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Images for building repair; more images...

Images, Alexander Turnbull Library

In the foreground PM John Key drives a bulldozer over Christchurch; in the background two engineers read a newspaper report that says 'P.M. gives false demolition number, PM gives false World Cup hope' and one of them says 'Now I know why those things are called BULLdozers..' Context - Prime Minister John Key is sticking to a government estimate that 10,000 Christchurch homes will need to be razed despite criticism that he should wait for official figures; he also stated that 100,000 homes may need repairs, despite Civil Defence saying it has only checked 70,000 homes so far. John Key was also insisting that there was a chance of keeping World Cup rugby games in Christchurch but an official announcement on 16 March dashed those hopes. Quantity: 1 digital cartoon(s).

Images, Alexander Turnbull Library

A woman in a burqa walks out of the 'Church of the Multi-denominations'. The church has a steeple and an onion dome. Context: The cartoonist says that the cartoon was drawn for a satirical piece about the rebuilding of Christchurch. Because of the number of churches damaged, including the Anglican cathedral, The cartoon suggests that there should just build one massive church on the AMI stadium site that all religions can use on their particular day....spires would be raised and lowered etc. Quantity: 1 digital cartoon(s).

Audio, Radio New Zealand

The beloved Christchurch Arts Centre - built in the 1870s - has slowly been reopening after repairs and restoration. An open day last weekend saw the public getting their first look into the complex's school of art building since the earthquakes. One beneficiary has been singer-songwriter Bic Runga, who has kick-started the Arts Centre Te Matatiki Toi Ora's revived Creative Residencies programme. She tells Mark Amery she's been trying out all sorts of new things. Applications for Bic's song-writing workshop in Christchurch in early July close on Friday 31 May.

Images, Alexander Turnbull Library

Shows a helicopter spray painting Christchurch with the Canterbury colours of black and red. Someone in the helicopter yells that 'it's gotta be better than tint of TC3'. Context: Probably refers to the apology by Earthquake Recovery Minister Gerry Brownlee for offending Christchurch's TC3 residents after saying he was 'sick and tired' of their moaning. TC3 means 'technical category 3'. Land classified TC3 is the mostly badly quake-damaged considered economically repairable. Quantity: 1 digital cartoon(s).

Images, Alexander Turnbull Library

Shows a carcass that represents the Christchurch Cathedral with many people rushing to try to save it from demolition. Context: the extremely controversial debate about whether the Christchurch Cathedral which was severely damaged in the earthquakes, should be demolished, rebuilt on the same site in the same style or partially demolished and made into a memorial. Quantity: 1 digital cartoon(s).

Research papers, University of Canterbury Library

The effects of soil-foundation-structure interaction (SFSI) have been a topic of discussion amongst the structural and geotechnical community for many decades. The complexity of the mechanisms, as well as the need for inter-disciplinary knowledge of geotechnical and structural dynamics has plagued the advancement and the consequent inclusion of SFSI effects in design. A rigorous performance-based design methodology should not just consider the performance of the superstructure but the supporting foundation system as well. Case studies throughout history (eg. Kobe 1995, Kocaeli 1999 and Christchurch earthquakes 2010-2011) have demonstrated that a poor performance at the foundation level can result in a full demolition of the structure and, in general terms, that the extent of damage to, and repairability of, the building system as a whole, is given by the combination of the damage to the soil, foundation and superstructure. The lack of consideration of the modifying factors of SFSI and an absence of intuitive performance levels for controlling foundation and soil behaviour under seismic loads has resulted in inadequate designs for buildings sited on soft soil. For engineers to be satisfied that their designs meet the given performance levels they must first, understand how SFSI affects the overall system performance and secondly have tools available to adequately account for it in their design/assessment. This dissertation presents an integrated performance-based design procedure for buildingfoundation systems that considers all of the major mechanisms of SFSI. A new soil-foundation macro-element model was implemented into a nonlinear finite element software and validated against several experimental tests. The numerical model was used to provide insights in to the mechanisms of SFSI and statistical analysis on the results yielded simple expressions that allow the behaviour to be quantified. Particular attention was paid to the effects of shear force on the foundation response and the quantification of the rocking mode of response. The residual deformations of the superstructure and distribution of forces up the structure were also investigated. All of the major SFSI mechanisms are discussed in detail and targeted numerical studies are used to explain and demonstrate concepts. The design procedure was validated through the design and assessment of a series of concrete buildings that were designed to account for the effects of SFSI.

