Journal of the Korea Academia-Industrial cooperation Society (한국산학기술학회논문지)

The Korea Academia-Industrial cooperation Society (한국산학기술학회)
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The Characteristics of Curvature Ductility Factor of Reinforced Concrete Hollow Section Beams

철근콘크리트 속빈 단면 보의 곡률연성지수 특성

  • Lee, Hyung-Joon (Dept. of Civil and Environmental Engineering, Hanbat National University)
  • 이형준 (한밭대학교 건설환경공학과)
  • Received : 2013.10.25
  • Accepted : 2013.12.05
  • Published : 2013.12.31
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Abstract

In highly elevated piers and long span beams, a hollow section is often used to reduce the self-weight and increase the flexural rigidity of members. Numerical analysis was conducted to obtain the moment-curvature curves and curvature ductility factor for the RC hollow section beams under a range of hollow portion sizes and reinforcement conditions in the upper flange and web. The curvature ductility factor was constantly maintained until the hollow portion size($b_i/b_o/h_i/h_o$) was less than or equal to 0.5. The curvature ductility factor decreased sharply if ($b_i/b_o/h_i/h_o$) was 0.7 or more. The curvature ductility factor of the beam decreased if reinforcement was provided in the web of the RC hollow section beam. To obtain the same level of the ductility factor as the singly reinforced section, the reinforcement should be provided in the upper flange as much as the web reinforcement.

콘크리트 구조물이 대형화됨에 따라 고교각, 장지간의 보 등 부재가 장대화되고 있으며, 장지간의 철근콘크리트 부재에서는 자중을 줄이고 강성을 증가시키기 위해 속빈 단면을 사용하는 것이 증가하는 추세이다. 본 연구에서는 철근콘크리트 속빈 단면 보의 모멘트-곡률 관계를 해석적 방법으로 구하여 속빈 부분의 크기, 상부플랜지와 복부의 철근 배치조건이 부재의 휨거동 및 곡률연성지수에 미치는 영향을 분석하였다. 속빈 부분의 크기($b_i/b_o$ 또는 $h_i/h_o$)가 0.5이하일 때에는 곡률연성지수가 일정하게 유지되며, 0.7이상이 되면 곡률연성지수가 급격히 감소하였다. 또한, 복부에 철근을 배치하면 곡률연성지수가 감소하며 단철근 보에서와 같은 수준의 연성지수를 얻기 위해서는 복부에 배치한 철근과 같은 양을 상부플랜지에 배치해야 하는 것으로 나타났다.

Keywords

References

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