a model of non-homogeneous saturated foundation is established by considering the transverse isotropy and non-homogeneity of foundation. In this model
the porosity
density
shear modulus and permeability coefficient change along the depth
and the coupling effect between parameters are also considered. Meanwhile
a parameter
non-uniform factor
is introduced to characterize the degree of non-homogeneity of foundation. The governing equation is established based on the Biot porous media theory. The differential operator method is applied to solve the control equation
and then the dispersion equation of Rayleigh wave in non-homogeneous saturated foundation is deduced. Results are verified by degrading the deduced results to homogeneous saturated foundation and single elastic foundation
respectively. Moreover
the propagation velocity
attenuation coefficient and displacement distribution of Rayleigh wave are analyzed using numerical examples. Results show that the non-homogeneity of saturated ground has significant influence on Rayleigh wave propagation velocity
attenuation
and displacement. Additionally
the particle trajectory is changed accordingly. This effect gradually decreases with an increase in the frequency. As the frequency approaches infinity
the Rayleigh wave velocity converges to the wave velocity in homogeneous elastic foundation. The non-homogeneity of foundation increases the impedance of Rayleigh wave propagation and accelerates the attenuation of Rayleigh wave displacement. In addition
the propagation depth is less than that of homogeneous saturated foundation. With the increase in non-homogeneity
the attenuation of vertical displacement of particles is more affected and the attenuation speed is faster than that of horizontal displacement. This difference leads to a small oblateness of the elliptical particle trajectory. Moreover
a smaller thickness of the non-homogeneity soil layer results in more non-homogeneous foundation
which has greater impacts on Rayleigh wave propagation.