Images, Alexander Turnbull Library

Text above reads 'Central Christchurch business owners protest' and the words 'Cordon Blur' (wordplay on famous cookery schools 'Cordon Bleu' and 'blur' as in 'unclear'). The cartoon shows a striped barrier bearing the words 'KEEP OUT' that is being torn to pieces. A second version continues the text to read 'Central Christchurch business owners protest as future directions unclear'. Context - Protests from angry Christchurch business owners locked out of the damaged CBD have intensified today, with police physically intervening when several protesters went inside the cordon. They are worried about the state of their businesses inside the red zone, and say they have not been allowed in to collect critical records and basic tools so they can carry on working outside the cordon. (NZ Herald 21 March 2011) Quantity: 2 digital cartoon(s).

Images, Alexander Turnbull Library

Finance Minister Bill English takes a chain saw to a huge tome that represents the 'NZ Government BUDGET May 2011'. Context - the Government says cutting budget spending is necessary because it is going to have to pay back money borrowed to rebuild Christchurch. The Government will face the biggest budget deficit in New Zealand's history at the end of the current financial year, Finance Minister Bill English says. (NZ Herald 31 March 2011) Quantity: 1 digital cartoon(s).

Audio, Radio New Zealand

A school leader says the Ministry of Education of wasted millions of taxpayer dollars over years of earthquake repairs, and was obstructive and misleading. The building budget at Christchurch Girls High School has blown out by 50 percent to $40 million and it's not finished, even after five years of work. Mike Lay, who was chair of the board of trustees for most of those years, until 2018, says the ministry botched the job then targeted him when he tried to hold it accountable. He told Phil Pennington about the school's struggle to get the school re-built properly.

Images, Alexander Turnbull Library

Text reads 'Rebuilding projects'. The first of the two frames shows collapsed buildings in Christchurch after the earthquake and the second frame shows leader of the Labour Party Phil Goff sorely in need of 'credibility' as he makes the 'V' for victory sign with both hands. Context - the rebuilding of Christchurch after the earthquake of 22 March 2011 and Phil Goff's disastrous personal polling as 'preferred PM' and the concomitant problems for the Labour Party with elections in November of this year. Colour and black and white versions of this cartoon are available Quantity: 2 digital cartoon(s).

Research papers, University of Canterbury Library

The Canterbury earthquakes in 2010 and 2011 had a significant impact on landlords and tenants of commercial buildings in the city of Christchurch. The devastation wrought on the city was so severe that in an unprecedented response to this disaster a cordon was erected around the central business district for nearly two and half years while demolition, repairs and rebuilding took place. Despite the destruction, not all buildings were damaged. Many could have been occupied and used immediately if they had not been within the cordoned area. Others had only minor damage but repairs to them could not be commenced, let alone completed, owing to restrictions on access caused by the cordon. Tenants were faced with a major problem in that they could not access their buildings and it was likely to be a long time before they would be allowed access again. The other problem was uncertainty about the legal position as neither the standard form leases in use, nor any statute, provided for issues arising from an inaccessible building. The parties were therefore uncertain about their legal rights and obligations in this situation. Landlords and tenants were unsure whether tenants were required to pay rent for a building that could not be accessed or whether they could terminate their leases on the basis that the building was inaccessible. This thesis looks at whether the common law doctrine of frustration could apply to leases in these circumstances, where the lease had made no provision. It analyses the history of the doctrine and how it applies to a lease, the standard form leases in use at the time of the earthquakes and the unexpected and extraordinary nature of the earthquakes. It then reports on the findings of the qualitative empirical research undertaken to look at the experiences of landlords and tenants after the earthquakes. It is argued that the circumstances of landlords and tenants met the test for the doctrine of frustration. Therefore, the doctrine could have applied to leases to enable the parties to terminate them. It concludes with a suggestion for reform in the form of a new Act to govern the special relationship between commercial landlords and tenants, similar to legislation already in place covering other types of relationships like those in residential tenancies and employment. Such legislation could provide dispute resolution services to enable landlords and tenants to have access to justice to determine their legal rights at all times, and in particular, in times of crisis.

