• Title/Summary/Keyword: PS 강거더의 실험

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Experimental and Analytical Studies on the Non-Linear behaviors of Pre-Stressed Steel H-Beams (프리스트레스트 H형강 거더의 비선형 거동에 대한 실험적 및 이론적 연구)

  • Kim, Moon-Young;Kim, Nak-Kyung;Oh, Yong-Hwan
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.32 no.6
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    • pp.359-366
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    • 2019
  • Experimental and analytical studies on the behavioral characteristics of a pre-stressed (PS) steel girder are conducted to investigate the effects of deviators on the non-linear inelastic properties of the PS system. In this regard, 4 test specimens consisting of a steel H-beam, a straight cable with eccentricity, anchorages, and deviators are built and failure tests are performed under two-point loading. In addition, in-plane elastic deformation theories for the PS system without a deviator, and with three deviators at regular intervals are analytically formulated and solved using a symbolic calculation technique. To verify the validity of the experimental and the proposed analytical theories, the results obtained using FEM models composed of beam elements, rigid beam elements, and truss cable elements, are compared to the experimental results and the analytical solutions. As a result, it is determined that externally installed un-bonded deviators inhibit flexural deformation of the deformed beam to such an extent that their elastic stiffness, and failure strength are significantly improved compared to those of the PS system without deviators.

An Experimental Study on the Girder-Abutment Connection for the Steel-Concrete Composite Rigid-Frame Bridge Integrated with PS Bars (PS 강봉으로 일체화된 강합성 라멘교의 거더-교대 접합부의 거동에 관한 실험적 연구)

  • Lee, Sang-Yoon;Ahn, Young-Soo;Oh, Min-Ho;Chung, Jee-Seung;Yang, Sung-Don
    • Journal of the Korea Concrete Institute
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    • v.24 no.4
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    • pp.453-463
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    • 2012
  • Steel-concrete composite rigid-frame bridge is a type of integral bridge having advantages in bridge maintenance and structural efficiency from eliminating expansion joints and bridge supports, the main problems in bridge maintenance. The typical steel-concrete composite rigid-frame bridge has the girder-abutment connection where a part of its steel girder is embedded in abutment for integrity. However, the detail of typical girder-abutment connection is complex and increases the construction cost, especially when a part of steel girder is embedded. Recently, a new type of bridge was proposed to compensate for the disadvantages of complex details and cost increase. The compensation are expected to improve efficiency of construction by simplifying the construction detail of the girder-abutment connection. In this study, a static load test has been carried out to examine the behavior of the girder-abutment connection using real-scale specimens. The results of the test showed that the girder-abutment connection of proposed girder bridge has sufficient flexural capacity and rebars to control concrete crack should be placed on the top of abutment.

Structural Performance Analysis of New Type CFTA Girder Bridge (신형식 CFTA 거더 교량의 구조성능평가)

  • Lee, Ji-O;Jeong, Min-Chul;Park, Kyung-Hoon;Kong, Jung-Sik
    • Journal of the Korean Society of Hazard Mitigation
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    • v.11 no.1
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    • pp.15-22
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    • 2011
  • In this research, static load test is performed to verify the arch effect and structural performance of CFTA(Concrete-Filled and Tied steel tubular Arch) girder, and FE(Finite Element) analysis is performed to investigate validity of the test result. CFTA girder is designed to maximize the benefit of each material, such as steel plate, filled concrete and PS tendon. Static load test is performed based on the frame-analysis result of 12m sample miniature model. The result of static load test is that structural performance and safety of CFTA girder are confirmed and there is different deflection mode with other structural form result from arch effect. FE analysis with ABAQUS is also performed to show the validity of the truck collision safety and static load test.

Flexural Behavior of Segmental U-Girder and Composite U-Girder Using Ultra High Performance Concrete (초고강도 섬유보강 콘크리트를 사용한 분절형 U거더 및 합성 U거더의 휨거동)

  • Lee, Seung-Jae;Makhbal, Tsas-Orgilmaa;Kim, Sung-Tae;Han, Sang-Mook
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.5 no.3
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    • pp.290-297
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    • 2017
  • The flexural behavior tests of UHPC segmental U-girder and composite U-girder which has 160MPa compressive strength and 15.4m length were carried out. The test variables are volume fraction of steel fibers and slab over the U-girder. Each U-girder has longitudinal re-bars in web and lower flange. PS tendons which has 2 of 15.2mm diameter in upper flange and PS tendons which has 7 of 15.2mm diameter in lower flange were arranged and prestressed at onetime in U-girder connection stage. Enough strong prestressing force which applied to U-girder due to ultra high performance concrete strength can withstand the self weight and dead load in U-girder stage. By comparison with the brittle behavior of U-girder, composite U-girder showed the stable and ductile behavior. After the construction of slab over U-girder, flexural load capacity of composite U-girder can bear the design load in final construction stage with only one time prestressing operation which already carried out in U-girder stage. This simple prestressing method due to the ultra high strength concrete have the advantage in construction step and cost. The shear key which has narrow space has the strong composite connection between ultra high strength concrete U-girder and high strength concrete slab didn't show any slip and opening right before failure load.

