Structural seismic attributes of Auckland’s commercial building stock

Abstract

As part of past hazard modelling projects in New Zealand, pilot studies have been performed to determine building typological information relevant to structural engineers and seismological hazard researchers. Relevant typological information includes construction material, structural configuration, age of the structure, number of stories, as well as the presence of structural vulnerabilities including parapets, geometric irregularities, pounding potential, and short column effects. The procurement of such typological information permits risk modellers to compose more accurate simulations, structural engineers to develop assessment and retrofit techniques for prototypical buildings, and for large asset owners to more precisely evaluate their risk profiles in comparison to the total building population. However, these studies have often been limited by the availability of structural plans and specifications and, in particular, efficient database storage of such relevant information on a large scale. Hence, many of these pilot studies have consisted mostly of visual inspections from street walks in a few specific cities within the country, with the data then being extrapolated to other cities in proportion to census data and commercial real estate figures. As territorial authorities, government agencies, and other large asset owners are responding to regulatory and market forces in the wake of the 2010-2011 Canterbury earthquakes to assess and retrofit buildings determined to be particularly vulnerable to earthquakes, an opportunity exists to expand upon the knowledge of structural typologies within New Zealand’s commercial building stock. Two departments at Auckland Council – Building Control and Property – are currently engaging in proactive efforts to assess thousands of commercial and industrial buildings across the Auckland region. Auckland is expected to have the most varied building stock containing representative examples of nearly all types of buildings throughout New Zealand given that it houses one-third of the country’s population and has been isolated from major, infrastructure-destroying earthquakes such as other major New Zealand population centres have experienced in the past 150 years that have subsequently resulted in those areas having more homogenous building stocks today.