Shear-waves velocity determination of soils from in-situ Rayleigh waves measurements

The knowledge of the shear-waves velocity structure in the very shallow depth is of great concern in many engineering problems, such as the design of foundations or the site effects studies. Traditionally, the measurements of shear wave velocity have been made using invasive borehole techniques. We present in this paper a fast and economical method based on dispersion analysis of Rayleigh waves recorded during a seismie refraction survey. Phase velocity of fundamental Rayleigh wave mode were inverted for the shear-wave velocity structure, Numerous synthetic tests have been performed in order to evaluate the method in terms of constrains, parameters and resolution. The method has been applied on three sites in order to demonstrate the feasibility of this conventional approach. A good correlation is observed between the results of independent methods, since the lateral homogeneity is observed on the studied area. Models derived from me data were tested by calculating synthetic seismograms for the fundamental mode from surface wave theory.