阿里亚斯强度衰减关系分析

本文选取美国NGA强震数据库中与我国大陆构造环境相近的美国西部、中亚和我国台湾地区的自由地表强震记录，计算其水平向阿里亚斯强度；采用分步回归法依次求取近场饱和项、距离衰减项、震级项、断层类型项和场地类别项的系数，得出衰减模型，并基于回归结果与实际数据的对比，分析了残差随距离或震级的分布.与前人工作得出的全球活动板块边界、新西兰和我国台湾地区的3种阿里亚斯强度衰减模型进行的比较显示，在M_W6.5或远场区域4种模型的结果较接近，近场区域在高震级和低震级时有一定差异.最后，选取2008年汶川M_W7.9和2013年芦山M_W6.8两次地震的强震记录对模型进行检验，结果显示本文衰减关系均与实际数据拟合得很好，表明本文的模型适用于我国大陆地区的相关研究. 

Attenuation relationship of Arias intensity

In this paper, the strong ground motion data recorded in earthquakes of western America, central Asia, and Taiwan area are selected from the Next Generation Attenuation strong motion database to develop the attenuation relationship of Arias intensity. A step-regression method is applied to obtain the coefficients of near-field saturation, distance, magnitude, fault type and site classification in the attenuation model. The distribution of residuals with distance and magnitude is analyzed by comparing the regression results with the actual data. The comparison of this attenuation model with those from previous studies shows that all these models are similar for M_W6.5 or in the far field, but have some differences in the near field when the magnitude is higher or lower. Finally, the strong motion data of Wenchuan earthquake and Lushan earthquake are taken to verify the model, and the result show the attenuation relationship fits the data very well, suggesting that the obtained model in this paper be suitable for Chinese mainland.