• Title/Summary/Keyword: High-Strength bolts

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Evaluation of Shear Performance for CSB (Confined Socket Bolt) Shear Connector (CSB (Confined Socket Bolt) 전단연결재의 전단 성능 평가 )

  • Seung-Hyeon Hwang;Ju-Hyun Mun;Jong-Kook Hong;Jong-Cheol Jeon;Jae-Il Sim
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.27 no.2
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    • pp.8-16
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    • 2023
  • This study evaluated a shear capacity of confined socket-bolt (CSB) shear connector developed for utilizing cast in placed pile (CIP) as a permanent underground wall. The push-out tests were performed in the specimens with different CIP types, CSB shear connector types, L/d, and concrete compressive strengths of concrete pile, and with or without waterproofing at interfaces between CIP and underground wall. Test results showed that the specimens with a H-shaped pile were fractured in the CSB shear connector, while the fracture concentrated in the concrete part of the specimens with a reinforced concrete pile was alleviated as the compressive strength of the concrete pile increased, resulting in the severe fracture of CSB shear connector. The maximum shear capacities of the specimens with high strength bolts and reinforcing bars used as CSB shear connector were approximately 1.22 and 1.20 times higher than those of the specimens with a H-shaped pile, respectively, and 1.10 and 1.16 times higher than those of the specimens with a reinforced concrete pile, respectively. Meanwhile, the maximum shear capacity was not significantly affected by the embedding length of the CSB shear connector and overlapping length of reinforcing bar. The predicted shear capacities calculated from the KDS standards were lower than the measured values of all specimens tested in this study.

The Experimental Study on Transverse Field Joint Method of Precast Road Deck Slab of Double Deck Tunnel in Great Depth (대심도 복층터널 프리캐스트 중간슬래브의 횡방향 현장이음방식에 대한 실험연구)

  • Lee, Doo-Sung;Kim, Bo-Yeon;Bae, Chul-Gi;Hur, Jae-Hun
    • Journal of the Korea Concrete Institute
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    • v.29 no.1
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    • pp.23-32
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    • 2017
  • The joints between precast PSC slabs of the intermediate road slab in double deck tunnel are inevitably generated in the road traffic vehicle traveling direction. Therefore, it is important to make the behavior of parts on the joint in one piece. The imtermediate road slab system of double deck tunnel in great depth proposed in this study will be constructed with precast PSC slab in order to minimize the construction period. And the joint connection between the precast slab has been developed in two methods: the 'Transverse tendon reinforcement method' and 'High strength bolts connection method'. Also, the experiments were performed for the full scale model in order to evaluate the performance of the intermediate road deck slab with two type joints systems, the structural stability was verified through the F.E.M analsysis. The results of static loading test and F.E.M analysis investigated a very stable behavior of intermediate road deck slab in double deck tunnel applying the joint methods developed in this study, in the cracks and deflections to satisfy the design standards of Highway Roads Bridges (2011), it was determined that there is no problem even servicebility.