Experimental Investigation on the Performance Levels and Drift Capacity of SRC Columns

摘要

To promote the performance-based seismic design and assessment of steel-reinforced concrete (SRC) structures, 27 SRC columns, varying axial load ratio n, steel ratio ρ_(ss), and shear span ratio λ, were tested under quasi-static cyclic loadings. The failure modes, hysteretic response, performance levels (PLs), damage states and drift limits of the SRC columns were reported and discussed. The results showed that the failure mode shifted gradually from flexural to shear as λ decreased, but the deformability was not weakened obviously. Six PLs were defined based on the backbone curve of the SRC columns. Each PL was correlated to a damage state that represents a specific macroscopic damage extent. The relative error of drift limits between performance levels and damage states was less than 9 on average. Parametric analysis showed that n and ρ_(ss) were the most influential factors for drift limits, whereas X had an ignorable effect. Then, practical regression formulas were established in terms of n and ρ_(ss) for drift limits of three key PLs (PL1, PL5, and PL6) of the SRC columns, and they were in good agreement with the experimental results. Finally, the average damage indices of PL1 to PL6, calculated using the model proposed in this paper, were 0.26, 0.45, 0.65, 0.83, 0.95, and 0.99, respectively.