Using PLAXIS, it is possible to simulate soil-structure interaction. Here the influence of a vibrating source on its surrounding soil is studied. Due to the three dimensional nature of the problem, an axisymmetric model is used. The physical damping due to the viscous effects is taken into consideration via the Rayleigh damping. Also, due to axisymmetry 'geometric damping' can be significant in attenuating the vibration. The modelling of the boundaries is one of the key points. In order to avoid spurious wave reflections at the model boundaries (which do not exist in reality), special conditions have to be applied in order to absorb waves reaching the boundaries.