Simulation of the crosshole method in isotropic and anisotropic media

The crosshole seismic method was simulated using a finite element model with a diagonal mass matrix and a direct integration of the equations of motion in the time domain. The results were compared to those of a more efficient but also more restricted formulation using discrete Green's functions. The effects of the type of excitation, the shape of the applied pulse and the position of the receiver with respect to the source on the shape of the recorded motions were investigated for isotropic and cross anisotropic soil deposits. The computed times of arrival of the different waves were compared to those predicted using curved ray path theory to assess the accuracy of this much simpler procedure as a means to interpret the experimental data and determine the soil properties. Copyright © 1999 John Wiley & Sons, Ltd.