Dynamic Parameters Inversion Of Foundation Soil Based On Rayleigh Wave Theory

Considering the influence of environment vibration, and based on the Rayleigh Wave Theory, the frequency dispersion curves, cut-off frequency and some other characteristics of layered soil models are calculated, the shear wave velocities of foundation soil are inverted through genetic algorithm and some other parameters of foundation soil are obtained.The transfer matrix method is often used in the analysis of wave propagation in homogeneously elastic medium with horizontal multilayer. Some analytical methods are introduced, such as transfer matrix method in rectangular coordinate system and fast vector and fast scalar algorithm in cylindrical coordinate, thin-layer method with stiffer matrix and so on.The Rayleigh dispersion curves of multilayered soil are calculated by means of thin-layer method and fast scalar method, respectively, in which two-layered and three-layered soil model are adopted. In addition, the disperse properties of multilayered soil are analyzed, and it is found that the thin layer method is superior to rapid scalar method in low frequency domain, while in the high frequency domain it has little difference between each other. The Rayleigh wave's properties of four multilayer soil models are compared by means of thin-layer method particularly.In the dynamic parameters inversion of foundation soil, by means of the genetic algorithm, the shear wave velocities for two common soil models are calculated based on the effective phase velocity-frequency dispersion curve, and then other parameters of multilayer foundation soil are acquired by the transformation relationship between the media's parameters.