INSIGHTS ON THE SASW NONDESTRUCTIVE TESTING METHOD

Spectral analysis of surface waves (SASW) is a nondestructive and in-s itu method used for determining the thickness and elastic properties o f pavement and soil sites using the dispersion characteristics of surf ace waves. In this paper, computer simulations of actual surface wave field tests are used to clarify errors that may arise in experimental dispersion curves of pavement sites when the usual test and data analy sis procedures of the SASW method are followed. Two aspects of these p rocedures are considered: (i) relative phase angle unwrapping and (ii) source-to-near-receiver distance. The results of these simulations re veal that the currently used procedures may lead to erroneous results for some sites; the simulations offer valuable insights on the underly ing causes. An overview of the theoretical aspects and field procedure s of the surface wave method is briefly presented.