Double wall barriers as mitigation measures for ground vibration transmission

Stiff wall barriers can be effective in reducing the transmission of environmental ground vibration. Up to now, single wall barriers have mostly been studied. In building acoustics, however, double walls are used in order to realize a high level of sound insulation. In this paper, the potential of using double jet-grout walls in reducing ground vibration transmission is investigated. The three-dimensional free field response due to a point load and a simplified train load is computed using a two-and-a-half dimensional finite element methodology. Double jet-grout wall barriers are found to be slightly more effective than single wall barriers, in particular when the thickness of the walls and the intermediate soil matches a quarter Rayleigh wavelength. The largest increase in vibration reduction is found for the area closest to the vibration source, where the vibration levels have the highest values.