Application of Different Algorithms to an Inversion of Rayleigh Wave Dispersion Curve

Abstract

Inversion of surface wave dispersion curve is a important process for Vs analysis. We tried three algorithms which are the genetic algorithm (GA), least squared method (LSM) and neighbourhood algorithm (NA). These algorithms were utilized for inversion of dispersion curve obtained from surface wave method. Both synthetic and measured data sets were considered. Calculated dispersion curves in the synthetic test study by using GA, NA and LSM algorithms fitted observed dispersion curve with acceptable misfits. Surface wave methods were utilized on measured data in order to determine elastic ground characteristic of Dokuz Eylul University campus in Izmir (Turkey). The variation of shear wave velocity (Vs) with depth could be determined by using dispersive behaviour of Rayleigh waves in surface wave analysis methods. The shear wave velocity cross-sections were obtained by inversion of dispersion curves. The estimated parameters which were obtained from all algorithms were compared with each other and calculated dispersion curves in the field test study by GA, NA and LSM algorithms fitted observed dispersion curve with acceptable misfits as synthetic study. Results of calculated dispersion curves which were obtained from all algorithms are compared with observed dispersion curve. Shear wave velocity cross sections were prepared for all algorithms.