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Research papers, University of Canterbury Library

As a result of the Canterbury earthquakes, over 60% of the concrete buildings in the Christchurch Central Business District have been demolished. This experience has highlighted the need to provide guidance on the residual capacity and repairability of earthquake-damaged concrete buildings. Experience from 2010 Chile indicates that it is possible to repair severely damaged concrete elements (see photo at right), although limited testing has been performed on such repaired components. The first phase of this project is focused on the performance of two lightly-reinforced concrete walls that are being repaired and re-tested after damage sustained during previous testing.

Research papers, University of Canterbury Library

This poster presents preliminary results of ongoing experimental campaigns at the Universities of Auckland and Canterbury, aiming at investigating the seismic residual capacity of damaged reinforced concrete plastic hinges, as well as the effectiveness of epoxy injection techniques for restoring their stiffness, energy dissipation, and deformation capacity characteristics. This work is part of wider research project which started in 2012 at the University of Canterbury entitled “Residual Capacity and Repairing Options for Reinforced Concrete Buildings”, funded by the Natural Hazards Research Platform (NHRP). This research project aims at gaining a better understanding and providing the main end-users and stakeholders (practitioner engineers, owners, local and government authorities, insurers, and regulatory agencies) with comprehensive evidence-based information and practical guidelines to assess the residual capacity of damaged reinforced concrete buildings, as well as to evaluate the feasibility of repairing and thus support their delicate decision-making process of repair vs. demolition or replacement.

Articles, UC QuakeStudies

A document which explains the pre-approval process for specialist lining contractors working on the SCIRT horizontal repair programme.This document has had sections removed and redacted to protect contractors' commercial interests.For a current list of approved contractors authorised to carry out lining works on Christchurch City Council assets, contact the Council.

Research papers, University of Canterbury Library

essential systems upon which the well-being and functioning of societies depend. They deliver a service or a good to the population using a network, a combination of spatially-distributed links and nodes. As they are interconnected, network elements’ functionality is also interdependent. In case of a failure of one component, many others could be momentarily brought out-of-service. Further problems arise for buried infrastructure when it comes to buried infrastructure in earthquake and liquefaction-prone areas for the following reasons: • Technically more demanding inspections than those required for surface horizontal infrastructure • Infrastructure subject to both permanent ground displacement and transient ground deformation • Increase in network maintenance costs (i.e. deterioration due to ageing material and seismic hazard) These challenges suggest careful studies on network resilience will yield significant benefits. For these reasons, the potable water network of Christchurch city (Figure 1) has been selected for its well-characterized topology and its extensive repair dataset.

Videos, UC QuakeStudies

A video of a presentation by Ian Campbell, Executive General Manager of the Stronger Christchurch Rebuild Team (SCIRT), during the third plenary of the 2016 People in Disasters Conference. The presentation is titled, "Putting People at the Heart of the Rebuild".The abstract for this presentation reads: On the face of it, the Stronger Christchurch Infrastructure Rebuild Team (SCIRT) is an organisation created to engineer and carry out approximately $2B of repairs to physical infrastructure over a 5-year period. Our workforce consists primarily of engineers and constructors who came from far and wide after the earthquakes to 'help fix Christchurch'. But it was not the technical challenges that drew them all here. It was the desire and ambition expressed in the SCIRT 'what we are here for' statement: 'to create resilient infrastructure that gives people security and confidence in the future of Christchurch'. For the team at SCIRT, people are at the heart of our rebuild programme. This is recognised in the intentional approach SCIRT takes to all aspects of its work. The presentation will touch upon how SCIRT communicated with communities affected by our work and how we planned and coordinated the programme to minimise the impacts, while maximising the value for both the affected communities and the taxpayers of New Zealand and rate payers of Christchurch funding it. The presentation will outline SCIRT's very intentional approach to supporting, developing, connecting, and enabling our people to perform, individually, and collectively, in the service of providing the best outcome for the people of Christchurch and New Zealand.

