Abstract: Based on the Biot’s theory of porous media, the dynamic response of heterogeneous saturated soil subjected to strip loading is researched. Applying the Helmholtz vector decomposition and Fourier transformation, the calculation formula of reverberation ray matrix method (RRMM) is established for two-dimensional transient response of fluid-saturated soil. Assuming that the material properties of the saturated soil have an exponential law distribution along the thickness-coordinate, by using numerical inverse Fourier transformation, the displacement, the stress and the pore pressure are obtained. The effect of heterogeneity on transient responses of graded saturated soil is demonstrated and discussed. The numerical result shows that there is a significant difference on dynamic response between heterogeneous saturated soil and homogeneous saturated soil. The amplitude of fluid pressure and stresses that right below the middle point of the strip load is increased when the soil heterogeneous degree becomes high. In addition, the vibration frequencies of displacement, fluid pressure and stress increase with the increasing of soil heterogeneous degree along the horizontal direction.

Key words: saturated soil, heterogeneity, reverberation ray matrix method, dynamic response