Study of maximum acceleration response spectrum for bi-directional ground motions
Wang Min1 Li Wenjie2 Zhu Aiping3 Fu Jianping2
1. Chongqing University of Arts and Science, Chongqing 402160, China;
2. Chongqing University, Chongqing 400045, China;
3. China Academy of Building Research, Beijing 100013, China
Abstract：In this study, the domestic and overseas representative response spectra of bi-directional horizontal ground motions are reviewed. It is found that the maximum value of the unidirectional acceleration spectra corresponding to all the possible horizontal acceleration recorders is the best representative value for bi-directional horizontal ground motions, which is termed as the bi-directional maximum acceleration (BdM) spectrum. Ground motion database for the site of type II with various ground motions is created to consider the difference between BdM spectrum and unidirectional acceleration (Und) spectrum. The results show that: (1) firstly, for the same ground motion in site of type II, BdM and Und are similar in the shape of spectrum, but the dynamic amplification factor of the former is generally higher than that of the latter, and their difference may increase with the period of structure. The mean value and standard deviation of BdM spectrum are 1.2 to 1.4 and 1.1 to 1.4 times those values obtained from Und spectrum, respectively, at the same period. (2) Secondly, compared to BdM spectrum, the first descending part of the design spectrum for site of type II in the national code of China is generally smaller, while for various ground motion types, the second descending part is generally smaller than BdM spectrum. As a result, for the structures designed for site of type II based on the design spectrum in the national code of China, value levels of the seismic design force may not be consistent, leading to inconsistent seismic safety levels of structures. Particularly, when choosing ground motion records on the basis of the target design spectrum to predict the seismic responses of structures in site of type II, the risk levels shall be inconsistent, which may result in the difference in actual seismic performance when the structural design is controlled by the uniform evaluation criteria.
王敏 李文杰 朱爱萍 傅剑平 . 地面运动双向最大加速度反应谱特性研究[J]. 土木工程学报, 2017, 50(10): 24-32.
Wang Min Li Wenjie Zhu Aiping Fu Jianping . Study of maximum acceleration response spectrum for bi-directional ground motions. 土木工程学报, 2017, 50(10): 24-32.
