地震动随机合成中与震源谱相关的动力学拐角频率  

Dynamic corner frequency in source spectral model for stochastic synthesis of ground motion

作　　者：孙晓丹 陶夏新[1,2] 王国新[3] 刘陶钧[1] 

机构地区：[1]哈尔滨工业大学土木工程学院,中国哈尔滨150090 [2]中国地震局工程力学研究所,中国哈尔滨150080 [3]大连理工大学土木水利学院,中国辽宁大连116024

出　　处：《地震学报》2009年第5期537-543,共7页Acta Seismologica Sinica

基　　金：国家自然科学基金项目(50778058;90715038);国家科技支撑计划课题(2006BAC13B02)资助

摘　　要：介绍了基于有限断层震源的地震动随机合成中静力学拐角频率和动力学拐角频率,讨论了两者的缺点;进而提出了一种改进的震源谱模型,它能够表达破裂面上地震波频率辐射不均匀性、大震时拐角频率随破裂面积增加而有所下降的趋势.据此,可以形成与该震源谱模型相关联的动力学拐角频率,应用于地震动的随机合成,避免结果对子源尺寸的依赖.通过对美国北岭MW6.7地震近场6个基岩台站合成的地震动与实际记录的比较,验证了本文方法的有效性.The static corner frequency and dynamic corner frequency in stochastic synthesis of ground motion of finite fault modeling are introduced, and conceptual disadvantages of the two are discussed. This paper proposes a source spectral model, which is capable of representing the non-uniform radiation of seismic wave on the fault plane and the trend of reduced corner frequency for enlarged rupture area. A new dynamic corner frequency can be drawn out directly from the model. The dependence of ground motion on the size of sub faults can be eliminated if this source spectral model is adopted in the synthesis. Finally, the proposed approach is validated by comparing the synthesized and observed ground motions at 6 rock-base stations during the 1994 Northridge earthquake in United States.

关 键 词：震源谱 动力学拐角频率 随机合成 有限断层 

分 类 号：TU311.3[建筑科学—结构工程]