汪维依, 冀昆, 温瑞智, 任叶飞. 考虑场址危险一致性的中国完备条件目标谱与记录选取[J]. 工程力学, 2024, 41(2): 71-82. DOI: 10.6052/j.issn.1000-4750.2022.03.0250
引用本文: 汪维依, 冀昆, 温瑞智, 任叶飞. 考虑场址危险一致性的中国完备条件目标谱与记录选取[J]. 工程力学, 2024, 41(2): 71-82. DOI: 10.6052/j.issn.1000-4750.2022.03.0250
WANG Wei-yi, JI Kun, WEN Rui-zhi, REN Ye-fei. SITE-SPECIFIC HAZARD CONSISTENT EXACT CONDITIONAL TARGET SPECTRUM AND SELECTION OF GROUND MOTION RECORDINGS FOR CHINA[J]. Engineering Mechanics, 2024, 41(2): 71-82. DOI: 10.6052/j.issn.1000-4750.2022.03.0250
Citation: WANG Wei-yi, JI Kun, WEN Rui-zhi, REN Ye-fei. SITE-SPECIFIC HAZARD CONSISTENT EXACT CONDITIONAL TARGET SPECTRUM AND SELECTION OF GROUND MOTION RECORDINGS FOR CHINA[J]. Engineering Mechanics, 2024, 41(2): 71-82. DOI: 10.6052/j.issn.1000-4750.2022.03.0250

考虑场址危险一致性的中国完备条件目标谱与记录选取

SITE-SPECIFIC HAZARD CONSISTENT EXACT CONDITIONAL TARGET SPECTRUM AND SELECTION OF GROUND MOTION RECORDINGS FOR CHINA

  • 摘要: 即使所处地区的宏观抗震设防烈度相同,不同城市的地震地质构造与活动性背景仍然存在差异。为使地震动输入与所在场址的地震危险性水平保持一致,该研究衔接我国第五代地震区划图的概率地震危险性分析结果,给出了完备条件目标谱的构建方法。采用与第五代地震区划图相同的三级潜源分布和地震动预测方程,进行目标场址的危险性分析与设定地震解耦,衔接三维(震级-经纬度)设定地震解耦结果,给出了考虑所有潜源走向与位置相对贡献的“完备”条件谱。以北京近郊某城市作为算例,结果表明,完备条件谱的均值介于使用长轴和短轴衰减关系的粗略条件谱之间,条件标准差高于粗略条件谱。研究给出的完备条件谱适用于我国区划图的长短轴类型衰减关系,可以很好体现潜源的空间分布特征与背景地震危险性差异。基于我国强震动记录数据库拟合的加速度反应谱相关系数得到的条件谱要略高于基于国外数据库的计算结果。为了实现加速度反应谱均值和标准差的高效匹配,该研究采取多元高斯分布的协方差矩阵近似替换完备条件谱高斯混合分布的协方差矩阵,结合贪心优化算法,选取得到满足目标完备条件谱分布的强震动记录数据集。研究结果系统给出了我国条件目标谱进行记录选取的构建思路与选波方案,可为后续全概率结构性态分析提供依据。

     

    Abstract: The seismic geological structure and the background seismicity varied between different cities or regions, even the corresponding design seismic intensity are identical. To make the hazard level consistent with the target site, this study proposed to construct the conditional spectrum (CS) based on the output of the fifth-generation seismic zonation map of China. The potential seismic sources and GMPE used in the zonation map were applied to carry out the PSHA and the disaggregation of earthquake scenarios. The 3D (magnitude-longitudes-latitude) disaggregation results were applied to construct the "exact" CS considering the contribution of different strikes of the seismic source area. A city in north China was taken as the example to illustrate the CS computation results. The comparison results indicated that the median value of an exact CS lies within the approximate CS using long axis and short axis, the conditional variance is higher than that of the approximate CS. The exact CS could reflect the spatial distribution of the potential seismic area sources and the difference in seismicity, and more suitable for China GMPE which has long axis and short axis equations. The correlation derived using China ground motion dataset would result in higher CS compared with that using PEER dataset. In this study, the covariance matrix of multivariate Gaussian distribution is adopted to approximately replace the covariance matrix of Gaussian mixture distribution of an exact CS. With greedy optimization algorithm, highly efficient matching of mean, standard deviation, and Sa distribution was realized. The exact CS constructed in this study and corresponding ground motion recordings selection could provide a basis for following performance-based analysis of structures.

     

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