This paper proposes a random field model of sequential ground motions, which considers the spatial correlation between the mainshock and aftershock from a stochastic view. First, the correlation between the mainshock and aftershock under the physical “source–path–local site” mechanism is explained. Based on the mechanism, the point-source model, and uniform-isotropic-medium model, a random single-point model for sequential ground motion with eight basic parameters is presented. Second, the random field model is developed from the random single-point model. More than 1000 pairs of sequential ground motions are used to identify and analyze statistically the basic parameters in the model. Moreover, the probability distribution of each parameter is presented based on copula functions. The results show that the spatial correlations of sequential ground motions can be effectively simulated based on the proposed random field model. Furthermore, it is possible to realistically reproduce the attenuation and time lag of ground motions at a local site.

中文翻译：

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连续地面运动的随机场模型

本文提出了一种连续地面运动的随机场模型，该模型从随机角度考虑了主震和余震之间的空间相关性。首先，解释了在物理“源－路径－本地站点”机制下的主震和余震之间的相关性。基于该机理，点源模型和均匀各向同性介质模型，提出了具有八个基本参数的连续地面运动随机单点模型。其次，从随机单点模型发展随机场模型。超过1000对连续的地面运动用于识别和统计分析模型中的基本参数。此外，基于copula函数给出了每个参数的概率分布。结果表明，基于所提出的随机场模型可以有效地模拟连续地震动的空间相关性。此外，有可能在本地实际再现地面运动的衰减和时滞。