Images, Alexander Turnbull Library

A rat in a business suit representing 'insurance companies' carries a briefcase labelled 'Total replacement policies' and follows a fellow rat into a large hole 'loop holes' that leads into a collapsed building. The rat says 'Woo-hoo! Home sweet home!' Context - Problems for people whose houses were damaged in the Christchurch earthquakes. One of the options presented to residents in the red zone, ideal for people with replacement policies, was the government bought your land, and you dealt directly with your insurers about your house. However they got a shock when insurers told them they won't replace their homes, they'll only repair them, even though they're earmarked for certain demolition. Quantity: 1 digital cartoon(s).

Images, UC QuakeStudies

A digitally manipulated image of liquefaction around a house in Avondale. The photographer comments, "The bottom of the gates were swallowed up by liquefaction, but the house still looked in good condition, which was confirmed by builders just going in to work on the property. It is in the Christchurch red zone, which after testing has been deemed unsuitable for houses to be built on. All the land will be bought by the Government and they would also buy any properties that could be repaired. The remaining insured property owners will get a payment from the insurance company. All the buildings are condemned to be knocked down".

Images, Alexander Turnbull Library

Shows a sick and damaged Christchurch Anglican Cathedral in a hospital bed with two attendants. The Cathedral asks 'Can ya just pull the plug and let me die peacefully?'. Context refers to recent comments by Bishop Victoria Matthews that the Christchurch Cathedral is 'being left to die with no dignity' because of ongoing legal battles about its future. There has been ongoing debate and controversy over whether the Cathedral should be demolished, reconstructed or restored following damage suffered in the February 2011 Earthquake. Quantity: 1 digital cartoon(s).

Images, Alexander Turnbull Library

A business owner has been allowed into the 'Red Zone' in the Christchurch CBD in order to investigate the damage to his business premises. He is dismayed to discover that he has forgotten his keys; the Civil Defence officer who is with him, looks at him askance as the door is the only part of his premises still standing. Context - Some time after the earthquake of 22 March 2011 business owners were allowed through the cordon to collect belongings and see their premises for themselves. Colour and black and white versions of this cartoon are available Quantity: 2 digital cartoon(s).

Research papers, University of Canterbury Library

Unreinforced masonry churches in New Zealand, similarly to everywhere else in the word have proven to be highly vulnerable to earthquakes, because of their particular construction features. The Canterbury (New Zealand) earthquake sequence, 2010-2011 caused an invaluable loss of local architectural heritage and of churches, as regrettably, some of them were demolished instead of being repaired. It is critical for New Zealand to advance the data collection, research and understanding pertaining to the seismic performance and protection of church buildings, with the aim to:

Images, Alexander Turnbull Library

Minister for Christchurch Recovery, Gerry Brownlee drives a huge tractor among debris that spells out 'Due Process' and says 'In order to get Christchurch back on its feet again we have to bring parliament to its knees. Context - The minister says he is happy with the speed of the work being done, as he wants tomake sure those involved in the rebuild portion of the recovery effort are well prepared. The bill establishes the Canterbury Earthquake Recovery Authority (Cera) and empowers it to lead reconstruction efforts in Christchurch. It gives Cera specific powers to get information from any source, to requisition and build on land and to carry out demolitions. It can also take over local authorities if they are not working effectively on recovery work. Quantity: 1 digital cartoon(s).

Images, Alexander Turnbull Library

Depicts huge elderly woman with 'CERA' on her dress scolding smaller adult dressed as schoolboy near bustop with sign 'CBD red zone tours' Text reads 'And don't talk to strangers and don't cross the road and remember to eat your lunch..' Context: After the 22 Feburary 2011 earthquake in Christchurch, the central business district (CBD) was marked as a red zone. Red zone areas were deemed unsuitable for habitation due to significant damage and at high risk of further damage from low levels of earth shaking. CERA (Christchurch Earthquake Recovery Authority) ran public bus tours of the Christchurch CBD from November to December 2011. For safety reasons the public was not allowed off the buses as it was a dangerous and active demolition site. Quantity: 1 digital cartoon(s).

