近场地震动格林函数的解析法与数值法对比研究

COMPARISON OF GREEN'S FUNCTION OF NEAR-FIELD GROUND MOTION DUE TO ANALYTICAL METHOD AND NUMERICAL METHOD

摘要:

分析了在均匀弹性介质中,分别用解析方法和三维波动有限元数值方法计算无限全空间近场地震动的格林函数的理论与方法。将震源处理分为:(1)计算单一位错点源单位脉冲引起的格林函数;(2)用有限断层模型将断面划分为若干子源并有时间延迟,叠加所有子源的格林函数。本文以1994年美国北岭地震为例,用解析法和数值方法分别计算了LV3、PCD、MCN三个场地的格林函数,并进行了对比分析。

Abstract:

The theoiry and method of Green's function of near-field ground motion is calculating in all-around infinite space in terms of single media by analytical method and 3-D finite element difference numerical method are analysed. For the same earthquake, the source can be considered as a single point source or finite several seismic sub-sources on a finite fault plane. Green's function is caused by plus of a point source or by pluses of all sub-sources with reliable time delay. Take the Northridge earthquake in 1994, U.S.A, as an example, Green's function at three rock seismic stations (LV3, PCD, MCN) are computed and analyzed due to both methods. The results show better coherence.