Appendix D History of vibration criteria
D1 Human sensitivity to vibration
The sensitivity of people to vibration depends on the direction in which the vibration acts and its frequency content. There are also summation effects for complex vibration-containing components at different frequencies. In many instances, however, the 'filtering' effect of resonances, buildings and other structures causes vibration energy to concentrate in a narrow frequency band.
In general, satisfactory or 'acceptable' magnitudes of vibration are related to the probability of adverse comments from building occupants and are not determined by other factors such as short term health hazards or working efficiency. In dwellings, adverse comments often arise when occupants perceive the vibration, note that it is associated with a source outside their home (or outside their control), and assume that the vibration has potential to damage their building or contents.
People exhibit wide variations of vibration tolerance. Responses depend on social and cultural factors, psychological attitudes, expectations regarding the degree of intrusion and other connotations associated with the sources of vibration (e.g. smell, dust, fear). In dwellings, the magnitudes of vibration considered 'acceptable' to most people are barely above thresholds of perception.
In office environments, slightly higher vibration values are usually considered acceptable, as there appears to be an expectation by the occupants that a small level of detectable movement is 'normal'. Similarly, even higher vibration values are considered acceptable in workshop or factory environments.
In most cases the occupants' expectations of what is a 'normal', safe vibration environment for the surroundings determines the acceptable values, rather than any direct effects on physical comfort or ability to carry out tasks or activities. At values of vibration higher than the acceptable values, more direct adverse effects such as distraction, irritation and subsequent interference with quiet activities or sleep patterns may also occur. The presence of other vibration-related effects (e.g. audible rattling of loose objects, visible movement of household contents and windows), which can also arise at values of vibration that are barely detectable, also tends to heighten concern about vibration and its effects.
D2 Policies and guidelines of authorities
Before the release of this guideline, DEC's general guideline for the evaluation and assessment of vibration was set out in Chapter 174 of the Environmental noise control manual.
The approach adopted was a subset of BS 6472- 1984, Evaluation of human exposure to vibration in buildings (1 Hz to 80 Hz).
The content of the 1984 issue of the British Standard was a precursor to ISO 2631.2-1989, which was published in Australia as AS 2670.2-1990.
In the USA, the still current ANSI S3.29-1983 Guide to the evaluation of human exposure to vibration in buildings (re-confirmed in 1996) contains almost identical guidance to that presented in the 1984 issue of the British Standard.
Since 1984, BS 6472 underwent a further revision and was re-released in 1992 to address what was seen as ISO 2631's 'insufficient information to allow proper evaluation of human response to vibration in buildings'. The more recent British Standard conforms in substantial measure with the ISO document, but contains significant additional guidance, and has been updated to take account of developments in vibration evaluation and assessment (particularly in relation. to complex patterns of vibration and 'vibration dose' concepts). A bibliography of data published elsewhere to support the approach adopted in BS 6472-1992 appears in Appendix D to the standard, and key items are listed in the references and bibliography in this guideline.
The latest release of BS 6472 includes information on the evaluation of intermittent vibration by introducing a 'vibration dose' concept. This approach can be used for the evaluation and assessment of vibration from trains, heavy road vehicles, construction activity and other vibration sources which are not continuous. These are potential sources of widespread disturbance in the community, and it is therefore important that appropriate techniques be provided for their assessment.
Other issues clarified in the latest version of BS 6472 include improved guidance on the degrees of community response associated with various values of vibration and better illustrative examples of applications of the standard's procedures.
The revised ISO 2631.1-1997 reflects the 1992 changes in BS 6472, and AS 2670.1-2001 was revised to reflect ISO 2631.1-1997. ISO 2631.2-2003 was redrafted to harmonise it with ISO 2631.1-1997, but at the time of writing the Australian Standard has not yet been revised. ISO 2631.2-2003 does not include guideline values for human comfort, citing the range of values as being too widespread for reproduction in an international standard. It was considered appropriate to update the DEC's vibration guideline to the approach embodied in BS 6472- 1992.
Furthermore, the previous guideline in Chapter 174 of the Environmental noise control manual addresses only z-axis vibration. Given the frequent occurrence of vibration along the x- and y-axes (e.g. due to acoustic excitation, and x- and y-axis ground vibration from some sources), information on evaluation and assessment of vibration along these axes should be provided, and therefore is included in this guideline.
D2.2 Practices adopted in other areas of Australia
At the time of publication, none of the environmental regulatory or protection agencies in other states or territories of Australia have published formal guidelines relating to vibration in buildings.
For the assessment of vibration in general, other states and territories appear to rely on the findings and recommendations of competent investigators engaged by relevant parties to investigate complaints or to assist in planning for new developments. In general, there seems to be reliance on ISO 2631 and BS 6472, in much the same manner as DEC's previous guideline in Chapter 174 of the Environmental noise control manual.
Other government authorities in NSW (e.g. Railcorp, Australian Railtrack Corporation, Roads and Traffic Authority, Department of Planning, and local councils) have been following DEC's previous guideline (based on the previous BS 6472) when assessing potential human discomfort from vibration.
Page last updated: 12 June 2013