中文摘要：

以往的增量动力分析（Incremental Dynamic Analysis,IDA）研究主要是针对单向地震下的对称结构,而对于地震动的多维性、结构偏心引起的扭转效应的影响则考虑较少。为此,设计了一幢5层的偏心结构模型,选取Taft双向地震记录为双向激励对结构模型进行多维增量动力分析。分析了结构在地震下的扭转效应对边缘框架反应的放大作用,并基于IDA能力曲线对结构模型进行多性能水准抗震评估。通过算例分析得到以下结论：基于IDA的结构抗震评估方法,概念清晰,操作简单;偏心结构在双向地震下的扭转效应会导致部分边缘框架的反应放大,且地震强度越大这种放大效应越明显;当考虑双向地震作用时,直接采用建议的双向IDA方法进行结构性能分析更具合理性。

英文摘要：

The previous researches about incremental dynamic analysis（IDA） focused on the single directional earthquake motions and symmetric structures,and the influences of multi-dimensional earthquake motions and structural eccentricities were not considered.So,a 5-storey asymmetric building is designed,and the Taft bi-directional earthquake records are selected as the earthquake excitations of the example building for the multi-dimensional IDA.The amplification effect of torsion on the responses of edge frames of this example building subjected to the bi-directional earthquake motions is analyzed,and the seismic ability of multi-performance levels of this example building is evaluated based on the IDA capacity curves.The analysis results of the example indicate the following： The seismic evaluation method based on IDA has clear concept and is easy to operate.The torsion effect can induce the amplification of responses of partial edge members of asymmetric structures,and this character is more obvious with the increase of earthquake intensity.For the situation of structures subjected to bidirectional earthquake motions,it is more reasonable to use the bidirectional IDA method for analyzing structural seismic performance.