Journal of the Korea Concrete Institute (콘크리트학회논문집)

Korea Concrete Institute (한국콘크리트학회)
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Structural Behavior of Concrete Girder Continuous Bridges Strengthened with External Tendons Considering the Efficiency at Negative Moment Region

부모멘트부의 효율성을 고려한 외부강선으로 보강된 콘크리트 거더 연속교의 거동

  • Han, Man-Yop (Dept. of Civil Systems Engineering, Ajou University) ;
  • Cho, Byeong-Du (Dept. of Civil Systems Engineering, Ajou University) ;
  • Jeon, Se-Jin (Dept. of Civil Systems Engineering, Ajou University)
  • 한만엽 (아주대학교 건설시스템공학과) ;
  • 조병두 (아주대학교 건설시스템공학과) ;
  • 전세진 (아주대학교 건설시스템공학과)
  • Received : 2013.04.18
  • Accepted : 2013.07.27
  • Published : 2013.10.31
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Abstract

An effective method was proposed in this study which can improve the strengthening effect of continuous girder bridges by external tendons. The improvement of the proposed strengthening method in comparison with conventional methods was analyzed by applying equivalent load concept. In order to verify the strengthening effect, the enhancement of load-carrying capacity achieved by external prestressing was investigated through the test of continuous beams that were or were not strengthened by the external prestressing. The continuous beams were fabricated by making the deck slab continuous according to general construction practice of an actual concrete girder bridge. The test results showed that the deflections and strains of the strengthened beam were significantly reduced when comparing with those of the non-strengthened beam for the same level of external loads, and the stiffness of the member increased by strengthening. In particular, it was verified that the proposed method can effectively reduce the tensile stresses of the deck caused by negative moment at the intermediate supports of a continuous bridge.

이 연구에서는 연속 거더교의 외부강선 보강 효과를 극대화할 수 있는 효율적인 방법을 도출하였다. 등가하중개념을 적용하여 기존 방법 대비 제안된 보강 방법의 개선점을 명확히 분석하였다. 보강 효과의 검증을 위해 연속보의 외부강선 보강 실험을 실시하여 외부강선에 의한 내하력 향상 효과를 고찰하였다. 연속보 실험체는 콘크리트 거더 연속교의 일반적인 시공법과 동일하게 바닥판 슬래브 부분만을 연속화하여 제작하였다. 실험 결과 동일한 크기의 외력이 작용할 때 외부강선이 보강된 실험체는 보강되지 않은 실험체에 비해 처짐이나 변형률이 대폭 감소하는 경향을 보였으며, 부재의 강성도 또한 증가하였다. 특히 제안된 방법은 연속교 중간 지점부의 부모멘트에 의한 바닥판의 인장응력을 효과적으로 감소시킬 수 있음이 확인되었다.

Keywords

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