Images, Alexander Turnbull Library

Three people stand looking down at a small model of the 'Christchurch CBD'. One of the people says 'Love the safer low-rise plan What's the scale?' A second man says 'Scale? Er this is the actual size!' Context: Christchurch Mayor Bob Parker has dedicated the draft plan for a new-look Christchurch CBD to those lost in the February earthquake. The CBD will be about a quarter of its original size under the draft plan which was unanimously adopted by the council today. (TVNZ 11 August 2011) Quantity: 1 digital cartoon(s).

Research papers, University of Canterbury Library

Recent severe earthquakes, such as Christchurch earthquake series, worldwide have put emphasis on building resilience. In resilient systems, not only life is protected, but also undesirable economic effects of building repair or replacement are minimized following a severe earthquake. Friction connections are one way of providing structure resilience. These include the sliding hinge joint with asymmetric friction connections (SHJAFCs) in beam-to-column connections of the moment resisting steel frames (MRSFs), and the symmetric friction connections (SFCs) in braces of the braced frames. Experimental and numerical studies on components have been conducted internationally. However, actual building performance depends on the many interactions, occurring within a whole building system, which may be difficult to determine accurately by numerical modelling or testing of structural components alone. Dynamic inelastic testing of a full-scale multi-storey composite floor building with full range of non-structural elements (NSEs) has not yet been performed, so it is unclear if surprises are likely to occur in such a system. A 9 m tall three-storey configurable steel framed composite floor building incorporating friction-based connections is to be tested using two linked bi-directional shake tables at the International joint research Laboratory of Earthquake Engineering (ILEE) facilities, Shanghai, China. Beams and columns are designed to remain elastic during an earthquake event, with all non-linear behaviour occurring through stable sliding frictional behaviour, dissipating energy by SHJAFCs used in MRFs and SFCs in braced frames, with and without Belleville springs. Structural systems are configurable, allowing different moment and braced frame structural systems to be tested in two horizontal directions. In some cases, these systems interact with rocking frame or rocking column system in orthogonal directions subjected to unidirectional and bidirectional horizontal shaking. The structure is designed and detailed to undergo, at worst, minor damage under series of severe earthquakes. NSEs applied include precast-concrete panels, glass curtain walling, internal partitions, suspended ceilings, fire sprinkler piping as well as some other common contents. Some of the key design considerations are presented and discussed herein

Research papers, University of Canterbury Library

Capacity design and hierarchy of strength philosophies at the base of modern seismic codes allow inelastic response in case of severe earthquakes and thus, in most traditional systems, damage develops at well-defined locations of reinforced concrete (RC) structures, known as plastic hinges. The 2010 and 2011 Christchurch earthquakes have demonstrated that this philosophy worked as expected. Plastic hinges formed in beams, in coupling beams and at the base of columns and walls. Structures were damaged permanently, but did not collapse. The 2010 and 2011 Christchurch earthquakes also highlighted a critical issue: the reparability of damaged buildings. No methodologies or techniques were available to estimate the level of subsequent earthquakes that RC buildings could still sustain before collapse. No repair techniques capable of restoring the initial condition of buildings were known. Finally, the cost-effectiveness of an eventual repair intervention, when compared with a new building, was unknown. These aspects, added to nuances of New Zealand building owners’ insurance coverage, encouraged the demolition of many buildings. Moreover, there was a perceived strong demand from government and industry to develop techniques for assessing damage to steel reinforcement bars embedded in cracked structural concrete elements. The most common questions were: “Have the steel bars been damaged in correspondence to the concrete cracks?”, “How much plastic deformation have the steel bars undergone?”, and “What is the residual strain capacity of the damaged bars?” Minimally invasive techniques capable of quantifying the level and extent of plastic deformation and residual strain capacity are not yet available. Although some studies had been recently conducted, a validated method is yet to be widely accepted. In this thesis, a least-invasive method for the damage-assessment of steel reinforcement is developed. Based on the information obtained from hardness testing and a single tensile test, it is possible to estimate the mechanical properties of earthquake-damaged rebars. The reduction in the low-cycle fatigue life due to strain ageing is also quantified. The proposed damage assessment methodology is based on empirical relationships between hardness and strain and residual strain capacity. If damage is suspected from in situ measurements, visual inspection or computer analysis, a bar may be removed and more accurate hardness measurements can be obtained using the lab-based Vickers hardness methodology. The Vickers hardness profile of damaged bars is then compared with calibration curves (Vickers hardness versus strain and residual strain capacity) previously developed for similar steel reinforcement bars extracted from undamaged locations. Experimental tests demonstrated that the time- and temperature-dependent strain-ageing phenomenon causes changes in the mechanical properties of plastically deformed steels. In particular, yield strength and hardness increases, whereas ductility decreases. The changes in mechanical properties are quantified and their implications on the hardness method are highlighted. Low-cycle fatigue (LCF) failures of steel reinforcing bars have been observed in laboratory testing and post-earthquake damage inspections. Often, failure might not occur during a first seismic event. However, damage is accumulated and the remaining fatigue life is reduced. Failure might therefore occur in a subsequent seismic event. Although numerous studies exist on the LCF behaviour of steel rebars, no studies had been conducted on the strain-ageing effects on the remaining fatigue life. In this thesis, the reduction in fatigue life due to this phenomenon is determined through a number of experimental tests.

