Low Damage Seismic Design (LDSD) guidance material being developed by Engineering NZ is considering a design drift limit for multi-storey buildings of 0.5% at a new damage control limit state (DCLS). The impact of this new design requirement on the expected annual loss due to repair costs is investigated for a four-storey office building with reinforced concrete walls located in Christchurch. The LDSD guidance material aims to reduce the expected annual loss of complying buildings to below 0.1% of building replacement cost. The research tested this expectation. Losses were estimated in accordance with FEMA P58, using building responses from non-linear time history analyses (performed with OpenSees using lumped plasticity models). The equivalent static method, in line with NZS 1170.5 and NZS 3101, was used to design the building to LDSD specifications, representing a future state-of-practice design. The building designed to low-damage specification returned an expected annual loss of 0.10%, and the building designed conventionally returned an expected annual loss of 0.13%. Limitations with the NZS 3101 method for determining wall stiffness were identified, and a different method acknowledging the relationship between strength and stiffness was used to redesign the building. Along with improving this design assumption, the study finds that LDSD design criteria could be an effective way of limiting damage and losses.
For some people, religion, spirituality and faith (RSF) serves an important function, helping them deal with difficult everyday life challenges. This qualitative ethnographic study examines how and in what ways a group of Cantabrians engaged with RSF in dealing with diverse forms of significant trauma – from moments of crisis through to more extended processes of recovery. The research is located within the context of post-earthquake Christchurch, and is based on fieldwork undertaken in 2012–2013. It explores the experiences of respondents representing traditional Christian and non-orthodox, non-Christian faith paths. The thesis draws on data from participant stories to emphasise the subjective experience of RSF and trauma. It argues that in times of crisis, some people draw on RSF to help them address difficult life challenges. The study demonstrates the breadth, diversity and significance of such resourcing, as well as the sometimes surprising, unanticipated forms that this engagement with RSF may take. Contrary to theories that emphasise the marginalisation of religion during times of intense distress, the thesis shows that in varying moments of crisis, people for whom RSF is important, may draw on diverse forms of RSF as a matter of priority to help them.
Little is known about The Wizard of New Zealand who took centre stage in Christchurch's Cathedral Square from the 70s until the Christchurch earthquakes in 2011, which saw the city in a state of disrepair. A man who challenged political, social and cultural ideology, The Wizard posed provocative questions in this public space, much to the delight, and sometimes dismay, of passersby. But the background to why The Wizard was there in the first place has been something of a mystery... until now. Sonia Yee finds out more in this episode of Eyewitness.
Advanced seismic effective-stress analysis is used to scrutinize the liquefaction performance of 55 well-documented case-history sites from Christchurch. The performance of these sites during the 2010-2011 Canterbury earthquake sequence varied significantly, from no liquefaction manifestation at the ground surface (in any of the major events) to severe liquefaction manifestation in multiple events. For the majority of the 55 sites, the simplified liquefaction evaluation procedures, which are conventionally used in engineering practice, could not explain these dramatic differences in the manifestation. Detailed geotechnical characterization and subsequent examination of the soil profile characteristics of the 55 sites identified some similarities but also important differences between sites that manifested liquefaction in the two major events of the sequence (YY-sites) and sites that did not manifest liquefaction in either event (NN-sites). In particular, while the YY-sites and NN-sites are shown to have practically identical critical layer characteristics, they have significant differences with regard to their deposit characteristics including the thickness and vertical continuity of their critical zones and liquefiable materials. A CPT-based effective stress analysis procedure is developed and implemented for the analyses of the 55 case history sites. Key features of this procedure are that, on the one hand, it can be fully automated in a programming environment and, on the other hand, it is directly equivalent (in the definition of cyclic resistance and required input data) to the CPT-based simplified liquefaction evaluation procedures. These features facilitate significantly the application of effective-stress analysis for simple 1D free-field soil-column problems and also provide a basis for rigorous comparisons of the outcomes of effective-stress analyses and simplified procedures. Input motions for the analyses are derived using selected (reference) recordings from the two major events of the 2010-2011 Canterbury earthquake sequence. A step-by-step procedure for the selection of representative reference motions for each site and their subsequent treatment (i.e. deconvolution and scaling) is presented. The focus of the proposed procedure is to address key aspects of spatial variability of ground motion in the near-source region of an earthquake including extended-source effects, path effects, and variation in the deeper regional geology.
Observations of out-of-plane (OOP) instability in the 2010 Chile earthquake and in the 2011 Christchurch earthquake resulted in concerns about the current design provisions of structural walls. This mode of failure was previously observed in the experimental response of some wall specimens subjected to in-plane loading. Therefore, the postulations proposed for prediction of the limit states corresponding to OOP instability of rectangular walls are generally based on stability analysis under in-plane loading only. These approaches address stability of a cracked wall section when subjected to compression, thereby considering the level of residual strain developed in the reinforcement as the parameter that prevents timely crack closure of the wall section and induces stability failure. The New Zealand code requirements addressing the OOP instability of structural walls are based on the assumptions used in the literature and the analytical methods proposed for mathematical determination of the critical strain values. In this study, a parametric study is conducted using a numerical model capable of simulating OOP instability of rectangular walls to evaluate sensitivity of the OOP response of rectangular walls to variation of different parameters identified to be governing this failure mechanism. The effects of wall slenderness (unsupported height-to-thickness) ratio, longitudinal reinforcement ratio of the boundary regions and length on the OOP response of walls are evaluated. A clear trend was observed regarding the influence of these parameters on the initiation of OOP displacement, based on which simple equations are proposed for prediction of OOP instability in rectangular walls.
