ABSTRACT This study investigated the collapse capacity of inelastic single-degree-of-freedom (SDOF) systems subjected to mainshock-aftershock earthquake sequences. A hysteretic model incorporating strength and stiffness deterioration was used to describe the inelastic behaviors of SDOF systems under seismic excitations. An ATC63 far-field record set was adopted as seed mainshock records to synthesize earthquake sequences. An extended IDA method was employed to calculate the collapse capacity of inelastic SDOF systems subjected to mainshock-aftershock earthquake sequences by scaling the earthquake sequence as a whole. An extensive parametric study was conducted for examining the effects of hysteretic model parameters and artificial earthquake sequences synthesized by different methods and with near-field and far-field mainshock earthquakes on system collapse capacity. Through comparing the collapse capacity for mainshock-aftershock earthquake sequences and that for mainshock earthquakes only, it is found that aftershocks can yield a significant reduction on the median collapse capacity for all systems and lead to an important increase on the dispersion of collapse capacity for the systems at most periods. Based on the parametric study results, empirical expressions were proposed to predict the aftershock-induced reduction and increase on the median and dispersion of collapse capacity, respectively.

中文翻译：

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受主震-余震地震序列影响的非弹性单自由度系统的坍塌能力

摘要 本研究调查了非弹性单自由度 (SDOF) 系统在主​​震-余震地震序列下的倒塌能力。结合强度和刚度退化的滞后模型用于描述地震激发下单自由度系统的非弹性行为。采用ATC63远场记录集作为种子主震记录合成地震序列。采用扩展的 IDA 方法，通过将地震序列作为一个整体进行缩放来计算非弹性单自由度系统在主震-余震地震序列作用下的倒塌能力。进行了广泛的参数研究，以检查滞后模型参数和通过不同方法合成的人工地震序列以及近场和远场主震地震对系统倒塌能力的影响。通过比较主震-余震地震序列的倒塌能力与仅主震地震的倒塌能力，发现余震可以显着降低所有系统的倒塌能力中值，并导致系统倒塌能力离散度的显着增加。系统在大多数时期。根据参数研究结果，分别提出了经验表达式来预测余震引起的坍塌能力中值和离散度的减少和增加。通过比较主震-余震地震序列的倒塌能力与仅主震地震的倒塌能力，发现余震可显着降低所有系统的倒塌能力中值，并导致系统倒塌能力离散度的显着增加。系统在大多数时期。根据参数研究结果，分别提出了经验表达式来预测余震引起的坍塌能力中值和离散度的减少和增加。通过比较主震-余震地震序列的倒塌能力与仅主震地震的倒塌能力，发现余震可显着降低所有系统的倒塌能力中值，并导致系统倒塌能力离散度的显着增加。系统在大多数时期。根据参数研究结果，分别提出了经验表达式来预测余震引起的坍塌能力中值和离散度的减少和增加。