混凝土结构地震需求参数敏感性分析

Sensitivity analysis of earthquake demand parameters

对基本不确定因素通过结构体系进行传递,并对使结构的地震需求参数出现不确定性的过程进行分析,探讨将FOSM法、Tornado图形法和直接统计法应用于敏感性分析的优势和局限性。以1个典型混凝土框架结构为例,综合运用一次二阶矩方法、Tornado图表法和直接统计法,估计4种结构地震需求参数对于一系列基本不确定因素的敏感度,进而对基本不确定因素的重要性进行排序。研究结果表明:结构的地震需求对地震动的强度和特征最敏感,其次为结构阻尼、质量和混凝土抗压强度,而对其他不确定因素不太敏感,这为结构随机地震反应分析以及概率地震需求分析提供了依据。

The uncertainty generation of earthquake demand parameters（EDP） caused by a series of basic uncertain factors was analyzed.The advantages and limitations of FOSM method,Tornado Diagram method and mathematical statistics method were discussed for sensitivity analysis.Taking a typical frame structure as an example,the sensitivity of four kinds of earthquake demand parameters to a series of basic uncertainties was estimated using the three kinds of methods and the basic uncertainties were sorted according to their importance obtained by sensitivity analysis.The results show that EDP are the most sensitive to the intensity measure and the profile of ground motions,rather less sensitive to the viscous damp,the mass and the concrete compressive strength,but not sensitive to other basic uncertainties,which provides the evidence for the random response and probabilistic seismic demand analysis of structures efficiently.