A prominent Christchurch property investor says the Government's anchor projects meant to help rebuild the city faster, has instead slowed it down.
After the 2011 earthquake, the Government launched a recovery plan for the CBD, which had 16 anchor projects designed to spur on the rebuild.
However, many have been plagued by delays and are still unfinished.
Property investor Antony Gough told RNZ reporter Anan Zaki that unlike the Government, it was the private sector which ploughed ahead with the rebuild.
The whare whakairo or traditional Māori meeting house plays an important part in Māori society and identity. These whare tell the tale of their origin, and in so doing, the origins of their people. The analysis of the meeting house, the histories expressed in its decorative carvings and structural elements are inextricably linked with and dependent upon the structure of the world created by myth and the Māori worldview. However, due to the deleterious effects of colonisation, the art of wood carving and associated architectural practices - central to Māori identity, suffered decline in many parts of the country, leading to the decline of Māori culture and identity. Sir Apirana Ngata instigated the National Institute of Māori Arts and Crafts to resurrect the dying art of Māori carving and carved houses would be a catalyst for the restoration of Māori culture throughout the country. Ngata saw these whare whakairo as being the heart of Māori communities by establishing a renewed sense of belonging and identification with space for Māori, through the telling of tribal histories and emphasising key geographical features. New threats in the form of global hegemony and urbanisation have further impacted on Māori notions of identity, creating a generation of displaced urban Māori youth. This research proposes to establish an architectural response to capture displaced Māori youth through the resurrection of the Māori carving school and return to them the lost stories of their cultural history and identity. This program will be developed within the complex challenges that exist within post-earthquake Ōtautahi/Christchurch, where many have lost homes and livelihoods, especially Māori youth in the Eastern Suburbs. The building elements of the proposed Māori carving school give reference to the historio-cultural features of the original Ōtautahi/Christchurch landscape that are situated in tribal song and myth. It is envisioned that the development of a Māori carving school will help restore Māori identity and a renewed sense of belonging, and allow for the telling of this generations stories through traditional narratives.
In response to the February 2011 earthquake, Parliament enacted the Canterbury Earthquake Recovery Act. This emergency legislation provided the executive with extreme powers that extended well beyond the initial emergency response and into the recovery phase. Although New Zealand has the Civil Defence Emergency Management Act 2002, it was unable to cope with the scale and intensity of the Canterbury earthquake sequence. Considering the well-known geological risk facing the Wellington region, this paper will consider whether a standalone “Disaster Recovery Act” should be established to separate an emergency and its response from the recovery phase. Currently, Government policy is to respond reactively to a disaster rather than proactively. In a major event, this typically involves the executive being given the ability to make rules, regulations and policy without the delay or oversight of normal legislative process. In the first part of this paper, I will canvas what a “Disaster Recovery Act” could prescribe and why there is a need to separate recovery from emergency. Secondly, I will consider the shortfalls in the current civil defence recovery framework which necessitates this kind of heavy governmental response after a disaster. In the final section, I will examine how
Brooklands Lagoon / Te Riu o Te Aika Kawa (‘Brooklands’) is an important wetland and estuarine ecosystem in Canterbury. It is a site of cultural significance to Ngāi Tūāhuriri, and is also valued by the wider community. Home to an array of life, it is connected to the Pūharakekenui/Styx and Waimakariri rivers, and is part of a wetland landscape complex that includes the Avon-Heathcote / Ihutai estuary to the south and the Ashley / Rakahuri estuary to the north. Notionally situated within the territorial boundary of Christchurch City Council and jurisdictionally encompassed by the regional council Environment Canterbury, it has been legally determined to be part of the coastal marine area. The complicated administrative arrangements for the lagoon mirror the biophysical and human challenges to this surprisingly young ecosystem since its formation in 1940.
Here we present a synthesis of the historical events and environmental influences that have shaped Brooklands Lagoon. Before existing as an intertidal ecosystem, the Waimakariri river mouth was situated in what is now the southern end of the lagoon. A summary timeline of key events is set out in the table below. These included the diversion of the Waimakariri River mouth via the construction of Wrights Cut in the 1930s, which influenced the way that the lower reaches of the river interacted with the land and sea. A large flood in 1940 shifted the river mouth ~2 to 3 kilometres north, that created the landscape that we see today. However, this has not remained stable, as the earthquake sequence in 2010 and 2011 subsided the bed of the estuary.
The changes are ongoing, as sea level rise and coastal inundation will place ongoing pressure on the aquatic ecosystem and surrounding land. How to provide accommodation space for Brooklands as an estuary will be a key planning and community challenge, as Environment Canterbury begins the engagement for the review of its Regional Coastal Plan. There is also a requirement to safeguard its ecological health under the 2020 National Policy Statement on Freshwater Management. This will necessitate an integrated mountains to sea (ki uta ki tai) management approach as the lagoon is affected by wider catchment activities. We hope that this report will contribute to, and inform these processes by providing a comprehensive historical synthesis, and by identifying considerations for the future collaborative management of Brooklands Lagoon, and protection of its values. In essence, we suggest that Te Riu o Te Aika Kawa deserves some sustained aroha.
