Seismic Isolation: New Zealand Applications

Abstract

Seismic isolation of structures has been applied in New Zealand since 1973. To date approximately 45 bridges, 3 large buildings and a few other structures have been protected with this technique. These include 40 bridges and 2 buildings designed by Works and Development Services Corporation (NZ) Ltd (WORKS). Numerous energy dissipating devices have been developed and tested by New Zealand researchers. Six of these designs have proved to be convenient and economical and have been incorporated in the seismic isolation systems of the structures built. Development work on seismic isolation devices is continuing in New Zealand and contact with specialists from other countries - in particular from Japan and the United States of America - is being maintained. Seismic isolation has been found to be a cost effective means of mitigating earthquake effects, particularly if the long term benefits of reduced seismic damage and disruption are taken into consideration.

Protecting vibration-sensitive contents: an investigation of floor accelerations in seismically isolated buildings

“…Owing to the lengthened period and the damping provided by the isolation system, the seismic forces and the floor accelerations are significantly reduced. Seismic isolation proved its success in many cases and is being implemented in many projects throughout the world (Mckay et al 1990;Kitagawa and Midorikawa 1998;Nagarajaiah and Xiaohong 2000;Asher et al 2001;De La Llera et al 2004;Pan et al 2005;Kamada and Fujita 2008;Bachman 2009). Recent analytical and experimental research studies show that properly designed seismic base isolation systems can reduce peak floor accelerations effectively.…”

Experimental analysis of the seismic response of one base-isolation building according to different levels of shaking: example of the Martinique earthquake (2007/11/29) Mw 7.3

“…This solution has become a popular, proven earthquake design technique used throughout the world for traditional buildings (e.g., Martelli and Forni 2002;McKay et al 1990), bridges (e.g., Kunde and Jangid 2003) and even for nuclear power stations (e.g., Tajirian et al 1990) While seismic feedback in countries exposed to a high seismic risk confirms the efficiency of these systems, only very few cases of instrumented buildings have provided strong motion recordings to enable understanding of the way these supports actually work in real conditions in order to offer convincing proof to overcome the doubts of those reluctant to use them.…”