Research papers, University of Canterbury Library

In the last century, seismic design has undergone significant advancements. Starting from the initial concept of designing structures to perform elastically during an earthquake, the modern seismic design philosophy allows structures to respond to ground excitations in an inelastic manner, thereby allowing damage in earthquakes that are significantly less intense than the largest possible ground motion at the site of the structure. Current performance-based multi-objective seismic design methods aim to ensure life-safety in large and rare earthquakes, and to limit structural damage in frequent and moderate earthquakes. As a result, not many recently built buildings have collapsed and very few people have been killed in 21st century buildings even in large earthquakes. Nevertheless, the financial losses to the community arising from damage and downtime in these earthquakes have been unacceptably high (for example; reported to be in excess of 40 billion dollars in the recent Canterbury earthquakes). In the aftermath of the huge financial losses incurred in recent earthquakes, public has unabashedly shown their dissatisfaction over the seismic performance of the built infrastructure. As the current capacity design based seismic design approach relies on inelastic response (i.e. ductility) in pre-identified plastic hinges, it encourages structures to damage (and inadvertently to incur loss in the form of repair and downtime). It has now been widely accepted that while designing ductile structural systems according to the modern seismic design concept can largely ensure life-safety during earthquakes, this also causes buildings to undergo substantial damage (and significant financial loss) in moderate earthquakes. In a quest to match the seismic design objectives with public expectations, researchers are exploring how financial loss can be brought into the decision making process of seismic design. This has facilitated conceptual development of loss optimisation seismic design (LOSD), which involves estimating likely financial losses in design level earthquakes and comparing against acceptable levels of loss to make design decisions (Dhakal 2010a). Adoption of loss based approach in seismic design standards will be a big paradigm shift in earthquake engineering, but it is still a long term dream as the quantification of the interrelationships between earthquake intensity, engineering demand parameters, damage measures, and different forms of losses for different types of buildings (and more importantly the simplification of the interrelationship into design friendly forms) will require a long time. Dissecting the cost of modern buildings suggests that the structural components constitute only a minor portion of the total building cost (Taghavi and Miranda 2003). Moreover, recent research on seismic loss assessment has shown that the damage to non-structural elements and building contents contribute dominantly to the total building loss (Bradley et. al. 2009). In an earthquake, buildings can incur losses of three different forms (damage, downtime, and death/injury commonly referred as 3Ds); but all three forms of seismic loss can be expressed in terms of dollars. It is also obvious that the latter two loss forms (i.e. downtime and death/injury) are related to the extent of damage; which, in a building, will not just be constrained to the load bearing (i.e. structural) elements. As observed in recent earthquakes, even the secondary building components (such as ceilings, partitions, facades, windows parapets, chimneys, canopies) and contents can undergo substantial damage, which can lead to all three forms of loss (Dhakal 2010b). Hence, if financial losses are to be minimised during earthquakes, not only the structural systems, but also the non-structural elements (such as partitions, ceilings, glazing, windows etc.) should be designed for earthquake resistance, and valuable contents should be protected against damage during earthquakes. Several innovative building technologies have been (and are being) developed to reduce building damage during earthquakes (Buchanan et. al. 2011). Most of these developments are aimed at reducing damage to the buildings’ structural systems without due attention to their effects on non-structural systems and building contents. For example, the PRESSS system or Damage Avoidance Design concept aims to enable a building’s structural system to meet the required displacement demand by rocking without the structural elements having to deform inelastically; thereby avoiding damage to these elements. However, as this concept does not necessarily reduce the interstory drift or floor acceleration demands, the damage to non-structural elements and contents can still be high. Similarly, the concept of externally bracing/damping building frames reduces the drift demand (and consequently reduces the structural damage and drift sensitive non-structural damage). Nevertheless, the acceleration sensitive non-structural elements and contents will still be very vulnerable to damage as the floor accelerations are not reduced (arguably increased). Therefore, these concepts may not be able to substantially reduce the total financial losses in all types of buildings. Among the emerging building technologies, base isolation looks very promising as it seems to reduce both inter-storey drifts and floor accelerations, thereby reducing the damage to the structural/non-structural components of a building and its contents. Undoubtedly, a base isolated building will incur substantially reduced loss of all three forms (dollars, downtime, death/injury), even during severe earthquakes. However, base isolating a building or applying any other beneficial technology may incur additional initial costs. In order to provide incentives for builders/owners to adopt these loss-minimising technologies, real-estate and insurance industries will have to acknowledge the reduced risk posed by (and enhanced resilience of) such buildings in setting their rental/sale prices and insurance premiums.

