Selection of ground motions for use in nonlinear dynamic analysis is one of the most critical steps for both code-based design and probabilistic seismic risk assessment of structures. In practice, time-domain spectrum-matching methods, which add wavelet functions to an initial acceleration time series, have been widely used to obtain a record whose response spectrum closely matches the desired target spectrum. Although the spectral shape is known to be a good predictor of structural response, it does not represent the critical aspects of the velocity pulses, such as pulse amplitude and pulse period for near-fault ground motions. The Instantaneous Power (IP(T₁)), defined as the maximum rate of change of energy of the bandpass-filtered velocity time series over a short time interval given by half of the structural period, has been shown to be an effective alternative parameter to capture effects of the presence of a velocity pulse and the pulse period in near-fault record selection. We introduce an approach to modify time series so as to simultaneously match a target response spectrum and IP spectrum over a specified period interval. We demonstrate that the records modified using the proposed approach produce results comparable to those obtained using unscaled records, and prevent potential bias in structural response, relative to results when matching is performed without consideration of IP.

在基于代码的设计和结构的概率地震风险评估中，选择用于非线性动力分析的地震动是最关键的步骤之一。在实践中，将小波函数添加到初始加速时间序列的时域频谱匹配方法已被广泛用于获得其响应频谱与所需目标频谱紧密匹配的记录。尽管已知频谱形状可以很好地预测结构响应，但它并不代表速度脉冲的关键方面，例如近断层地面运动的脉冲幅度和脉冲周期。瞬时功率（IP（T ₁））（定义为在短时间间隔内由结构周期的一半给出的带通滤波速度时间序列的最大能量变化率）已被证明是捕获存在a效应的有效替代参数近故障记录选择中的速度脉冲和脉冲周期。我们介绍一种修改时间序列的方法，以便在指定的时间间隔内同时匹配目标响应频谱和IP频谱。我们证明，使用提议的方法修改的记录所产生的结果与使用未缩放记录所获得的结果可比，并且相对于在不考虑IP的情况下进行匹配的结果，可以防止结构响应中的潜在偏差。