Analytical Investigation of Transient Wave Propagation in One-Dimensional Unsaturated Poroelastic Materials

Abstract EN

As a dynamic response, the wave propagation phenomenon usually varies with different media.

In this study, the dynamic response of unsaturated poroelastic materials to an impulse load has been analytically investigated.

The governing equations, in the Laplace domain, of the unsaturated poroelastic soil in terms of the variables us (solid displacement), pf (pore fluid pressure), and pa (pore air pressure) will be derived.

These equations will be simplified in a one-dimensional form.

The solutions that include the dynamic response to the vertical displacement of solid particles and to the variations of fluid and air pressures will be provided which are applicable for an arbitrary loading form.

The solutions were validated with the results for saturated soil presented in the literature.

The effect of material parameters on dynamic response was analysed through a series of parameter studies.

It was found that increasing the porosity or fluid saturation effectively increases the amplitude of fluid and air pressures as well as the wave velocity.

Although increasing the fluid saturation leads to solid displacement gradually decreases gradually, it results in increasing the amplitude of fluid and air pressure.

The fluid saturation increasing above 0.9 results in wave travels faster significantly.

The variation of fluid intrinsic permeability has little influence on the soil dynamic response until it reaches a high level.

The findings of this study can help for better understanding of one-dimensional wave propagation in unsaturated soil.