Lessons from the Field; Steel Structure Performance in Earthquakes in New Zealand from 2010 to 2016

Abstract

First the Canterbury earthquake series of 2010/2012 and then the Kaikoura Earthquake of 2016 have significantly impacted the building stock in central and southern New Zealand, subjecting a wide range of buildings and building components to earthquake shaking ranging from moderate to severe. The economic and social costs of these earthquakes have been severe, but the lessons learned on how buildings and building systems designed and detailed to New Zealand provisions have performed have been invaluable. We have learned more about this from these earthquakes then from the many reconnaissance trips undertaken to overseas earthquakes over the 50 years of the New Zealand Society for Earthquake Engineering. This paper focusses on the performance of steel framed buildings in two major New Zealand cities, Christchurch and Wellington, with greatest emphasis on multi-storey buildings, but also covering light steel framed housing. It addresses such issues as the magnitude and structural impact of the earthquake series, how the various systems performed against the design expectations and briefly covers some of the research underway to quantify where there were differences between the observed performance and the expected performance.