Images, Alexander Turnbull Library

'The Politician' cartoon strip. A member of the government staff reads in a newspaper 'These emergency powers they've given the minister are the equivalent of war powers' and he adds 'and he's making the most of them!' The second frame shows a minister wearing a military uniform with cap that includes copious braiding and medals; he is sitting behind a desk labelled 'Minister General'. Context - Canterbury Earthquake Recovery Authority (CERA) will be established as a stand-alone government department to enable an effective, timely and co-ordinated rebuilding and recovery effort in Canterbury. The controversial bill empowers the new Canterbury Earthquake Recovery Authority (Cera) to take control of councils it believes are failing on reconstruction work. Quantity: 1 digital cartoon(s).

Images, Alexander Turnbull Library

Shows a shamrock superimposed on the city of Christchurch. It represents the green zone. Context: Probably refers to the zoning review process for those insured residential property owners who wish to query their land zoning. Zoning of flat land in greater Christchurch began in June last year and was completed last month. Over that period 7253 properties were zoned red as unsuitable for residential occupation due to significant earthquake damage; while a further 180,000 properties were zoned green as suitable for residential occupation, some with conditions. (rebuildchristchurch, 15 June 2012) Quantity: 1 digital cartoon(s).

Research papers, University of Canterbury Library

On 22 February 2011, Ōtautahi Christchurch was struck by a devastating earthquake. The city was changed forever: lives were lost, buildings destroyed and much of the city’s infrastructure needed to be repaired or replaced. One of the unexpected outcomes of the process of recovery was the volume of archaeological work that was carried out in the city, including the substantial amount of buildings archaeology that was undertaken (that is, recording standing buildings prior to and during their demolition, using archaeological techniques). Amongst the numerous buildings recorded in this way were 101 houses from across the city (but concentrated in those areas hit hardest by the earthquakes), built between 1850 and 1900. This work yielded a wealth of data about what houses in the city looked like in the nineteenth century. It is this data that forms the core of my thesis, providing an opportunity to examine the question of what life was like in nineteenth century Christchurch through these houses and the people who built them. Christchurch was founded in 1850 by European settlers, most of whom were English. These people came to New Zealand to build a better life for themselves and their families. For many of them, this ‘better life’ included the possibility of owning their own home and, in some instances, building that house (or at least, commissioning its construction). The buildings archaeology data collected following the Canterbury earthquakes enabled a detailed analysis of what houses in the city looked like in the nineteenth century – their form, and both their external and internal appearance – and how this changed as the century progressed. A detailed examination of the lives of those who built 21 of the houses enabled me to understand why each house looked the way it did, and how the interplay of class, budget and family size and expectations (amongst other factors) shaped each house. It is through these life stories that more about life in Christchurch in the nineteenth century was revealed. These are stories of men and women, of success and failure, of businesses and bankruptcies. There are themes that run through the stories: class, appearances, death, religion, gender, improvement. Just as importantly, though, they reveal the everyday experiences of people as they set about building a new city. Thus, through the archaeology of the houses and the history of the people who built them, an earthquake has revealed more about life in nineteenth century Christchurch, as well as providing the means for a deeper understanding of the city’s domestic architecture.

Research papers, University of Canterbury Library

Earthquake Engineering is facing an extraordinarily challenging era, the ultimate target being set at increasingly higher levels by the demanding expectations of our modern society. The renewed challenge is to be able to provide low-cost, thus more widely affordable, high-seismic-performance structures capable of sustaining a design level earthquake with limited or negligible damage, minimum disruption of business (downtime) or, in more general terms, controllable socio-economical losses. The Canterbury earthquakes sequence in 2010-2011 has represented a tough reality check, confirming the current mismatch between societal expectations over the reality of seismic performance of modern buildings. In general, albeit with some unfortunate exceptions, modern multi-storey buildings performed as expected from a technical point of view, in particular when considering the intensity of the shaking (higher than new code design) they were subjected to. As per capacity design principles, plastic hinges formed in discrete regions, allowing the buildings to sway and stand and people to evacuate. Nevertheless, in many cases, these buildings were deemed too expensive to be repaired and were consequently demolished. Targeting life-safety is arguably not enough for our modern society, at least when dealing with new building construction. A paradigm shift towards damage-control design philosophy and technologies is urgently required. This paper and the associated presentation will discuss motivations, issues and, more importantly, cost-effective engineering solutions to design buildings capable of sustaining low-level of damage and thus limited business interruption after a design level earthquake. Focus will be given to the extensive research and developments in jointed ductile connections based upon controlled rocking & dissipating mechanisms for either reinforced concrete and, more recently, laminated timber structures. An overview of recent on-site applications of such systems, featuring some of the latest technical solutions developed in the laboratory and including proposals for the rebuild of Christchurch, will be provided as successful examples of practical implementation of performance-based seismic design theory and technology.

