根据断层位错分布、破裂过程、传播路径等研究结果,采用层状半空间的理论格林函数方法,合成日本福冈地震近场竖向地震动.并将合成结果与观测记录进行比较.结果可知,两者峰值大小接近.当频率在5Hz以内,合成所得竖向加速度Fourier幅值谱与观测结果基本一致.研究结果表明,场地不是特别复杂的情况下,采用层状半空间格林函数方法能有效地估计近场竖向地震动.
The slip distributions on the fault, the source rupture process and the other seismic parameters of Fukuoka Earthquake determined by Japanese researchers are accepted in this paper. The vertical ground motion of Fukuoka Earthquake in near field is synthesized by using Green's function method for a layered half-space. A comparative study of the acceleration time history of the calculated results and records are carried out. The peak values of the calculated results are close to that of the records. The Fourier spectra of the calculated acceleration time history are basically identical with those of the records while the frequency is below 5 Hz. A conclusion is drawn that the vertical ground motion in the near field can be effectively estimated by the method of computing Green's functions for a layered half-space in the condition of the uniform geologic site.