Small-strain damping profiles developed from geotechnical laboratory testing have been observed to be smaller than the damping inferred from the observed site amplification from downhole array recordings. This study investigates the high-frequency spectral decay parameter (κ0) of earthquake motions from soil sites and evaluates the use of κ0 to constrain the small-strain damping profile for one-dimensional site response analysis. Using data from 51 sites from the Kiban-Kyoshin strong motion network (KiK-net) array in Japan and six sites from California, a relationship was developed between κ0 at the surface and both the 30-m time-averaged shear wave velocity (Vs30) and the depth to the 2.5 km/s shear wave velocity horizon (Z2.5). This relationship demonstrates that κ0 increases with decreasing Vs30 and increasing Z2.5. An approach is developed that uses this relationship to establish a target κ0 from which to constrain the small-strain damping profile used in one-dimensional site response analysis. This approach to develop κ0-consistent damping profiles for site response analysis is demonstrated through a recent site amplification study of Central and Eastern North America for the NGA-East project.

中文翻译：

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0 用于土壤场地：来自 Kik-net 场地的观察及其在场地响应分析中约束小应变阻尼剖面的用途

已观察到由岩土实验室测试开发的小应变阻尼剖面小于从井下阵列记录观察到的现场放大推断的阻尼。本研究调查了来自土壤场地的地震运动的高频频谱衰减参数 (κ0)，并评估了使用 κ0 约束一维场地响应分析的小应变阻尼剖面的情况。使用来自日本 Kiban-Kyoshin 强震网络 (KiK-net) 阵列的 51 个站点和加利福尼亚州的 6 个站点的数据，开发了地表 κ0 与 30 米时间平均横波速度 (Vs30) 之间的关系) 和到 2.5 km/s 横波速度层 (Z2.5) 的深度。这种关系表明 κ0 随着 Vs30 的降低和 Z2.5 的增加而增加。开发了一种方法，该方法使用该关系来建立目标 κ0，从该目标 κ0 约束用于一维现场响应分析的小应变阻尼剖面。最近针对 NGA-East 项目对北美中部和东部进行的场地放大研究证明了这种为场地响应分析开发 κ0 一致阻尼曲线的方法。