The recent instances of seismic activity in Canterbury (2010/11) and Kaikōura (2016) in New Zealand have exposed an unexpected level of damage to non-structural components, such as buried pipelines and building envelope systems. The cost of broken buried infrastructure, such as pipeline systems, to the Christchurch Council was excessive, as was the cost of repairing building envelopes to building owners in both Christchurch and Wellington (due to the Kaikōura earthquake), which indicates there are problems with compliance pathways for both of these systems. Councils rely on product testing and robust engineering design practices to provide compliance certification on the suitability of product systems, while asset and building owners rely on the compliance as proof of an acceptable design. In addition, forensic engineers and lifeline analysts rely on the same product testing and design techniques to analyse earthquake-related failures or predict future outcomes pre-earthquake, respectively. The aim of this research was to record the actual field-observed damage from the Canterbury and Kaikōura earthquakes of seismic damage to buried pipeline and building envelope systems, develop suitable testing protocols to be able to test the systems’ seismic resilience, and produce prediction design tools that deliver results that reflect the collected field observations with better accuracy than the present tools used by forensic engineers and lifeline analysts. The main research chapters of this thesis comprise of four publications that describe the gathering of seismic damage to pipes (Publication 1 of 4) and building envelopes (Publication 2 of 4). Experimental testing and the development of prediction design tools for both systems are described in Publications 3 and 4. The field observation (discussed in Publication 1 of 4) revealed that segmented pipe joints, such as those used in thick-walled PVC pipes, were particularly unsatisfactory with respect to the joint’s seismic resilience capabilities. Once the joint was damaged, silt and other deleterious material were able to penetrate the pipeline, causing blockages and the shutdown of key infrastructure services. At present, the governing Standards for PVC pipes are AS/NZS 1477 (pressure systems) and AS/NZS 1260 (gravity systems), which do not include a protocol for evaluating the PVC pipes for joint seismic resilience. Testing methodologies were designed to test a PVC pipe joint under various different simultaneously applied axial and transverse loads (discussed in Publication 3 of 4). The goal of the laboratory experiment was to establish an easy to apply testing protocol that could fill the void in the mentioned standards and produce boundary data that could be used to develop a design tool that could predict the observed failures given site-specific conditions surrounding the pipe. A tremendous amount of building envelope glazing system damage was recorded in the CBDs of both Christchurch and Wellington, which included gasket dislodgement, cracked glazing, and dislodged glazing. The observational research (Publication 2 of 4) concluded that the glazing systems were a good indication of building envelope damage as the glazing had consistent breaking characteristics, like a ballistic fuse used in forensic blast analysis. The compliance testing protocol recognised in the New Zealand Building Code, Verification Method E2/VM1, relies on the testing method from the Standard AS/NZS 4284 and stipulates the inclusion of typical penetrations, such as glazing systems, to be included in the test specimen. Some of the building envelope systems that failed in the recent New Zealand earthquakes were assessed with glazing systems using either the AS/NZS 4284 or E2/VM1 methods and still failed unexpectedly, which suggests that improvements to the testing protocols are required. An experiment was designed to mimic the observed earthquake damage using bi-directional loading (discussed in Publication 4 of 4) and to identify improvements to the current testing protocol. In a similar way to pipes, the observational and test data was then used to develop a design prediction tool. For both pipes (Publication 3 of 4) and glazing systems (Publication 4 of 4), experimentation suggests that modifying the existing testing Standards would yield more realistic earthquake damage results. The research indicates that including a specific joint testing regime for pipes and positioning the glazing system in a specific location in the specimen would improve the relevant Standards with respect to seismic resilience of these systems. Improving seismic resilience in pipe joints and glazing systems would improve existing Council compliance pathways, which would potentially reduce the liability of damage claims against the government after an earthquake event. The developed design prediction tool, for both pipe and glazing systems, uses local data specific to the system being scrutinised, such as local geology, dimensional characteristics of the system, actual or predicted peak ground accelerations (both vertically and horizontally) and results of product-specific bi-directional testing. The design prediction tools would improve the accuracy of existing techniques used by forensic engineers examining the cause of failure after an earthquake and for lifeline analysts examining predictive earthquake damage scenarios.
Today RNZ's Midday supervising producer, Denise Garland, looks at two brand new podcasts. Collapse is a podcast from Stuff, all about the Christchurch earthquakes in the lead up the to 10th anniversary of the devastating quake on February 22nd. She also looks at NZ Wars - Stories of Tainui from RNZ which over the three episodes covers the war of Waikato in the 1860s, the great war for New Zealand, a defining conflict of New Zealand.
