Seismic response of gravity dams suffering spectrum-matched ground motions with different pulse characteristics

• Published in: Structures (Oxford) Vol. 69; p. 107302
• Main Authors: Su, Wei, Wang, Xiang-Chao, Xu, Yan-Jie, Wang, Jin-Ting
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.11.2024
• Subjects: Gravity dam; Ground motions; Non-pulse-like; Pulse-like; Seismic response; Spectral matching; Pulse-like; Spectral matching; Ground motions; Gravity dam; Seismic response; Non-pulse-like
• ISSN: 2352-0124; 2352-0124
• DOI: 10.1016/j.istruc.2024.107302

Previous studies recognized that the effects of pulse-like ground motions not only depend on the characteristics of the velocity pulse, but also on the relationship between the characteristics of the velocity pulse and the dynamic properties of the structure. In practical engineering, ground motions matched to the design spectrum are generally used to evaluate the seismic response of structures. However, the effects on the structural response of spectrum-matched ground motions with different pulse characteristics are not clear. For this issue, 15 pulse-like records and 15 non-pulse-like records are selected for the seismic analysis of the Pine Flat dam. The initial step involves performing nonlinear seismic analysis of the Pine Flat dam using the 30 selected ground motions, all of which are scaled to the same PGA. Subsequently, these selected ground motions are modified using a spectral matching method to align with a specified design response spectrum while retaining their main characteristics, and the nonlinear seismic analysis of the dam is further conducted. This study reveals that when considering ground motions with the same PGA, pulse-like ground motions pose a higher risk to the dam compared to non-pulse-like ground motions. Nevertheless, following the spectral matching process, the dynamic responses of the Pine Flat dam subject to pulse-like and non-pulse-like ground motions show no significant differences. Finally, based on the results of this study, it is suggested that the spectra of different pulse types should be summarized and analyzed independently to more accurately evaluate the impact of pulse-like and non-pulse-like ground motions on structral response.