A Wave Based Method for the analysis of a fully and partially saturated halfspace under harmonic loading

The dynamic response of a fully or partially saturated halfspace due to vibrations from traffic or rotating machinery can significantly be influenced by water and air phases within the pores. An extension of the Wave Based Method (WBM) is presented to consider these influences and to propose an efficient numerical method for the dynamic analysis of fully and partially saturated soil layers. Biot's theory for the low frequency range and the Berryman-Thigpen-Chin model (BTC model) are introduced and a transmitting boundary condition is implemented to approximate the Sommerfeld radiation condition. Moreover, coupling conditions for dry, fully and partially saturated soil layers are formulated and involved into a weighted Galerkin approach. The accuracy of the WBM is evaluated for a fully saturated and a layered halfspace with different degrees of saturation. For this, numerical examples are compared with reference solutions from literature. It is shown that the WBM delivers adequate field responses and succeeds in modeling different types of system behaviour, which are characteristic for a fully saturated and layered halfspace.