Damping coefficients for near-fault ground motion response spectra
Damping coefficients for near-fault ground motion response spectra
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DOI：
10.1016/j.soildyn.2010.09.009
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发表时间：
2011-03
影响因子：
4
通讯作者：
D. Hubbard;G. Mavroeidis
中科院分区：
文献类型：
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作者：
D. Hubbard;G. Mavroeidis
阻尼系数在地震工程中经常被用作一种简单的方法，用于将与5%的粘性阻尼比相关的伪加速度或位移反应谱调整为配备有基础隔震和/或补充耗能装置的结构设计所需的较高粘性阻尼值。在这项研究中，计算了近断层地震动作用下单自由度系统在大范围周期和阻尼水平下的阻尼系数。结果表明，阻尼系数建议的设计规范和以前的研究，主要是基于远场地震动记录，往往是不保守的近断层地震激励。本文提出了一种新的阻尼系数计算方法，可用于地震断层附近的工程分析和设计。这包括相对于在近断层区域记录的地面速度脉冲的持续时间的周期轴的归一化。脉冲持续时间受断层面上的上升时间控制，并与地震震级成正比。
Damping coefficients are frequently used in earthquake engineering as a simple way to adjust the pseudo-acceleration or displacement response spectra associated with a viscous damping ratio of 5% to the higher values of viscous damping needed for design of structures equipped with base isolation and/or supplemental energy dissipation devices. In this study, damping coefficients for the single-degree-of-freedom system subjected to near-fault ground motions are calculated for a large range of periods and damping levels. The results indicate that damping coefficients proposed in design codes and previous studies, based primarily on far-field ground motion records, tend to not be conservative for near-fault seismic excitations. A new approach is recommended for the derivation of damping coefficients appropriate for engineering analysis and design in the immediate vicinity of the earthquake fault. This includes the normalization of the period axis with respect to the duration of the ground velocity pulses recorded in the near-fault region. The pulse duration is controlled by the rise time on the fault plane and scales directly with earthquake magnitude.