层状介质中有限震源引起的地面运动的计算——对点源情形的拓展

Calculation of the ground motion generated by a finite source in stratified media:An extension of the point-source case

从分层均匀介质中地震波传播的基本理论出发,参考已有的利用广义反射透射系数矩阵方法计算分层均匀介质中点源引起的地面运动的方法和程序,考虑了任意几何特征的有限震源及有限震源的震源机制随时间和空间发生变化的可能性,并考虑了并行计算的发展方向,本文对点源情况下的计算流程进行了改进,重新设计编写了计算程序GRTMatSyn,使其不但适应于点源的情形,也适应于任意几何形状的、有限的、震源机制随时间和空间变化的有限震源的情形.为了验证该程序的可靠性和计算效率,设计了必要的有限震源模型和观测点分布,计算了地面运动,并与已有的被广泛认可的计算有限平面断层引起的地面运动的程序CompSyn的计算结果进行了对比分析.结果表明,GRTMatSyn的计算结果可靠、计算效率较高.

From fundamental theory of seismic wave propagation in stratified media, with reference to the techniques and applications already developed for calculating point-source-caused ground motion using generalized reflection and transmission matrices method, and with consideration of arbitrary geometry and tempo-spatially variable focal mechanisms of finite sources, as well as develop- ment trend of parallel computation, we improved computing-flow in the point- source case and developed a new program, GRTMatSyn, to be suitable for both point sources and finite sources with arbitrary geometries and tempo--spatially variable mechanisms. Numerical tests were carried out with necessary models of finite sources and observation points for reliability and computing efficiency of the application. The results were compared with those from CompSyn, a widely recognized program for calculating ground motion caused by a finite plane fault. The comparison indicated that the application developed in this study is reliable and rather more efficient.