Role of Forward Model in Surface-Wave Studies to Delineate a Buried High-Velocity Layer

Abstract

Procedures are tested and compared for processing Rayleigh surface wave data to obtain one-dimensional shear wave velocity profiles for a hypothetical site that contains a buried high-velocity layer (HVL). The main purpose of such an investigation would be to discriminate and characterize the HVL. When target dispersion curves are derived from synthetic time histories, for the most part, the HVL is better identified when profiles are inverted using only the fundamental mode of Rayleigh wave propagation, rather than a more compatible but more complex forward model. The outcomes imply that in practice, a simple forward model might be more successful in recovering a complex profile than a more sophisticated model because for the latter, adequate interpretation of the field data requires more accuracy than might be achievable with conventional approaches.