KSCE Journal of Civil and Environmental Engineering Research (대한토목학회논문집)

Korean Society of Civil Engeneers (대한토목학회)
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Seismic Performance of Column-Footing Connection of Modular Pier using CFT

CFT를 이용한 모듈러 교각 기둥-기초 연결부의 내진성능

  • 김지영 (단국대학교 토목환경공학과) ;
  • 김기도 (단국대학교 토목환경공학과) ;
  • 마향욱 (대우건설기술연구원 토목연구팀) ;
  • 정철헌 (단국대학교 토목환경공학과)
  • Received : 2013.09.27
  • Accepted : 2013.11.11
  • Published : 2014.02.01
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Abstract

The CFT (Concrete Filled steel Tubes) column-footing connection is cast-in-place embedded type which provides simple construction procedure, low cost, and superior structural performance. In this study, CFT column-footing connection of modular pier is proposed and structural performance is evaluated by experimental tests. To evaluate structural performance of the CFT column-footing connection, a series of experimental tests were performed for the 4 specimens with different embedded depth. As a result of the quasi-static test, the specimen with 0.6D (0.6 times the outside diameter of steel tube) embedded depth showed relatively low ductility than other specimens with larger embedded depth due to cone failure of base concrete occurred during the lower loading step. On the contrary, cone failure of the base concrete was not observed in the specimens with larger embedded depth than 0.9D, but typical flexural failure in lower part of CFT column was observed. With the analyses of force-displacement curve, displacement ductility, and energy dissipation capacity, it is concluded that the rational range of embedded depth of the CFT column-footing connection is from 0.9D to 1.2D in view of good seismic performance.

CFT 기둥은 시공이 간단하고 경제적이며 구조성능이 우수한 현장타설 매입형 연결 형식이다. 본 연구에서는 모듈러 교각에 적용되는 CFT 기둥-기초 연결부 형식을 제안하고, 실험을 통하여 구조성능을 평가하였다. 기둥-기초 연결부의 구조성능을 평가하기 위해서 기초부 콘크리트에 매입되는 CFT 기둥의 매입깊이를 변수로 총 4개의 실험체를 제작하여 실험을 수행하였다. 준정적 실험결과, 매입깊이가 0.6D인 실험체에서는 낮은 하중단계에서 기초부의 콘파괴로 인하여 상대적으로 낮은 연성능력을 보였다. 그러나 매입깊이가 0.9D 이상인 실험체에서는 기초부의 콘파괴가 방지되고 CFT 기둥 하단부에서 전형적인 휨파괴 거동을 보이며 높은 연성능력을 발휘하였다. 하중-변위 이력곡선, 변위 연성도 및 에너지 소산능력 등을 분석한 결과, 제안된 CFT 기둥-기초 연결부의 매입깊이는 0.9D~1.2D 수준이 내진성능을 발휘하는 합리적인 수준인 것으로 평가되었다.

Keywords

References

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