As cities evolve, change and grow, the need and desire for adaptable architecture becomes evident across the nation. Architecture needs to undertake techniques that are flexible in order to adapt and align with the development of future generations in New Zealand. The Education industry is a primary example of a sector which requires flexibility within both classroom architectural form and interior configuration. This is a resultant of the recently updated Ministry of Education requirements; which state that every new classroom built or renovated nationwide, must implement the MoE classroom design standards for Innovative Learning Environments. ILE teaching spaces are configured as an open plan interior, supporting flexibility in classroom arrangement and teaching techniques. ILE classrooms are capable of evolving and adapting as educational practices evolve and change, allowing schools to remain modern and future focused. As part of this movement to ILE, the Ministry of Education has also recently made an attempt to improve the quality of temporary classrooms. This has been done by looking into the initiation of a programme that utilizes relocatable classroom buildings. Relocatable classrooms have been selected for multiple reasons, primarily flexibility. Flexibility is key for a school environment as it allows the school to actively respond to fluctuating school rolls. It is anticipated that the programme will provide a faster delivery process with a standardised design that allows the classrooms to be relocated from one school to another with relative ease. Following the devastating February 2011 earthquake the Greater Christchurch Region, the Education sector is in the midst of the Canterbury Schools Rebuild Programme. As a repercussion of this natural disaster, the majority of Christchurch schools have redevelopment or rebuild projects in progress, with preliminary design phases already in action for a small group of select schools regarded as high priority. The primary funding for these projects are sourced from insurance money, implementing tight budget restrictions, affecting the architectural design, quality and speed of the construction and repair works. The available funding limits the affordable classroom options to basic teaching spaces that have been stripped back to simple architectural forms, dictating not only the re-design, but also how our future generations will learn. Thus causing the development of the new student-led learning ILE concept to become controlled by existing construction techniques and the Rebuild Programmes budget restrictions. This thesis focuses on the future proofing of New Zealand schools by providing an affordable and time efficient alternative option to the current static, traditional construction, an option that has the ability to cater to the unpredictable fluctuating school rolls across the nation. This has been done by developing a prefabricated system for standalone classroom blocks. These blocks have the ability to be relocated between different school sites, dynamically catering to the unpredictable school roll numbers experienced across New Zealand. This site flexibility is reflected with the interior flexibility in the classrooms, enhancing the internal teaching space composition and challenges the existing design standards set by the Ministry of Education for Innovative Learning Environments. This system is called “Flexi-Ed”. Flexibility has been a key driver for this thesis, as the prefabricated structure is have to be flexible in three ways; first in the sense of being easy to assemble and disassemble. Second by offering flexible interior learning environments and thirdly the joints of the structure are designed with the ability to be flexible in order to cope with seismic activity. These three principles will provide schools with long term flexibility, minimal on-site interruption and heighten the standard of ILE across the nation. I strive to provide schools with long term flexibility and minimal site interruption, whilst heightening the standard of Innovative Learning Environments across New Zealand.
RNZ is launching a new podcast today marking the tenth anniversary of Christchurch earthquake.
It's called Fragments: Firsthand accounts of the February 2011 earthquakes.
The podcast features interviews done with quake survivors recorded in the months following the devastating earthquake recorded by locals Julie Hutton and Sandra Close.
RNZ checked in with some of the people Hutton and Close spoke to ten years on from the disaster.
Katy Gosset produced and presented the podcast.
An earlier version of this article failed to reference the work from Julie Hutton and Sandra Close.
The last seven years have seen southern New Zealand a ected by several large and damaging earthquakes: the moment magnitude (MW) 7.8 Dusky Sound earthquake on 15 July 2009, the MW 7.1 Dar eld (Canterbury) earthquake on 4 September 2010, and most notably the MW 6.2 Christchurch earthquake on 22 February 2011 and the protracted aftershock sequence. In this thesis, we address the postseismic displacement produced by these earthquakes using methods of satellite-based geodetic measurement, known as Interferometric Synthetic Aperture Radar (InSAR) and Global Positioning System (GPS), and computational modelling. We observe several ground displacement features in the Canterbury and Fiordland regions during three periods: 1) Following the Dusky Sound earthquake; 2) Following the Dar eld earthquake and prior to the Christchurch earthquake; and 3) Following the Christchurch earthquake until February 2015. The ground displacement associated with postseismic motion following the Dusky Sound earthquake has been measured by continuous and campaign GPS data acquired in August 2009, in conjunction with Di erential Interferometric Synthetic Aperture Radar (DInSAR) observations. We use an afterslip model, estimated by temporal inversion of geodetic data, with combined viscoelastic rebound model to account for the observed spatio-temporal patterns of displacement. The two postseismic processes together induce a signi cant displacement corresponding to principal extensional and contractual strain rates of the order of 10⁻⁷ and 10⁻⁸ yr⁻¹ respectively, across most of the southern South Island. We also analyse observed postseismic displacement following the Dusky Sound earthquake using a new inversion approach in order to describe afterslip in an elasticviscoelastic medium. We develop a mathematical framework, namely the "Iterative Decoupling of Afterslip and Viscoelastic rebound (IDAV)" method, with which to invert temporally dense and spatially sparse geodetic observations. We examine the IDAV method using both numerical and analytical simulations of Green's functions. For the post-Dar eld time interval, postseismic signals are measured within approximately one month of the mainshock. The dataset used for the post-Dar eld displacement spans the region surrounding previously unrecognised faults that ruptured during the mainshock. Poroelastic rebound in a multi-layered half-space and dilatancy recovery at shallow depths provide a satisfactory t with the observations. For the post-Christchurch interval, campaign GPS data acquired in February 2012 to February 2015 in four successive epochs and 66 TerraSAR-X (TSX) SAR acquisitions in descending orbits between March 2011 and May 2014 reveal approximately three years of postseismic displacement. We detect movement away from the satellite of ~ 3 mm/yr in Christchurch and a gradient of displacement of ~ 4 mm/yr across a lineament extending from the westernmost end of the Western Christchurch Fault towards the eastern end of the Greendale East Fault. The postseismic signals following the Christchurch earthquake are mainly accounted for by afterslip models on the subsurface lineament and nearby faults.
These research papers explore the concept of vulnerability in international human rights law. In the wake of the Christchurch earthquakes of 2010-2011, this research focuses on how "vulnerability" has been used and developed within the wider human rights discourse. They also examine jurisprudence of international human rights bodies, and how the concept of "vulnerability" has been applied. The research also includes a brief investigation into the experiences of vulnerable populations in disaster contexts, focusing primarily on the experiences of "vulnerable persons" in the Christchurch earthquakes and their aftermath.
