Generation and Propagation of Microseismic Signals from Footsteps.

摘要

A study was conducted to investigate the generation and propagation of microseismic signals from man-walking targets. To illustrate the relation between terrain parameters and Rayleigh wage generation and propagation, the problem was divided into four parts, which were then studied graphically. These parts were: (a) the target-ground interaction, (b) energy coupling to the substrate, (c) Rayleigh wave propagation from the source, and (d) transmission of Rayleigh waves over surface macrogeometry features. Parameters that are included in the terrain model are: (a) surface rigidity in terms of nonlinear surface spring constants and (b) subsurface rigidity in terms of seismic properties (wave velocities and bulk density) and layer thickness. The terrain combinations include a wide variation in site conditions and have realism in terms of environments found in nature. Sample problems are included to demonstrate the signal construction techniques and are analyzed to show the effect of the various terrain parameters on the generation and propagation of the Rayleigh waves.