Seismic collapse risk assessment of super high-rise buildings considering modeling uncertainty: A case study

摘要

Based on the multiple stripes analysis method and the first-order second-moment method, a seismic collapse risk assessment considering the modeling uncertainty is carried out for a 118-story super high-rise building with a typical mega-frame/core-tube/outrigger resisting system. The sensitivity of the median collapse capacity of the building to eight main parameters is analyzed, and then the modeling uncertainty is determined. Both the effects of the characterization methods of bidirectional ground motion intensities and the selection of the ground motion intensity measure (IM) on the aleatory randomness are investigated. The mean estimates approach and the confidence interval method are used to incorporate both the modeling uncertainty and the aleatory randomness, and then the annual collapse probability, the collapse probability at the maximum considered earthquake (MCE) intensity level and the acceptable values of the collapse margin ratios (CMRs) with different confidence levels for the building are calculated. The results show that the influence of the modeling uncertainty on the collapse capacity of the super high-rise structure is negligible, the aleatory randomness caused by the record-to-record variability is significant, and an appropriate ground motion IM can significantly reduce the aleatory randomness.