Ductile Behavior of Ultra High Performance Fiber Reinforced Concrete Segmental Box Girder (초고강도 섬유보강 콘크리트 분절형 박스거더의 연성 거동)

  • Jeong, Min-Seon;Park, Sung-Yong;Han, Sang-Mook
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.5 no.3
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    • pp.282-289
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    • 2017
  • The flexural behavior tests of UHPC segmental Box girder which has 160MPa compressive strength and 15.4m length were carried out. The test variables are area of prestressing wires, volume fraction of steel fibers and longitudinal reinforcing bars in upper flange and web. PS tendons which has 32 strands of 15.2mm diameter in lower flange, 24 strands and 14 strands in lower flange were arranged and volume fraction of 2%, 1.5% and 1.0% is used in box girder concrete. UHPFRC box girder which has 32 strands in lower flange showed the over reinforcement and brittle behavior. UHPFRC box girder which has 24 strands showed the similar peak load as 32 strands girder and ductile behavior as large deflection. UHPFRC box girder which has 14 strands showed half of the peak load of 24 strands box girder and ductile behavior. After the application of the formular for the reinforcement index to the behavior of the UHPFRC box girders, reinforcement index does not determine the characteristic of behavior of UHPFRC box girder exactly. So the index should consider the dimension precisely and modify the reference value corresponding to the 0.005 strain of the prestressing strands.

Structural Characteristics Analysis of Steel Box Girder Bridge being stressed the PS Steel Wires at the Upper Slab of the Intermediate Support (지점부 상부슬래브에 PS강선 긴장된 강 박스거더교의 구조적 특성 분석)

  • Cha, Tae-Gweon;Jang, Il-Young
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.25 no.2
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    • pp.1-7
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    • 2021
  • The concrete deck slab at the continuous span support of the steel box girder bridge is a structure that is combined with the upper flange. It is a structure that can cause tension cracks in the deck slab at the support causing problems such as durability degradation in long span bridges. This is because the tensile stress in the longitudinal direction of the slab exceeds the design tensile strength due to the effects of dead load and live load when applying a long span. Accordingly, it is necessary to control tensile cracking by adding a reinforcing bar in the axial direction to the slab at the support and to introduce additional compressive stress. To solve this problem, a structural system of a steel box girder bridge was proposed that introduces compressive stress as PS steel wire tension in the tensile stress section of the upper slab in the continuous support. The resulting structural performance was compared and verified through the finite element analysis and the steel wire tension test of the actual specimen. By introducing compressive stress that can control the tensile stress and cracking of the slab generated in the negative moment through the tension of the PS steel wire, it is possible to improve structural safety and strengthen durability compared to the existing steel box girder bridge.

Fatigue Capacity Evaluation of the Girder-Abutment Connection for the Steel-Concrete Composite Rigid-Frame Bridge Integrated with PS Bar (PS 강봉으로 일체화된 강합성 라멘교의 거더-교대 접합부에 대한 피로 성능 평가)

  • Ahn, Young-Soo;Oh, Min-Ho;Chung, Jee-Seung;Lee, Sang-Yoon
    • Journal of the Korea Concrete Institute
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    • v.24 no.3
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    • pp.249-258
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    • 2012
  • Integral and rigid frame bridges have advantages in bridge maintenance and structural efficiency by eliminating expansion joints and bridge supports. However, the detail of typical girder-abutment connection is rather complex and increases construction cost depending on construction detail. For the purpose of compensating disadvantages such as complexity and additional cost, a new type of bridge is proposed in this study, which improves the efficiency of construction by simplifying the construction detail of girder-abutment connection. The proposed bridge has the connection detail of steel girder and abutment integrated by prestressed PS bar installed in the connection. In this study, finite element analysis and fatigue load test are conducted to evaluate the fatigue capacity of the proposed girder-abutment connection. The results of the finite element analysis revealed that the possibility of the fatigue damage in the girder-abutment connection is very low. The results of the fatigue load test verified that the integrity of the girder and abutment connection is maintained after 2,000,000 cycles of fatigue loading.

Static Behavior of the Prestressed Concrete Deck Slab for Steel-Concrete Composite Two-Girder Bridges (강합성 2거더교 PSC 바닥판의 정적 거동)

  • 김영진;주봉철;이정우;김병석;박성용
    • Journal of the Korea Concrete Institute
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    • v.14 no.4
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    • pp.503-512
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    • 2002
  • Generally, the girder spacing of the two-girder composite bridge is from 5m up to 15m. To ensure the structural safety according to Korean Bridge Design Specification, the deck depth should be from 33 cm upto 73 cm. Using the transversal prestressing strands in concrete deck, we can reduce its depth about 10%. However, there is little experience on the design and construction of prestressed concrete(PSC) decks in Korea. This paper focuses on the behaviors of PSC deck. A literature survey is performed widely. Considering the characteristics of the two-girder bridge and the construction conditions in Korea, a cast-in-place PSC deck is recommended for the two-girder bridge with 6m girder spacing. To examine its structural behaviors and safety, three partial model deck specimens(3 m$\times$5 m) with real scale are fabricated md tested. One(PS34-RS) is 34cm depth with the stiffness restraint in longitudinal edges for simulating the real bridge deck. Another(PS34-NS) is same depth without the stiffness restraint, and the other(PS28-NS) is 28cm depth with the stiffness restraint. Under the static patch loading, each specimen had a larger ultimate flexural strength than the design value. Specimens with the stiffness restraint (PS34-RS and PS28-RS) showed the punching shear failure mode and specimen without that(PS34-NS) showed the flexural failure mode.