【摘要】 运用经验格林函数方法,对2008年6月13日日本岩手—宫城(MW6.9)地震进行了近场强地面运动的模拟研究.首先,利用震源谱拟合方法和遗传优化算法计算了经验格林函数法所需的参数,进而估算求得了此次地震主断层面上强震生成区的面积和上升时间.基于所获得的震源模型,计算了近震源区域的强地面运动时程,并同实际观测记录在时域和频域作了分析比较.结果显示,多数台站合成谱与观测谱符合得很好,部分台站两者在低频上有一定的偏差.通过遗传算法搜寻,所得强震生成区的面积与经验关系预测的一致,而上升时间则比经验关系预测的要小.更多还原

【Abstract】 The near-source strong ground motion of the 2008 Iwate-Miyagi,Japan(MW6.9) earthquake was simulated using the empirical Green’s function (EGF) method. Firstly,we applied the source spectral fitting method and Genetic Algorithm (GA) to calculate the parameters of EGF. And then,estimated the size of strong motion generation area (SMGA) and rise time for this earthquake using GA. Finally,based on the source model,we calculated the synthetic velocity waveforms for the stations located in the near fault area and compared them with the observed records. The results show that for most stations the synthetic waveforms match the observed records very well. But in low frequency spectrum,the coherence is not so good at some stations. We found that the size of the SMGA follows the results by the self-similar scaling law,while the rise time is smaller than the predicted value by that law.更多还原