Forward modeling of Rayleigh surface waves for analytical characterization of dominant dispersion trends: Fid-Bau Portal

Forward modeling of Rayleigh surface waves for analytical characterization of dominant dispersion trends

Lin, Shibin / Yi, Ting‐Hua / Ashlock, Jeramy / Gucunski, Nenad

Forward modeling is of critical importance for inversion analysis of surface wave methods to obtain shear‐wave velocity (V_S) profiles of soil sites. The dynamic stiffness matrix (DSM) method can provide forward modeling of Rayleigh surface waves to simulate complex wave propagation in layered soil sites. However, contamination from body waves and interference of multiple Rayleigh wave modes can reduce the accuracy of theoretical dispersion curves, especially at irregular soil sites with embedded low‐velocity or high‐velocity layers. An analytical method is developed herein to combine the techniques of the multichannel analysis of surface waves method with the DSM method to improve the accuracy of the theoretical dispersion analysis for soil sites. The proposed method implements multichannel analysis of the analytical displacement responses to capture dominant dispersion trends. Comparison of the results obtained with the new method against those from the transfer matrix method and the literature indicates that the new method can (1) effectively minimize the effects of contamination caused by body waves and interference from several Rayleigh wave modes, and (2) generate accurate dominant dispersion trends for soil sites with various stiffness profiles, especially for the high‐frequency dispersion characteristics of the profiles with embedded low‐velocity layers.