내부 구속 중공 철근 콘크리트 기둥의 내진 특성에 관한 매개 변수 연구

A nonlinear concrete model was developed for a new-type column, internally confined hollow RC column (ICH RC column), with modification of Mander et al.'s uniaxial stress-strain model. An ICH RC column is a hollow RC column which has a straight or corrugated tube inside of itself to enhance its ductility or stiffness by internal confinement. To determine stress-strain model of the concrete in an ICH RC column, possible failure modes of an ICH RC column were suggested and confining pressure was derived from equilibriums for each failure mode. From derived equations, a computer program was coded and the developed analysis model was verified by being compared with results from previous experimental researches. Parametric studies were performed for some examples and the analytical results showed that internally confined concrete has enhanced strength and ductility with comparison of unconfined or biaxially confined concrete.