鋼筋混凝土梁受震超額強度因子之研究

The purpose of this project is to find out the relationship between overstrength factor (<o) for different types of reinforcement and the magnitude of seismic intensity which represented by drift ratio. Furthermore, check whether different types of reinforcement have the same strain hardening overstrength factor (<har) when the same drift ratio (DR) occurs. This project collect the data tested from RC beams subjected to cyclic loading. Those beams having the longitudinal reinforcement of SD420 and SD690 represent as normal strength and high strength RC beams, respectively. The study adopted the Brooke's (2011) method to calculate α_mat and α_har of the steel bar for the normal strength and high-strength RC beams. The findings of this project have led to the conclusion that both α_har and α_mat have no significant difference between the steel grade of SD420 and SD690. However, α_har increases linearly as the drift ratio (DR) rises. In addition, if combine the data of all RC beams neglecting the longitudinal reinforcement grades (SD420 and SD690), the upper limit of the 95% confidence level of α_mat is 1.11; if DR = 3.5%, the upper limit of the 95% confidence level ofα_har, DR = 3.5% is 1.12, which can be obtained α_har, DR = 3.5% = 1.25, this value is the same as the recommended value in ACI 318-19.