SR209 Base isolation of plant items in buildings (2018)

This study evaluated the available off-the-shelf vibration isolators for their suitability as seismic isolators. The function of a seismic isolator is to reduce the acceleration levels that the equipment will be subjected to when installed in a building experiencing earthquake excitation.

While there were found to be many off-the-shelf vibration isolators available, they were all unsuitable as seismic isolators. This was because they were required to be snubbed for stability, meaning that they were effectively restrained against lateral movement and would be subjected to generally the same earthquake forces as an item rigidly mounted on the floor of the structure.

Three truly seismic isolators were found in the literature review. None of these isolators would be expected to provide a vibration isolation function as well. Two of these systems have an ability to return to the start position because they have either elastic locators or run on a curved surface.