SASW is a non-destructive geophysical testing method to assess the mechanical properties of soils, concrete, tunnelling, and pavements. It involves generating surface waves using a seismic source, such as a hammer or shaker, and recording the waves using geophones or accelerometers placed at different distances from the source. By analysing the dispersion characteristics of the surface waves, such as phase velocity versus frequency, engineers can estimate the shear wave velocity profile of the subsurface material. This information is crucial for assessing the mechanical properties of the soil, concrete, or pavement layers, which is essential for designing foundations, evaluating pavement conditions, assessing the condition and properties of concrete and tunnels, and assessing seismic hazards.

One of the key advantages of SASW is its non-destructive nature, which means that it does not require the extraction of soil, concrete, or pavement samples for testing. This non-destructive aspect allows engineers to assess the properties of the subsurface without causing any damage to the site, making it particularly useful for assessing existing structures or evaluating the condition of pavements. These contrasts with destructive testing methods commonly used in geotechnical, tunnelling and pavement engineering, which involve physically extracting samples from the ground, concrete, or pavement.