抗地震倒塌能力谱研究

应用基于IDA的倒塌易损性分析方法,定量评估了单自由度结构体系的抗地震倒塌能力,提出了结构抗地震倒塌能力谱的概念。抗地震倒塌能力谱由抗倒塌能力均值谱和离散度谱两部分构成,不仅可用于估计结构在不同超越概率地震作用下的倒塌率,还可根据罕遇地震/特大地震作用下的倒塌率目标,建立基于倒塌率目标的抗震设计方法。由于传统抗震设计的R-μ-T谱未考虑结构的倒塌状态,因此,建议采用R-μ-T谱和抗地震倒塌能力谱分别折减设防地震和罕遇地震/特大地震作用下的弹性地震作用需求,以实现"小震不坏、中震可修、大震不倒"的抗震设计目标。

Study of collapse resistant capacity spectrum

This paper quantitatively evaluates the earthquake-induced-collapse resistance of the single-degree-of-freedom structural system through collapse fragility analysis based on incremental dynamic analysis, and proposes the concept of the collapse resistant capacity spectrum. The collapse resistant capacity spectrum is composed of the median spectrum and the dispersion spectrum. The CRC spectrum is useful to estimate the collapse probability of building structures subjected to the earthquake of given intensity level. And it is also utilized to establish the collapse probability targeted seismic design by which the structure is designed to satisfy the prescribed collapse probability under collapse-prevention-level earthquakes/mega-earthquakes. Since the R-μ-T spectrum does not focus on the collapse state, it is proposed that, the elastic seismic action required by the fortification-level earthquake and the collapse-prevention-level earthquake/mega-earthquake are reduced by the classical R-μ-T spectrum and the CRC spectrum, respectively, so as to rationally realize the three level seismic design target as prescribed in the Chinese code for seismic design.