Propagation of a Compressional Pulse in a Layered Solid

摘要

A solution is given for the problem of propagation of a compressional pulse in a solid half-space which is overlain by a solid layer of different properties. The point source is situated at the depth 1/2H, H denoting the thickness of the layer. Theoretical seismograms of the vertical displacement w at the surface are evaluated out to ranges r = 20H. The solution is obtained by the exact ray theory. The displacement due to the source was assumed to have a shape which at large distances reduces to a saw-tooth. The once-reflected waves from the interface, PP and PS, are strongly marked. The Rayleigh wave is already recognizable at r =5H, and is fully developed at r =20H. The method of ray theory is applied far into the region where the normal mode theory converges well. (Author)