基于耐震时程法的锈蚀 RC 框架结构抗地震倒塌能力评估

Reinforcement corrosion would degrade the seismic performance of reinforced concrete (RC)structures, leading more vulnerability of structures to collapse under earthquakes. Therefore, it is necessary to evaluate the seismic collapse capacity for the RC structures with corroded reinforcement. Currently, the incremental dynamic analysis (IDA)approach is widely used for the assessment of seismic collapse capacity of structures. However, it often costs numerous time and has low computational efficiency. To solve this problem, this study adopts the endurance time method to evaluate the seismic collapse capacity for corroded RC frames. For illustration, a typical RC frame is designed according to Chinese code as the study case. The corroded rates of zero, 10% and 20% are considered. The endurance time method and IDA method are both used to calculate the seismic collapse fragility curves and collapse margin ratios for the corroded RC frames. The results show that collapse margin ratio decreases with the increase of corrosion rate. Make a comparison of the results by the endurance time method and IDA method. It is found that they yield similar resutes of the collapse fragility curves and collapse margin ratios. This reveals that the endurance time method could be an efficient replacement of IDA method for seismic collapse capacity assessment of structures.