Downhole

The method is aimed at characterizing the subsoil based on compressional (P-) and/or shear (S-) wave velocities obtained by an analysis of the travel times of such waves.

The method consists in lowering a borehole geophone in a PVC cased borehole, generate P- and/or S-waves at the surface and recording their arrival time at multiple depths.

This method responds to the ASTM D7400 and it is most commonly applied for geotechnical foundation analysis, dynamic soil analysis, Vs30 soil classification, etc.

Typical setup scheme and example of an acquired record of S-waves down to a depth of 30m