SR156 Base isolation of low-rise light and medium-weight buildings (2007)

This is the first of a series of study reports prepared during research into base isolation of low-rise buildings. Reference is made to four BRANZ unpublished preliminary reports on this subject. However, the key findings from these unpublished reports are reproduced herein.

The potential for application of the Roglider and Roball base-isolation systems for seismic protection of low-rise building is examined. It was concluded that most buildings would be susceptible to excessive movement under wind loading, unless the isolators were placed under concrete floor slabs when the weight of the structure above (factored by the effective isolator friction coefficient) would often be adequate to resist the wind forces while still giving good seismic protection.

A set-up using this arrangement was tested. The protection given to contents was examined, and it was noted that protection for rocking-body type contents (e.g. bottles) was small.

A literature survey was performed to examine other types of isolation systems. A modification of two of these was selected as being the most likely candidates for general application.