A Tentative Noise Control Method for Buildings above Railway Tunnels

In this paper, a design method to reduce the transmission of structure-borne sound in buildings to be built above railway tunnels is studied. The case studied is similar to the one studied previously by the author in the sense that the building is founded on rock. However, in the present case, the load-bearing columns on the first floor are not placed above other load-bearing columns or walls. Analytical models for the propagation of structure-borne sound upward in the buildings are derived. The models are based on the assumption that the initial vibrational energy that propagates from the foundation is in the form of quasi-longitudinal waves. The propagation of bending and quasi-longitudinal waves in the load-bearing columns is considered. A finite ground impedance is taken into account as well as the wave reflection from the roof. A parametric survey is conducted to investigate the influence of certain important geometrical properties of the first floor on the sound transmission. Finally, the results are compared with previous results for a “normal” building and it is shown that the relocation of the columns can considerably reduce the sound transmission upward in the building.