A comprehensive technique for identification of modal properties (i.e. natural periods and equivalent modal damping ratios) of building structures is presented. The proposed identification technique employs a combination of multiple system identification methods; it utilizes the benefits and suppresses the shortcomings of each method to provide a succinct set of modal properties for building structures. Using the proposed modal identification technique, modal properties of 80 buildings with a total of 896 distinct seismic event and building direction records were identified. Simplified and practical equations for modal quantities along with the variation of such parameters for different structural system types, building height, and amplitude of excitation are studied and presented. A critical assessment of other similar studies and results are presented.

中文翻译：

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建筑结构抗震设计的自然周期和模态阻尼比评估

提出了一种用于识别建筑结构模态特性（即自然周期和等效模态阻尼比）的综合技术。所提出的识别技术采用了多种系统识别方法的组合；它利用每种方法的优点并抑制其缺点，为建筑结构提供一组简洁的模态属性。使用所提出的模态识别技术，共识别了 80 座建筑物的模态特性，共有 896 个不同的地震事件和建筑物方向记录。研究并提出了模态量的简化和实用方程，以及这些参数在不同结构系统类型、建筑高度和激励幅度下的变化。