Following devastating earthquakes in 2010 and 2011 in Christchurch, there is an opportunity to use sustainable urban design variables to redevelop the central city in order to address climate change concerns and reduce CO₂ emissions from land transport. Literature from a variety of disciplines establishes that four sustainable urban design variables; increased density, mixed-use development, street layout and city design, and the provision of sustainable public transport, can reduce car dependency and vehicle kilometres travelled within urban populations- widely regarded as indicators of the negative environmental effects of transport. The key question for the research is; to what extent has this opportunity been seized by NZ’s Central Government who are overseeing the central city redevelopment? In order to explore this question the redevelopment plans for the central city of Christchurch are evaluated against an adapted urban design matrix to determine whether a reduction in CO₂ emissions from land transport is likely to be achieved through their implementation. Data obtained through interviews with experts is used to further explore the extent to which sustainable urban design variables can be employed to enhance sustainability and reduce CO₂ emissions. The analysis of this data shows that the four urban design variables will feature in the Central Government’s redevelopment plans although the extent to which they are employed and their likely success in reducing CO₂ emissions will vary. Ultimately, the opportunity to redevelop the central city of Christchurch to reduce CO₂ emissions from land transport will be undermined due to timeframe, co-ordination, and leadership barriers.
Located on the edge of two tectonic plates, New Zealand has numerous fault lines and seismic risk across the whole country. The way this risk is communicated affects whether people prepare effectively or at all. Research has shown that perceptions of risk are affected by slight changes in wording, and that probabilities commonly reported by experts and media are often interpreted subjectively based on context. In the context of volcanoes, research has found that given a certain probability of a volcano in a specific time window, people perceive risk as higher in later time intervals within that window. The present study examines this pattern with regard to earthquakes and aftershocks in the New Zealand context. Participants in both Wellington (N = 102) and Christchurch (N = 98) were presented an expert statement of earthquake risk within a given time window in Wellington and aftershock risk in Christchurch, and asked to rate their perception of risk in specific intervals across the time window. For a Wellington earthquake, participants perceived risk as incrementally higher toward the end of the 50 year time window whereas for a Christchurch aftershock, risk perception increased slightly for the first three intervals of the 12 month time window. Likelihood of preparing was constant over the time windows, with Wellington citizens rating themselves more likely than Christchurch citizens to prepare for either an earthquake or aftershock, irrespective of current level of preparedness. These findings suggest that people view earthquakes as more likely later toward the end of a given time window and that they view aftershocks very differently to scientific predictions.
In this thesis, focus is given to develop methodologies for rapidly estimating specific components of loss and downtime functions. The thesis proposes methodologies for deriving loss functions by (i) considering individual component performance; (ii) grouping them as per their performance characteristics; and (iii) applying them to similar building usage categories. The degree of variation in building stock and understanding their characteristics are important factors to be considered in the loss estimation methodology and the field surveys carried out to collect data add value to the study. To facilitate developing ‘downtime’ functions, this study investigates two key components of downtime: (i) time delay from post-event damage assessment of properties; and (ii) time delay in settling the insurance claims lodged. In these two areas, this research enables understanding of critical factors that influence certain aspects of downtime and suggests approaches to quantify those factors. By scrutinising the residential damage insurance claims data provided by the Earthquake Commission (EQC) for the 2010- 2011 Canterbury Earthquake Sequence (CES), this work provides insights into various processes of claims settlement, the time taken to complete them and the EQC loss contributions to building stock in Christchurch city and Canterbury region. The study has shown diligence in investigating the EQC insurance claim data obtained from the CES to get new insights and build confidence in the models developed and the results generated. The first stage of this research develops contribution functions (probabilistic relationships between the expected losses for a wide range of building components and the building’s maximum response) for common types of claddings used in New Zealand buildings combining the probabilistic density functions (developed using the quantity of claddings measured from Christchurch buildings), fragility functions (obtained from the published literature) and cost functions (developed based on inputs from builders) through Monte Carlo simulations. From the developed contribution functions, glazing, masonry veneer, monolithic and precast concrete cladding systems are found to incur 50% loss at inter-storey drift levels equal to 0.027, 0.003, 0.005 and 0.011, respectively. Further, the maximum expected cladding loss for glazing, masonry veneer, monolithic, precast concrete cladding systems are found to be 368.2, 331.9, 365.0, and 136.2 NZD per square meter of floor area, respectively. In the second stage of this research, a detailed cost breakdown of typical buildings designed and built for different purposes is conducted. The contributions of structural and non- structural components to the total building cost are compared for buildings of different usages, and based on the similar ratios of non-structural performance group costs to the structural performance group cost, four-building groups are identified; (i) Structural components dominant group: outdoor sports, stadiums, parkings and long-span warehouses, (ii) non- structural drift-sensitive components dominant group: houses, single-storey suburban buildings (all usages), theatres/halls, workshops and clubhouses, (iii) non-structural acceleration- sensitive components dominant group: hospitals, research labs, museums and retail/cold stores, and (iv) apartments, hotels, offices, industrials, indoor sports, classrooms, devotionals and aquariums. By statistically analysing the cost breakdowns, performance group weighting factors are proposed for structural, and acceleration-sensitive and drift-sensitive non-structural components for all four building groups. Thus proposed building usage groupings and corresponding weighting factors facilitate rapid seismic loss estimation of any type of building given the EDPs at storey levels are known. A model for the quantification of post-earthquake inspection duration is developed in the third stage of this research. Herein, phase durations for the three assessment phases (one rapid impact and two rapid building) are computed using the number of buildings needing inspections, the number of engineers involved in inspections and a phase duration coefficient (which considers the median building inspection time, efficiency of engineer and the number of engineers involved in each assessment teams). The proposed model can be used: (i) by national/regional authorities to decide the length of the emergency period following a major earthquake, and estimate the number of engineers required to conduct a post-earthquake inspection within the desired emergency period, and (ii) to quantify the delay due to inspection for the downtime modelling framework. The final stage of this research investigates the repair costs and insurance claim settlement time for damaged residential buildings in the 2010-2011 Canterbury earthquake sequence. Based on the EQC claim settlement process, claims are categorized into three groups; (i) Small Claims: claims less than NZD15,000 which were settled through cash payment, (ii) Medium Claims: claims less than NZD100,000 which were managed through Canterbury Home Repair Programme (CHRP), and (iii) Large Claims: claims above NZD100,000 which were managed by an insurance provider. The regional loss ratio (RLR) for greater Christchurch for three events inducing shakings of approximate seismic intensities 6, 7, and 8 are found to be 0.013, 0.066, and 0.171, respectively. Furthermore, the claim duration (time between an event and the claim lodgement date), assessment duration (time between the claim lodgement day and the most recent assessment day), and repair duration (time between the most recent assessment day and the repair completion day) for the insured residential buildings in the region affected by the Canterbury earthquake sequence is found to be in the range of 0.5-4 weeks, 1.5- 5 months, and 1-3 years, respectively. The results of this phase will provide useful information to earthquake engineering researchers working on seismic risk/loss and insurance modelling.
