Efficient Acquisition and Holistic Analysis of Rayleigh Waves

Surface-wave analysis is nowadays widely considered for a number of goals ranging from geotechnical investigations to seismic-hazard studies. The most common approach is surely represented by the analysis of active or passive multi-channel data used to depict the phase velocity spectrum from which dispersion curves are then depicted and inverted.

The presented methodology attempts to obtain a robust sub-surface model in spite of the light equipment (a single [at least] bi-axial geophone) and the straightforward field procedures.

The active method here presented can be considered as an improvement of the classical MFA (Multiple Filter Analysis) method and is based on the joint analysis of the vertical and radial group-velocity spectra, together with the Radial-to-Vertical Spectral Ratio (RVSR).

After introducing the fundamental points charactering its implementation, a case study is presented also comparing the obtained sub-surface model with the one obtained considering a standard approach based on multi-channel active (MASW — Multichannel Analysis of Surface Waves) and passive (ESAC — Extended Spatial Autocorrelation) data jointly considered with the Horizontal-to-Vertical Spectral Ratio (HVSR).