- Title
- Securing of unreinforced masonry parapets and facades – from fundamental research to national policy
- Creator
- Ingham, J. M.; Dizhur, D.; Giaretton, M.; Walsh, K. Q.; Derakshan, H.; Jafarzadeh, R.; Griffith, M. C.; Masia, M. J.
- Publisher Link
- http://dx.doi.org/10th Australasian Masonry Conference. Proceedings of the10th Australasian Masonry Conference (Sydney, Australia 11-2-2018)
- Relation
- https://eprints.qut.edu.au/120075/
- Publisher
- The University of Newcastle, Think Brick Australia, Concrete Masonry Association of Australia
- Resource Type
- conference paper
- Date
- 2018
- Description
- In 2004 researchers at the University of Auckland commenced a 6-year study on the earthquake response of unreinforced masonry (URM) buildings. The study began with efforts to count the national inventory of URM buildings, gain an understanding of representative material characteristics, do structural testing on sub-assemblages and undertake both lab and field studies on larger test specimens representative of real buildings. These efforts concluded in September 2010 with the release of a draft guidance document for professional engineers on how to undertake detailed seismic assessment and improvement of URM buildings. The first event in the Canterbury earthquake sequence occurred on 4 September 2010. Researchers from the University Auckland collaborated with colleagues from Adelaide and Newcastle in Australia in the reporting of damage to URM buildings, and further experimental studies were initiated as collaborations between New Zealand and Australia. The research team reported findings at the Canterbury Earthquakes Royal Commission, and many of their recommendations were adopted in the formal recommendations of the Commission and eventually found their way into the Building (Earthquake-prone Buildings) Amendment Bill passed by the New Zealand Parliament and receiving Royal Assent on 13 May 2016 , . Meanwhile, members of the research team participated in writing a national guidance document for professional engineers tasked with assessment and improvement of unreinforced masonry buildings, published by NZSEE . This guidance document extended upon but retained many of the recommendations from the draft document produced by the research team in 2010. This updated document was adopted as the nationally-recognised procedure for consistency in practice across the profession and nationwide seminars were delivered to professional engineers to explain its usage. Attention then turned to developing cost-effective and structurally validated solutions for securing of URM facades, recognising that the collapse of parapets, chimneys and façade walls of both cavity and solid construction were the primary contributors to deaths occurring in earthquakes due to collapsed earthquake prone URM buildings. Solutions were validated via testing on a low-cost purpose-built shake table built by the research team. In early 2016 a project was initiated as a collaboration between the University of Auckland and Auckland Council, extending the already-existing collaborative relationship with the intent of using data from Council-owned URM buildings that had been the subject of earthquake assessment and strengthening designs, to extract details on the true costs of detailed seismic assessment and earthquake strengthening. The reason for collaboration with Auckland Council specifically was a response to the realisation that this data was extremely difficult to secure from professional engineers and buildings owners due to commercial sensitivity, whereas Auckland Council was happy to release this data as a public service. From a critique of the cost data it was established that securing of URM parapets cost approximately $1000 /m of façade, and that the cost was relatively insensitive to the level of seismicity at the site. This data was first communicated to the New Zealand Ministry of Culture and Heritage and helped to inform their development of a $12 million national fund to support earthquake prone heritage buildings, announced on 12 August 2016 . On 14 November 2016 the Mw 7.8 Kaikoura earthquake initiated a new round of building damage inspections, along with a realisation that the significant risk of a major aftershock in the Wellington region meant that the likelihood of deaths due to falling unreinforced masonry facades was elevated to roughly 10 times the usual risk, which was already high when recognising that the primary fault line separating the Pacific plate from the Australian plate passes through central Wellington. On 19 December 2016 a charrette was held between researchers, practitioners and representatives of central and local government to discuss possible strategies for how to address this elevated risk of fatalities due to URM facades, convened by QuakeCoRE, the newly established Centre of Research Excellence for Earthquake Resilience. Data presented to policy writers included building inventories, validated structural solutions, and costings for implementation of securing solutions. The outcome from the day was a recommendation that efforts be instituted to secure URM facades in the lower North Island and upper South Island, with a particular focus on heritage precincts with high pedestrian traffic. On 25 January 2017 the Minister for Building and Construction, the Hon Dr Nick Smith, used emergency powers introduced after the Kaikoura earthquake to require that owners of approximately 300 high-risk URM buildings in Wellington, Lower Hutt and Blenheim be earthquake strengthened by securing their street-facing parapets and facades . The Government set aside $3M for financial support for building owners, and owners have 12 months to complete their securing. Owners can apply for financial support from the Government up to a maximum of $15,000 for securing of a façade or $10,000 for a parapet. On 26 January 2017 members of the research team received written confirmation from the Programme Manager for the branch of the New Zealand Government responsible for building performance, confirming that the research described above and shared with the policy writers on 19 December 2016 had been an important contribution to the setting of policy. Implementation of the policy and full securing of these 300 parapets and facades will presumably be concluded by the time of 10AMC. Over 13 years the research team had succeeded in both developing national guidance document for professional engineers, and associated training in the use of these techniques, plus influencing both national policy on earthquake prone buildings and more specifically emergency legislation for the securing of URM parapets and facades.
- Subject
- unreinforced masonry; parapet; facade; legislation
- Identifier
- http://hdl.handle.net/1959.13/1479557
- Identifier
- uon:50326
- Identifier
- ISBN:9780725900151
- Language
- eng
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