How the shear wave velocity inversion affects the seismic motion

The effect of shear wave velocity profile inversion, when the top layer is stiffer than the one below overlaying the bedrock, was studied in terms of seismic local response. The present work identifies the most common Italian geological settings where Vs profile inversions are possible, associating typical mechanical and geotechnical properties to each layer. Based on this subsoil models, 1D site response analyses were performed to evaluate the influence of the stiffness inversion on ground shaking in terms of shear strain profiles and acceleration response spectra at the ground surface. In particular, stochastic 1D analyses were carried out via Monte Carlo method assuming assigned statistical distribution for Vs profiles and nonlinear G/G0-g and D-g curves