Research papers, University of Canterbury Library

Field surveys and experimental studies have shown that light steel or timber framed plasterboard partition walls are particularly vulnerable to earthquake damage prompting the overarching objective of this research, which is to further the development of low damage seismic systems for non-structural partition walls in order to facilitate their adoption by industry to assist with reducing the losses associated with the maintenance and repair cost of buildings across their design life. In particular, this study focused on the behaviour of steel-framed partition walls systems with novel detailing that aim to be “low-damage” designed according to common practice for walls used in commercial and institutional buildings in New Zealand. This objective was investigated by (1) investigating the performance of a flexible track system proposed by researchers and industry by experimental testing of full-scale specimens; (2) investigating the performance of the seismic gap partition wall systems proposed in a number of studies, further developed in this study with input from industry, by experimental testing of full-scale specimens; and (3) investigating the potential implications of using these systems compared with traditionally detailed partition wall systems within multi-storey buildings using the Performance Based Earthquake Engineering loss assessment methodology. Three full-scale testing frames were designed in order to replicate, under controlled laboratory conditions, the effects of seismic shaking on partition walls within multi-storey buildings by the application of quasi-static uni-directional cyclic loading imposing an inter-storey drift. The typical configuration for test specimens was selected to be a unique “y-shape”, including one angled return wall, with typical dimensions of approximately 2400 mm along the main wall and 600 mm along (approximately) the returns walls with a height of 2405 mm from floor to ceiling. The specimens were aligned within test frames at an oblique angle to the direction of loading in order to investigate bi- directional effects. Three wall specimens with flexible track detailing, two identical plane specimens and the third including a doorway, were tested. The detailing involved removing top track anchors within the proximity of wall intersections, thus allowing the tracks to ‘bow’ out at these locations. Although the top track anchors were specified to be removed the proximity of wall intersections, a construction error was made whereby a single top track slab to concrete anchor was left in at the three-way wall junction. Despite this error, the experimental testing was deemed worthwhile since such errors will also occur in practice and because the behaviour of the wall can be examined with this fixing in mind. The specimens also included an acoustic/fire sealant at the top lining to floor boundary. In addition to providing drift capacities, the force-displacement behaviour is also reported, the dissipated energy was computed, and the parameters of the Wayne-Stewart hysteretic model were fitted to the results. The specimen with the door opening behaved significantly different to the plane specimens: damage to the doorway specimen began as cracking of the wallboard propagating from the corners of the doorway following which the L- and Y- shaped junctions behaved independently, whereas damage to the plane specimens began as cracking of the wallboard at the top of the L-junction and wall system deformed as a single unit. The results suggest that bi-directional behaviour is important even if its impact cannot be directly quantified by the experiments conducted. Damage to sealant implies that the bond between