Spectral and intensity indices of near-fault ground motions based on different focal mechanisms
Du Yongfeng1,2 Xu Tianni1 Hong Na1
1. Institute of Earthquake Protection and Disaster Mitigation, Lanzhou University of Technology, Lanzhou 730050, China
2. Western Center of Disaster Mitigation in Civil Engineer of Ministry of Education, Lanzhou University of Technology, Lanzhou 730050, China
Abstract：In this study, 118 near-fault pulse ground motion records are classified according to different soil conditions and focal mechanisms, based on the simplified model of base-isolated structural system of two degrees of freedom, the elastic-plastic response spectra are obtained by using state-space method and fourth-order Runge-Kutta method, and the effects of site conditions and focal mechanism on structural response spectra are analyzed. In order to explore the selection problems of the intensity indices for seismic response analysis of base-isolated structure, the correlation between elastic-plastic structural responses and intensity indices composed of PGA、PGV and PGD are discussed. The results show that the average acceleration response spectra under the reverse fault ground motions and the average displacement response spectra under reverse oblique fault ground motions are largest, but the laws of average velocity response spectra are not obvious in three site conditions. For different site conditions and focal mechanisms, the correlation degrees between intensity indices and structural response are different. Hence, when studying the seismic response of base-isolated structure under near-fault ground motions, it is recommended to select and adjust ground motion inputs using different intensity indices with different site condition and focal mechanisms considered.
杜永峰 徐天妮 洪娜. 不同震源机制的近断层脉冲型地震动频谱特性及强度指标研究[J]. 土木工程学报, 2017, 50(5): 81-87.
Du Yongfeng Xu Tianni Hong Na. Spectral and intensity indices of near-fault ground motions based on different focal mechanisms. 土木工程学报, 2017, 50(5): 81-87.
