Improved seismic fragility modeling from empirical data
Improved seismic fragility modeling from empirical data
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DOI：
10.1016/j.strusafe.2007.05.004
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发表时间：
2008-07
影响因子：
5.8
通讯作者：
D. Štraub;A. Kiureghian
中科院分区：
文献类型：
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作者：
D. Štraub;A. Kiureghian
改进的经验脆弱性模型解决了地震性能观测之间的统计依赖性，这种依赖性是由影响观测的常见但未知的因素引起的。所提出的模型通过在各个组件的极限状态的公式中明确包含公共变量来解释这种依赖性。此外，在模型参数的估计中考虑了连续地震期间同一分量的观测结果是相关的这一事实。正如考虑变电站设备脆弱性的数值例子所证明的那样，改进的公式可以导致与经验观察中统计独立性的传统假设所获得的脆弱性估计值显着不同。此外，传统方法低估了与由此产生的脆弱性估计相关的统计不确定性。本文最后调查了统计不确定性和组件统计依赖性对系统脆弱性的影响。数值例子表明这些影响是显着的，必须在冗余系统的分析中得到解决。
The improved empirical fragility model addresses statistical dependence among observations of seismic performances, which arises from common but unknown factors influencing the observations. The proposed model accounts for this dependence by explicitly including common variables in the formulation of the limit state for individual components. Additionally, the fact that observations of the same component during successive earthquakes are correlated is considered in the estimation of the model parameters. As demonstrated by numerical examples considering the fragility of electrical substation equipment, the improved formulation can lead to significantly different fragility estimates than those obtained with the conventional assumption of statistical independence among the empirical observations. Furthermore, the conventional approach underestimates the statistical uncertainty associated with the resulting fragility estimates. The paper concludes with an investigation of the effects of statistical uncertainty and component statistical dependence on the system fragility. Numerical examples demonstrate that these effects are significant and must be addressed in the analysis of redundant systems.