Bulletin of the New Zealand Society for Earthquake Engineering https://bull.nzsee.org.nz/index.php/bnzsee <p>Bulletin of the New Zealand Society for Earthquake Engineering</p> New Zealand Society for Earthquake Engineering en-US Bulletin of the New Zealand Society for Earthquake Engineering 1174-9857 <ol> <li>You warrant that you have the authority to act as the agent of all the authors of this article for the purpose of entering into this agreement.</li> <li>You hereby grant a <a href="https://creativecommons.org/licenses/by/4.0" target="_blank" rel="noopener">Creative Commons Attribution (CC-BY) license</a> in the article to the general public.</li> <li>You agree to require that a citation to the original publication of the article in the Bulletin of the New Zealand Society for Earthquake Engineering be included in any attribution statement satisfying the attribution requirement of the Creative Commons license of paragraph 2.</li> <li>You retain ownership of all rights under copyright in all versions of the article, and all rights not expressly granted in this agreement.</li> <li>To the extent that any edits made by the publisher to make the article suitable for publication in the journal amount to copyrightable works of authorship, the publisher hereby assigns all right, title, and interest in such edits to you. The publisher agrees to verify with you any such edits that are substantive. You agree that the license of paragraph 2 covers such edits.</li> <li>You further warrant that: <ol type="a"> <li>The article is original, has not been formally published in any other peer-reviewed journal or in a book or edited collection, and is not under consideration for any such publication.</li> <li>You are the sole author(s) of the article, and that you have a complete and unencumbered right to make the grants you make.</li> <li>The article does not libel anyone, invade anyone’s copyright or otherwise violate any statutory or common law right of anyone, and that you have made all reasonable efforts to ensure the accuracy of any factual information contained in the article. You agree to indemnify the publisher against any claim or action alleging facts which, if true, constitute a breach of any of the foregoing warranties or other provisions of this agreement, as well as against any related damages, losses, liabilities, and expenses incurred by the publisher.</li> </ol> </li> <li>This is the entire agreement between you and the publisher, and it may be modified only in writing. It will be governed by the laws of New Zealand. It will bind and benefit our respective assigns and successors in interest, including your heirs.</li> </ol> The 2014 South Napa earthquake and its relevance for New Zealand https://bull.nzsee.org.nz/index.php/bnzsee/article/view/141 <p>The South Napa earthquake occurred on Sunday, 24 August 2014 at 3.20 am local time at a depth of 10.7 km, having MW 6.0 and causing significant damage to unreinforced masonry (URM) buildings in the City of Napa and generating strong ground shaking in a region well known for its wine production. Parallels exist between the damage in past New Zealand earthquakes, particularly to unreinforced masonry buildings, and the disruption in the Marlborough region following the recent 2013 MW 6.5 Seddon earthquake. Furthermore, the event was the largest to have occurred in Northern California since the 1989 Loma Prieta earthquake 25 years earlier, and hence was an important event for the local community of earthquake researchers and professionals regarding the use of a physical and virtual clearinghouse for data archiving of damage observations. Because numerous URM buildings in the City of Napa had been retrofitted, there was significant interest regarding the observed performance of different retrofitting methods.</p> <p>Following a brief overview of the earthquake affected area and previous earthquakes to have caused damage in the Napa Valley region, details are provided regarding the characteristics of the 2014 South Napa earthquake, the response to the earthquake including placarding procedures and barricading, and more specific details of observed building and non-structural damage. Aspects of business continuity following the South Napa earthquake are also considered. One conclusion is that in general the seismic retrofitting of URM buildings in the Napa region proved to be very successful, and provides an important benchmark as New Zealand begins to more actively undertake seismic assessment and retrofitting of its earthquake prone building stock. It is also concluded that there are sufficient similarities between New Zealand and California, and a rich network of contacts that has developed following the hosting of many US visitors to New Zealand in conjunction with the 2010/2011 Canterbury earthquakes, that it is sensible for the New Zealand earthquake engineering community to maintain a close focus on ongoing earthquake preparedness and mitigation methods used and being developed in USA, and particularly in California.