地震研究

改进的经验格林函数方法弃掉以往完全用经验方法确定用于合成大震的小震数目的方法,考虑了大地震断层各个子断层位错的不均匀性,使得经验格林函数方法的物理意义更加清楚。用改进的经验格林函数方法,以汶川M_S6.4余震记录作为经验格林函数模拟了九寨白河台、松潘安宏台、皋兰台和成都中和4个台站的加速度时程,与以往的经验格林函数方法比较,模拟结果的反应谱与记录符合得更好,证明了改进的经验格林函数方法可以反映震源位错的复杂分布,可以在工程地震中用来估计场地地震动过程。

The improved Empirical Green's Function method considers the displacement heterogeneity at each sub-faults of fault of main shock,makes the physical meaning of Empirical Green's Function method clearly,and abandons previous empirical method which confirms small earthquake numbers used to synthesize main shock. We use Wenchuan M_S6.4 aftershock records as the Empirical Green's function,and simulate the acceleration time histories at Baihe Station in Jiuzhai County,Anhong Station in Songpan Country,Gaolan Station and Zhonghe Station in Chengdu by the improved Empirical Green's function method. Compared with former results by Empirical Green's function method,response spectrums in the simulation results are more closer to the records,which prove the complicated distributions of epicenter displacements can be reflected by the improved Empirical Green's function method,this method can be used to estimate site ground motion processes in engineering seismology.

引言
1 经验格林函数方法的改进
2 用改进的经验格林函数方法模拟汶川地震动
3 讨论

图1 Haskell矩形断层模型中表示的断层平面和坐标<br/>Fig.1 Fault plane and coordinate represented in the Hakell rectangular fault model

图1 Haskell矩形断层模型中表示的断层平面和坐标
Fig.1 Fault plane and coordinate represented in the Hakell rectangular fault model

图2 按照小震尺寸,把大地震断层<br/>划分为NL×NW个单元<br/>Fig.2 Main shock fault is divided into NL×NW elements based on the dimension of small earthquakes

图2 按照小震尺寸,把大地震断层
划分为NL×NW个单元
Fig.2 Main shock fault is divided into NL×NW elements based on the dimension of small earthquakes

图3 汶川地震断层示意图

图4 汶川地震断层的计算模型<br/>Fig.4 Computational model of Wenchuan MS8.0 earthquake

图4 汶川地震断层的计算模型
Fig.4 Computational model of Wenchuan MS8.0 earthquake

表1 汶川MS6.4余震参数<br/>Tab.1 Parameters of Wenchuan MS6.4 aftershock

表1 汶川MS6.4余震参数
Tab.1 Parameters of Wenchuan MS6.4 aftershock

图5 九寨白河台三种情况下汶川地震东西方向(a)、竖直方向(b)加速度时程和反应谱比较<br/>Fig.5 Comparison of EW(a)and vertical(b)acceleration time-histories and response spectrum of Wenchuan M8.0 earthquake recorded by Baihe Station in Jiuzhai Country in three situations

图5 九寨白河台三种情况下汶川地震东西方向(a)、竖直方向(b)加速度时程和反应谱比较
Fig.5 Comparison of EW(a)and vertical(b)acceleration time-histories and response spectrum of Wenchuan M8.0 earthquake recorded by Baihe Station in Jiuzhai Country in three situations

图6 松潘安宏台三种情况下汶川地震东西(a)、南北方向(b)加速度时程和反应谱比较<br/>Fig.6 Comparison of EW(a)and SN(b)acceleration time-histories and response spectrum of Wenchuan M8.0 earthquake recorded by Anhong Station in Songpan Country in three situations

图6 松潘安宏台三种情况下汶川地震东西(a)、南北方向(b)加速度时程和反应谱比较
Fig.6 Comparison of EW(a)and SN(b)acceleration time-histories and response spectrum of Wenchuan M8.0 earthquake recorded by Anhong Station in Songpan Country in three situations

图7 皋兰台三种情况下汶川地震东西(a)、南北方向(b)加速度时程和反应谱比较<br/>Fig.7 Comparison of EW(a)and SN(b)acceleration time-histories and response spectrum of Wenchuan M8.0 earthquake recorded by Gaolan Station in three situations

图7 皋兰台三种情况下汶川地震东西(a)、南北方向(b)加速度时程和反应谱比较
Fig.7 Comparison of EW(a)and SN(b)acceleration time-histories and response spectrum of Wenchuan M8.0 earthquake recorded by Gaolan Station in three situations

图8 成都中和台三种情况下汶川地震南北(a)、东西(b)、竖直方向(c)加速度时程和反应谱比较<br/>Fig.8 Comparison of EW(a)and SN(b)acceleration time-histories and response spectrum of Wenchuan M8.0 earthquake recorded by Zhonghe Station in Chengdu in three situations

图8 成都中和台三种情况下汶川地震南北(a)、东西(b)、竖直方向(c)加速度时程和反应谱比较
Fig.8 Comparison of EW(a)and SN(b)acceleration time-histories and response spectrum of Wenchuan M8.0 earthquake recorded by Zhonghe Station in Chengdu in three situations

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备注

引言

1 经验格林函数方法的改进

2 用改进的经验格林函数方法模拟汶川地震动

3 讨论

期刊信息