The downhole test requires a surface source capable to generate S- and P-waves and a borehole receiver with a multi-directional sensor array. S- and P-wave velocities are measured and the dynamic soil parameters (shear and Young’s modulus) are calculated.

A sledge hammer (equipped with a trigger element) and a wooden beam can serve as source if the survey depth is limitted.

Closer details on the downhole method can be found in the Downhole Method Description.

S-Wave Excitation using a Hammer