JOINT INVERSION ANALYSIS USING THE DISPERSION CHARACTERISTICS OF LOVE AND RAYLEIGH WAVES

초록

Rayleigh wave and Love wave are the major elastic waves in the category of surface waves. It is known that Love wave is not disturbed by P waves because of the particle movement direction. Therefore, the information that a Love wave carries is more distinct and clearer than the Rayleigh wave. In this study, the dispersion characteristics of Love waves were investigated by theoretical and experimental approaches using the SASW technique. Theoretical analyses were performed for the multi-layered ground to determine the phase velocities of the Love wave as well as those of Rayleigh wave. Also, SASW tests were performed at geotechnical sites to verify the results obtained by the theoretical analysis. Based on this research, the joint inversion analysis which uses both Love wave and Rayleigh wave dispersion information was proposed. Purpose of the joint inversion analysis is to improve accuracy and convergence of inversion results. The proposed technique consists of a forward modeling using modified transfer matrix, a sensitivity matrix determined to the ground system, and a DLSS (Damped Least Square Solution) as an inversion technique. The theoretical analysis and the field testing results indicated that the joint inversion analysis can be applied to better evaluate the stiffness of subsurface structures.