Recent advances in engineering characteristics of near-fault ground motions and seismic effects of building structures

Abstract

Severe damages of civil infrastructures under near-fault ground motions have impelled the community of earthquake engineering to pay intensive attention and investigation to their engineering characteristics and structural seismic effects. This paper reviews the recent research advances of authors in the engineering characteristics of near-fault ground motions and seismic responses and base-isolated performance analysis of building structures. Firstly, two non-structure-specific intensity measures, such as improved effective peak acceleration and velocity (IEPA, IEPV) were proposed. Two frequency content parameters were also suggested, namely the mean period of Hilbert marginal spectrum Tmh, and coefficient of variance of dominant instantaneous frequency of Hilbert spectrum Hcov which reflects the frequency nonstationary degree of ground motions. Meanwhile, a new stochastic model to synthesize near-fault impulsive ground motions with the feature of the strongest pulse was established. Then, the chaotic and fractal/multifractal characteristics of strong earthquake ground motions were analyzed deeply to explore their complexity from a novel perspective of nonlinear dynamics, and the inherent relation between fractal dimensions and period parameters of near-fault motions was exposed. Moreover, the mechanism of interstory deformation of tall building was illustrated based on engineering properties of pulse-like ground motions and generalized drift spectral analysis. Finally, the influence of ground motion properties on the seismic responses and performance of tall structures and base isolated buildings was revealed.