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Characteristics of the shear behavior of RC rectangular sectional columns and initial shear strength considering the ratio of longitudinal bars

RC 사각단면 기둥의 전단거동특성과 축방향철근비를 고려한 초기전단강도

  • 이종석 (울산대학교 건설환경공학부) ;
  • 선창호 (울산대학교 건설환경공학부) ;
  • 김익현 (울산대학교 건설환경공학부)
  • Published : 2010.04.30

Abstract

It is well known that the shear strength of an RC column subjected to a lateral force decreases with the increase of the displacement ductility of column. This decreasing rate of shear strength is quite dependent on the initial shear strength. Therefore, the evaluation of the initial shear strength is important to predict the shear strength with reasonable accuracy. The shear behavior is complex because many parameters, such as the sectional shape, aspect ratio, axial force, longitudinal bars and ductility, are mutually interactive. In this study, the initial shear strength has been investigated by experiments varying parameters such as the aspect ratios, void ratios, ratio of longitudinal bars and sectional types. A new empirical equation for the initial shear strength, considering the ratio of the longitudinal bars, has been proposed and its validity has been assessed.

횡하중을 받는 RC 기둥의 전단강도는 기둥의 변위연성도가 증가함에 따라 감소하는 것으로 알려져 있다. 연성도의 증가에 따른 전단강도의 감소율은 초기전단강도에 따라 크게 좌우되므로 이를 합리적으로 예측하기 위해서는 초기전단강도의 평가가 매우 중요하다. 기둥의 전단거동은 단면모양, 형상비, 축력, 축방향철근비, 연성도 등 다양한 요인에 의하여 영향을 받아 복잡하다. 본 연구에서는 형상비, 단면의 중공비, 축방향철근비, 중공 및 중실단면을 변수로 하는 시험체를 제작하여 실험적 연구를 수행하여 전단거동특성을 살펴보았다. 또한, 축방향철근이 전단강도에 미치는 영향을 분석하여 형상비와 축력을 고려한 기존의 초기전단평가식을 보완하였으며, 그 타당성을 검증하였다.

Keywords

References

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