is composed of deck plate, longitudinal rib, and transverse ribs. The orthotropic steel decks have high possibility to fatigue damage due to numbers of welded connection part, the heavy contact loadings, and the increase of repeated loadings. Generally, the local stress by the repeated loadings of heavy vehicles causes the orthotropic steel deck bridge to fatigue cracks. The increase of traffic volume and heavy vehicle loadings are promoted the possibility of fatigue cracks. Thus, it is important to exactly evaluate the structural behavior of bridge considering the contact loading area of heavy vehicles and real load patterns of heavy trucks which have effects on the bridge. This study estimated the effect of contact area of design loads and real traffic vehicles through the finite element analysis considering the real loading conditions. The finite element analysis carried out 4 cases of loading patterns in the orthotropic steel deck bridge. Also, analysis estimated the influence of contact area of real truck loadings by the existence of diaphragm plate. The result of finite element analysis indicated that single tire loadings of real trucks occurred higher local stress than one of design loadings, and especially the deck plate got the most influence by the single tire loading. It was found that the diaphragm attachment at joint part of longitudinal ribs and transverse ribs had no effects on the improvement of structural performance against fatigue resistance in elastic analysis.

Analytical Study on the Characteristic of Fatigue Behavior in Connection Parts of Orthotropic Steel Decks with Retrofitted Structural Details in Longitudinal Rib (세로리브 내부 보강상세에 따른 강바닥판 연결부의 피로거동 특성에 관한 해석적 연구)

  • Sun, Chang Won;Park, Kyung Jin;Kyung, Kab Soo;Kim, Kyo Hoon
    • Journal of Korean Society of Steel Construction
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    • v.20 no.1
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    • pp.105-119
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    • 2008
  • In steel deck bridges suffering directly on wheel load according to the number of serviced years, the occurrence of fatigue cracks increases in structural details, which includes the cross section parts of the longitudinal rib and transversal rib, and so on. Through the control method for these fatigue cracks the increased thickness of the steel deck plate or the application of retrofit detail to the inside of the longitudinal rib was observed to be effective. This study suggests structural details for the retrofitted and non-retrofitted longitudinal rib. The target details in this study are the connection parts of the lo ngitudinal and transversal rib, and the slit parts of transverse rib where fatigue cracks were frequently reported in previous studies. In the analyses, detailed structural analyses were performed as parameters, which include the shape, change of size and attached position. From the results the stress reduction in the target details was observed to be larger in the retroffited details. Also, the improvement of fatigue strength is more effective in the retrofitted details with the vertical rib than the bulkhead plate.

Three-dimensional finite element static analysis and safety evaluation of attachable roadside barriers on bridges (탈·부착식 교량 방호울타리의 3차원 유한요소 정적해석 및 안전성 평가)

  • Lee, Sang-Youl
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.4
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    • pp.2414-2418
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    • 2014
  • This study carried out three-dimensional finite element analysis and structural safety evaluation of attachable roadside barriers. The effects of diaphragm distance and the number of bolts on displacements and maximum stresses for various parameters are studied using the LS-DYNA finite element program for this study. In this study, the existing finite element analysis of barriers using the LS-DYNA program is further extended to study static behaviors and structural safety of the barrier with module structures connected by anchor bolt inserted through concrete bridge decks. The numerical results for six parameters are verified by comparing different models with displacements and stress distribution occurred in the barrier and shows good structural performance.

A Study on the Fatigue Design of Joint Detail of Vertical Stiffener in Two-Girder Bridge (2거더교의 수직보강재 연결상세부의 피로설계에 관한 연구)

  • Kwon, Soon Cheol;Kyung, Kab Soo;Park, Jin Eun
    • Journal of Korean Society of Steel Construction
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    • v.21 no.1
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    • pp.93-103
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    • 2009
  • Two-girder bridge is composed of primary members such as deck slab and main girder, and secondary member such as cross beam, vertical and horizontal stiffeners etc,. Two-girder bridge is prescribed as a non-redundant load path structure in the ASSHTO and the Korean Highway Bridge Design Code. Such structure is that if one girder is damaged, problems of function and safety of the bridge are caused. From the reasons, fatigue cracks in two-girder bridge can affect safety of the bridge seriously. Therefore, in this paper, fatigue evaluation was performed at connection parts of vertical stiffener and web with radius of curvature of scallop of vertical stiffener and thickness of web as variables. Such joint is known as a detail which has high possibility of fatigue crack in the bridge. Based upon the analytical results, preferable joint detail in terms of fatigue and simple empirical formula for fatigue evaluation of the detail were suggested.

Design of Vam Cong Cable Stayed Bridge in Vietnam (베트남 밤콩 사장교의 설계)

  • Lee, Yong-Jin;Kang, Jeong-Woon;Bae, Sang-Woon;Yun, Yeon-Suk;Lho, Byeong-Cheol
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.1 no.2
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    • pp.120-127
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    • 2013
  • Vam Cong Cable Stayed Bridge which has 450m main span length is one of the Central Mekong Delta Region Connectivity Project and is located in Cuu Long Delta Region. It has steel-concrete composite girder with 4 lane and the type of cable is multi strand cable. The improved H-shape pylon and cast-in-place bored piles were applied. High strength concrete is applied for pylon, precast concrete slab and Cast-in-Situ concrete pile to ensure the structural safety. The present paper describe the design specifications and main features of Vam Cong Cable Stayed Bridge design.

