Dimensionless analysis of pulse-like effects on the seismic behavior of a dam based on wavelet-decomposed near-fault ground motions. (October 2021)

• Record Type: Journal Article
• Authors: Xu, Qiang; Xu, Shutong; Chen, Jianyun; Li, Jing
• Is Part Of: Structures. Volume 33(2021)
• Page Start: 2003
• Page End: 2018
• Publication Date: 2021-10
• Subjects: Dimensionless analysis -- Near-fault pulse-like ground motions -- Seismic parameter -- Concrete gravity dam -- Dynamic response; Structural engineering -- Periodicals; 624.1
• DOI: 10.1016/j.istruc.2021.05.069
• Languages: English
• ISSNs: 2352-0124

Abstract

Abstract: In this paper, the inherent self-similarity between seismic characteristics and the dynamic behavior of a concrete gravity dam under decomposed near-fault ground motions is investigated. The representative low- and high-frequency components were decomposed using the continuous wavelet transform method to explore their effects on the dam response. The Koyna concrete gravity dam system was used as the basis for a numerical model. A series of dam dynamic responses under near-fault motion with and without pulse properties were obtained by numerical analyses. The relationship between the proposed dimensionless indices (intensity measure ratio ( ΦIM ), pulse period ratio ( T 1 / T p )), and response ratio ( ΨEDP, m ) was established to study the inherent self-similarity in the dynamic behavior of dams, which has an explicit physical significance with smaller dispersion. The response proportions of two main frequency components in the original near-fault record were revealed. Furthermore, a series of new threshold values were calculated based on the intersection of the pulse and high-frequency ratios, and the range of influence of the low- and high-frequency components was quantitatively divided. Finally, a predictive model was proposed for the dam responses to near-fault ground motions containing the proposed dimensionless indices that exhibited reasonable patterns. The pulse-like seismic characteristics and seismic responses to near-fault ground motions were analyzed and selected in the context of sensitivity, inherent self-similarity, threshold point, and regression error. Results show that the self-similarity between Φ S a ( T 1 ), ΦASI and ΨDVR, pulse, Ψ DVR n, p u l s e is superior to that of other parameter ratios, indicating that more attention should be given to the role of intensity and pulse parameters in practical concrete dam seismic design.