Experimental estimation of soil profiles through spatial phases analysis of surface waves

The proposed techniques in recent years for the analysis of superficial waves with multiple transducers have been focused in the identification of different types of waves in the ground. The multistation tests avoid the ambiguous phase unwrapping procedure required to obtain experimental dispersion curves for the SASW technique. However, the soil profiles with stiffness inversion in depth involve the contribution of higher modes, and the inversion process through “apparent” or “effective” dispersion curves presents difficulties since these contributions depend of the transducers layout. The technique proposed herein is based on the test simulation through an updating model with low computational cost and good accuracy that include all propagation modes. Two actual test cases performed with only six transducers shows the advantages of a new objective function called “spatial phase dispersion” whose experimental determination does not require subjective interventions by the analyst.