Relief Hole for Improvement of Fatigue Strength in Welded Intersections of Transverse and Longitudinal Ribs in Orthotropic Deck (가로리브와 U리브 용접부의 피로강도 향상을 위한 응력완화홀)

  • Jung, Kyoung Sup;Nam, Seung Hoon;Yang, Keon Bong;Kim, Kyoung Nam
    • Journal of Korean Society of Steel Construction
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    • v.26 no.5
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    • pp.419-430
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    • 2014
  • On going researches which are being made on the welded joints at the intersections of closed ribs such as U-ribs with floor-beams in ortho-tropic steel decks still have been used the shape of scallops with or with not diaphragm inside. Stress Relief Hole(SRH) being presented in this study was investigated in order to reduce the fatigue damage in the intersections of U-rib with floor-beam. Finally, it is verified that circular SRHs sufficiently relief the concentration stress at the intersections of U-rib with floor-beam and shows that SRH can be offer one of the methods that can prevent the fatigue damage in these structural details.

Evaluation for Ultimate Flexural Strength of Steel Composite Girder with High Strength Concrete (고강도 콘크리트 강합성 거더의 극한휨강도 실험 평가)

  • Kim, Woon Hak;Lee, Juwon;Lee, Seokmin
    • Journal of the Society of Disaster Information
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    • v.16 no.4
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    • pp.796-805
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    • 2020
  • Purpose: A static loading test was performed to evaluate the ultimate flexural strength of a girder in which 80MPa high-strength concrete was synthesized on the compressive flange of the I-shape steel girder. Method: This test is designed and fabricated two types of specimens with different shear-connection specifications, and evaluated their ultimate flexural behavior until reaching the extreme event limit states. In addition, the ultimate strength was evaluated by comparing the test results and the results of the strain compatibility method. Result: By confirming the displacement within 0.02mm as a result of the relative slip measurement, it was verified that the two specimens secured perfect bonding. Therefore, the difference in the shear specification does not have a great effect on the stiffness, and if the specimens are completely synthesized, there is no difference in the behavior until it reaches the extreme-event limit states. Conclusion: The girder to be tested has a working load within the elastic range and meets the usability requirements for allowable deflection. Therefore, even if a part of the casing is subjected to the tensile force at the level of cracking, the deck will first reach the compression failure due to the role of the reinforcing bar.

A Numerical Study on Load Distribution Factors for Simplified Composite H-Beam Panel Bridges (강합성 초간편 H형강 교량의 하중분배계수에 관한 해석적 연구)

  • Park, Jong Sup;Kim, Jae Heung
    • Journal of Korean Society of Steel Construction
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    • v.21 no.3
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    • pp.221-232
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    • 2009
  • The load distribution factor (LDF) values of simplified composite H beam panel bridges (SCHPBs) that were subjected to one lane and two lane loads were investigated using three dimensional finite element analyses with the computer program ABAQUS (2007). This study considered some design parameters such as the slab thickness, the steel plate thickness, the span length, and the continuity of the SCHPBs in the development of new LDFs. The distribution values that were obtained from these analyses were compared with those from the AASHTO Standard, LRFD, and the equations presented by Tarhini and Frederick, Huo et al., Back and Shin, and Cai. The AASHTO Standard distribution factors for SCHPBs were found to be very conservative. Sometimes, the distribution values from the finite element analyses for interior girders were similar to the results of the AASHTO LRFD, whereas the values for exterior girders were conservative in most cases. The new distribution values that were presented in this study produced LDFs that are more conservative than those from the finite element method. For the simple application of the design to SCHPBs, bridge engineers can use 0.42 for the interior girder and 0.32 for the exterior girder. The proposed values improve the current design procedure for the LDF problem and increase SCHPB design efficiency.

Cyclic Seismic Testing of Cruciform Concrete-Filled U-Shape Steel Beam-to-H Column Composite Connections (콘크리트채움 U형합성보-H형강기둥 십자형 합성접합부의 내진성능)

  • Park, Chang-Hee;Lee, Cheol-Ho;Park, Hong-Gun;Hwang, Hyeon-Jong;Lee, Chang-Nam;Kim, Hyoung-Seop;Kim, Sung-Bae
    • Journal of Korean Society of Steel Construction
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    • v.23 no.4
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    • pp.503-514
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    • 2011
  • In this research, the seismic connection details for two concrete-filled U-shape steel beam-to-H columns were proposed and cyclically tested under a full-scale cruciform configuration. The key connecting components included the U-shape steel section (450 and 550 mm deep for specimens A and B, respectively), a concrete floor slab with a ribbed deck (165 mm deep for both specimens), welded couplers and rebars for negative moment transfer, and shear studs for full composite action and strengthening plates. Considering the unique constructional nature of the proposed connection, the critical limit states, such as the weld fracture, anchorage failure of the welded coupler, local buckling, concrete crushing, and rebar buckling, were carefully addressed in the specimen design. The test results showed that the connection details and design methods proposed in this study can well control the critical limit states mentioned above. Especially, the proposed connection according to the strengthening strategy successfully pushed the plastic hinge to the tip of the strengthened zone, as intended in the design, and was very effective in protecting the more vulnerable beam-to-column welded joint. The maximum story drift capacities of 6.0 and 6.8% radians were achieved in specimens A and B, respectively, thus far exceeding the minimumlimit of 4% radians required of special moment frames. Low-cycle fatigue fracture across the beam bottom flange at a 6% drift level was the final failure mode of specimen A. Specimen B failed through the fracture of the top splice plate of the bolted splice at a very high drift ratio of 8.0% radian.