We run our MASW surveys in Melbourne using a 24-channel seismograph with 4.5 Hz geophones spaced at 2 m intervals along a 48 m spread. A sledgehammer source generates surface waves that we invert to produce a 1D shear wave velocity profile down to 30 m. This gives us the VS30 value directly — no borehole needed. The whole setup fits in a ute, which matters when you're working across Melbourne's varied terrain, from the flat basalt plains of the west to the stiffer sedimentary formations in the east. Before we deploy the array we always check for buried services and surface obstructions. The data acquisition takes about two hours per line, and we process the dispersion curves in the field using SeisImager software. For projects that also require direct strength data we can combine the MASW line with a standard penetration test at a target depth to cross-validate the shear wave results.
A MASW survey gives you the VS30 profile in a single afternoon — no borehole, no spoils, no access restrictions.