</p> Bruce Galloway Jason M. Ingham Copyright (c) 2015 Bruce Galloway, Jason M. Ingham https://creativecommons.org/licenses/by/4.0 2015-03-31 2015-03-31 48 1 1 30 10.5459/bnzsee.48.1.1-30 URM bearing wall building seismic risk mitigation on the west coast of the United States https://bull.nzsee.org.nz/index.php/bnzsee/article/view/142 <p>Unreinforced masonry (URM) buildings are the most common target for seismic risk mitigation programmes, due to their long history of poor seismic performance. While seismic risk mitigation must make use of sound engineering methodologies, good public policy is at the heart of successful programmes. Past URM seismic risk mitigation efforts on the west coast of the United States are summarized herein, as valuable insights have been gained from both successful and unsuccessful programmes. Programme details such as compliance deadlines, retrofit design techniques, and retrofit/demolition rates are provided for cities throughout California, Oregon and Washington states, and the overall observed effectiveness of mandatory versus non-mandatory seismic strengthening programmes is discussed.</p> Brandon Paxton Fred Turner Ken Elwood Jason M. Ingham Copyright (c) 2015 Brandon Paxton, Fred Turner, Ken Elwood, Jason M. Ingham https://creativecommons.org/licenses/by/4.0 2015-03-31 2015-03-31 48 1 31 40 10.5459/bnzsee.48.1.31-40 Floor diaphragms and a truss method for their analysis https://bull.nzsee.org.nz/index.php/bnzsee/article/view/143 <p>Floor diaphragms form a critical component of seismic resistant buildings, but unfortunately, in the main their analysis and design in New Zealand leaves much to be desired. No worse example exists than the CTV Building in Christchurch. Despite the critical importance of diaphragms, there is a paucity of code provisions and design guidance relating to them.</p> <p>Using generic examples, the author describes a number of common diaphragm design deficiencies. These include diaphragms where valid load paths do not exist; diaphragms where the floors are not properly connected to the lateral load resisting elements, diaphragms that lack adequate flexural capacity and where re-entrant corners are not properly accounted for, and transfer diaphragms into which the reactions from the walls above cannot be properly introduced or transmitted.</p> <p>Three main types of seismic diaphragm action are discussed – ‘inertial,’ ‘transfer’ and ‘compatibility.’ These are, respectively, the direct inertial load on a floor that must be carried back to the lateral load resisting elements, the transfer forces that occur when major changes in floor area and lateral load resisting structure occur between storeys, and the compatibility forces that must exist to force compatible displacements between incompatible elements, such as shear walls or braced frames and moment frames, or as a result of redistribution.</p> <p>The author presents a simple Truss Method that allows complex diaphragms to be analysed for multiple load cases, providing accurate force distributions without the multiple models that conventional strut and tie methods would require. Being a type of strut and tie method, the Truss Method is compliant with requirements in NZS3101:2006 [1] to use strut and tie models for the analysis and design of certain aspects of diaphragm behaviour.</p> J.M. Scarry Copyright (c) 2015 J.M. Scarry https://creativecommons.org/licenses/by/4.0 2015-03-31 2015-03-31 48 1 41 62 10.5459/bnzsee.48.1.41-62 Suitability of CFT columns for New Zealand moment frames https://bull.nzsee.org.nz/index.php/bnzsee/article/view/144 <p>Composite steel-concrete construction uses steel and concrete together to provide the possibility of a system with better performance, and/or lower cost, than using either material alone. This paper firstly subjectively evaluates the advantages and disadvantages of a number of composite concrete filled tubular (CFT) column-connection systems proposed/used around the world in terms of their likely acceptance in moment frames in New Zealand. Then, the cost of a conventional one-way moment-resisting steel frame system is compared with a similarly behaving frame using rectangular concrete filled steel tubular (CFT) columns. It is shown for these studies conducted on one-way frames that composite CFT column construction with beam end-plate connections is generally more expensive than conventional steel column construction.</p> Ponpong Chunhaviriyakul Gregory A. MacRae Dave Anderson G. Charles Clifton Roberto T. Leon Copyright (c) 2015 Ponpong Chunhaviriyakul, Gregory A. MacRae, Dave Anderson, G. Charles Clifton, Roberto T. Leon https://creativecommons.org/licenses/by/4.0 2015-03-31 2015-03-31 48 1 63 79 10.5459/bnzsee.48.1.63-79