Comparing response of SDF systems to near‐fault and far‐fault earthquake motions in the context of spectral regions
Comparing response of SDF systems to near‐fault and far‐fault earthquake motions in the context of spectral regions
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DOI：
10.1002/eqe.92
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发表时间：
2001-12
影响因子：
4.5
通讯作者：
A. Chopra;C. Chintanapakdee
中科院分区：
文献类型：
--
作者：
A. Chopra;C. Chintanapakdee
尽管结构对近断层和远断层地震动的反应有很大的不同，但本文的目的是将基于远断层运动的弹性和非弹性反应谱的众所周知的概念和结果推广到近断层运动。在反应谱的加速度、速度和位移敏感区域的背景下，比较了弹性和非弹性SDF系统对这两种运动的响应的某些方面，从而得出以下结论。(1)与远断层运动相比，近断层运动的速度敏感区较窄，加速度敏感区和位移敏感区较宽，较窄的速度敏感区向较长的周期移动。(2)尽管对于相同的延性系数，近断层地震动比远断层地震动施加了更大的强度需求--两者的需求都表示为各自弹性需求的一小部分--但两种运动的强度折减系数Ry在相应的谱区域上是相似的。(3)类似地，在相应的谱区域上，非弹性和弹性系统的变形比um/u0相似。(4)Ry(和um/u0)的设计方程应明确识别频谱区域，以便只要使用适当的Ta、Tb和Tc值，相同的方程就适用于各种类型的地面运动。(5)T_a=0.04 S，T_b=0.35 S，T_c=0.79 S的维氏-纽马克设计方程对近断层地震动正向分量同样有效。版权所有©2001 John Wiley&Sons，Ltd.
In spite of important differences in structural response to near‐fault and far‐fault ground motions, this paper aims at extending well‐known concepts and results, based on elastic and inelastic response spectra for far‐fault motions, to near‐fault motions. Compared are certain aspects of the response of elastic and inelastic SDF systems to the two types of motions in the context of the acceleration‐, velocity‐, and displacement‐sensitive regions of the response spectrum, leading to the following conclusions. (1) The velocity‐sensitive region for near‐fault motions is much narrower, and the acceleration‐sensitive and displacement‐sensitive regions are much wider, compared to far‐fault motions; the narrower velocity‐sensitive region is shifted to longer periods. (2) Although, for the same ductility factor, near‐fault ground motions impose a larger strength demand than far‐fault motions—both demands expressed as a fraction of their respective elastic demands—the strength reduction factors Ry for the two types of motions are similar over corresponding spectral regions. (3) Similarly, the ratio um/u0 of deformations of inelastic and elastic systems are similar for the two types of motions over corresponding spectral regions. (4) Design equations for Ry (and for um/u0) should explicitly recognize spectral regions so that the same equations apply to various classes of ground motions as long as the appropriate values of Ta, Tb and Tc are used. (5) The Veletsos–Newmark design equations with Ta=0.04 s, Tb=0.35 s, and Tc=0.79 s are equally valid for the fault‐normal component of near‐fault ground motions. Copyright © 2001 John Wiley & Sons, Ltd.