Abstract Multi-pulse characteristics of near-fault ground motions, such as the number of inherent pulses, pulse periods, and amplitudes, have notable influences on the response of structures. To investigate these important parameters, an automatic detection procedure, which is conducted on the rough pulse signal that is extracted by the HHT method, is proposed in this work. This procedure can localize all inherent pulses in the time domain independently and discontinuously. Important parameters can be automatically obtained at the same time. Then, statistical relationships between these multi-pulse parameters and earthquake parameters, including moment magnitudes, site conditions (Vs30), rupture distances and types of faults, are investigated comprehensively. With an increasing number of pulses, the multi-pulse ground motions are more likely to be recorded in relatively limited areas. All pulse periods in a velocity record are similar to each other and can be represented by the period of the pulse with the largest energy (TPE). TPEs are almost identical to periods of the first pulse in the time domain (TP1). They are related not only to magnitudes but also to fault-types and site conditions. New empirical models are proposed in this work according to fault-types that can predict most TPEs across all magnitudes (from 5.7 to 7.6). For amplitudes, all PGVs of inherent pulses can be expressed by the PGV of the pulse with the largest energy (PGVE) in a linear attenuation relationship. PGVEs are related to rupture distances, site conditions, and fault-types. New empirical models are also developed in this work.

中文翻译：

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近断层地震动的多脉冲特性

摘要 近断层地震动的多脉冲特性，如固有脉冲数、脉冲周期、振幅等，对结构的响应有显着影响。为了研究这些重要参数，本文提出了一种自动检测程序，该程序对通过 HHT 方法提取的粗脉冲信号进行。该过程可以独立且不连续地定位时域中的所有固有脉冲。同时可自动获取重要参数。然后，综合研究了这些多脉冲参数与地震参数之间的统计关系，包括矩震级、场地条件（Vs30）、破裂距离和断层类型。随着脉冲数的增加，多脉冲地面运动更有可能被记录在相对有限的区域。速度记录中的所有脉冲周期彼此相似，可以用能量最大的脉冲周期 (TPE) 表示。TPE 几乎与时域 (TP1) 中第一个脉冲的周期相同。它们不仅与震级有关，而且与断层类型和现场条件有关。在这项工作中，根据可以预测所有量级（从 5.7 到 7.6）的大多数 TPE 的故障类型，提出了新的经验模型。对于幅度，固有脉冲的所有PGV都可以用线性衰减关系中最大能量脉冲的PGV（PGVE）来表示。PGVE 与破裂距离、场地条件和断层类型有关。在这项工作中还开发了新的经验模型。