Thousands of people have turned out for the National Memorial Service in Ōtautahi today, where the 185 victims who died in the Christchurch earthquake 10 years ago are being remembered.
Maurice Gardiner's sister, Donna Manning, died in the CTV building collapse.
Ms Manning was the presenter of CTV's Good Living Show, and her brother describes her as someone who was the life and soul of the party, and cared deeply for others.
As Christchurch prepares to mark 10 years since its deadly earthquake, the impact of that day continues to be felt differently. The less affluent eastern suburbs, which bore the brunt of the damage, continue to lag behind the rest of the city in their recovery. The former dean of Christchurch and fellow east sider, Peter Beck, told Conan Young that while government agencies such as EQC often failed people in their hour of need, what did not fail was the willingness of people to help out their neighbours.
A buckling-restrained braced frame (BRBF) is a structural bracing system that provides lateral strength and stiffness to buildings and bridges. They were first developed in Japan in the 1970s (Watanabe et al. 1973, Kimura et al. 1976) and gained rapid acceptance in the United States after the Northridge earthquake in 1994 (Bruneau et al. 2011). However, it was not until the Canterbury earthquakes of 2010/2011, that the New Zealand construction market saw a significant uptake in the use of buckling-restrained braces (BRBs) in commercial buildings (MacRae et al. 2015). In New Zealand there is not yet any documented guidance or specific instructions in regulatory standards for the design of BRBFs. This makes it difficult for engineers to anticipate all the possible stability and strength issues within a BRBF system and actively mitigate them in each design. To help ensure BRBF designs perform as intended, a peer review with physical testing are needed to gain building compliance in New Zealand. Physical testing should check the manufacturing and design of each BRB (prequalification testing), and the global strength and stability of each BRB its frame (subassemblage testing). However, the financial pressures inherent in commercial projects has led to prequalification testing (BRB only testing) being favoured without adequate design specific subassemblage testing. This means peer reviewers have to rely on BRB suppliers for assurances. This low regulation environment allows for a variety of BRBF designs to be constructed without being tested or well understood. The concern is that there may be designs that pose risk and that issues are being overlooked in design and review. To improve the safety and design of BRBFs in New Zealand, this dissertation studies the behaviour of BRBs and how they interact with other frame components. Presented is the experimental test process and results of five commercially available BRB designs (Chapter 2). It discusses the manufacturing process, testing conditions and limitations of observable information. It also emphasises that even though subassemblage testing is impractical, uniaxial testing of the BRB only is not enough, as this does not check global strength or stability. As an alternative to physical testing, this research uses computer simulation to model BRB behaviour. To overcome the traditional challenges of detailed BRB modelling, a strategy to simulate the performance of generic BRB designs was developed (Chapter 3). The development of nonlinear material and contact models are important aspects of this strategy. The Chaboche method is employed using a minimum of six backstress curves to characterize the combined isotropic and kinematic hardening exhibited by the steel core. A simplified approach, adequate for modelling the contact interaction between the restrainer and the core was found. Models also capture important frictional dissipation as well as lateral motion and bending associated with high order constrained buckling of the core. The experimental data from Chapter 2 was used to validate this strategy. As BRBs resist high compressive loading, global stability of the BRB and gusseted connection zone need to be considered. A separate study was conducted that investigated the yielding and buckling strength of gusset plates (Chapter 4). The stress distribution through a gusset plate is complex and difficult to predict because the cross-sectional area of gusset plate is not uniform, and each gusset plate design is unique in shape and size. This has motivated design methods that approximate yielding of gusset plates. Finite element modelling was used to study the development of yielding, buckling and plastic collapse behaviour of a brace end bolted to a series of corner gusset plates. In total 184 variations of gusset plate geometries were modelled in Abaqus®. The FEA modelling applied monotonic uniaxial load with an imperfection. Upon comparing results to current gusset plate design methods, it was found that the Whitmore width method for calculating the yield load of a gusset is generally un-conservative. To improve accuracy and safety in the design of gusset plates, modifications to current design methods for calculating the yield area and compressive strength for gusset plates is proposed. Bolted connections are a popular and common connection type used in BRBF design. Global out-of-plane stability tends to govern the design for this connection type with numerous studies highlighting the risk of instability initiated by inelasticity in the gussets, neck of the BRB end and/or restrainer ends. Subassemblage testing is the traditional method for evaluating global stability. However, physical testing of every BRBF variation is cost prohibitive. As such, Japan has developed an analytical approach to evaluate out-of-plane stability of BRBFs and incorporated this in their design codes. This analytical approach evaluates the different BRB components under possible collapse mechanisms by focusing on moment transfer between the restrainer and end of the BRB. The approach have led to strict criteria for BRBF design in Japan. Structural building design codes in New Zealand, Europe and the United States do not yet provide analytical methods to assess BRB and connection stability, with prototype/subassemblage testing still required as the primary means of accreditation. Therefore it is of interest to investigate the capability of this method to evaluate stability of BRBs designs and gusset plate designs used in New Zealand (including unstiffened gusset connection zones). Chapter 5 demonstrates the capability of FEA to study to the performance of a subassemblage test under