The shear wave velocity (Vs) of the subsurface can be a critical parameter for calculating liquefaction potential, site amplification, site classification, Vs30 and for many other engineering purposes. Southern Geophysical Ltd specialises in obtaining shear wave information about the subsurface. The Vs can be measured directly in boreholes using downhole and crosshole shear wave tests, or with shear wave reflection surveys. Shear wave velocities can also be measured indirectly using Multi-channel Analysis of Surface Waves (MASW), Refraction Microtremor studies (ReMi), and Horizontal to Vertical Spectral Ratio measurements (HVSR).

We have extensive experience in:

• Downhole shear wave testing (maximum depth 130m)
• Crosshole shear wave testing
• CPT rig cross hole shear wave testing
• Active and passive Multichannel Analysis of Surface Waves (MASW)
• HVSR measurements