plasterboard and sealant is important for its seismic performance. Careful quality control is advised as defects in the bond may significantly impact its ability to withstand seismic movement. Two specimens with seismic gap detailing were tested: a steel stud specimen and a timber stud specimen. Observed drift capacities were significantly greater than traditional plasterboard partition systems. Equations were used to predict the drift at which damage state 1 (DS1) and damage state 2 (DS2) would initiate. The equation used to estimate the drift at the onset of DS1 accurately predicted the onset of plaster cracking but overestimated the drift at which the gap filling material was damaged. The equation used to predict the onset of DS2 provided a lower bound for both specimens and also when used to predict results of previous experimental tests on seismic gap systems. The gap-filling material reduced the drift at the onset of DS1, however, it had a beneficial effect on the re-centring behaviour of the linings. Out-of-plane displacements and return wall configuration did not appear to significantly impact the onset of plaster cracking in the specimens. A loss assessment according to the PBEE methodology was conducted on four steel MRF case study buildings: (1) a 4-storey building designed for the Christchurch region, (2) a 4-storey building designed for the Wellington region, (3) a 12-storey building designed for the Christchurch region, and (4) a 12- storey building designed for the Wellington region. The fragility parameters for a traditional partition system, the flexible track partition system, and the seismic gap steel stud and timber stud partition systems were included within the loss assessment. The order (lowest to highest) of each system in terms of the expected annual losses of each building when incorporating the system was, (1) the seismic gap timber stud system, (2) the seismic gap steel stud system, (3) the traditional/baseline system, and (4) the flexible track system. For the seismic gap timber stud system, which incurred the greatest reduction in expected annual losses for each case study building, the reduction in expected annual losses in comparison to the losses found when using the traditional system ranged from a 5% to a 30% reduction. This reinforces the fact that while there is a benefit to the using low damage partition systems in each building the extent of reduction in expected annual losses is significantly dependent on the particular building design and its location. The flexible track specimens had larger repair costs at small hazard levels compared to the traditional system but smaller repair costs at larger hazard levels. However, the resulting expected annual losses for the flexible track system was higher than the traditional system which reinforces findings from past studies which observed that the greatest contribution to expected annual losses arises from low to moderate intensity shaking seismic events (low hazard levels).

Images, Alexander Turnbull Library

Text at top left reads 'Earthquake... aftershock... or "new event"... one thing remains constant...' Below is a snail with 'EQC payments' printed on its shell. Context - This is a reference to the problems that Christchurch people are having in getting payments from the EQC (Earthquake Commission) Disgruntled tradespeople who are owed hundreds of thousands of dollars by EQC are considering legal action. Remaining unpaid can mean that companies may have to consider laying people off. The Amalgamated Workers Union says delays in EQC payments for housing repair work in quake-hit Christchurch are building to a crisis point. Two versions of this cartoon are available Quantity: 2 digital cartoon(s).