cyclic loading – resembling that of a diagonal ground storey BRBF with bolted connections. A series of detailed models were developed using the strategy presented in Chapter 3. The geometric features of BRB 6.5a (Chapter 2) were used as a basis for the BRBs modelled. To capture the different failure mechanisms identified in Takeuchi et al. (2017), models varied the length that the cruciform (non-yielding) section inserts into the restrainer. Results indicate that gusset plates designed according to New Zealand’s Steel Structures Standard (NZS 3404) limit BRBF performance. Increasing the thickness of the gusset plates according to modifications discussed in Chapter 4, improved the overall performance for all variants (except when Lin/ Bcruc = 0.5). The effect of bi-directional loading was not found to notably affect out-of-plane stability. Results were compared against predictions made by the analytical method used in Japan (Takeuchi method). This method was found to be generally conservative is predicting out-of-plane stability of each BRBF model. Recommendations to improve the accuracy of Takeuchi’s method are also provided. The outcomes from this thesis should be helpful for BRB manufacturers, researchers, and in the development of further design guidance of BRBFs.
The Canterbury earthquake sequence of 2010-2011 wrought ruptures in not only the physical landscape of Canterbury and Christchurch’s material form, but also in its social, economic, and political fabrics and the lives of Christchurch inhabitants. In the years that followed, the widespread demolition of the CBD that followed the earthquakes produced a bleak landscape of grey rubble punctuated by damaged, abandoned buildings. It was into this post-earthquake landscape that Gap Filler and other ‘transitional’ organisations inserted playful, creative, experimental projects to bring life and energy back into the CBD. This thesis examines those interventions and the development of the ‘Transitional Movement’ between July 2013 and June 2015 via the methods of walking interviews and participant observation. This critical period in Christchurch’s recovery serves as an example of what happens when do-it-yourself (DIY) urbanism is done at scale across the CBD and what urban experimentation can offer city-making. Through an understanding of space as produced, informed by Lefebvre’s thinking, I explore how these creative urban interventions manifested a different temporality to orthodox planning and demonstrate how the ‘soft’ politics of these interventions contain the potential for gentrification and also a more radical politics of the city, by creating an opening space for difference.
This study analyses the Earthquake Commission’s (EQC) insurance claims database to investigate the influence of seismic intensity and property damage resulting from the Canterbury Earthquake Sequence (CES) on the repair costs and claim settlement duration for residential buildings. Firstly, the ratio of building repair cost to its replacement cost was expressed as a Building Loss Ratio (BLR), which was further extended to Regional Loss Ratio (RLR) for greater Christchurch by multiplying the average of all building loss ratios with the proportion of building stock that lodged an insurance claim. Secondly, the total time required to settle the claim and the time taken to complete each phase of the claim settlement process were obtained. Based on the database, the regional loss ratio for greater Christchurch for three events producing shakings of intensities 6, 7, and 8 on the modified Mercalli intensity scale were 0.013, 0.066, and 0.171, respectively. Furthermore, small (less than NZD15,000), medium (between NZD15,000 and NZD100,000), and large (more than NZD100,000) claims took 0.35-0.55, 1.95-2.45, and 3.35-3.85 years to settle regardless of the building’s construction period and earthquake intensities. The number of claims was also disaggregated by various building characteristics to evaluate their relative contribution to the damage and repair costs.
Though rare and unpredictable, earthquakes can and do cause catastrophic destruction when they impact unprepared and vulnerable communities. Extensive damage and failure of vulnerable buildings is a key factor which contributes to seismic-related disasters, making the proactive management of these buildings a necessity to reduce the risk of future disasters arising. The devastating Canterbury earthquakes of 2010 and 2011 brought the urgency of this issue to national importance in New Zealand. The national earthquake-prone building framework came into effect in 2017, obligating authorities to identify existing buildings with the greatest risk of collapse in strong earthquakes and for building owners to strengthen or demolish these buildings within a designated period of time. Though this framework is unique to New Zealand, the challenge of managing the seismic risk of such buildings is common amongst all seismically-active countries. Therefore, looking outward to examine how other jurisdictions legally manage this challenge is useful for reflecting on the approaches taken in New Zealand and understand potential lessons which could be adopted. This research compares the legal framework used to reduce the seismic risk of existing buildings in New Zealand with that of the similarly earthquake-prone countries of Japan and Italy. These legal frameworks are examined with a particular focus on the proactive goal of reducing risk and improving resilience, as is the goal of the international Sendai Framework for Disaster Risk Reduction 2015-2030. The Sendai Framework, which each of the case study countries have committed to and thus have obligations under, forms the legal basis of the need for states to reduce disaster risk in their jurisdictions. In particular, the states’ legal frameworks for existing building risk reduction are examined in the context of the Sendai priorities of understanding disaster risk, strengthening disaster risk governance, and investing in resilience. While this research illustrates that the case study countries have each adopted more proactive risk reduction frameworks in recent years in anticipation of future earthquakes, the frameworks currently focus on a very narrow range of existing buildings and thus are not currently sufficient for promoting the long-term resilience of building stocks. In order to improve resilience, it is argued, legal frameworks need to include a broader range of buildings subject to seismic risk reduction obligations and also to broaden the focus on long-term monitoring of potential risk to buildings.
