Due to a lack of the hoop action of lateral reinforcements the effective confining force in rectangular sections reduces compared to circular ones. Therefore, the stress-strain model obtained from the experimental data with circular sections overestimates the lateral confinement effect in rectangular sections, which evaluates seismic safety margin of overall structural system excessively. In this study experiments with laterally-confined square sections have been performed and the characteristic values composing stress-strain model have been analyzed. With introduction of section coefficients, in addition, the new unified stress-strain model applicable to square sections as well as circular ones has been proposed.

• 선창호(울산대학교 건설환경공학부) | Sun, Chang Ho
• 정혁창(태인ENC) | Jeong, Hyeok Chang
• 김익현(울산대학교 건설환경공학부) | Kim, Ick hyun Corresponding author