汶川地震余震震源参数及地震动衰减与场地影响参数反演分析

喻畑1)　李小军2)

汶川地震余震震源参数及地震动衰减与场地影响参数反演分析

喻畑1)　李小军2)

1) 中国哈尔滨150028中国地震局工程力学研究所 2) 中国北京 100081 中国地震局地球物理研究所

详细信息

中图分类号: P315.9
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出版历程
- 发布日期: 2012-08-29

Inversion of strong motion data for source parametersof Wenchuan aftershocks, attenuation functionand average site effect

Yu Tian　Li Xiaojunupcom sh a

1) Institute of Engineering Mechanics， China Earthquake Administration， Harbin 150028, China2) Institute of Geophysics, China Earthquake Administration, Beijing 100081, China

摘要

摘要: 基于强震动观测台钻孔数据，统计得到了四川、甘肃地区20 m深的浅硬土层场地平均剪切波速模型．通过与美国加州地区的波速模型对比，结合四川、甘肃地区地震预报的地壳模型，延拓剪切波速模型至40 km．应用四分之一波长法计算了浅硬土层场地的平均场地放大系数．利用场地放大系数，消除13次余震中浅硬场地的台站场地响应，反演了龙门山断层上、下盘的介质品质因子以及13次余震的有效应力降．通过与普通土层场地的强震动记录对比，对浅硬土层场地的放大系数进行调整，得到了深厚土层场地的平均放大系数．
- 反演　有效应力降　品质因子　平均场地效应　汶川余震
Abstract: The average shear-wave velocity profile for shallow soil sites at a depth of 20 m is derived from the drilling data of strong motion stations in Sichuan and Gansu provinces. Combined with the profile of California and the crust model used inearthquake prediction study for Sichuan Province, the average shear-wave velocity profile is extended to 40 km. The site amplification factor for shallow soil sites is generated by using the quarter wave-length method. Then, the quality factors of different zones, the effective stress drop and kappa value at shallow soil sites are deduced from the Fourier amplitude spectra of 13 aftershocks of the Wenchuan earthquake. Due to different site effects, the strong motion data at deep soil sites show a large bias from the inverted model. According to the bias, the site amplification factor for deep soil sites is derived from revision of the site amplification factor for shallow soil sites.

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参考文献(1)

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