Study on inelastic displacement ratio spectra for near-fault pulse-type
ground motions
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Zhai Changhai (µÔ³¤º£)1, Li Shuang (Àîˬ)1‡, Xie Lili (лÀñÁ¢)1,2,
and Sun Yamin (ËïÑÇÃñ)1
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1. School of Civil Engineering, Harbin Institute of Technology, Harbin
150090, China
2. Institute of Engineering Mechanics, China Earthquake Administration, Harbin
150080, China
Abstract: In displacement-based seismic design,
inelastic displacement ratio spectra (IDRS) are particularly useful for
estimating the maximum lateral inelastic displacement demand of a nonlinear SDOF
system from the maximum elastic displacement demand of its counterpart linear
elastic SDOF system. In this study, the characteristics of IDRS for near-fault
pulse-type ground motions are investigated based on a great number of earthquake
ground motions. The influence of site conditions, ratio of peak ground velocity
(PGV) to peak ground acceleration (PGA), the PGV, and the maximum incremental
velocity (MIV) on IDRS are also evaluated. The results indicate that the effect
of near-fault ground motions on IDRS are significant only at periods between 0.2
s - 1.5 s, where the amplification can approach 20%. The PGV/PGA ratio has the
most significant influence on IDRS among the parameters considered. It is also
found that site conditions only slightly affect the IDRS.
Keywords: near-fault pulse-type ground motion;
inelastic displacement ratio spectrum; ground motion parameter;PGV/PGA; site
condition