Videos, UC QuakeStudies

A video of a presentation by Dr Duncan Webb, Partner at Lane Neave, during the third plenary of the 2016 People in Disasters Conference. The presentation is titled, "Loss of Trust and other Earthquake Damage".The abstract for this presentation reads as follows: It was predictable that the earthquakes which hit the Canterbury region in 2010 and 2011 caused trauma. However, it was assumed that recovery would be significantly assisted by governmental agencies and private insurers. The expectation was that these organisations would relieve the financial pressures and associated anxiety caused by damage to property. Some initiatives did exactly that. However, there are many instances where difficulties with insurance and related issues have exacerbated the adverse effects of the earthquakes on people's wellness. In some cases, stresses around property issues have become and independent source of extreme anxiety and have had significant impacts on the quality of people's lives. Underlying this problem is a breakdown in trust between citizen and state, and insurer and insured. This has led to a pervading concern that entitlements are being denied. While such concerns are sometimes well founded, an approach which is premised on mistrust is frequently highly conflicted, costly, and often leads to worse outcomes. Professor Webb will discuss the nature and causes of these difficulties including: the complexity of insurance and repair issues, the organisational ethos of the relevant agencies, the hopes of homeowners and the practical gap which commonly arises between homeowner expectation and agency response. Observations will be offered on how the adverse effects of these issues can be overcome in dealing with claimants, and how such matters can be managed in a way which promotes the wellness of individuals.

Research papers, The University of Auckland Library

Eccentrically Braced Frames (EBFs) are a widely used seismic resisting structural steel system. Since their inception in the late 1970s, they have been a viable option with an available stiffness that is between simple braced systems and moment resisting systems. A similar concept, the linked column frame (LCF), uses shear links between two closely spaced columns. In both cases, the key component is the active link or the shear link, and this component is the objective of this study. The performance of high rise EBF buildings in the 2010 and 2011 Christchurch earthquakes was beyond that which was expected, especially considering the very high accelerations recorded. As the concrete high-rises were torn down, two EBF buildings remained standing and only required some structural repair. These events prompted a renewed interest in bolted shear links, as well as their performance. While some research into replaceable shear links had already been done (Mansour, 2011), the objectives of this study were to improve on the shear link itself, with the consideration that links built in the future are likely to be bolted. The main components of this study were to: 1. Reduce or eliminate the requirements for intermediate web stiffeners, as they were suspected of being detrimental to performance. Furthermore, any reduction in stiffening requirements is a direct fabrication cost saving. Links with low web aspect ratios were found to achieve exceptional ductilities when no stiffeners were included, prompting new design equations. 2. Ensure that the stresses in the ends of links are adequately transferred into the endplates without causing fractures. Although most of the experimental links had web doubler plates included, four had varied lengths of such doubler plates from 0.0 in. to 8.0 in. The link without any doubler plates performed to a similar level to its peers, and thus it is likely that links with quality end details may not need web doubler plates at all. 3. Evaluate the performance of a link with double sided stiffeners without the use of web welds, as opposed to conventional single sided, welded stiffeners. This link performed well, and web-weld-less double sided stiffeners may be an economical alternative to conventional stiffeners for deeper sections of links. 4. Evaluate the performance of a link with thin endplates that are made efficient with the use of gusset plates. This link performed to an acceptable level and provides evidence for a cost effective alternative to thick endplates, especially considering the high overstrength end moments in links, typically requiring 16-bolt connections. 5. Examine the potential use of an alternative EBF arrangement where the collector beam is over sized, and the link section is formed by cutting out parts of the beam's web. After running a series of finite element models each with a unique variation, a number of approximate design rules were derived such that future research could develop this idea further experimentally. 6. Ensure that during testing, the secondary elements (members that are not the shear link), do not yield and are not close to yielding. None of the instrumented elements experienced any unexpected yielding, however the concerns for high stresses in the collector beam panel zone during design were warranted. The use of an existing New Zealand design equation is recommended as an extra check for design codes worldwide. The above objectives were mainly conducted experimentally, except: the data set for item 1 was greatly expanded through the use of a calibrated numerical model which was then used in an extensive parametric study; item 5 was purely finite element based; and, a small parametric study was included for item 3 in an attempt to expand on the trends found there.