To better understand characteristics of seismic signals of tracked vehicles measured when passing a sensor line,we numerically modelled force-pulse responses of a layered soil that is similar in its seismic properties...To better understand characteristics of seismic signals of tracked vehicles measured when passing a sensor line,we numerically modelled force-pulse responses of a layered soil that is similar in its seismic properties to that found at the original measurement site.The vertical-force pulses from the road wheels rolling over the track elements are fitted to the measured ones.Single-pulse seismic waves vary with distance due to diff erent wave types,refl ections at layer boundaries,vehicle velocity and relative position of the left and right track elements.They are computed by a modelling program and superposed at sensor positions with the appropriate slant distance and time shift for each track element.These sum signals are in qualitative agreement with those from the original measurements.However,they are several magnitudes weaker and much smoother.Furthermore,higher frequencies are damped much less at larger distances.Due to the large variability of the sum signals,recognition of tracked-vehicle types exclusively through their seismic signals seems diffi cult.展开更多
文摘To better understand characteristics of seismic signals of tracked vehicles measured when passing a sensor line,we numerically modelled force-pulse responses of a layered soil that is similar in its seismic properties to that found at the original measurement site.The vertical-force pulses from the road wheels rolling over the track elements are fitted to the measured ones.Single-pulse seismic waves vary with distance due to diff erent wave types,refl ections at layer boundaries,vehicle velocity and relative position of the left and right track elements.They are computed by a modelling program and superposed at sensor positions with the appropriate slant distance and time shift for each track element.These sum signals are in qualitative agreement with those from the original measurements.However,they are several magnitudes weaker and much smoother.Furthermore,higher frequencies are damped much less at larger distances.Due to the large variability of the sum signals,recognition of tracked-vehicle types exclusively through their seismic signals seems diffi cult.
