PREDICTION OF GROUND VIBRATION FROM TRAINS USING SEISMIC REFLECTIVITY METHODS FOR A POROUS SOIL

Biotʹs model of wave propagation in porous isotropic materials is explored for predicting ground vibration from rail vehicles on vertically heterogeneous isotropic saturated soil and rock using seismic reflectivity methods combined with a multi-degree-of-freedom model of a transit vehicle bogie. A sketch of the mathematical theory, canonical results for step loads on a porous half-space, spectral responses for simple layer profiles, and an example of a prediction for rail transit vehicles are presented. The model indicates that saturation of the soil introduces excess attenuation in the vibration response of the soil, and that both pitch and roll moments in addition to vertical forces caused by the vehicle bogie may be significant sources of vibration.