In seismic design, hollow section concrete columns offer advantages by reducing the weight and seismic mass compared to concrete section RC bridge columns. However, the flexure-shear behavior and spirals strain of hollow section concrete columns are not well-understood. Octagonal RC bridge columns of a small-scale model were tested under cyclic lateral load with constant axial load. The volumetric ratio of the transverse spiral hoop of all specimens is 0.00206. The test results showed that the structural performance of the hollow specimen, such as the initial crack pattern, initial stiffness, and diagonal crack pattern, was comparable to that of the solid specimen. However, the lateral strength and ultimate displacement of the hollow specimen noticeably decreased after the drift ratio of 3%. The columns showed flexure-shear failure at the final stage. Analytical and experimental investigations are presented in this study to understand a correlation confinement steel ratio with neutral axis and a correlation between the strain of spirals and the shear resistance capacity of steel in hollow and solid section concrete columns. Furthermore, shear strength components (Vc, Vs., Vp) and concrete stress were investigated.

A B S T R A C T
1. 서 론
2. 실험변수 및 실험
    2.1 실험변수 및 실험체 제원
    2.2 재하실험
3. 실험결과
    3.1 파괴거동
    3.2 하중-변위 이력곡선 및 포락곡선
4. 철근의 변형률
    4.1 철근 변형률
    4.2 중립축 위치
    4.3 비선형 해석
5. 철근의 변형률과 전단성능
    5.1 철근의 변형률과 전단강도
    5.2 전단성능 모델 적용
    5.3 콘크리트 전단응력
6. 곡 률
7. 결 론
REFERENCES

• 고성현(제주국제대학교 토목공학과) | Ko Seong Hyun (Department of Civil Engineering, Jeju International University) Corresponding author