The peak inelastic displacement of single‐degree‐of‐freedom bilinear systems (⁠Sdi⁠) is an effective intensity measure linking ground‐motion features to the inelastic response and subsequent structural and nonstructural damage of engineered systems. This study develops a region‐specific ground‐motion model for Sdi considering source, path, and site effects and explicitly accounting for the spatial correlation between intraevent residuals when the model parameters are estimated. The model is developed based on 2427 two‐component horizontal ground‐motion records from 85 events in northern Italy with magnitudes ranging from 4.0 to 6.4 and source‐to‐site distances less than 200 km. An exponential stationary and isotropic model is considered to represent the spatial correlation properties of Sdi (after scrutinizing the appropriateness of the underlying assumptions for such a model). Comparisons are performed with existing models in the literature in terms of Sdi estimates, as well as the (spatial correlation) effective range parameter. Two practical applications of the developed model are presented: one on estimating the spatial distribution of Sdi (as an essential ingredient for seismic loss assessments) and one on the engineering validation of region‐specific ground‐motion simulations. Challenges regarding such validations are also discussed.

中文翻译：

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考虑空间相关特性的意大利北部非弹性谱位移的区域特定地面运动模型

单自由度双线性系统（⁠Sdi⁠）的峰值非弹性位移是一种有效的强度度量，将地震动特征与工程系统的非弹性响应以及随后的结构和非结构破坏联系在一起。这项研究针对Sdi开发了一个区域特定的地面运动模型，其中考虑了源，路径和站点的影响，并在估计模型参数时明确考虑了事件内残差之间的空间相关性。该模型基于意大利北部的85个事件的2427个两分量水平地面运动记录而开发，震级范围从4.0到6.4，源到站点的距离小于200 km。指数平稳和各向同性模型被认为代表了Sdi的空间相关性（在仔细检查了该模型的基本假设的适用性之后）。根据Sdi估计值以及（空间相关性）有效范围参数，与文献中的现有模型进行比较。提出了已开发模型的两个实际应用：一个是估计Sdi的空间分布（作为地震损失评估的基本要素），另一个是对特定地区地面运动模拟的工程验证。还讨论了有关此类验证的挑战。以及（空间相关性）有效范围参数。提出了已开发模型的两个实际应用：一个是估计Sdi的空间分布（作为地震损失评估的基本要素），另一个是对特定地区地面运动模拟的工程验证。还讨论了有关此类验证的挑战。以及（空间相关性）有效范围参数。提出了已开发模型的两个实际应用：一个是估计Sdi的空间分布（作为地震损失评估的基本要素），另一个是对特定地区地面运动模拟的工程验证。还讨论了有关此类验证的挑战。