• Title/Summary/Keyword: Structural-dominated Mode

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Seismic performance of precast assembled bridge piers with hybrid connection

  • Shuang, Zou;Heisha, Wenliuhan;Yanhui, Liu;Zhipeng, Zhai;Chongbin, Zhang
    • Structural Engineering and Mechanics
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    • v.85 no.3
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    • pp.407-417
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    • 2023
  • Precast assembled bridge piers with hybrid connection (PASP) use both tendons and socket connections. To study the seismic performance of PASP, a full-scale in-situ test was performed based on an actual bridge project. The elastic-plastic fiber model of PASP was established using finite element software, and numerical analyses were performed to study the influence of prestress degree and socket depth on the PASP seismic performance. The results show that the typical failure mode of PASP under horizontal load is bending failure dominated by concrete cracking at the joint between the column and cushion cap. The cracking of the pier concrete and opening of joints depend on the prestress degree and socket depth. The prestressing tendons and socket connection can provide enough ductility, strength, restoration capability, and bending strength under small horizontal displacements. Although the bearing capacity and post yield stiffness of the pier can be improved to some extent by increasing the prestressing force, ductility is reduced, and residual deformation is increased. Overall, there are reasonable minimum socket depths to ensure the reliability of the socket connection.

The Strain of Transverse Steel and Concrete Shear Resistance Degradation after Yielding of Reinforced Concrete Circular Pier (철근콘크리트 원형 교각의 횡방향철근 변형률과 항복이후 콘크리트 전단저항 저감)

  • Ko, Seong Hyun
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.22 no.1
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    • pp.147-157
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    • 2018
  • The basis of capacity design has been explicitly or implicitly regulated in most bridge design specifications. It is to guarantee ductile failure of entire bridge system by preventing brittle failure of pier members and any other structural members until the columns provides fully enough plastic rotation capacity. Brittle shear is regarded as a mode of failure that should be avoided in reinforced concrete bridge pier design. To provide ductility behavior of column, the one of important factors is that flexural hinge of column must be detailed to ensure adequate and dependable shear strength and deformation capacity. Eight small scale circular reinforced concrete columns were tested under cyclic lateral load with 4.5 aspect ratio. The test variables are longitudinal steel ratio, transverse steel ratio, and axial load ratio. Eight flexurally dominated columns were tested. In all specimens, initial flexural-shear cracks occurred at 1.5% drift ratio. The multiple flexural-shear crack width and length gradually increased until the final stage. The angles of the major inclined cracks measured from the vertical column axis ranged between 42 and 48 degrees. In particular, this study focused on assessing transverse reinforcement contribution to the column shear strength. Transverse reinforcement contribution measured during test. Each three components of transverse reinforcement contribution, axial force contribution and concrete contribution were investigated and compared. It was assessed that the concrete stresses of all specimen were larger than stress limit of Korea Bridge Design Specifications.