A Damping Modification Factor Prediction Model for Horizontal Displacement Spectrum from Subduction Slab Earthquakes in Japan Accounting for Site Conditions
A Damping Modification Factor Prediction Model for Horizontal Displacement Spectrum from Subduction Slab Earthquakes in Japan Accounting for Site Conditions
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DOI：
10.1785/0120190156
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发表时间：
2020-04
影响因子：
3
通讯作者：
Jun Zhou;John X. Zhao
中科院分区：
文献类型：
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作者：
Jun Zhou;John X. Zhao
本文使用Zhao、Jiang等人（2016）研究中的类似数据集，提出了一个不含震源和路径参数的日本俯冲板地震阻尼修正因子（DMF）模型。基于站点周期的站点类被用作站点效果代理。DMF模型基于13种阻尼比和34个谱周期的谱，在1% ~ 30%的阻尼比和0.03 ~ 5.0 s的谱周期范围内均可计算DMF模型。分别使用谱周期对数的简单四阶多项式和阻尼比对数的简单二次函数来模拟谱周期和阻尼比的影响。该模型满足边界条件，即DMF值在很短的光谱周期内等于1.0；在长谱周期，不同阻尼比下的dmf收敛于1.0，满足长周期恒定位移谱。模型的标准差小于地震动预测方程的标准差。所有的标准差都随阻尼比的对数的增加而线性变化。本研究中提出的dmf与Zhao、Jiang等人（2016）研究的频谱相结合，产生了可用于工程设计的平滑位移频谱。在0.2-3.0 s的光谱周期范围内，本研究的DMF值接近Daneshvar等人（2016）的结果，但在短周期内，差异是显著的。残差分布表明，dmf还与震源和路径参数有关。本文提出的模型不包括源和路径变量的影响，因此该模型可以用于缩放没有已知幅度和源距离的5%阻尼谱。
A damping modification factor (DMF) model without source and path parameters is presented in this article for subduction slab earthquakes in Japan, using a similar dataset in the Zhao, Jiang, et al. (2016) study. Site classes based on site periods were used as the site-effect proxy. DMF models were derived from spectra of 13 damping ratios and 34 spectral periods, and the DMF can be calculated for any damping ratio between 1% and 30% and at any spectral period between 0.03 and 5.0 s. A simple fourth-order polynomial for the logarithm of the spectral periods and a simple quadratic function of the logarithm of damping ratios were used to model the effects of spectral periods and damping ratios, respectively. The model satisfies boundary conditions that require the DMF values equal to 1.0 at very short spectral periods; at long spectral periods, the DMFs for different damping ratios appear to converge to 1.0 to satisfy the constant displacement spectrum at long periods. Model standard deviations are smaller than those for the ground-motion prediction equations. All standard deviations vary linearly with the increasing logarithm of damping ratios. The DMFs presented in this study combined with the spectrum from the Zhao, Jiang, et al. (2016) study produce smoothed displacement spectrum that may be used for engineering designs. In a spectral period range of 0.2–3.0 s, the DMF values from this study are close to those by Daneshvar et al. (2016), but, at short periods, the difference is significant. The residual distribution suggests that DMFs also depend on earthquake source and path parameters. The model presented in this article does not include the effect of source and path variables so that this model can be used to scale a 5% damped spectrum without a known magnitude and a source distance.