BS 7385-2:1993

This Part of BS 7385 gives guidance on the levels of vibration above which building structures could be damaged. It identifies the factors which influence the vibration response of buildings, and describes the basic procedure for carrying out measurements. Vibrations of both transient and continuous character are considered. A method of assessment which takes into account the characteristics of the vibration, the building and the measured data is given. It is appropriate for the types of investigation given in BS 7385-1, but for detailed engineering analysis, criteria other than the vibration levels may need to be considered.

Only the direct effect of vibration on buildings is considered. The indirect effects on the building structure due to ground movement, the movement of loose objects within buildings, the possibility of damage to sensitive equipment and the effect of vibration on people are outside the scope of this Part of BS 7385. There is a major difference between the sensitivity of people in feeling vibration and the onset of levels of vibration which damage the structure. Levels of vibration at which adverse comment from people is likely are below levels of vibration which damage buildings, except at lower frequencies. The evaluation of human exposure to vibration in buildings is covered in BS 6472.

This Part of BS 7385 does not consider the many other causes of cracking in buildings; cracking commonly occurs in buildings whether they are exposed to vibration or not (see annex A).

Damage due to earthquakes, air overpressure, wind or the sea are also outside the scope of this Part of BS 7385. It is applicable only to vibration transmitted through the ground and not to vibration set up by machinery within a building. Chimneys, bridges and underground structures such as chambers, tunnels and pipelines are not covered.