Vibration Guidelines used in Australia

1       Human Comfort

Humans are capable of detecting vibration at levels, which are well below those causing risk of damage to a building.

Guidelines for acceptable levels for human exposure to vibration in buildings are provided in Australian Standard AS 2670.2[1]. Guidelines are given in terms of satisfactory vibration levels related to the minimum adverse comment level by building occupants. AS2670.2 provides the vibration limits for both continuous and intermittent vibration to prevent adverse comment in residential buildings.

More recently, the New South Wales Department of Environment and Conservation (NSW DECC) has adopted a dose-based approach, using the vibration dose value (VDV) as documented in its vibration assessment guideline[2] and BS6472[3].

Vibration criteria that have been set with consideration to the BS 6472 is recognised as the preferred standard for assessing the “human comfort criteria” for residential building types. The standard defines vibration limits in terms of Peak Particle Velocity (PPV) (mm/s). These values are limits that may cause loss of amenity to the occupant. BS 6472 also recognizes that higher vibration levels are tolerable for short-term construction projects as undue restriction on vibration levels can significantly prolong construction works and result in greater annoyance.

Another British Standard that contains human response criteria for construction activities and utilises the most practical unit of measurement, which is peak particle velocity is BS 5228-2[4].

The degrees of perception for humans are also suggested by the continuous vibration level categories given in DIN 4150 Part 2[5].

2       Building Damage

There is little reliable information on the threshold of vibration-induced damage in buildings. Although vibrations induced in buildings by ground-borne excitation are often noticeable, there is little evidence that they even produce even cosmetic damage (such as small cracks in plaster)[6]. This lack of data is one of the reasons why the British Standards Institution (BSI) did not provide guidance before 1992 and why there is still no International Organization for Standardization (ISO) guidance limits. It also indicates that damage solely attributable to vibrations is not common. Some European countries have provided quantitative guidance in their codes for some years.

Nonetheless, there are several standards that we can be refer to.

2.1     British Standard

The relevant British standard is BS7385: Part 2:1993[8]. This standard was developed form an extensive review pf UK data, relevant national and international documents and other published data, which yielded very few cases on vibration damage in structures. Part 2 of the standard gives specific guidance on the levels of vibration below which building structures are considered to be at minimal risk.

The standard states in Annex A, that, ‘the age of the existing condition of a building are factors to consider in assessing the tolerance to vibration. If a building is in a very unstable state, then it will tend to be more vulnerable to the possibility of damage arising from vibration or any other ground-borne disturbance”.

2.2     AUSTRALIAN STANDARD

There is no specific Australian Standard referring to structural vibration in buildings. However, Appendix J of AS 2187.2 – 1993[9] recommends maximum peak particle velocities measured at the ground surface due to blasting. The lower recommended peak particle velocity is 5 mm/s. The standard states however, that structures, which may be particularly susceptible to ground-borne vibration, should be examined on an individual basis. It is suggested that in the absence of a particular site-specific study then a maximum peak particle velocity of 5 mm/s is used.