Continuous Surface Wave (CSW) testing provides in-situ stiffness profiles without boreholes or sampling and the associated potential for sample disturbance. Stiffness is averaged over the test length, normally 3m, so gives a representative bulk sample, avoiding the problems of very local variation in ground conditions.
Unlike many other stiffness measurements CSW provides a small-strain stiffness (G0), a 'baseline' measurement at a known strain which can then be readily adjusted ('strain softened') to actual design strains. GSS provides stiffness data in an easy-to-use spreadsheet, allowing the user to input design strains. Data is also ideal for 3D ground modelling or BIM applications.
There is excellent published data to prove the equivalence of CSW data with other more expensive techniques such as downhole seismic testing or large scale load tests.
