Release Time:2019-03-09  Hits:

Indexed by: Journal Papers

Date of Publication: 2015-05-01

Journal: SOIL DYNAMICS AND EARTHQUAKE ENGINEERING

Included Journals: EI、SCIE

Volume: 72

Page Number: 12-23

ISSN: 0267-7261

Key Words: Near-fault ground motions; Multi-scaling behavior; Multifractal detrended fluctuation analysis; Irregularity; Generalized Hurst exponent; Long-range correlation

Abstract: This study aims to reveal the multi-scaling behavior and quantify the irregularity of near-fault earthquake ground motions from a new perspective of multifractal theory. Based on multifractal detrended fluctuation analysis, the multifractal characteristic parameters of acceleration time series for typical near-fault ground motions are calculated, and their correlations with two period parameters (i.e., mean period T-m and characteristic period T-c) and box-counting fractal dimensions are analyzed. Numerical results of strong nonlinear dependence of generalized Hurst exponents h(q) upon the fluctuation orders q indicate that near-fault ground motions present the multifractal properties and long-range correlation obviously. Furthermore, the scaling exponent h(2) of near-fault records has a strong correlation with their periods T-m and T-c, and strongly negative correlation with their box dimension. Moreover, h(2) can be regarded as a measure of frequency content and irregularity degree of strong earthquake ground motions. Finally, it is pointed out that the long-range correlation of small and large fluctuation is the major source of multifractality of near-fault ground motions. (C) 2015 Elsevier Ltd. All rights reserved.