Seismic Behavior and Drift Limits of Different Performance Levels for Steel Reinforced Concrete Columns

摘要

Six half scale steel reinforced concrete (SRC) columns were tested under cyclic loading. The effects of the axial compression ratio and stirrup ratio on the hysteretic characteristics of SRC columns were investigated. Test results indicated that the displacement ductility index decreased with the increasing of the axial load and increased with the increasing of the stirrup ratio. According to the damage characteristic and test data, a series of performance parameters and corresponding limit value that can be used to appraise the performance level of SRC columns under earthquake was proposed. It is suggested that the crack width and stress level of longitudinal bar, residual drift and ultimate drift index can be adopted as the key parameters to appraise the different seismic performance levels, i.e. functional, repairable and collapse avoidable, respectively. If the story drift index be used as an appraisal parameter, it is recommended that the limit values for the four performance levels, i.e. fully operation, operation, repairable and collapse avoidable be 1/250, 1/150, 1/50 and 1/35, respectively. The conclusions of this paper can be used as references for the performance based seismic design of SRC structures.