While societal messages can encourage an unhealthy strive for perfection, the notion of embracing individual flaws and openly displaying vulnerabilities can appear foreign and outlandish. However, when fallibility is acknowledged and imperfection embraced, intimate relationships built on foundations of acceptance, trust and understanding can be established. In an architectural context, similar deep-rooted connections can be formed between a people and a place through the retention of layers of historical identity. When a building is allowed to age with blemishes laid bare for all to see, an architectural work can exhibit a sense of 'humanising vulnerability' where the bruises and scars it bears are able to visually communicate its contextual narrative. This thesis explores the notion of designing to capitalise on past decay through revitalisation of the former Wood Brothers Flour Mill in Addington, Christchurch (1891). Known as one of the city's last great industrial buildings, the 130-year-old structure remains hugely impressive due to its sheer size and scale despite being abandoned and subject to vandalism for a number of years. Its condition of obsolescence ensured the retention of visible signs of wear and tear in addition to the extensive damage caused by the 2010-12 Canterbury earthquakes. In offering a challenge to renovation and reconstruction as a means of conservation, this thesis asks if 'doing less' has the potential to 'do more'. How can an understanding of architecture as an ongoing process inform a design approach to celebrate ageing and patina? While the complex is undergoing redevelopment at the time of writing, the design project embraces the condition of the historic buildings in the immediate aftermath of the earthquakes and builds upon the patina of the mill and adjacent flour and grain store in developing a design for their adaptation as a micro-distillery. Research into the traditional Japanese ideology of wabi-sabi and its practical applications form the basis for a regenerative design approach which finds value in imperfection, impermanence and incompleteness. The thesis combines a literature review, precedent review and site analysis together with a design proposal. This thesis shows that adaptive reuse projects can benefit from an active collaboration with the processes of decay. Instead of a mindset where an architectural work is considered the finished article upon completion of construction, an empathetic and sensitive design philosophy is employed in which careful thought is given to the continued preservation and evolution of a structure with the recognition that evidence of past wear, tear, patina and weathering can all contribute positively to a building's future. In this fashion, rather than simply remaining as relics of the past, buildings can allow the landscape of their urban context to shape and mould them to ensure that their architectural experience can continue to be enjoyed by generations to come.
At the conclusion of the 2010 and 2011 Canterbury earthquakes more than 5100 homes had been deemed unsafe for habitation. The land and buildings of these were labelled “red zoned” and are too badly damaged for remediation. These homes have been demolished or are destined for demolition. To assist the red zone population to relocate, central government have offered to ‘buy out’ home owners at the Governmental Value (GV) that was last reviewed in 2007. While generous in the economic context at the time, the area affected was the lowest value land and housing in Christchurch and so there is a capital shortfall between the 2007 property value and the cost of relocating to more expensive properties. This shortfall is made worse by increasing present day values since the earthquakes. Red zone residents have had to relocate to the far North and Western extremities of Christchurch, and some chose to move even further to neighbouring towns or cities. The eastern areas and commercial centres close to the red zone are affected as well. They have lost critical mass which has negatively impacted businesses in the catchments of the Red Zone. This thesis aims to repopulate the suburbs most affected by the abandonment of the red zone houses. Because of the relative scarcity of sound building sites in the East and to introduce affordability to these houses, an alternative method of development is required than the existing low density suburban model. Smart medium density design will be tested as an affordable and appropriate means of living. Existing knowledge in this field will be reviewed, an analysis of what East Christchurch’s key characteristics are will occur, and an examination of built works and site investigations will also be conducted. The research finds that at housing densities of 40 units per hectare, the spatial, vehicle, aesthetic needs of East Christchurch can be accommodated. Centralising development is also found to offer better lifestyle choices than the isolated suburbs at the edges of Christchurch, to be more efficient using existing infrastructure, and to place less reliance on cars. Stronger communities are formed from the outset and for a full range of demographics. Eastern affordable housing options are realised and Christchurch’s ever expanding suburban tendencies are addressed. East Christchurch presently displays a gaping scar of devastated houses that ‘The New Eastside’ provides a bandage and a cure for. Displaced and dispossessed Christchurch residents can be re-housed within a new heart for East Christchurch.
Christchurch artist Mike Beer creates miniature models of Christchurch buildings that were lost in the Canterbury earthquakes. Through these tiny models Mike hopes to remind people of the buildings that once shaped the city - and bring back the feelings and memories associated with them. Mike, who goes by the name Ghostcat, says It's all about the connections people have with a time, and place. His models are to be displayed at Fiksate Gallery in Christchuch from April 9.
The Aromaunga Baxters Flowers nursery in Heathcote, Christchurch sits right above the point where the earthquake struck on 22 February 2011. The greenhouses on the steep slopes of the Port Hills, as well as a big old villa and other brick buildings were badly damaged. Ten years on co-owner John Baxter says the earthquake damage is still being repaired, but sales have been boosted by a lack of imported flowers due to Covid-19 restrictions.
Sam Johnson founded the Student Volunteer Army from a Facebook page in response to the Christchurch earthquakes. Sam spoke with Karyn on air ten years ago today, and he shares his memories including how the Student Volunteer Army has grown into a nationwide movement.
Misko Cubrinovski is interested how the ground and the structures on - and in - it behave during an earthquake.
