The Near Surface Profiling Based on the Rayleigh Wave Dispersive Properties for Vector Displacement

In the work presented the joint analysis of the frequency dependence of the Rayleigh wave velocity (dispersion characteristics) and the frequency dependence of the ratio between horizontal and vertical projections of displacement amplitudes was conducted. The inversion of the shear wave velocity profile together with the Poisson’s ratio was performed by satisfying the minimum root-mean-square deviation between the measured and calculated values. The Rayleigh wave velocity and the ratio between vertical and horizontal projections of displacement were measured. The density was assumed either constant or corresponding to the Gardner’s equation. Seismic waves launching was provided by different types of seismic sources: vertical vibrator (vertical force) mounted on the free surface, impulsive force source (blow of the hammer on an anvil) and pseudorandom source (two pedestrians walking along the line connecting the receiving geophones). The signals were recorded by two digital multichannel engineering seismic stations «Lakkolit X-M2» (produced in «Geotech», Moscow). The technique proposed in this paper enables eliminating the ambiguity of the inverse problem solution and reveals new possibilities for monitoring and diagnostics natural media in-situ.