Determination of the damping ratio by multi-channel spectral analysis of seismic downhole data
Soil dynamic parameters such as the damping ratio are of major interest in earthquake engineering. We’ve currently published a publication which comes back to a relationship between attenuation and velocity dispersion of body waves which replaces the measurement of the amplitude characteristics of seismic signals by a frequency dependent velocity function. The implementation of this method has previously shown to be difficult because of the very small levels of dispersion observed in seismic data. Our approach aims to overcome the problem by applying a multi-channel spectral analysis which is widely used in surface wave testing to calculate a velocity dispersion. The velocity dispersion curve is extracted from a phase velocity–frequency spectrum and the damping ratio is calculated by fitting a theoretical dispersion curve to the extracted curve. The method is demonstrated on correlated data of a seismic downhole test performed using an S-wave vibrator source.
You can find the paper below following link: https://doi.org/10.1002/nsg.12010