地震研究

采用基于动力学拐角频率的随机有限断层法,首先模拟计算了东台、如皋及大丰3个台站记录的2006年江苏东台3.8级地震的地震动,并与其实际记录进行比较研究,验证了该方法的计算结果能够较好地反映出江苏地区主震剪切波的主要特征。随后运用该方法模拟计算了1979年江苏溧阳6.0级地震震源区内156个虚拟观测点的地震动,并通过内插值的方式得到此次地震的加速度场分布情况; 随后依据峰值加速度统计方法和模糊评定方法,分别计算此次地震的理论烈度分布,结果显示:两种烈度划分方法的结果与实际调查的烈度分布都基本一致,但模糊评定方法的划分结果更加接近真实的烈度分布。

Firstly,using stochastic finite faults method based on the dynamic corner frequency,we simulated the synthetic ground motion of Dongtai M3.8 earthquake,Jiangsu in 2006 recorded by Dongtai,Rugao and Dafeng stations and compared synthetic ground motion with the actual ground motion recordings.We find that the synthetic ground motion using improved stochastic finite faults method can better reflects the main features of shear wave of main shock in Jiangsu area.Secondly,we apply this method to simulate the synthetic ground motion of 156 virtual observation points in source region and got the distribution of synthetic acceleration field of Liyang M6.0 earthquake in 1976.Thirdly,we respectively calculated the theoretical distribution of seismic intensity by peak acceleration statistical method and fuzzy evaluation method.The results showed that the intensity classification results by two methods essentially consistent with that of the actual investigation.However,intensity classification result by the fuzzy evaluation method is more consistent with distribution of actual intensity.

引言
1 基于动力学拐角频率的随机有限断层法
2 地震动的合成
3 地震烈度的划分
4 结论与讨论

图1 随机有限断层法的几何示意图<br/>Fig.1 Geometric schematic diagram of stochastic finite faults method

图1 随机有限断层法的几何示意图
Fig.1 Geometric schematic diagram of stochastic finite faults method

图2 溧阳M6.0地震、东台MW3.8地震的<br/>震中位置及震源机制<br/>Fig.2 Epicenter locations and focal mechanisms of Liyang M6.0 and Dongtai MW3.8 earthquakes

图2 溧阳M6.0地震、东台MW3.8地震的
震中位置及震源机制
Fig.2 Epicenter locations and focal mechanisms of Liyang M6.0 and Dongtai MW3.8 earthquakes

表1 两次地震的震源破裂参数<br/>Tab.1 Source rupture parameters of two earthquakes

表1 两次地震的震源破裂参数
Tab.1 Source rupture parameters of two earthquakes

表2 随机有限断层法的基本参数<br/>Tab.2 Basic parameters of stochastic finite faults method

表2 随机有限断层法的基本参数
Tab.2 Basic parameters of stochastic finite faults method

图3 东台(a)、如皋(b)及大丰台(c)的合成<br/>地震动和实际记录波形及阻尼比为2%的反应谱<br/>Fig.3 Synthetic ground motions and the actual waveforms recorded by Dongtai(a),Rugao(b),Dafeng(c)Stations,and their response spectrum of damping ratio is 2%

图3 东台(a)、如皋(b)及大丰台(c)的合成
地震动和实际记录波形及阻尼比为2%的反应谱
Fig.3 Synthetic ground motions and the actual waveforms recorded by Dongtai(a),Rugao(b),Dafeng(c)Stations,and their response spectrum of damping ratio is 2%

图4 溧阳M6.0地震的子断层及滑动模型<br/>Fig.4 Sub-faults and the sliding model of Liyang M6.0 earthquake

图4 溧阳M6.0地震的子断层及滑动模型
Fig.4 Sub-faults and the sliding model of Liyang M6.0 earthquake

图5 溧阳M6.0地震的实际烈度(a)(据胡连英<br/>等,1997)和合成地震动的理论烈度(b)<br/>Fig.5 Actual intensity(a)(according to Hu et al,1997)and the theory intensity of synthetic ground motion based on two methods(b)of Liyang M6.0 earthquake

图5 溧阳M6.0地震的实际烈度(a)(据胡连英
等,1997)和合成地震动的理论烈度(b)
Fig.5 Actual intensity(a)(according to Hu et al,1997)and the theory intensity of synthetic ground motion based on two methods(b)of Liyang M6.0 earthquake

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备注

引言

1 基于动力学拐角频率的随机有限断层法

2 地震动的合成

3 地震烈度的划分

4 结论与讨论

期刊信息